<?php
require_once './Inflector.php';

class DatabaseException extends Exception {}

class DatabaseConnectException extends DatabaseException
{
  public function __toString()
  {
    return "Database Connect Error!\nMessage: {$this->getMessage()}\nCode: {$this->getCode()}";
  }
}

class DatabaseSqlException extends DatabaseException
{
  protected $sql;

  public function __construct($sql, $message, $code = null)
  {
    parent::__construct($message, $code);
    $this->setSql($sql);
  }

  public function setSql($sql)
  {
    $this->sql = $sql;
  }

  public function getSql()
  {
    return $this->sql;
  }

  public function __toString()
  {
    return "Database Sql Error!\nSQL: {$this->getSql()}\nMessage: {$this->getMessage()}\nCode: {$this->getCode()}";
  }
}

class Database extends mysqli
{
  const FETCH_TYPE_ASSOC = 1;
  const FETCH_TYPE_ROW = 2;
  
  public function __construct($host = null, $username = null, $passwd = null, $dbname = null, $port = null, $socket = null)
  {
    parent::__construct($host, $username, $passwd, $dbname, $port, $socket);
    if ($this->errno)
      throw new DatabaseConnectException($this->error, $this->errno);
  }

  public function query($sql, $resultmode = MYSQLI_STORE_RESULT) {
    if (($result = parent::query($sql, $resultmode)) === false)
      throw new DatabaseSqlException($sql, $this->error, $this->errno);
    return $result;
  }
  
  public function fetchCol($sql)
  {
    $rows = array();
    $result = $this->query($sql);
    while ($row = $result->fetch_row())
      $rows[] = $row[0];
    return $rows;
  }

  public function fetchOne($sql)
  {
    $result = $this->query($sql);
    if ($row = $result->fetch_row())
      return $row[0];
    return null;
  }

  public function fetchRow($sql, $type = self::FETCH_TYPE_ASSOC)
  {
    $result = $this->query($sql);
    if ($row = $this->createRow($result, $type))
      return $row;
    return null;
  }

  public function fetchAll($sql, $type = self::FETCH_TYPE_ASSOC)
  {
    $rows = array();
    $result = $this->query($sql);
    while ($row = $this->createRow($result, $type))
      $rows[] = $row;
    return $rows;
  }
  
  protected function createRow($result, $type)
  {
    if ($type === self::FETCH_TYPE_ASSOC)
      return $result->fetch_assoc();
    elseif ($type === self::FETCH_TYPE_ROW)
      return $result->fetch_row();
    else
      throw new DatabaseException('Unknown fetch type: "' . $type . '"');
  }

  public function insert($tableName, array $data) {
    $keys = $values = array();
    foreach ($data as $k => $v) {
      $keys[] = $this->quoteIdentifier($k);
      $values[] = $this->quote($v);
    }
    $keys = implode(', ', $keys);
    $values = implode(', ', $values);

    $sql = "INSERT INTO " . $this->quoteIdentifier($tableName) . "($keys) VALUES($values)";
    $this->query($sql);
  }

  public function update($tableName, array $data, $where = null) {
    $setters = array();
    foreach ($data as $k => $v)
      $setters[] = $this->quoteIdentifier($k) . ' = ' . $this->quote($v);
    $setters = implode(', ', $setters);

    $sql = "UPDATE " . $this->quoteIdentifier($tableName) . " SET $setters";
    if ($where !== null)
      $sql .= " WHERE $where";

    $this->query($sql);
  }

  public function delete($tableName, $where = null) {
    $sql = "DELETE FROM " . $this->quoteIdentifier($tableName);
    if ($where !== null)
      $sql .= " WHERE $where";
    $this->query($sql);
  }

  public function quote($value) {
    if ($value === null)
      return 'NULL';

    if (is_bool($value))
      return (int)$value;

    if (is_numeric($value))
      return $value;

    if ($value instanceof DatabaseExpression)
      return $value->__toString();

    return "'" . $this->real_escape_string((string)$value) . "'";
  }
  
  public function quoteInto($sql, $value) {
    if (is_array($value)) {
      foreach ($value as $val)
        if (($pos = strpos($sql, '?')) !== false)
          $sql = substr_replace($sql, $this->quote($val), $pos, 1);
        else
          break;
    } else {
      $sql = str_replace('?', $this->quote($value), $sql);
    }
    return $sql;
  }
  
  public function quoteIdentifier($ident)
  {
    $ident = explode('.', $ident);
    $quoted = array();
    foreach ($ident as $id)
      $quoted[] = '`' . $id . '`';
    return implode('.', $quoted);
  }
  
  public function setEncoding($encoding)
  {
    $this->query('SET NAMES ' . $encoding);
  }
}

class DatabaseExpression
{
  private $expression;

  public function __construct($expression)
  {
    $this->expression = (string)$expression;
  }

  public function __toString()
  {
    return $this->expression;
  }
}