<?php
/**
 * Database class.
 * Class to interact with the database for the program.
 */
class Database {

	##########################################################

	/* Database Details */
	private $database_server;   // database server, provided by user.
	private $database_username; // database username, provided by user.
	private $database_password; // database password, provided by user, can be blank.
	private $database_database; // database name, provided by user

	/* Program Cache */
	private $query; // stores the last query resource here.
	private $error; // stores the program error here.  get_error() retrieves it for public use.

	##########################################################

	/**
	 * init function.
	 * Inits the class, attempts to connect and select the database.
	 * @access public
	 * @param array $database_details
	 * @return bool
	 */
	public function init($database_details) {

		/* 	Checks to see if the data we got was in the form of an array. */
		if(!is_array($database_details)) {
			$this->error = "Database details must be in the form of an array.";
			return false;
		}

		/* 	Checks to see if any values were empty.. other then password.. */
		if(empty($database_details["server"]) || empty($database_details["username"]) || empty($database_details["database"])) {
			$this->error = "One of the required database details was left blank.";
			return false;
		}

		/* Lets set the details now to the class */
		$this->database_server = $database_details["server"];
		$this->database_username = $database_details["username"];
		$this->database_password = $database_details["password"];
		$this->database_database = $database_details["database"];

		/* Now we need to try and connect to the MySQL server, if it isn't good, we stop here. */
		if(!$this->connect_mysql()) {
			return false;
		}

		/* Now we need to try and select the database from the MySQL server, if it doesn't turn back good, stop. */
		if(!$this->select_database()) {
			return false;
		}

		// passed.
		return true;
	}


	########################
	# Connection Functions #
	########################

	/**
	 * connect_mysql function.
	 * Attempts to connect to MySQL with user provided details.
	 * @access private
	 * @return bools
	 */
	private function connect_mysql() {
		/* This below will try and connect to the MySQL server with the details. */
		$connnect_resource = @mysql_connect($this->database_server, $this->database_username, $this->database_password);

		/* If it didn't work, we need to get the error from MySQL, and stop */
		if(!$connect_resource) {
			$this->error = mysql_error();
			return false;
		}

		return true; // it seems to have worked!
	}

	/**
	 * select_db function.
	 * Attempts to select a database from the MySQL server with the provided details.
	 * @access private
	 * @return bool
	 */
	private function select_db() {
		/* This will try and select the database from the MySQL server. */
		$select_resource = @mysql_select_db($this->database_database);

		/* If it didn't go successfully, we need to get the error from MySQL and stop here. */
		if(!$select_resource)  {
			$this->error = mysql_error();
			return false;
		}

		return true; // selected it successfully! :)
	}

	###################
	# Query functions #
	###################

	/**
	 * query function.
	 * Executes a provided query on the MySQL server and stores and returns it.
	 * @access public
	 * @param string $query_text
	 * @return mysql_query_resource
	 */
	public function query($query_text) {

		/* We must have some sort of query to run.. checks it. */
		if(empty($query_text)) {
			$this->error = "Query must have some text to execute";
			return false;
		}

		$query = @mysql_query($query_text); // execute the query.
		$this->query = $query; // store the resource in this class.

		return $query; // return the resource.
	}

	/**
	 * num_rows function.
	 * Numbers the rows returned on a given query.
	 * @access public
	 * @param mysql_query_resource $query_resource. (default: '')
	 * @return mysql_num_rows_resource
	 */
	public function num_rows($query_resource = '') {
		$query_resource = ($query_resource = '') ? $this->query : $query_resource; // if the query resource is blank, use last query.

		$num_rows = @mysql_num_rows($query_resource); // execute it..

		return $num_rows; // return the num_rows resource.
	}

	/**
	 * fetch_object function.
	 * Fetch's an object with the data from a query
	 * @access public
	 * @param mysql_query_resource $query_resource
	 * @return mysql_object_resource
	 */
	public function fetch_object($query_resource = '') {
		$query_resource = ($query_resource = '') ? $this->query : $query_resource; // if the query resource is blank, use last query.

		$fetch_object = @mysql_fetch_object($query_resource); // fetch it..

		return $fetch_object; // return the object.
	}

	/**
	 * fetch_array function.
	 * Fetch's an array with the data from a query.
	 * @access public
	 * @param mysql_query_resource $query_resource. (default: '')
	 * @return mysql_array_resource
	 */
	public function fetch_array($query_resource = '') {
		$query_resource = ($query_resource = '') ? $this->query : $query_resource; // if the query resource is blank, use last query.

		$fetch_array = @mysql_fetch_array($query_resource); // fetch it..

		return $fetch_array; // return the array.
	}

	/**
	 * count_table function.
	 * Counts up all the rows in a table.  Faster then just mysql_num_rows() the table.
	 * @access public
	 * @param string $table_name
	 * @return int
	 */
	public function count_table($table_name) {

		/* Checks to make sure the table name is not empty. */
		if(empty($table_name)) {
			$this->error = "You need a table name to count!"; // sets the program error.
			return false;
		}

		$this->query("SELECT COUNT(*) FROM `$table_name`"); // execute the count query.. faster then just numing all the rows.
		$count = $this->mysql_fetch_array(); // gets the array for the count.

		return $count[0]; // return the count.
	}

	###################
	# Class Functions #
	###################

	/**
	 * get_error function.
	 * Get's the error from the class, if any.
	 * @access public
	 * @return string
	 */
	public function get_error() {
		return $this->error;
	}
}