<?php
/**
* @package Walmo.tv
* @version 0.0.1
* @author @_mvader
* @copyright Walmo.tv 2010-11
*/

/*
 * Database abstraction layer
 * Abstract class to connect and interact with Walmo's database
 */

abstract class Database
{
    private static $dbHost = 'localhost';
    private static $dbUser = 'root';
    private static $dbPass = 'root';
    private static $dbName = 'walmo';
    protected $query;
    protected $rows = array();
    private $conn;

    abstract public function get();
    abstract public function set();
    abstract public function update();
    abstract public function delete();

    /**
     * openConnection
     * Establishes database connection
     * @params: none
     */

    private function openConnection()
    {
        $this->conn = mysql_connect(self::$dbHost, self::$dbUser, self::$dbPass) or die("Error establishing database connection");
        $selected_db = mysql_select_db(self::$dbName, $this->conn) or die("Can't find the database " . $this->dbName);
    }

    /**
     * closeConnection
     * Closes the database connection
     * @params: none
     */

    private function closeConnection()
    {
        mysql_close($this->conn);
    }

    /**
     * query
     * This function executes a query without returning anything
     * @params: $q [string]
     */

    protected function query($q)
    {
        $this->openConnection();
        mysql_query($q, $this->conn) or die(mysql_error($this->conn));
        $this->closeConnection();
    }

    /**
     * getQuery
     * This function returns an associative array with the result received from a query
     * @params: $q [string]
     */

    protected function getQuery($q)
    {
        $this->openConnection();
        $result = mysql_query($q, $this->conn) or die("Query error");
        $this->closeConnection();
        return $this->fetch($result);
    }

    /**
     * fetch
     * Fetches into an array the data received from a query
     * @params: $f [object]
     */

    public function fetch($f)
    {
        return mysql_fetch_assoc($f);
    }

    /**
     * buildQuery
     * Builds a query with the given array
     * @params: $array [array], $mode [string]
     * Array structure:
     * $array = array(
     *      ['TABLE']       => '',
     *      ['FIELDS']      => array(),
     *      ['VALUES']      => array(), // $array['VALUES'][i] = $array['FIELDS'][i] || Optional
     *      ['WHERE']       => '', // optional
     *      ['MISC']        => '', // optional
     * );
     */

    public function buildQuery(array $array, $mode)
    {
        if(is_array($array) && !empty($array) && !empty($mode))
        {
            switch ($mode)
            {
                /*
                 * Build an update query
                 */

                case 'update':
                    $query = 'UPDATE ';
                    foreach($array as $key => $value)
                    {
                        if($key == 'TABLE')
                        {
                            $query .= ' ' . $value . ' SET ';
                        }

                        if($key == 'FIELDS')
                        {
                            if(is_array($value))
                            {
                                $first = true;
                                foreach($value as $field)
                                {
                                    if($first)
                                    {
                                        $query .= $field;
                                    }
                                    else
                                    {
                                        $query .= ', ' . $field;
                                    }
                                    $first = false;
                                }
                            }
                            else
                            {
                                $query .= $value;
                            }
                        }

                        if($key == 'WHERE')
                        {
                            $query .= ' WHERE ' . $value;
                        }

                        if($key == 'MISC')
                        {
                            $query .= ' ' . $value;
                        }
                    }
                break;

                /*
                 * Build an insert query
                 */

                case 'insert':
                    $query = 'INSERT INTO ';
                    foreach($array as $key => $value)
                    {
                        if($key == 'TABLE')
                        {
                            $query .= $value . ' ';
                        }

                        if($key == 'FIELDS')
                        {
                            if(is_array($value))
                            {
                                $first = true;
                                foreach($value as $field)
                                {
                                    if($first)
                                    {
                                        $query .= "(" . $field;
                                    }
                                    else
                                    {
                                        $query .= ", " . $field;
                                    }
                                    $first = false;
                                }
                            }
                            else
                            {
                                $query .= $value . ' ';
                            }
                        }

                        if($key == 'VALUES')
                        {
                            if(is_array($value))
                            {
                                $first = true;
                                foreach($value as $field)
                                {
                                    if($first)
                                    {
                                        $query .= ") VALUES ('" . $field;
                                    }
                                    else
                                    {
                                        $query .= "', '" . $field;
                                    }
                                    $first = false;
                                }
                                $query .= "')";
                            }
                            else
                            {
                                $query .= ") VALUES ('" . $value . "')";
                            }
                        }
                    }
                break;

                /*
                 * Build a select query
                 */

                case 'select':
                    $query = 'SELECT ';
                    foreach($array as $key => $value)
                    {
                        if($key == 'TABLE')
                        {
                            $query .= ' FROM ' . $value . ' ';
                        }

                        if($key == 'FIELDS')
                        {
                            if(is_array($value))
                            {
                                $first = true;
                                foreach($value as $field)
                                {
                                    if($first)
                                    {
                                        $query .= $field;
                                    }
                                    else
                                    {
                                        $query .= ', ' . $field;
                                    }
                                    $first = false;
                                }
                            }
                            else
                            {
                                $query .= $value . ' ';
                            }
                        }

                        if($key == 'WHERE')
                        {
                            $query .= ' WHERE ' . $value;
                        }

                        if($key == 'MISC')
                        {
                            $query .= ' ' . $value;
                        }
                    }
                break;

                /*
                 * Build a delete query
                 */

                case 'delete':
                    $query = 'DELETE FROM ';
                    foreach($array as $key => $value)
                    {
                        if($key == 'TABLE')
                        {
                            $query .= $value;
                        }

                        if($key == 'WHERE')
                        {
                            $query .= ' WHERE ' . $value;
                        }
                    }
                break;

                default:
                    trigger_error('Error @ build_query() => Mode not specified.');
            }

            return $query;
        }
        else
        {
            trigger_error('Error @ build_query() => Data error.');
        }
    }

    /**
     * cleanString
     * Cleans a string and removes illegal characters
     * @params: $var [string]
     */

    public function cleanString($var)
    {
        $var = preg_replace("[^A-Za-z0-9]", "", $var);
        $var = str_replace(" ", "-", $var);
        $var = strtolower($var);
        return $var;
    }

    /**
     * affectedRows
     * Returns the number of affected rows by the previous query executed
     * @params: none
     */

    public function affectedRows()
    {
        return ($this->conn) ? @mysql_affected_rows($this->conn) : false;
    }

    /**
     * freeResult
     * Releases the memory used by a query previously executed
     * @params: $query [object]
     */

    public function freeResult($query)
    {
        mysql_free_result($query);
    }

    /**
     * sanitize
     * Cleans a variable before storing it in the databse
     * @params: $var [string]
     * Note: use $var = (int) $var; for integer values
     */

    public function sanitize($var)
    {
        $this->openConnection();
        $var = mysql_real_escape_string($var,$this->conn);
        $this->closeConnection();
        return $var;
    }
}