use std::borrow::Borrow;
use std::default::Default;
use std::fs;
use std::fmt;
use std::io;
use std::io::Read;
use std::io::Write as NewWrite;
use std::net;
use std::net::SocketAddr;
use std::path;
use std::str::FromStr;
use std::ops::Deref;
use std::ops::DerefMut;
use std::collections::HashMap;

use super::consts;
use super::consts::Command;
use super::consts::ColumnType;
use super::io::Read as MyRead;
use super::io::Write;
use super::io::Stream;
use super::io::Stream::UnixStream;
use super::io::Stream::TcpStream;
use super::io::TcpStream::Insecure;
use super::error::MyError::{
    MyIoError,
    MySqlError,
    MyDriverError
};
use super::error::DriverError::{
    CouldNotConnect,
    UnsupportedProtocol,
    Protocol41NotSet,
    UnexpectedPacket,
    MismatchedStmtParams,
    SetupError,
    ReadOnlyTransNotSupported,
};
use super::error::MyResult;
#[cfg(feature = "ssl")]
use super::error::DriverError::SslNotSupported;
use super::scramble::scramble;
use super::packet::{OkPacket, EOFPacket, ErrPacket, HandshakePacket, ServerVersion};
use super::value::Value;
use super::value::{ToRow, from_value, from_value_opt};
use super::value::Value::{NULL, Int, UInt, Float, Bytes, Date, Time};

use byteorder::LittleEndian as LE;
use byteorder::{ByteOrder, ReadBytesExt, WriteBytesExt};
use unix_socket as us;

pub mod pool;

#[derive(PartialEq, Eq, Clone, Copy, Debug)]
pub enum IsolationLevel {
    ReadUncommitted,
    ReadCommitted,
    RepeatableRead,
    Serializable,
}

impl fmt::Display for IsolationLevel {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            IsolationLevel::ReadUncommitted => write!(f, "READ UNCOMMITTED"),
            IsolationLevel::ReadCommitted => write!(f, "READ COMMITTED"),
            IsolationLevel::RepeatableRead => write!(f, "REPEATABLE READ"),
            IsolationLevel::Serializable => write!(f, "SERIALIZABLE"),
        }
    }
}

#[derive(Debug)]
pub struct Transaction<'a> {
    conn: ConnRef<'a>,
    committed: bool,
    rolled_back: bool,
}

impl<'a> Transaction<'a> {
    fn new(conn: &'a mut MyConn) -> Transaction<'a> {
        Transaction {
            conn: ConnRef::ViaConnRef(conn),
            committed: false,
            rolled_back: false,
        }
    }

    fn new_pooled(conn: pool::MyPooledConn) -> Transaction<'a> {
        Transaction {
            conn: ConnRef::ViaPooledConn(conn),
            committed: false,
            rolled_back: false,
        }
    }

    /// See [`MyConn#query`](struct.MyConn.html#method.query).
    pub fn query<'c, T: AsRef<str> + 'c>(&'c mut self, query: T) -> MyResult<QueryResult<'c>> {
        self.conn.query(query)
    }

    /// See [`MyConn#prepare`](struct.MyConn.html#method.prepare).
    pub fn prepare<'c, T: AsRef<str> + 'c>(&'c mut self, query: T) -> MyResult<Stmt<'c>> {
        self.conn.prepare(query)
    }

    /// See [`MyConn#prep_exec`](struct.MyConn.html#method.prep_exec).
    pub fn prep_exec<'c, A: AsRef<str> + 'c, T: ToRow>(&'c mut self, query: A, params: T) -> MyResult<QueryResult<'c>> {
        self.conn.prep_exec(query, params)
    }

    /// Will consume and commit transaction.
    pub fn commit(mut self) -> MyResult<()> {
        try!(self.conn.query("COMMIT"));
        self.committed = true;
        Ok(())
    }

    /// Will consume and rollback transaction. You also can rely on `Drop` implementation but it
    /// will swallow errors.
    pub fn rollback(mut self) -> MyResult<()> {
        try!(self.conn.query("ROLLBACK"));
        self.rolled_back = true;
        Ok(())
    }
}

impl<'a> Drop for Transaction<'a> {
    /// Will rollback transaction.
    fn drop(&mut self) {
        if ! self.committed && ! self.rolled_back {
            let _ = self.conn.query("ROLLBACK");
        }
    }
}

/***
 *     .d8888b.  888                  888
 *    d88P  Y88b 888                  888
 *    Y88b.      888                  888
 *     "Y888b.   888888 88888b.d88b.  888888
 *        "Y88b. 888    888 "888 "88b 888
 *          "888 888    888  888  888 888
 *    Y88b  d88P Y88b.  888  888  888 Y88b.
 *     "Y8888P"   "Y888 888  888  888  "Y888
 *
 *
 *
 */
#[derive(Eq, PartialEq, Clone, Debug)]
struct InnerStmt {
    params: Option<Vec<Column>>,
    columns: Option<Vec<Column>>,
    statement_id: u32,
    num_columns: u16,
    num_params: u16,
    warning_count: u16,
}

impl InnerStmt {
    fn from_payload(pld: &[u8]) -> io::Result<InnerStmt> {
        let mut reader = &pld[1..];
        let statement_id = try!(reader.read_u32::<LE>());
        let num_columns = try!(reader.read_u16::<LE>());
        let num_params = try!(reader.read_u16::<LE>());
        let warning_count = try!(reader.read_u16::<LE>());
        Ok(InnerStmt{statement_id: statement_id,
                     num_columns: num_columns,
                     num_params: num_params,
                     warning_count: warning_count,
                     params: None,
                     columns: None})
    }
}

/// Possible ways to pass conn to a statement or transaction
#[derive(Debug)]
enum ConnRef<'a> {
    ViaConnRef(&'a mut MyConn),
    ViaPooledConn(pool::MyPooledConn),
}

impl<'a> Deref for ConnRef<'a> {
    type Target = MyConn;

    fn deref<'c>(&'c self) -> &'c MyConn {
        match *self {
            ConnRef::ViaConnRef(ref conn_ref) => conn_ref,
            ConnRef::ViaPooledConn(ref conn) => conn.as_ref(),
        }
    }
}

impl<'a> DerefMut for ConnRef<'a> {
    fn deref_mut<'c>(&'c mut self) -> &'c mut MyConn {
        match *self {
            ConnRef::ViaConnRef(ref mut conn_ref) => conn_ref,
            ConnRef::ViaPooledConn(ref mut conn) => conn.as_mut(),
        }
    }
}

/// Mysql
/// [prepared statement](http://dev.mysql.com/doc/internals/en/prepared-statements.html).
#[derive(Debug)]
pub struct Stmt<'a> {
    stmt: InnerStmt,
    conn: ConnRef<'a>,
}

impl<'a> Stmt<'a> {
    fn new(stmt: InnerStmt, conn: &'a mut MyConn) -> Stmt<'a> {
        Stmt {
            stmt: stmt,
            conn: ConnRef::ViaConnRef(conn),
        }
    }

    fn new_pooled(stmt: InnerStmt, pooled_conn: pool::MyPooledConn) -> Stmt<'a> {
        Stmt {
            stmt: stmt,
            conn: ConnRef::ViaPooledConn(pooled_conn),
        }
    }

    /// Returns a slice of a [`Column`s](struct.Column.html) which represents
    /// `Stmt`'s params if any.
    pub fn params_ref(&self) -> Option<&[Column]> {
        match self.stmt.params {
            Some(ref params) => Some(params.as_ref()),
            None => None
        }
    }

    /// Returns a slice of a [`Column`s](struct.Column.html) which represents
    /// `Stmt`'s columns if any.
    pub fn columns_ref(&self) -> Option<&[Column]> {
        match self.stmt.columns {
            Some(ref columns) => Some(columns.as_ref()),
            None => None
        }
    }

    /// Returns index of a `Stmt`'s column by name.
    pub fn column_index<T: AsRef<str>>(&self, name: T) -> Option<usize> {
        match self.stmt.columns {
            None => None,
            Some(ref columns) => {
                let name = name.as_ref().as_bytes();
                for (i, c) in columns.iter().enumerate() {
                    if c.name == name {
                        return Some(i)
                    }
                }
                None
            }
        }
    }

    /// Executes prepared statement with an arguments passed as a
    /// [`ToRow`](../value/trait.ToRow.html) implementor.
    ///
    /// ```rust
    /// # use mysql::conn::pool;
    /// # use mysql::conn::MyOpts;
    /// # use mysql::value::{from_value, IntoValue, ToValue, Value};
    /// # use std::thread::Thread;
    /// # use std::default::Default;
    /// # use std::iter::repeat;
    /// # fn get_opts() -> MyOpts {
    /// #     MyOpts {
    /// #         user: Some("root".to_string()),
    /// #         pass: Some("password".to_string()),
    /// #         tcp_addr: Some("127.0.0.1".to_string()),
    /// #         tcp_port: 3307,
    /// #         ..Default::default()
    /// #     }
    /// # }
    /// # let opts = get_opts();
    /// # let pool = pool::MyPool::new(opts).unwrap();
    /// let mut stmt0 = pool.prepare("SELECT 42").unwrap();
    /// let mut stmt1 = pool.prepare("SELECT ?").unwrap();
    /// let mut stmt12 = pool.prepare("SELECT ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?").unwrap();
    ///
    /// // It is better to pass tuple as a params when executing statements of arity <= 11
    /// for row in stmt0.execute(()).unwrap() {
    ///     assert_eq!(from_value::<u8>(row.unwrap().pop().unwrap()), 42);
    /// }
    /// // just do not forget about trailing comma in case of arity = 1
    /// for row in stmt1.execute((42,)).unwrap() {
    ///     assert_eq!(from_value::<u8>(row.unwrap().pop().unwrap()), 42);
    /// }
    ///
    /// // If you do not want to lose ownership of param, when you should pass it by referense
    /// let word = "hello".to_string();
    /// for _ in 0..2 {
    ///     for row in stmt1.execute((&word,)).unwrap() {
    ///         assert_eq!(from_value::<String>(row.unwrap().pop().unwrap()),"hello");
    ///     }
    /// }
    ///
    /// // If you want to execute statement of arity > 11, then you can pass &[&ToValue]
    /// // as params.
    /// let params: &[&ToValue] = &[&1, &2, &3, &4, &5, &6, &7, &8, &9, &10, &11, &12];
    /// for row in stmt12.execute(params).unwrap() {
    ///     let row: Vec<u8> = row.unwrap().into_iter().map(from_value::<u8>).collect();
    ///     assert_eq!(row, vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]);
    /// }
    /// // but be aware of implicit copying, so if you have huge params and do not care
    /// // about ownership, then better to use plain Vec<Value>.
    /// let mut params: Vec<Value> = Vec::with_capacity(12);
    /// for i in 1..13 {
    ///     params.push(repeat('A').take(i * 1000).collect::<String>().into_value());
    /// }
    /// for row in stmt12.execute(params).unwrap() {
    ///     let row: Vec<String> = row.unwrap().into_iter().map(from_value::<String>).collect();
    ///     for i in 1..13 {
    ///         assert_eq!(row[i-1], repeat('A').take(i * 1000).collect::<String>());
    ///     }
    /// }
    /// ```
    pub fn execute<'s, T: ToRow>(&'s mut self, params: T) -> MyResult<QueryResult<'s>> {
        self.conn.execute(&self.stmt, params)
    }

    fn prep_exec<T: ToRow>(mut self, params: T) -> MyResult<QueryResult<'a>> {
        let params = params.to_row();
        let (columns, ok_packet) = try!(self.conn._execute(&self.stmt, &params));
        Ok(QueryResult::new(ResultConnRef::ViaStmt(self), columns, ok_packet, true))
    }
}

/***
 *     .d8888b.           888
 *    d88P  Y88b          888
 *    888    888          888
 *    888         .d88b.  888 888  888 88888b.d88b.  88888b.
 *    888        d88""88b 888 888  888 888 "888 "88b 888 "88b
 *    888    888 888  888 888 888  888 888  888  888 888  888
 *    Y88b  d88P Y88..88P 888 Y88b 888 888  888  888 888  888
 *     "Y8888P"   "Y88P"  888  "Y88888 888  888  888 888  888
 *
 *
 *
 */

/// Mysql
/// [`Column`](http://dev.mysql.com/doc/internals/en/com-query-response.html#packet-Protocol::ColumnDefinition).
#[derive(Clone, Eq, PartialEq, Debug)]
pub struct Column {
    /// Schema name.
    pub schema: Vec<u8>,
    /// Virtual table name.
    pub table: Vec<u8>,
    /// Phisical table name.
    pub org_table: Vec<u8>,
    /// Virtual column name.
    pub name: Vec<u8>,
    /// Phisical column name.
    pub org_name: Vec<u8>,
    /// Default values.
    pub default_values: Vec<u8>,
    /// Maximum length of the field.
    pub column_length: u32,
    /// Column character set.
    pub character_set: u16,
    /// Flags.
    pub flags: consts::ColumnFlags,
    /// Column type.
    pub column_type: consts::ColumnType,
    /// Max shown decimal digits
    pub decimals: u8
}

impl Column {
    #[inline]
    fn from_payload(command: u8, pld: &[u8]) -> io::Result<Column> {
        let mut reader = pld.as_ref();
        // Skip catalog
        let _ = try!(reader.read_lenenc_bytes());
        let schema = try!(reader.read_lenenc_bytes());
        let table = try!(reader.read_lenenc_bytes());
        let org_table = try!(reader.read_lenenc_bytes());
        let name = try!(reader.read_lenenc_bytes());
        let org_name = try!(reader.read_lenenc_bytes());
        let _ = try!(reader.read_lenenc_int());
        let character_set = try!(reader.read_u16::<LE>());
        let column_length = try!(reader.read_u32::<LE>());
        let column_type = try!(reader.read_u8());
        let flags = consts::ColumnFlags::from_bits_truncate(try!(reader.read_u16::<LE>()));
        let decimals = try!(reader.read_u8());
        // skip filler
        try!(reader.read_u16::<LE>());
        let mut default_values = Vec::with_capacity(reader.len());
        if command == Command::COM_FIELD_LIST as u8 {
            let len = try!(reader.read_lenenc_int());
            try!(reader.take(len).read_to_end(&mut default_values));
        }
        Ok(Column{schema: schema,
                  table: table,
                  org_table: org_table,
                  name: name,
                  org_name: org_name,
                  character_set: character_set,
                  column_length: column_length,
                  column_type: From::from(column_type),
                  flags: flags,
                  decimals: decimals,
                  default_values: default_values})
    }
}

/***
 *    888b     d888           .d88888b.           888
 *    8888b   d8888          d88P" "Y88b          888
 *    88888b.d88888          888     888          888
 *    888Y88888P888 888  888 888     888 88888b.  888888 .d8888b
 *    888 Y888P 888 888  888 888     888 888 "88b 888    88K
 *    888  Y8P  888 888  888 888     888 888  888 888    "Y8888b.
 *    888   "   888 Y88b 888 Y88b. .d88P 888 d88P Y88b.       X88
 *    888       888  "Y88888  "Y88888P"  88888P"   "Y888  88888P'
 *                       888             888
 *                  Y8b d88P             888
 *                   "Y88P"              888
 */
/// Mysql connection options.
///
/// For example:
///
/// ```ignore
/// let opts = MyOpts {
///     user: Some("username".to_string()),
///     pass: Some("password".to_string()),
///     db_name: Some("mydatabase".to_string()),
///     ..Default::default()
/// };
/// ```
#[derive(Clone, Eq, PartialEq, Debug)]
pub struct MyOpts {
    /// TCP address of mysql server (defaults to `127.0.0.1`).
    pub tcp_addr: Option<String>,
    /// TCP port of mysql server (defaults to `3306`).
    pub tcp_port: u16,
    /// Path to unix socket of mysql server (defaults to `None`).
    pub unix_addr: Option<path::PathBuf>,
    /// User (defaults to `None`).
    pub user: Option<String>,
    /// Password (defaults to `None`).
    pub pass: Option<String>,
    /// Database name (defaults to `None`).
    pub db_name: Option<String>,
    /// Prefer socket connection (defaults to `true`).
    ///
    /// Will reconnect via socket after TCP connection to `127.0.0.1` if `true`.
    pub prefer_socket: bool,
    // XXX: Wait for keepalive_timeout stabilization
    /// Commands to execute on each new database connection.
    pub init: Vec<String>,

    #[cfg(feature = "ssl")]
    /// #### Only available if `ssl` feature enabled.
    /// Perform or not ssl peer verification (defaults to `false`).
    /// Only make sense if ssl_opts is not None.
    pub verify_peer: bool,

    #[cfg(feature = "ssl")]
    /// #### Only available if `ssl` feature enabled.
    /// SSL certificates and keys in pem format.
    /// If not None, then ssl connection implied.
    ///
    /// `Option<(ca_cert, Option<(client_cert, client_key)>)>.`
    pub ssl_opts: Option<(path::PathBuf, Option<(path::PathBuf, path::PathBuf)>)>
}

impl MyOpts {
    fn get_user(&self) -> String {
        match self.user {
            Some(ref x) => x.clone(),
            None => String::new(),
        }
    }
    fn get_pass(&self) -> String {
        match self.pass {
            Some(ref x) => x.clone(),
            None => String::new()
        }
    }
    fn get_db_name(&self) -> String {
        match self.db_name {
            Some(ref x) => x.clone(),
            None => String::new()
        }
    }
}

#[cfg(feature = "ssl")]
impl Default for MyOpts {
    fn default() -> MyOpts {
        MyOpts{
            tcp_addr: Some("127.0.0.1".to_string()),
            tcp_port: 3306,
            unix_addr: None,
            user: None,
            pass: None,
            db_name: None,
            prefer_socket: true,
            init: vec![],
            verify_peer: false,
            ssl_opts: None,
        }
    }
}

#[cfg(not(feature = "ssl"))]
impl Default for MyOpts {
    fn default() -> MyOpts {
        MyOpts{
            tcp_addr: Some("127.0.0.1".to_string()),
            tcp_port: 3306,
            unix_addr: None,
            user: None,
            pass: None,
            db_name: None,
            prefer_socket: true,
            init: vec![],
        }
    }
}

/***
 *    888b     d888           .d8888b.
 *    8888b   d8888          d88P  Y88b
 *    88888b.d88888          888    888
 *    888Y88888P888 888  888 888         .d88b.  88888b.  88888b.
 *    888 Y888P 888 888  888 888        d88""88b 888 "88b 888 "88b
 *    888  Y8P  888 888  888 888    888 888  888 888  888 888  888
 *    888   "   888 Y88b 888 Y88b  d88P Y88..88P 888  888 888  888
 *    888       888  "Y88888  "Y8888P"   "Y88P"  888  888 888  888
 *                       888
 *                  Y8b d88P
 *                   "Y88P"
 */

/// Mysql connection.
#[derive(Debug)]
pub struct MyConn {
    opts: MyOpts,
    stream: Option<Stream>,
    stmts: HashMap<String, InnerStmt>,
    server_version: ServerVersion,
    affected_rows: u64,
    last_insert_id: u64,
    max_allowed_packet: usize,
    capability_flags: consts::CapabilityFlags,
    connection_id: u32,
    status_flags: consts::StatusFlags,
    seq_id: u8,
    character_set: u8,
    last_command: u8,
    connected: bool,
    has_results: bool,
}

impl MyConn {
    #[cfg(not(feature = "ssl"))]
    /// Creates new `MyConn`.
    pub fn new(opts: MyOpts) -> MyResult<MyConn> {
        let mut conn = MyConn {
            opts: opts,
            stream: None,
            stmts: HashMap::new(),
            seq_id: 0u8,
            capability_flags: consts::CapabilityFlags::empty(),
            status_flags: consts::StatusFlags::empty(),
            connection_id: 0u32,
            character_set: 0u8,
            affected_rows: 0u64,
            last_insert_id: 0u64,
            last_command: 0u8,
            max_allowed_packet: consts::MAX_PAYLOAD_LEN,
            connected: false,
            has_results: false,
            server_version: (0, 0, 0),
        };
        try!(conn.connect_stream());
        try!(conn.connect());
        if conn.opts.unix_addr.is_none() && conn.opts.prefer_socket {
            let addr: Option<SocketAddr> = FromStr::from_str(
                conn.opts.tcp_addr.as_ref().unwrap().as_ref()).ok();
            let is_loopback = match addr {
                // XXX: Wait for is_loopback stabilization
                Some(SocketAddr::V4(addr)) => addr.ip().octets()[0] == 127,
                Some(SocketAddr::V6(addr)) => addr.ip().segments() == [0, 0, 0, 0, 0, 0, 0, 1],
                _ => false,
            };
            if is_loopback {
                match conn.get_system_var("socket") {
                    Some(path) => {
                        let path = from_value::<String>(path);
                        let opts = MyOpts{
                            unix_addr: Some(From::from(path)),
                            ..conn.opts.clone()
                        };
                        return MyConn::new(opts).or(Ok(conn));
                    },
                    _ => return Ok(conn)
                }
            }
        }
        for cmd in conn.opts.init.clone() {
            try!(conn.query(cmd));
        }
        return Ok(conn);
    }

    #[cfg(feature = "ssl")]
    /// Creates new `MyConn`.
    pub fn new(opts: MyOpts) -> MyResult<MyConn> {
        let mut conn = MyConn {
            opts: opts,
            stream: None,
            stmts: HashMap::new(),
            seq_id: 0u8,
            capability_flags: consts::CapabilityFlags::empty(),
            status_flags: consts::StatusFlags::empty(),
            connection_id: 0u32,
            character_set: 0u8,
            affected_rows: 0u64,
            last_insert_id: 0u64,
            last_command: 0u8,
            max_allowed_packet: consts::MAX_PAYLOAD_LEN,
            connected: false,
            has_results: false,
            server_version: (0, 0, 0),
        };
        try!(conn.connect_stream());
        try!(conn.connect());
        if let None = conn.opts.ssl_opts {
            if conn.opts.unix_addr.is_none() && conn.opts.prefer_socket {
                let addr: Option<SocketAddr> = FromStr::from_str(
                    conn.opts.tcp_addr.as_ref().unwrap().as_ref()).ok();
                let is_loopback = match addr {
                    Some(SocketAddr::V4(addr)) => addr.ip().octets()[0] == 127,
                    Some(SocketAddr::V6(addr)) => addr.ip().segments() == [0, 0, 0, 0, 0, 0, 0, 1],
                    _ => false,
                };
                if is_loopback {
                    match conn.get_system_var("socket") {
                        Some(path) => {
                            let path = from_value::<String>(path);
                            let opts = MyOpts{
                                unix_addr: Some(From::from(path)),
                                ..conn.opts.clone()
                            };
                            return MyConn::new(opts).or(Ok(conn));
                        },
                        _ => return Ok(conn)
                    }
                }
            }
        }
        for cmd in conn.opts.init.clone() {
            try!(conn.query(cmd));
        }
        return Ok(conn);
    }

    /// Resets `MyConn` (drops state then reconnects).
    pub fn reset(&mut self) -> MyResult<()> {
        if self.server_version > (5, 7, 2) {
            try!(self.write_command(Command::COM_RESET_CONNECTION));
            self.read_packet()
            .and_then(|pld| {
                match pld[0] {
                    0 => {
                        let ok = try!(OkPacket::from_payload(pld.as_ref()));
                        self.handle_ok(&ok);
                        self.last_command = 0;
                        self.stmts.clear();
                        Ok(())
                    },
                    _ => {
                        let err = try!(ErrPacket::from_payload(pld.as_ref()));
                        Err(MySqlError(err))
                    }
                }
            })
        } else {
            self.stream = None;
            self.stmts.clear();
            self.seq_id = 0;
            self.capability_flags = consts::CapabilityFlags::empty();
            self.status_flags = consts::StatusFlags::empty();
            self.connection_id = 0;
            self.character_set = 0;
            self.affected_rows = 0;
            self.last_insert_id = 0;
            self.last_command = 0;
            self.max_allowed_packet = consts::MAX_PAYLOAD_LEN;
            self.connected = false;
            self.has_results = false;
            try!(self.connect_stream());
            self.connect()
        }
    }

    fn get_mut_stream<'a>(&'a mut self) -> &'a mut Stream {
        self.stream.as_mut().unwrap()
    }

    #[cfg(feature = "openssl")]
    fn switch_to_ssl(&mut self) -> MyResult<()> {
        if self.stream.is_some() {
            let stream = self.stream.take().unwrap();
            let stream = try!(stream.make_secure(self.opts.verify_peer, &self.opts.ssl_opts));
            self.stream = Some(stream);
        }
        Ok(())
    }

    fn connect_stream(&mut self) -> MyResult<()> {
        if self.opts.unix_addr.is_some() {
            match us::UnixStream::connect(self.opts.unix_addr.as_ref().unwrap()) {
                Ok(stream) => {
                    self.stream = Some(Stream::UnixStream(stream));
                    Ok(())
                },
                _ => {
                    let path_str = format!("{}", self.opts.unix_addr.as_ref().unwrap().display());
                    Err(MyDriverError(CouldNotConnect(Some(path_str))))
                }
            }
        } else if self.opts.tcp_addr.is_some() {
            match net::TcpStream::connect(&(self.opts.tcp_addr.as_ref().unwrap().as_ref(),
                                             self.opts.tcp_port))
            {
                Ok(stream) => {
                    self.stream = Some(Stream::TcpStream(Some(Insecure(stream))));
                    Ok(())
                },
                _ => {
                    Err(MyDriverError(CouldNotConnect(self.opts.tcp_addr.clone())))
                }
            }
        } else {
            Err(MyDriverError(CouldNotConnect(None)))
        }
    }

    fn read_packet(&mut self) -> MyResult<Vec<u8>> {
        let old_seq_id = self.seq_id;
        let (data, seq_id) = try!(self.get_mut_stream().read_packet(old_seq_id));
        self.seq_id = seq_id;
        Ok(data)
    }

    fn write_packet(&mut self, data: &[u8]) -> MyResult<()> {
        let seq_id = self.seq_id;
        let max_allowed_packet = self.max_allowed_packet;
        self.seq_id = try!(self.get_mut_stream().write_packet(data, seq_id, max_allowed_packet));
        Ok(())
    }

    fn handle_handshake(&mut self, hp: &HandshakePacket) {
        self.capability_flags = hp.capability_flags;
        self.status_flags = hp.status_flags;
        self.connection_id = hp.connection_id;
        self.character_set = hp.character_set;
        self.server_version = hp.server_version;
    }

    fn handle_ok(&mut self, op: &OkPacket) {
        self.affected_rows = op.affected_rows;
        self.last_insert_id = op.last_insert_id;
        self.status_flags = op.status_flags;
    }

    fn handle_eof(&mut self, eof: &EOFPacket) {
        self.status_flags = eof.status_flags;
    }

    #[cfg(not(feature = "ssl"))]
    fn do_handshake(&mut self) -> MyResult<()> {
        self.read_packet().and_then(|pld| {
            let handshake = try!(HandshakePacket::from_payload(pld.as_ref()));
            if handshake.protocol_version != 10u8 {
                return Err(MyDriverError(UnsupportedProtocol(handshake.protocol_version)));
            }
            if !handshake.capability_flags.contains(consts::CLIENT_PROTOCOL_41) {
                return Err(MyDriverError(Protocol41NotSet));
            }
            self.handle_handshake(&handshake);
            self.do_handshake_response(&handshake)
        }).and_then(|_| {
            self.read_packet()
        }).and_then(|pld| {
            match pld[0] {
                0u8 => {
                    let ok = try!(OkPacket::from_payload(pld.as_ref()));
                    self.handle_ok(&ok);
                    Ok(())
                },
                0xffu8 => {
                    let err = try!(ErrPacket::from_payload(pld.as_ref()));
                    Err(MySqlError(err))
                },
                _ => Err(MyDriverError(UnexpectedPacket))
            }
        })
    }

    #[cfg(feature = "ssl")]
    fn do_handshake(&mut self) -> MyResult<()> {
        self.read_packet().and_then(|pld| {
            let handshake = try!(HandshakePacket::from_payload(pld.as_ref()));
            if handshake.protocol_version != 10u8 {
                return Err(MyDriverError(UnsupportedProtocol(handshake.protocol_version)));
            }
            if !handshake.capability_flags.contains(consts::CLIENT_PROTOCOL_41) {
                return Err(MyDriverError(Protocol41NotSet));
            }
            self.handle_handshake(&handshake);
            if self.opts.ssl_opts.is_some() && self.stream.is_some() {
                if self.stream.as_ref().unwrap().is_insecure() {
                    if !handshake.capability_flags.contains(consts::CLIENT_SSL) {
                        return Err(MyDriverError(SslNotSupported));
                    } else {
                        try!(self.do_ssl_request());
                        try!(self.switch_to_ssl());
                    }
                }
            }
            self.do_handshake_response(&handshake)
        }).and_then(|_| {
            self.read_packet()
        }).and_then(|pld| {
            match pld[0] {
                0u8 => {
                    let ok = try!(OkPacket::from_payload(pld.as_ref()));
                    self.handle_ok(&ok);
                    Ok(())
                },
                0xffu8 => {
                    let err = try!(ErrPacket::from_payload(pld.as_ref()));
                    Err(MySqlError(err))
                },
                _ => Err(MyDriverError(UnexpectedPacket))
            }
        })
    }

    #[cfg(feature = "ssl")]
    fn get_client_flags(&self) -> consts::CapabilityFlags {
        let mut client_flags = consts::CLIENT_PROTOCOL_41 |
                               consts::CLIENT_SECURE_CONNECTION |
                               consts::CLIENT_LONG_PASSWORD |
                               consts::CLIENT_TRANSACTIONS |
                               consts::CLIENT_LOCAL_FILES |
                               consts::CLIENT_MULTI_STATEMENTS |
                               consts::CLIENT_MULTI_RESULTS |
                               consts::CLIENT_PS_MULTI_RESULTS |
                               (self.capability_flags & consts::CLIENT_LONG_FLAG);
        if self.opts.get_db_name().len() > 0 {
            client_flags.insert(consts::CLIENT_CONNECT_WITH_DB);
        }
        if self.stream.is_some() && self.stream.as_ref().unwrap().is_insecure() {
            if self.opts.ssl_opts.is_some() {
                client_flags.insert(consts::CLIENT_SSL);
            }
        }
        client_flags
    }

    #[cfg(not(feature = "ssl"))]
    fn get_client_flags(&self) -> consts::CapabilityFlags {
        let mut client_flags = consts::CLIENT_PROTOCOL_41 |
                               consts::CLIENT_SECURE_CONNECTION |
                               consts::CLIENT_LONG_PASSWORD |
                               consts::CLIENT_TRANSACTIONS |
                               consts::CLIENT_LOCAL_FILES |
                               consts::CLIENT_MULTI_STATEMENTS |
                               consts::CLIENT_MULTI_RESULTS |
                               consts::CLIENT_PS_MULTI_RESULTS |
                               (self.capability_flags & consts::CLIENT_LONG_FLAG);
        if self.opts.get_db_name().len() > 0 {
            client_flags.insert(consts::CLIENT_CONNECT_WITH_DB);
        }
        client_flags
    }

    #[cfg(feature = "ssl")]
    fn do_ssl_request(&mut self) -> MyResult<()> {
        let client_flags = self.get_client_flags();
        let mut writer = io::Cursor::new(Vec::with_capacity(4 + 4 + 1 + 23));
        try!(writer.write_u32::<LE>(client_flags.bits()));
        try!(writer.write_all(&[0u8; 4]));
        try!(writer.write_u8(consts::UTF8_GENERAL_CI));
        try!(writer.write_all(&[0u8; 23]));
        self.write_packet(writer.into_inner().borrow())
    }

    fn do_handshake_response(&mut self, hp: &HandshakePacket) -> MyResult<()> {
        let client_flags = self.get_client_flags();
        let scramble_buf = scramble(hp.auth_plugin_data.as_ref(), self.opts.get_pass().as_bytes());
        let scramble_buf_len = if scramble_buf.is_some() { 20 } else { 0 };
        let mut payload_len = 4 + 4 + 1 + 23 + self.opts.get_user().len() + 1 + 1 + scramble_buf_len;
        if self.opts.get_db_name().len() > 0 {
            payload_len += self.opts.get_db_name().len() + 1;
        }
        let mut writer = io::Cursor::new(Vec::with_capacity(payload_len));
        try!(writer.write_u32::<LE>(client_flags.bits()));
        try!(writer.write_all(&[0u8; 4]));
        try!(writer.write_u8(consts::UTF8_GENERAL_CI));
        try!(writer.write_all(&[0u8; 23]));
        try!(writer.write_all(self.opts.get_user().as_bytes()));
        try!(writer.write_u8(0u8));
        try!(writer.write_u8(scramble_buf_len as u8));
        if let Some(scr) = scramble_buf {
            try!(writer.write_all(scr.as_ref()));
        }
        if self.opts.get_db_name().len() > 0 {
            try!(writer.write_all(self.opts.get_db_name().as_bytes()));
            try!(writer.write_u8(0u8));
        }
        self.write_packet(writer.into_inner().borrow())
    }

    fn write_command(&mut self, cmd: consts::Command) -> MyResult<()> {
        self.seq_id = 0u8;
        self.last_command = cmd as u8;
        self.write_packet(&[cmd as u8])
    }

    fn write_command_data(&mut self, cmd: consts::Command, buf: &[u8]) -> MyResult<()> {
        self.seq_id = 0u8;
        self.last_command = cmd as u8;
        let mut writer = io::Cursor::new(Vec::with_capacity(buf.len() + 1));
        let _ = writer.write_u8(cmd as u8);
        let _ = writer.write_all(buf);
        self.write_packet(writer.into_inner().borrow())
    }

    fn send_long_data(&mut self, stmt: &InnerStmt, params: &[Value], ids: Vec<u16>) -> MyResult<()> {
        for &id in ids.iter() {
            match params[id as usize] {
                Bytes(ref x) => {
                    for chunk in x.chunks(self.max_allowed_packet - 7) {
                        let chunk_len = chunk.len() + 7;
                        let mut writer = io::Cursor::new(Vec::with_capacity(chunk_len));
                        try!(writer.write_u32::<LE>(stmt.statement_id));
                        try!(writer.write_u16::<LE>(id));
                        try!(writer.write_all(chunk));
                        try!(self.write_command_data(Command::COM_STMT_SEND_LONG_DATA,
                                                     writer.into_inner().borrow()));
                    }
                },
                _ => unreachable!(),
            }
        }
        Ok(())
    }

    fn _execute(&mut self, stmt: &InnerStmt, params: &[Value]) -> MyResult<(Vec<Column>, Option<OkPacket>)> {
        if stmt.num_params != params.len() as u16 {
            return Err(MyDriverError(MismatchedStmtParams(stmt.num_params, params.len())));
        }
        let mut writer: io::Cursor<_>;
        match stmt.params {
            Some(ref sparams) => {
                let (bitmap, values, large_ids) =
                    try!(Value::to_bin_payload(sparams.as_ref(),
                                               params,
                                               self.max_allowed_packet));
                match large_ids {
                    Some(ids) => try!(self.send_long_data(stmt, params, ids)),
                    _ => ()
                }
                writer = io::Cursor::new(Vec::with_capacity(9 + bitmap.len() + 1 +
                                                            params.len() * 2 +
                                                            values.len()));
                try!(writer.write_u32::<LE>(stmt.statement_id));
                try!(writer.write_u8(0u8));
                try!(writer.write_u32::<LE>(1u32));
                try!(writer.write_all(bitmap.as_ref()));
                try!(writer.write_u8(1u8));
                for i in 0..params.len() {
                    match params[i] {
                        NULL => try!(writer.write_all(
                            &[sparams[i].column_type as u8, 0u8])),
                        Bytes(..) => try!(
                            writer.write_all(&[ColumnType::MYSQL_TYPE_VAR_STRING as u8, 0u8])),
                        Int(..) => try!(
                            writer.write_all(&[ColumnType::MYSQL_TYPE_LONGLONG as u8, 0u8])),
                        UInt(..) => try!(
                            writer.write_all(&[ColumnType::MYSQL_TYPE_LONGLONG as u8, 128u8])),
                        Float(..) => try!(
                            writer.write_all(&[ColumnType::MYSQL_TYPE_DOUBLE as u8, 0u8])),
                        Date(..) => try!(
                            writer.write_all(&[ColumnType::MYSQL_TYPE_DATE as u8, 0u8])),
                        Time(..) => try!(
                            writer.write_all(&[ColumnType::MYSQL_TYPE_TIME as u8, 0u8]))
                    }
                }
                try!(writer.write_all(values.as_ref()));
            },
            None => {
                writer = io::Cursor::new(Vec::with_capacity(4 + 1 + 4));
                try!(writer.write_u32::<LE>(stmt.statement_id));
                try!(writer.write_u8(0u8));
                try!(writer.write_u32::<LE>(1u32));
            }
        }
        try!(self.write_command_data(Command::COM_STMT_EXECUTE, writer.into_inner().borrow()));
        self.handle_result_set()
    }

    fn execute<'a, T: ToRow>(&'a mut self, stmt: &InnerStmt, params: T) -> MyResult<QueryResult<'a>> {
        let params = params.to_row();
        match self._execute(stmt, params.as_ref()) {
            Ok((columns, ok_packet)) => {
                Ok(QueryResult::new(ResultConnRef::ViaConnRef(self), columns, ok_packet, true))
            },
            Err(err) => Err(err)
        }
    }

    fn _start_transaction(&mut self,
                          consistent_snapshot: bool,
                          isolation_level: Option<IsolationLevel>,
                          readonly: Option<bool>) -> MyResult<()> {
        if let Some(i_level) = isolation_level {
            let _ = try!(self.query(format!("SET TRANSACTION ISOLATION LEVEL {}", i_level)));
        }
        if let Some(readonly) = readonly {
            if self.server_version < (5, 6, 5) {
                return Err(MyDriverError(ReadOnlyTransNotSupported));
            }
            let _ = if readonly {
                try!(self.query("SET TRANSACTION READ ONLY"))
            } else {
                try!(self.query("SET TRANSACTION READ WRITE"))
            };
        }
        let _ = if consistent_snapshot {
            try!(self.query("START TRANSACTION WITH CONSISTENT SNAPSHOT"))
        } else {
            try!(self.query("START TRANSACTION"))
        };
        Ok(())
    }

    fn send_local_infile(&mut self, file_name: &[u8]) -> MyResult<Option<OkPacket>> {
        use std::os::unix::ffi::OsStrExt;
        let path = ::std::ffi::OsStr::from_bytes(file_name);
        let path: path::PathBuf = From::from(path);
        let mut file = try!(fs::File::open(&path));
        let mut chunk = vec![0u8; self.max_allowed_packet];
        let mut r = file.read(&mut chunk[..]);
        loop {
            match r {
                Ok(n) => {
                    if n > 0 {
                        try!(self.write_packet(&chunk[..n]));
                    } else {
                        break;
                    }
                },
                Err(e) => {
                    return Err(MyIoError(e));
                }
            }
            r = file.read(&mut chunk[..]);
        }
        try!(self.write_packet(&[]));
        let pld = try!(self.read_packet());
        if pld[0] == 0u8 {
            let ok = try!(OkPacket::from_payload(pld.as_ref()));
            self.handle_ok(&ok);
            return Ok(Some(ok));
        }
        Ok(None)
    }

    fn handle_result_set(&mut self) -> MyResult<(Vec<Column>, Option<OkPacket>)> {
        let pld = try!(self.read_packet());
        match pld[0] {
            0x00 => {
                let ok = try!(OkPacket::from_payload(pld.as_ref()));
                self.handle_ok(&ok);
                Ok((Vec::new(), Some(ok)))
            },
            0xfb => {
                let mut reader = &pld[1..];
                let mut file_name = Vec::with_capacity(reader.len());
                try!(reader.read_to_end(&mut file_name));
                match self.send_local_infile(file_name.as_ref()) {
                    Ok(x) => Ok((Vec::new(), x)),
                    Err(err) => Err(err)
                }
            },
            0xff => {
                let err = try!(ErrPacket::from_payload(pld.as_ref()));
                Err(MySqlError(err))
            },
            _ => {
                let mut reader = &pld[..];
                let column_count = try!(reader.read_lenenc_int());
                let mut columns: Vec<Column> = Vec::with_capacity(column_count as usize);
                for _ in (0..column_count) {
                    let pld = try!(self.read_packet());
                    columns.push(try!(Column::from_payload(self.last_command, pld.as_ref())));
                }
                // skip eof packet
                try!(self.read_packet());
                self.has_results = true;
                Ok((columns, None))
            }
        }
    }

    fn _query(&mut self, query: &str) -> MyResult<(Vec<Column>, Option<OkPacket>)> {
        try!(self.write_command_data(Command::COM_QUERY, query.as_bytes()));
        self.handle_result_set()
    }

    /// Executes [`COM_PING`](http://dev.mysql.com/doc/internals/en/com-ping.html)
    /// on `MyConn`. Return `true` on success or `false` on error.
    pub fn ping(&mut self) -> bool {
        match self.write_command(Command::COM_PING) {
            Ok(_) => {
                // ommit ok packet
                let _ = self.read_packet();
                true
            },
            _ => false
        }
    }

    /// Starts new transaction with provided options.
    /// `readonly` is only available since MySQL 5.6.5.
    pub fn start_transaction<'a>(&'a mut self,
                                 consistent_snapshot: bool,
                                 isolation_level: Option<IsolationLevel>,
                                 readonly: Option<bool>) -> MyResult<Transaction<'a>> {
        let _ = try!(self._start_transaction(consistent_snapshot, isolation_level, readonly));
        Ok(Transaction::new(self))
    }

    /// Implements text protocol of mysql server.
    ///
    /// Executes mysql query on `MyConn`. [`QueryResult`](struct.QueryResult.html)
    /// will borrow `MyConn` until the end of its scope.
    pub fn query<'a, T: AsRef<str> + 'a>(&'a mut self, query: T) -> MyResult<QueryResult<'a>> {
        match self._query(query.as_ref()) {
            Ok((columns, ok_packet)) => {
                Ok(QueryResult::new(ResultConnRef::ViaConnRef(self), columns, ok_packet, false))
            },
            Err(err) => Err(err),
        }
    }

    fn _true_prepare(&mut self, query: &str) -> MyResult<InnerStmt> {
        try!(self.write_command_data(Command::COM_STMT_PREPARE, query.as_bytes()));
        let pld = try!(self.read_packet());
        match pld[0] {
            0xff => {
                let err =  try!(ErrPacket::from_payload(pld.as_ref()));
                Err(MySqlError(err))
            },
            _ => {
                let mut stmt = try!(InnerStmt::from_payload(pld.as_ref()));
                if stmt.num_params > 0 {
                    let mut params: Vec<Column> = Vec::with_capacity(stmt.num_params as usize);
                    for _ in 0..stmt.num_params {
                        let pld = try!(self.read_packet());
                        params.push(try!(Column::from_payload(self.last_command, pld.as_ref())));
                    }
                    stmt.params = Some(params);
                    try!(self.read_packet());
                }
                if stmt.num_columns > 0 {
                    let mut columns: Vec<Column> = Vec::with_capacity(stmt.num_columns as usize);
                    for _ in 0..stmt.num_columns {
                        let pld = try!(self.read_packet());
                        columns.push(try!(Column::from_payload(self.last_command, pld.as_ref())));
                    }
                    stmt.columns = Some(columns);
                    try!(self.read_packet());
                }
                Ok(stmt)
            }
        }
    }

    fn _prepare(&mut self, query: &str) -> MyResult<InnerStmt> {
        if let Some(inner_st) = self.stmts.get(query) {
            return Ok(inner_st.clone());
        }

        let inner_st = try!(self._true_prepare(query));
        self.stmts.insert(query.to_owned(), inner_st.clone());
        Ok(inner_st)
    }

    /// Implements binary protocol of mysql server.
    ///
    /// Prepares mysql statement on `MyConn`. [`Stmt`](struct.Stmt.html) will
    /// borrow `MyConn` until the end of its scope.
    ///
    /// This call will take statement from cache if has been prepared on this connection.
    pub fn prepare<'a, T: AsRef<str> + 'a>(&'a mut self, query: T) -> MyResult<Stmt<'a>> {
        match self._prepare(query.as_ref()) {
            Ok(stmt) => Ok(Stmt::new(stmt, self)),
            Err(err) => Err(err),
        }
    }

    /// Prepares and executes statement in one call.
    ///
    /// This call will take statement from cache if has been prepared on this connection.
    pub fn prep_exec<'a, A, T>(&'a mut self, query: A, params: T) -> MyResult<QueryResult<'a>>
    where A: AsRef<str> + 'a,
          T: ToRow {
        try!(self.prepare(query)).prep_exec(params.to_row())
    }

    fn more_results_exists(&self) -> bool {
        self.has_results
    }

    fn connect(&mut self) -> MyResult<()> {
        if self.connected {
            return Ok(());
        }
        self.do_handshake().and_then(|_| {
            Ok(from_value_opt::<usize>(self.get_system_var("max_allowed_packet").unwrap_or(NULL))
               .unwrap_or(0))
        }).and_then(|max_allowed_packet| {
            if max_allowed_packet == 0 {
                Err(MyDriverError(SetupError))
            } else {
                self.max_allowed_packet = max_allowed_packet;
                self.connected = true;
                Ok(())
            }
        })
    }

    fn get_system_var(&mut self, name: &str) -> Option<Value> {
        for row in self.query(format!("SELECT @@{};", name)).unwrap() {
            match row {
                Ok(mut r) => match r.len() {
                    0 => (),
                    _ => return Some(r.remove(0)),
                },
                _ => (),
            }
        }
        return None;
    }

    fn next_bin(&mut self, columns: &Vec<Column>) -> MyResult<Option<Vec<Value>>> {
        if ! self.has_results {
            return Ok(None);
        }
        let pld = match self.read_packet() {
            Ok(pld) => pld,
            Err(e) => {
                self.has_results = false;
                return Err(e);
            }
        };
        let x = pld[0];
        if x == 0xfe && pld.len() < 0xfe {
            self.has_results = false;
            let p = try!(EOFPacket::from_payload(pld.as_ref()));
            self.handle_eof(&p);
            return Ok(None);
        }
        let res = Value::from_bin_payload(pld.as_ref(), columns.as_ref());
        match res {
            Ok(p) => Ok(Some(p)),
            Err(e) => {
                self.has_results = false;
                Err(MyIoError(e))
            }
        }
    }

    fn next_text(&mut self, col_count: usize) -> MyResult<Option<Vec<Value>>> {
        if ! self.has_results {
            return Ok(None);
        }
        let pld = match self.read_packet() {
            Ok(pld) => pld,
            Err(e) => {
                self.has_results = false;
                return Err(e);
            }
        };
        let x = pld[0];
        if (x == 0xfe || x == 0xff) && pld.len() < 0xfe {
            self.has_results = false;
            if x == 0xfe {
                let p = try!(EOFPacket::from_payload(pld.as_ref()));
                self.handle_eof(&p);
                return Ok(None);
            } else /* x == 0xff */ {
                let p = ErrPacket::from_payload(pld.as_ref());
                match p {
                    Ok(p) => return Err(MySqlError(p)),
                    Err(err) => return Err(MyIoError(err))
                }
            }
        }
        let res = Value::from_payload(pld.as_ref(), col_count);
        match res {
            Ok(p) => Ok(Some(p)),
            Err(err) => {
                self.has_results = false;
                Err(MyIoError(err))
            }
        }
    }

    fn has_stmt(&self, query: &str) -> bool {
        self.stmts.contains_key(query)
    }
}

impl Drop for MyConn {
    fn drop(&mut self) {
        let keys: Vec<String> = self.stmts.keys().map(Clone::clone).collect();
        for key in keys {
            for stmt in self.stmts.remove(&key) {
                let data: [u8; 4] = [(stmt.statement_id & 0x000000FF) as u8,
                                     ((stmt.statement_id & 0x0000FF00) >> 08) as u8,
                                     ((stmt.statement_id & 0x00FF0000) >> 16) as u8,
                                     ((stmt.statement_id & 0xFF000000) >> 24) as u8,];
                let _ = self.write_command_data(Command::COM_STMT_CLOSE, &data);
            }
        }
    }
}

/***
 *    888b     d888          8888888b.                             888 888
 *    8888b   d8888          888   Y88b                            888 888
 *    88888b.d88888          888    888                            888 888
 *    888Y88888P888 888  888 888   d88P  .d88b.  .d8888b  888  888 888 888888
 *    888 Y888P 888 888  888 8888888P"  d8P  Y8b 88K      888  888 888 888
 *    888  Y8P  888 888  888 888 T88b   88888888 "Y8888b. 888  888 888 888
 *    888   "   888 Y88b 888 888  T88b  Y8b.          X88 Y88b 888 888 Y88b.
 *    888       888  "Y88888 888   T88b  "Y8888   88888P'  "Y88888 888  "Y888
 *                       888
 *                  Y8b d88P
 *                   "Y88P"
 */

/// Possible ways to pass conn to a query result
#[derive(Debug)]
enum ResultConnRef<'a> {
    ViaConnRef(&'a mut MyConn),
    ViaStmt(Stmt<'a>)
}

impl<'a> Deref for ResultConnRef<'a> {
    type Target = MyConn;

    fn deref<'c>(&'c self) -> &'c MyConn {
        match *self {
            ResultConnRef::ViaConnRef(ref conn_ref) => conn_ref,
            ResultConnRef::ViaStmt(ref stmt) => stmt.conn.deref(),
        }
    }
}

impl<'a> DerefMut for ResultConnRef<'a> {
    fn deref_mut<'c>(&'c mut self) -> &'c mut MyConn {
        match *self {
            ResultConnRef::ViaConnRef(ref mut conn_ref) => conn_ref,
            ResultConnRef::ViaStmt(ref mut stmt) => stmt.conn.deref_mut(),
        }
    }
}

/// Mysql result set for text and binary protocols.
///
/// If you want to get rows from `QueryResult` you should rely on implementation
/// of `Iterator` over `MyResult<Vec<Value>>` on `QueryResult`.
/// `Vec<Value>` is the current row representation.
///
/// ```rust
/// # use mysql::conn::pool;
/// # use mysql::conn::MyOpts;
/// # use mysql::value::Value;
/// # use std::thread::Thread;
/// # use std::default::Default;
/// # fn get_opts() -> MyOpts {
/// #     MyOpts {
/// #         user: Some("root".to_string()),
/// #         pass: Some("password".to_string()),
/// #         tcp_addr: Some("127.0.0.1".to_string()),
/// #         tcp_port: 3307,
/// #         ..Default::default()
/// #     }
/// # }
/// # let opts = get_opts();
/// # let pool = pool::MyPool::new(opts).unwrap();
/// let mut conn = pool.get_conn().unwrap();
///
/// for row in conn.prep_exec("SELECT ?", (42,)).unwrap() {
///     assert_eq!(row.unwrap(), vec![Value::Int(42)]);
/// }
/// ```
///
/// For more info on how to work with values please look at
/// [`Value`](../value/enum.Value.html) documentation.
#[derive(Debug)]
pub struct QueryResult<'a> {
    conn: ResultConnRef<'a>,
    columns: Vec<Column>,
    ok_packet: Option<OkPacket>,
    is_bin: bool,
}

impl<'a> QueryResult<'a> {
    fn new(conn: ResultConnRef<'a>,
           columns: Vec<Column>,
           ok_packet: Option<OkPacket>,
           is_bin: bool) -> QueryResult<'a>
    {
        QueryResult {
            conn: conn,
            columns: columns,
            ok_packet: ok_packet,
            is_bin: is_bin
        }
    }

    fn handle_if_more_results(&mut self) -> Option<MyResult<Vec<Value>>> {
        if self.conn.status_flags.contains(consts::SERVER_MORE_RESULTS_EXISTS) {
            match self.conn.handle_result_set() {
                Ok((cols, ok_p)) => {
                    self.columns = cols;
                    self.ok_packet = ok_p;
                    None
                },
                Err(e) => return Some(Err(e)),
            }
        } else {
            None
        }
    }

    /// Returns
    /// [`OkPacket`'s](http://dev.mysql.com/doc/internals/en/packet-OK_Packet.html)
    /// affected rows.
    pub fn affected_rows(&self) -> u64 {
        self.conn.affected_rows
    }

    /// Returns
    /// [`OkPacket`'s](http://dev.mysql.com/doc/internals/en/packet-OK_Packet.html)
    /// last insert id.
    pub fn last_insert_id(&self) -> u64 {
        self.conn.last_insert_id
    }

    /// Returns
    /// [`OkPacket`'s](http://dev.mysql.com/doc/internals/en/packet-OK_Packet.html)
    /// warnings count.
    pub fn warnings(&self) -> u16 {
        self.ok_packet.as_ref().map(|ok_p| ok_p.warnings).unwrap_or(0u16)
    }

    /// Returns
    /// [`OkPacket`'s](http://dev.mysql.com/doc/internals/en/packet-OK_Packet.html)
    /// info.
    pub fn info(&self) -> Vec<u8> {
        if self.ok_packet.is_some() {
            self.ok_packet.as_ref().unwrap().info.clone()
        } else {
            Vec::with_capacity(0)
        }
    }

    /// Returns index of a `QueryResult`'s column by name.
    pub fn column_index<T: AsRef<str>>(&self, name: T) -> Option<usize> {
        let name = name.as_ref().as_bytes();
        for (i, c) in self.columns.iter().enumerate() {
            if c.name == name {
                return Some(i)
            }
        }
        None
    }

    /// This predicate will help you if you are expecting multiple result sets.
    ///
    /// For example:
    ///
    /// ```ignore
    /// conn.query(r#"
    ///            CREATE PROCEDURE multi() BEGIN
    ///                SELECT 1;
    ///                SELECT 2;
    ///            END
    ///            "#);
    /// let mut result = conn.query("CALL multi()").unwrap();
    /// while result.more_results_exists() {
    ///     for x in result.by_ref() {
    ///         // On first iteration of `while` you will get result set from
    ///         // SELECT 1 and from SELECT 2 on second.
    ///     }
    /// }
    /// ```
    pub fn more_results_exists(&self) -> bool {
        self.conn.has_results
    }
}

impl<'a> Iterator for QueryResult<'a> {
    type Item = MyResult<Vec<Value>>;

    fn next(&mut self) -> Option<MyResult<Vec<Value>>> {
        let r = if self.is_bin {
            self.conn.next_bin(&self.columns)
        } else {
            self.conn.next_text(self.columns.len())
        };
        match r {
            Ok(r) => {
                match r {
                    None => self.handle_if_more_results(),
                    Some(r) => Some(Ok(r))
                }
            },
            Err(e) => Some(Err(e))
        }
    }
}

impl<'a> Drop for QueryResult<'a> {
    fn drop(&mut self) {
        while self.conn.more_results_exists() {
            while let Some(_) = self.next() {}
        }
    }
}

/***
 *    88888888888                   888
 *        888                       888
 *        888                       888
 *        888      .d88b.  .d8888b  888888 .d8888b
 *        888     d8P  Y8b 88K      888    88K
 *        888     88888888 "Y8888b. 888    "Y8888b.
 *        888     Y8b.          X88 Y88b.       X88
 *        888      "Y8888   88888P'  "Y888  88888P'
 *
 *
 *
 */

#[cfg(test)]
#[allow(non_snake_case)]
mod test {
    use std::borrow::ToOwned;
    use std::default::Default;
    use super::MyOpts;

    static USER: &'static str = "root";
    static PASS: &'static str = "password";
    static ADDR: &'static str = "127.0.0.1";
    static PORT: u16          = 3307;

    #[cfg(feature = "openssl")]
    pub fn get_opts() -> MyOpts {
        MyOpts {
            user: Some(USER.to_string()),
            pass: Some(PASS.to_string()),
            tcp_addr: Some(ADDR.to_string()),
            tcp_port: PORT,
            init: vec!["SET GLOBAL sql_mode = 'TRADITIONAL'".to_owned()],
            ssl_opts: Some((::std::convert::From::from("tests/ca-cert.pem"), None)),
            ..Default::default()
        }
    }

    #[cfg(not(feature = "ssl"))]
    pub fn get_opts() -> MyOpts {
        MyOpts {
            user: Some(USER.to_string()),
            pass: Some(PASS.to_string()),
            tcp_addr: Some(ADDR.to_string()),
            tcp_port: PORT,
            init: vec!["SET GLOBAL sql_mode = 'TRADITIONAL'".to_owned()],
            ..Default::default()
        }
    }

    mod my_conn {
        use std::iter;
        use std::env;
        use std::borrow::ToOwned;
        use std::fs;
        use std::io::Write;
        use time::{Tm, now};
        use super::super::{MyConn, MyOpts};
        use super::super::super::value::{ToValue, from_value};
        use super::super::super::value::Value::{NULL, Int, Bytes, Date};
        use super::get_opts;

        #[test]
        fn should_connect() {
            let mut conn = MyConn::new(get_opts()).unwrap();
            let mode = conn.query("SELECT @@GLOBAL.sql_mode").unwrap().next().unwrap().unwrap().remove(0);
            let mode = from_value::<String>(mode);
            assert!(mode.contains("TRADITIONAL"));
            assert!(conn.ping());
        }
        #[test]
        fn should_connect_with_database() {
            let mut conn = MyConn::new(MyOpts {
                db_name: Some("mysql".to_string()),
                ..get_opts()
            }).unwrap();
            assert_eq!(conn.query("SELECT DATABASE()").unwrap().next().unwrap().unwrap(),
                       vec![Bytes(b"mysql".to_vec())]);
        }
        #[test]
        fn should_execute_queryes_and_parse_results() {
            let mut conn = MyConn::new(get_opts()).unwrap();
            assert!(conn.query("CREATE TEMPORARY TABLE x.tbl(\
                                    a TEXT,\
                                    b INT,\
                                    c INT UNSIGNED,\
                                    d DATE,\
                                    e FLOAT
                                )").is_ok());
            assert!(conn.query("INSERT INTO x.tbl(a, b, c, d, e) VALUES (\
                                    'hello',\
                                    -123,\
                                    123,\
                                    '2014-05-05',\
                                    123.123\
                                )").is_ok());
            assert!(conn.query("INSERT INTO x.tbl(a, b, c, d, e) VALUES (\
                                    'world',\
                                    -321,\
                                    321,\
                                    '2014-06-06',\
                                    321.321\
                                )").is_ok());
            assert!(conn.query("SELECT * FROM unexisted").is_err());
            assert!(conn.query("SELECT * FROM x.tbl").is_ok());
            // Drop
            assert!(conn.query("UPDATE x.tbl SET a = 'foo'").is_ok());
            assert_eq!(conn.affected_rows, 2);
            assert!(conn.query("SELECT * FROM x.tbl WHERE a = 'bar'").unwrap().next().is_none());
            for (i, row) in conn.query("SELECT * FROM x.tbl")
                                .unwrap().enumerate() {
                let row = row.unwrap();
                if i == 0 {
                    assert_eq!(row[0], Bytes(b"foo".to_vec()));
                    assert_eq!(row[1], Bytes(b"-123".to_vec()));
                    assert_eq!(row[2], Bytes(b"123".to_vec()));
                    assert_eq!(row[3], Bytes(b"2014-05-05".to_vec()));
                    assert_eq!(row[4], Bytes(b"123.123".to_vec()));
                } else if i == 1 {
                    assert_eq!(row[0], Bytes(b"foo".to_vec()));
                    assert_eq!(row[1], Bytes(b"-321".to_vec()));
                    assert_eq!(row[2], Bytes(b"321".to_vec()));
                    assert_eq!(row[3], Bytes(b"2014-06-06".to_vec()));
                    assert_eq!(row[4], Bytes(b"321.321".to_vec()));
                } else {
                    unreachable!();
                }
            }
        }
        #[test]
        fn should_parse_large_text_result() {
            let mut conn = MyConn::new(get_opts()).unwrap();
            assert_eq!(
                conn.query("SELECT REPEAT('A', 20000000)").unwrap().next().unwrap().unwrap(),
                vec![Bytes(iter::repeat(b'A').take(20_000_000).collect())]
            );
        }
        #[test]
        fn should_execute_statements_and_parse_results() {
            let mut conn = MyConn::new(get_opts()).unwrap();
            assert!(conn.query("CREATE TEMPORARY TABLE x.tbl(\
                                    a TEXT,\
                                    b INT,\
                                    c INT UNSIGNED,\
                                    d DATE,\
                                    e DOUBLE\
                                )").is_ok());
            let _ = conn.prepare("INSERT INTO x.tbl(a, b, c, d, e)\
                          VALUES (?, ?, ?, ?, ?)")
            .and_then(|mut stmt| {
                let tm = Tm { tm_year: 114, tm_mon: 4, tm_mday: 5, tm_hour: 0,
                              tm_min: 0, tm_sec: 0, tm_nsec: 0, ..now() };
                let hello = b"hello".to_vec();
                assert!(stmt.execute((&hello, -123, 123, tm.to_timespec(), 123.123f64)).is_ok());
                assert!(stmt.execute(&[
                    &b"world".to_vec() as &ToValue,
                    &NULL as &ToValue,
                    &NULL as &ToValue,
                    &NULL as &ToValue,
                    &321.321f64 as &ToValue
                ][..]).is_ok());
                Ok(())
            }).unwrap();
            let _ = conn.prepare("SELECT * from x.tbl").and_then(|mut stmt| {
                for (i, row) in stmt.execute(()).unwrap().enumerate() {
                    let mut row = row.unwrap();
                    if i == 0 {
                        assert_eq!(row[0], Bytes(b"hello".to_vec()));
                        assert_eq!(row[1], Int(-123i64));
                        assert_eq!(row[2], Int(123i64));
                        assert_eq!(row[3], Date(2014u16, 5u8, 5u8, 0u8, 0u8, 0u8, 0u32));
                        assert_eq!(from_value::<f64>(row.pop().unwrap()), 123.123);
                    } else if i == 1 {
                        assert_eq!(row[0], Bytes(b"world".to_vec()));
                        assert_eq!(row[1], NULL);
                        assert_eq!(row[2], NULL);
                        assert_eq!(row[3], NULL);
                        assert_eq!(from_value::<f64>(row.pop().unwrap()), 321.321);
                    } else {
                        unreachable!();
                    }
                }
                Ok(())
            }).unwrap();
            let mut result = conn.prep_exec("SELECT ?, ?, ?", ("hello", 1, 1.1)).unwrap();
            let row = result.next().unwrap();
            let mut row = row.unwrap();
            assert_eq!(from_value::<f32>(row.pop().unwrap()), 1.1);
            assert_eq!(from_value::<i8>(row.pop().unwrap()), 1);
            assert_eq!(from_value::<String>(row.pop().unwrap()), "hello".to_string());
        }
        #[test]
        fn should_parse_large_binary_result() {
            let mut conn = MyConn::new(get_opts()).unwrap();
            let mut stmt = conn.prepare("SELECT REPEAT('A', 20000000);").unwrap();
            assert_eq!(
                stmt.execute(()).unwrap().next().unwrap().unwrap(),
                vec![Bytes(iter::repeat(b'A').take(20_000_000).collect())]
            );
        }
        #[test]
        fn should_start_commit_and_rollback_transactions() {
            let mut conn = MyConn::new(get_opts()).unwrap();
            assert!(conn.query("CREATE TEMPORARY TABLE x.tbl(a INT)").is_ok());
            let _ = conn.start_transaction(false, None, None).and_then(|mut t| {
                assert!(t.query("INSERT INTO x.tbl(a) VALUES(1)").is_ok());
                assert!(t.query("INSERT INTO x.tbl(a) VALUES(2)").is_ok());
                assert!(t.commit().is_ok());
                Ok(())
            }).unwrap();
            assert_eq!(conn.query("SELECT COUNT(a) from x.tbl").unwrap().next().unwrap().unwrap(),
                       vec![Bytes(b"2".to_vec())]);
            let _ = conn.start_transaction(false, None, None).and_then(|mut t| {
                assert!(t.query("INSERT INTO tbl(a) VALUES(1)").is_err());
                Ok(())
                // implicit rollback
            }).unwrap();
            assert_eq!(conn.query("SELECT COUNT(a) from x.tbl").unwrap().next().unwrap().unwrap(),
                       vec![Bytes(b"2".to_vec())]);
            let _ = conn.start_transaction(false, None, None).and_then(|mut t| {
                assert!(t.query("INSERT INTO x.tbl(a) VALUES(1)").is_ok());
                assert!(t.query("INSERT INTO x.tbl(a) VALUES(2)").is_ok());
                assert!(t.rollback().is_ok());
                Ok(())
            }).unwrap();
            assert_eq!(conn.query("SELECT COUNT(a) from x.tbl").unwrap().next().unwrap().unwrap(),
                       vec![Bytes(b"2".to_vec())]);
            let _ = conn.start_transaction(false, None, None).and_then(|mut t| {
                let _ = t.prepare("INSERT INTO x.tbl(a) VALUES(?)")
                .and_then(|mut stmt| {
                    assert!(stmt.execute((3,)).is_ok());
                    assert!(stmt.execute((4,)).is_ok());
                    Ok(())
                }).unwrap();
                assert!(t.commit().is_ok());
                Ok(())
            }).unwrap();
            assert_eq!(conn.query("SELECT COUNT(a) from x.tbl").unwrap().next().unwrap().unwrap(),
                       vec![Bytes(b"4".to_vec())]);
            let _ = conn.start_transaction(false, None, None). and_then(|mut t| {
                t.prep_exec("INSERT INTO x.tbl(a) VALUES(?)", (5,)).unwrap();
                t.prep_exec("INSERT INTO x.tbl(a) VALUES(?)", (6,)).unwrap();
                Ok(())
            }).unwrap();
        }
        #[test]
        fn should_handle_LOCAL_INFILE() {
            let mut conn = MyConn::new(get_opts()).unwrap();
            assert!(conn.query("CREATE TEMPORARY TABLE x.tbl(a TEXT)").is_ok());
            let mut path = env::current_dir().unwrap();
            path.push("local_infile.txt");
            {
                let mut file = fs::File::create(&path).unwrap();
                let _ = file.write(b"AAAAAA\n");
                let _ = file.write(b"BBBBBB\n");
                let _ = file.write(b"CCCCCC\n");
            }
            let query = format!("LOAD DATA LOCAL INFILE '{}' INTO TABLE x.tbl",
                                path.to_str().unwrap().to_owned());
            assert!(conn.query(query).is_ok());
            for (i, row) in conn.query("SELECT * FROM x.tbl")
                                .unwrap().enumerate() {
                let row = row.unwrap();
                match i {
                    0 => assert_eq!(row, vec!(Bytes(b"AAAAAA".to_vec()))),
                    1 => assert_eq!(row, vec!(Bytes(b"BBBBBB".to_vec()))),
                    2 => assert_eq!(row, vec!(Bytes(b"CCCCCC".to_vec()))),
                    _ => unreachable!()
                }
            }
            let _ = fs::remove_file(&path);
        }
        #[test]
        fn should_reset_connection() {
            let mut conn = MyConn::new(get_opts()).unwrap();
            assert!(conn.query("CREATE TEMPORARY TABLE `db`.`test` \
                                (`test` VARCHAR(255) NULL);").is_ok());
            assert!(conn.query("SELECT * FROM `db`.`test`;").is_ok());
            assert!(conn.reset().is_ok());
            assert!(conn.query("SELECT * FROM `db`.`test`;").is_err());
        }
        #[test]
        fn should_handle_multi_resultset() {
            let mut conn = MyConn::new(MyOpts {
                prefer_socket: false,
                db_name: Some("mysql".to_string()),
                ..get_opts()
            }).unwrap();
            assert!(conn.query("DROP PROCEDURE IF EXISTS multi").is_ok());
            assert!(conn.query(r#"CREATE PROCEDURE multi() BEGIN
                                      SELECT 1;
                                      SELECT 1;
                                  END"#).is_ok());
            for (i, row) in conn.query("CALL multi()")
                                .unwrap().enumerate() {
                match i {
                    0 | 1 => assert_eq!(row.unwrap(), vec![Bytes(b"1".to_vec())]),
                    _ => unreachable!(),
                }
            }
            let mut result = conn.query("SELECT 1; SELECT 2; SELECT 3;").unwrap();
            let mut i = 0;
            while { i += 1; result.more_results_exists() } {
                for row in result.by_ref() {
                    match i {
                        1 => assert_eq!(row.unwrap(), vec![Bytes(b"1".to_vec())]),
                        2 => assert_eq!(row.unwrap(), vec![Bytes(b"2".to_vec())]),
                        3 => assert_eq!(row.unwrap(), vec![Bytes(b"3".to_vec())]),
                        _ => unreachable!(),
                    }
                }
            }
        }
    }

    #[cfg(feature = "nightly")]
    mod bench {
        use test;
        use super::get_opts;
        use super::super::{MyConn};
        use super::super::super::value::Value::NULL;

        #[bench]
        fn simple_exec(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            bencher.iter(|| { let _ = conn.query("DO 1"); })
        }

        #[bench]
        fn prepared_exec(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            let mut stmt = conn.prepare("DO 1").unwrap();
            bencher.iter(|| { let _ = stmt.execute(()); })
        }

        #[bench]
        fn prepare_and_exec(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            bencher.iter(|| {
                let mut stmt = conn.prepare("SELECT ?").unwrap();
                let _ = stmt.execute((0,)).unwrap();
            })
        }

        #[bench]
        fn simple_query_row(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            bencher.iter(|| { let _ = conn.query("SELECT 1"); })
        }

        #[bench]
        fn simple_prepared_query_row(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            let mut stmt = conn.prepare("SELECT 1").unwrap();
            bencher.iter(|| { let _ = stmt.execute(()); })
        }

        #[bench]
        fn simple_prepared_query_row_with_param(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            let mut stmt = conn.prepare("SELECT ?").unwrap();
            bencher.iter(|| { let _ = stmt.execute((0,)); })
        }

        #[bench]
        fn simple_prepared_query_row_with_5_params(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            let mut stmt = conn.prepare("SELECT ?, ?, ?, ?, ?").unwrap();
            let params = (42i8, b"123456".to_vec(), 1.618f64, NULL, 1i8);
            bencher.iter(|| { let _ = stmt.execute(&params); })
        }

        #[bench]
        fn select_large_string(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            bencher.iter(|| { let _ = conn.query("SELECT REPEAT('A', 10000)"); })
        }

        #[bench]
        fn select_prepared_large_string(bencher: &mut test::Bencher) {
            let mut conn = MyConn::new(get_opts()).unwrap();
            let mut stmt = conn.prepare("SELECT REPEAT('A', 10000)").unwrap();
            bencher.iter(|| { let _ = stmt.execute(()); })
        }
    }
}