'use strict';

// MariaSQL Client
// -------
var inherits     = require('inherits')
var assign       = require('lodash/object/assign')
var Client_MySQL = require('../mysql')
var Promise      = require('../../promise')
var SqlString    = require('../../query/string')
var helpers      = require('../../helpers')
var pluck        = require('lodash/collection/pluck');

function Client_MariaSQL(config) {
  Client_MySQL.call(this, config)
}
inherits(Client_MariaSQL, Client_MySQL)

assign(Client_MariaSQL.prototype, {

  dialect: 'mariasql',

  driverName: 'mariasql',

  // Get a raw connection, called by the `pool` whenever a new
  // connection needs to be added to the pool.
  acquireRawConnection: function() {
    var connection = new this.driver();
    connection.connect(assign({metadata: true}, this.connectionSettings));
    return new Promise(function(resolver, rejecter) {
      connection
        .on('connect', function() {
          connection.removeAllListeners('end');
          connection.removeAllListeners('error');
          resolver(connection);
        })
        .on('error', rejecter);
    })
  },

  // Used to explicitly close a connection, called internally by the pool
  // when a connection times out or the pool is shutdown.
  destroyRawConnection: function(connection, cb) {
    connection.end()
    cb()
  },

  // Return the database for the MariaSQL client.
  database: function() {
    return this.connectionSettings.db;
  },

  // Grab a connection, run the query via the MariaSQL streaming interface,
  // and pass that through to the stream we've sent back to the client.
  _stream: function(connection, sql, stream) {
    return new Promise(function(resolver, rejecter) {
      connection.query(sql.sql, sql.bindings)
        .on('result', function(result) {
          result
            .on('row', rowHandler(function(row) { stream.write(row); }))
            .on('end', function(data) { resolver(data); });
        })
        .on('error', function(err) { rejecter(err); });
    });
  },

  // Runs the query on the specified connection, providing the bindings
  // and any other necessary prep work.
  _query: function(connection, obj) {
    var tz  = this.connectionSettings.timezone || 'local';
    return new Promise(function(resolver, rejecter) {
      if (!obj.sql) return resolver()
      var rows = [];
      var query = connection.query(SqlString.format(obj.sql, obj.bindings, false, tz), [])
      query.on('result', function(result) {
        result.on('row', rowHandler(function(row) { rows.push(row); }))
        .on('end', function(data) {
          obj.response = [rows, data];
          resolver(obj);
        });
      })
      .on('error', rejecter)
    });
  },

  // Process the response as returned from the query.
  processResponse: function(obj, runner) {
    var response = obj.response;
    var method   = obj.method;
    var rows     = response[0];
    var data     = response[1];
    if (obj.output) return obj.output.call(runner, rows/*, fields*/);
    switch (method) {
      case 'select':
      case 'pluck':
      case 'first':
        var resp = helpers.skim(rows);
        if (method === 'pluck') return pluck(resp, obj.pluck);
        return method === 'first' ? resp[0] : resp;
      case 'insert':
        return [data.insertId];
      case 'del':
      case 'update':
      case 'counter':
        return data.affectedRows;
      default:
        return response;
    }
  }  

})

function parseType(value, type) {
  switch (type) {
    case 'DATETIME':
    case 'TIMESTAMP':
      return new Date(value);
    case 'INTEGER':
      return parseInt(value, 10);
    default:
      return value;
  }
}

function rowHandler(callback) {
  var types;
  return function(row, meta) {
    if (!types) types = meta.types;
    var keys = Object.keys(types);
    for (var i = 0, l = keys.length; i < l; i++) {
      var type = keys[i];
      row[type] = parseType(row[type], types[type]);
    }
    callback(row);
  };
}

module.exports = Client_MariaSQL