/*eslint max-len: 0, no-var:0 */

const charsRegex = /[\0\b\t\n\r\x1a"'\\]/g; // eslint-disable-line no-control-regex
const charsMap = {
  '\0': '\\0',
  '\b': '\\b',
  '\t': '\\t',
  '\n': '\\n',
  '\r': '\\r',
  '\x1a': '\\Z',
  '"': '\\"',
  "'": "\\'",
  '\\': '\\\\',
};

function wrapEscape(escapeFn) {
  return function finalEscape(val, ctx = {}) {
    return escapeFn(val, finalEscape, ctx);
  };
}

function makeEscape(config = {}) {
  const finalEscapeDate = config.escapeDate || dateToString;
  const finalEscapeArray = config.escapeArray || arrayToList;
  const finalEscapeBuffer = config.escapeBuffer || bufferToString;
  const finalEscapeString = config.escapeString || escapeString;
  const finalEscapeObject = config.escapeObject || escapeObject;
  const finalWrap = config.wrap || wrapEscape;

  function escapeFn(val, finalEscape, ctx) {
    if (val === undefined || val === null) {
      return 'NULL';
    }
    switch (typeof val) {
      case 'boolean':
        return val ? 'true' : 'false';
      case 'number':
        return val + '';
      case 'object':
        if (val instanceof Date) {
          val = finalEscapeDate(val, finalEscape, ctx);
        } else if (Array.isArray(val)) {
          return finalEscapeArray(val, finalEscape, ctx);
        } else if (Buffer.isBuffer(val)) {
          return finalEscapeBuffer(val, finalEscape, ctx);
        } else {
          return finalEscapeObject(val, finalEscape, ctx);
        }
    }
    return finalEscapeString(val, finalEscape, ctx);
  }

  return finalWrap ? finalWrap(escapeFn) : escapeFn;
}

function escapeObject(val, finalEscape, ctx) {
  if (val && typeof val.toSQL === 'function') {
    return val.toSQL(ctx);
  } else {
    return JSON.stringify(val);
  }
}

function arrayToList(array, finalEscape, ctx) {
  let sql = '';
  for (let i = 0; i < array.length; i++) {
    const val = array[i];
    if (Array.isArray(val)) {
      sql +=
        (i === 0 ? '' : ', ') + '(' + arrayToList(val, finalEscape, ctx) + ')';
    } else {
      sql += (i === 0 ? '' : ', ') + finalEscape(val, ctx);
    }
  }
  return sql;
}

function bufferToString(buffer) {
  return 'X' + escapeString(buffer.toString('hex'));
}

function escapeString(val, finalEscape, ctx) {
  let chunkIndex = (charsRegex.lastIndex = 0);
  let escapedVal = '';
  let match;

  while ((match = charsRegex.exec(val))) {
    escapedVal += val.slice(chunkIndex, match.index) + charsMap[match[0]];
    chunkIndex = charsRegex.lastIndex;
  }

  if (chunkIndex === 0) {
    // Nothing was escaped
    return "'" + val + "'";
  }

  if (chunkIndex < val.length) {
    return "'" + escapedVal + val.slice(chunkIndex) + "'";
  }

  return "'" + escapedVal + "'";
}

function dateToString(date, finalEscape, ctx) {
  const timeZone = ctx.timeZone || 'local';

  const dt = new Date(date);
  let year;
  let month;
  let day;
  let hour;
  let minute;
  let second;
  let millisecond;

  if (timeZone === 'local') {
    year = dt.getFullYear();
    month = dt.getMonth() + 1;
    day = dt.getDate();
    hour = dt.getHours();
    minute = dt.getMinutes();
    second = dt.getSeconds();
    millisecond = dt.getMilliseconds();
  } else {
    const tz = convertTimezone(timeZone);

    if (tz !== false && tz !== 0) {
      dt.setTime(dt.getTime() + tz * 60000);
    }

    year = dt.getUTCFullYear();
    month = dt.getUTCMonth() + 1;
    day = dt.getUTCDate();
    hour = dt.getUTCHours();
    minute = dt.getUTCMinutes();
    second = dt.getUTCSeconds();
    millisecond = dt.getUTCMilliseconds();
  }

  // YYYY-MM-DD HH:mm:ss.mmm
  return (
    zeroPad(year, 4) +
    '-' +
    zeroPad(month, 2) +
    '-' +
    zeroPad(day, 2) +
    ' ' +
    zeroPad(hour, 2) +
    ':' +
    zeroPad(minute, 2) +
    ':' +
    zeroPad(second, 2) +
    '.' +
    zeroPad(millisecond, 3)
  );
}

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

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

module.exports = {
  arrayToList,
  bufferToString,
  dateToString,
  escapeString,
  charsRegex,
  charsMap,
  escapeObject,
  makeEscape,
};