<?php

/***********************************************************************

  Copyright (C) 2002-2008  PunBB.org

  This file is part of PunBB.

  PunBB is free software; you can redistribute it and/or modify it

  under the terms of the GNU General Public License as published

  by the Free Software Foundation; either version 2 of the License,

  or (at your option) any later version.

  PunBB is distributed in the hope that it will be useful, but

  WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License

  along with this program; if not, write to the Free Software

  Foundation, Inc., 59 Temple Place, Suite 330, Boston,

  MA  02111-1307  USA

************************************************************************/

// Make sure we have built in support for SQLite

if (!function_exists('sqlite_open'))

	exit('This PHP environment doesn\'t have SQLite support built in. SQLite support is required if you want to use a SQLite database to run this forum. Consult the PHP documentation for further assistance.');

class DBLayer

{

	var $prefix;

	var $link_id;

	var $query_result;

	var $in_transaction = 0;

	var $saved_queries = array();

	var $num_queries = 0;

	var $error_no = false;

	var $error_msg = 'Unknown';

	function DBLayer($db_host, $db_username, $db_password, $db_name, $db_prefix, $p_connect)

	{

		// Prepend $db_name with the path to the forum root directory

		$db_name = PUN_ROOT.$db_name;

		$this->prefix = $db_prefix;

		if (!file_exists($db_name))

		{

			@touch($db_name);

			@chmod($db_name, 0666);

			if (!file_exists($db_name))

				error('Unable to create new database \''.$db_name.'\'. Permission denied.', __FILE__, __LINE__);

		}

		if (!is_readable($db_name))

			error('Unable to open database \''.$db_name.'\' for reading. Permission denied.', __FILE__, __LINE__);

		if (!is_writable($db_name))

			error('Unable to open database \''.$db_name.'\' for writing. Permission denied.', __FILE__, __LINE__);

		if ($p_connect)

			$this->link_id = @sqlite_popen($db_name, 0666, $sqlite_error);

		else

			$this->link_id = @sqlite_open($db_name, 0666, $sqlite_error);

		if (!$this->link_id)

			error('Unable to open database \''.$db_name.'\'. SQLite reported: '.$sqlite_error, __FILE__, __LINE__);

		else

			return $this->link_id;

	}

	function start_transaction()

	{

		++$this->in_transaction;

		return (@sqlite_query($this->link_id, 'BEGIN')) ? true : false;

	}

	function end_transaction()

	{

		--$this->in_transaction;

		if (@sqlite_query($this->link_id, 'COMMIT'))

			return true;

		else

		{

			@sqlite_query($this->link_id, 'ROLLBACK');

			return false;

		}

	}

	function query($sql, $unbuffered = false)

	{

		if (strlen($sql) > 140000)

			exit('Insane query. Aborting.');

		if (defined('PUN_SHOW_QUERIES'))

			$q_start = get_microtime();

		if ($unbuffered)

			$this->query_result = @sqlite_unbuffered_query($this->link_id, $sql);

		else

			$this->query_result = @sqlite_query($this->link_id, $sql);

		if ($this->query_result)

		{

			if (defined('PUN_SHOW_QUERIES'))

				$this->saved_queries[] = array($sql, sprintf('%.5f', get_microtime() - $q_start));

			++$this->num_queries;

			return $this->query_result;

		}

		else

		{

			if (defined('PUN_SHOW_QUERIES'))

				$this->saved_queries[] = array($sql, 0);

			$this->error_no = @sqlite_last_error($this->link_id);

			$this->error_msg = @sqlite_error_string($this->error_no);

			if ($this->in_transaction)

				@sqlite_query($this->link_id, 'ROLLBACK');

			--$this->in_transaction;

			return false;

		}

	}

	function query_build($query, $unbuffered = false)

	{

		$sql = '';

		if (isset($query['SELECT']))

		{

			$sql = 'SELECT '.$query['SELECT'].' FROM '.(isset($query['PARAMS']['NO_PREFIX']) ? '' : $this->prefix).$query['FROM'];

			if (isset($query['JOINS']))

			{

				foreach ($query['JOINS'] as $cur_join)

					$sql .= ' '.key($cur_join).' '.(isset($query['PARAMS']['NO_PREFIX']) ? '' : $this->prefix).current($cur_join).' ON '.$cur_join['ON'];

			}

			if (!empty($query['WHERE']))

				$sql .= ' WHERE '.$query['WHERE'];

			if (!empty($query['GROUP BY']))

				$sql .= ' GROUP BY '.$query['GROUP BY'];

			if (!empty($query['HAVING']))

				$sql .= ' HAVING '.$query['HAVING'];

			if (!empty($query['ORDER BY']))

				$sql .= ' ORDER BY '.$query['ORDER BY'];

			if (!empty($query['LIMIT']))

				$sql .= ' LIMIT '.$query['LIMIT'];

		}

		else if (isset($query['INSERT']))

		{

			$sql = 'INSERT INTO '.(isset($query['PARAMS']['NO_PREFIX']) ? '' : $this->prefix).$query['INTO'];

			if (!empty($query['INSERT']))

				$sql .= ' ('.$query['INSERT'].')';

			$sql .= ' VALUES('.$query['VALUES'].')';

		}

		else if (isset($query['UPDATE']))

		{

			$query['UPDATE'] = (isset($query['PARAMS']['NO_PREFIX']) ? '' : $this->prefix).$query['UPDATE'];

			$sql = 'UPDATE '.$query['UPDATE'].' SET '.$query['SET'];

			if (!empty($query['WHERE']))

				$sql .= ' WHERE '.$query['WHERE'];

		}

		else if (isset($query['DELETE']))

		{

			$sql = 'DELETE FROM '.(isset($query['PARAMS']['NO_PREFIX']) ? '' : $this->prefix).$query['DELETE'];

			if (!empty($query['WHERE']))

				$sql .= ' WHERE '.$query['WHERE'];

		}

		return $this->query($sql, $unbuffered);

	}

	function result($query_id = 0, $row = 0)

	{

		if ($query_id)

		{

			if ($row != 0)

				@sqlite_seek($query_id, $row);

			return @current(@sqlite_current($query_id));

		}

		else

			return false;

	}

	function fetch_assoc($query_id = 0)

	{

		if ($query_id)

		{

			$cur_row = @sqlite_fetch_array($query_id, SQLITE_ASSOC);

			if ($cur_row)

			{

				// Horrible hack to get rid of table names and table aliases from the array keys

				while (list($key, $value) = @each($cur_row))

				{

					$dot_spot = strpos($key, '.');

					if ($dot_spot !== false)

					{

						unset($cur_row[$key]);

						$key = substr($key, $dot_spot+1);

						$cur_row[$key] = $value;

					}

				}

			}

			return $cur_row;

		}

		else

			return false;

	}

	function fetch_row($query_id = 0)

	{

		return ($query_id) ? @sqlite_fetch_array($query_id, SQLITE_NUM) : false;

	}

	function num_rows($query_id = 0)

	{

		return ($query_id) ? @sqlite_num_rows($query_id) : false;

	}

	function affected_rows()

	{

		return ($this->query_result) ? @sqlite_changes($this->query_result) : false;

	}

	function insert_id()

	{

		return ($this->link_id) ? @sqlite_last_insert_rowid($this->link_id) : false;

	}

	function get_num_queries()

	{

		return $this->num_queries;

	}

	function get_saved_queries()

	{

		return $this->saved_queries;

	}

	function free_result($query_id = false)

	{

		return true;

	}

	function escape($str)

	{

		return is_array($str) ? '' : sqlite_escape_string($str);

	}

	function error()

	{

		$result['error_sql'] = @current(@end($this->saved_queries));

		$result['error_no'] = $this->error_no;

		$result['error_msg'] = $this->error_msg;

		return $result;

	}

	function close()

	{

		if ($this->link_id)

		{

			if ($this->in_transaction)

			{

				if (defined('PUN_SHOW_QUERIES'))

					$this->saved_queries[] = array('COMMIT', 0);

				@sqlite_query($this->link_id, 'COMMIT');

			}

			return @sqlite_close($this->link_id);

		}

		else

			return false;

	}

	function table_exists($table_name)

	{

		$result = $this->query('SELECT 1 FROM sqlite_master WHERE name = \''.$this->escape($table_name).'\' AND type=\'table\'');

		return $this->num_rows($result) > 0;

	}

	function field_exists($table_name, $field_name)

	{

		$result = $this->query('SELECT sql FROM sqlite_master WHERE name = \''.$this->escape($table_name).'\' AND type=\'table\'');

		if (!$this->num_rows($result))

			return false;

		return preg_match('/[\r\n]'.preg_quote($field_name).' /', $this->result($result));

	}

	function index_exists($table_name, $index_name)

	{

		$result = $this->query('SELECT 1 FROM sqlite_master WHERE tbl_name = \''.$this->escape($table_name).'\' AND name = \''.$this->escape($index_name).'\' AND type=\'index\'');

		return $this->num_rows($result) > 0;

	}

	function add_field($table_name, $field_name, $field_type, $allow_null, $default_value = null, $after_field = null)

	{

		if ($this->field_exists($table_name, $field_name))

			return;

		if ($default_value !== null && !is_int($default_value) && !is_float($default_value))

			$default_value = '\''.$this->escape($default_value).'\'';

		$this->query('ALTER TABLE '.$table_name.' ADD '.$field_name.' '.$field_type.($allow_null ? ' ' : ' NOT NULL').($default_value !== null ? ' DEFAULT '.$default_value : ' ')) or error(__FILE__, __LINE__);

	}

	function drop_field($table_name, $field_name)

	{

		// No DROP column in SQLite

		return;

	}

}