'use strict';

var SqlString = exports;
var helpers = require('../../helpers');

SqlString.escape = function (val, timeZone) {
  if (val == null) {
    return 'NULL';
  }

  switch (typeof val) {
    case 'boolean':
      return val ? 'true' : 'false';
    case 'number':
      return val + '';
  }

  if (val instanceof Date) {
    val = SqlString.dateToString(val, timeZone || 'local');
  }

  if (Buffer.isBuffer(val)) {
    return SqlString.bufferToString(val);
  }

  if (Array.isArray(val)) {
    return SqlString.arrayToList(val, timeZone);
  }

  if (typeof val === 'object') {
    try {
      val = JSON.stringify(val);
    } catch (e) {
      helpers.warn(e);
      val = val + '';
    }
  }

  val = val.replace(/[\0\n\r\b\t\\\'\"\x1a]/g, function (s) {
    switch (s) {
      case '\u0000':
        return '\\0';
      case '\n':
        return '\\n';
      case '\r':
        return '\\r';
      case '\b':
        return '\\b';
      case '\t':
        return '\\t';
      case '\u001a':
        return '\\Z';
      case '\'':
        return '\'\'';
      default:
        return '\\' + s;
    }
  });
  return '\'' + val + '\'';
};

SqlString.arrayToList = function (array, timeZone) {
  return array.map(function (v) {
    if (Array.isArray(v)) return '(' + SqlString.arrayToList(v, timeZone) + ')';
    return SqlString.escape(v, timeZone);
  }).join(', ');
};

SqlString.format = function (sql, values, timeZone) {
  values = values == null ? [] : [].concat(values);
  var index = 0;
  return sql.replace(/\?/g, function (match) {
    if (index === values.length) {
      return match;
    }
    var value = values[index++];
    return SqlString.escape(value, timeZone);
  });
};

SqlString.dateToString = function (date, timeZone) {
  var dt = new Date(date);

  if (timeZone !== 'local') {
    var tz = convertTimezone(timeZone);

    dt.setTime(dt.getTime() + dt.getTimezoneOffset() * 60000);
    if (tz !== false) {
      dt.setTime(dt.getTime() + tz * 60000);
    }
  }

  var year = dt.getFullYear();
  var month = zeroPad(dt.getMonth() + 1, 2);
  var day = zeroPad(dt.getDate(), 2);
  var hour = zeroPad(dt.getHours(), 2);
  var minute = zeroPad(dt.getMinutes(), 2);
  var second = zeroPad(dt.getSeconds(), 2);
  var millisecond = zeroPad(dt.getMilliseconds(), 3);

  return year + '-' + month + '-' + day + ' ' + hour + ':' + minute + ':' + second + '.' + millisecond;
};

SqlString.bufferToString = function bufferToString(buffer) {
  return 'X\'' + buffer.toString('hex') + '\'';
};

function zeroPad(number, length) {
  number = number.toString();
  while (number.length < length) {
    number = '0' + number;
  }

  return number;
}

function convertTimezone(tz) {
  if (tz === 'Z') return 0;

  var m = tz.match(/([\+\-\s])(\d\d):?(\d\d)?/);
  if (m) {
    return (m[1] === '-' ? -1 : 1) * (parseInt(m[2], 10) + (m[3] ? parseInt(m[3], 10) : 0) / 60) * 60;
  }
  return false;
}