<?php

/**
 * @package sapphire
 * @subpackage core
 */

/**
 * Global database interface, complete with static methods.
 * Use this class for interacting with the database.
 */
class DB {
	/**
	 * The global database connection.
	 * @var Database
	 */
	protected static $globalConn;
	
	/**
	 * The last SQL query run.
	 * @var string
	 */
	public static $lastQuery;
	
	/**
	 * Set the global database connection.
	 * Pass an object that's a subclass of Database.  This object will be used when {@link DB::query()}
	 * is called.
	 * @var Database $globalConn
	 */
	static function setConn($globalConn) {
		DB::$globalConn = $globalConn;
	}	
	
	/**
	 * Get the global database connection.
	 * @return Database
	 */
	static function getConn() {
		return DB::$globalConn;
	}
	
	/**
	 * Connect to a database.
	 * Given the database configuration, this method will create the correct subclass of Database,
	 * and set it as the global connection.
	 * @param array $database A map of options. The 'type' is the name of the subclass of Database to use. For the rest of the options, see the specific class.
	 */
	static function connect($databaseConfig) {
		if(!$databaseConfig['type']) user_error("DB::connect: Not passed a valid database config", E_USER_ERROR);
		$dbClass = $databaseConfig['type'];
		$conn = new $dbClass($databaseConfig);
		DB::setConn($conn);
	}
	
	/**
	 * Execute the given SQL query.
	 * @param string $sql The SQL query to execute
	 * @param int $errorLevel The level of error reporting to enable for the query
	 * @return Query
	 */
	static function query($sql, $errorLevel = E_USER_ERROR) { 
		DB::$lastQuery = $sql;
		return DB::$globalConn->query($sql, $errorLevel); 
	}
	
	/**
	 * Execute a complex manipulation on the database.
	 * A manipulation is an array of insert / or update sequences.  The keys of the array are table names,
	 * and the values are map containing 'command' and 'fields'.  Command should be 'insert' or 'update',
	 * and fields should be a map of field names to field values, including quotes.  The field value can
	 * also be a SQL function or similar.
	 * @param array $manipulation
	 */
	static function manipulate($manipulation) { 
		DB::$lastQuery = $manipulation;
		return DB::$globalConn->manipulate($manipulation); 
	}
	
	/**
	 * Get the autogenerated ID from the previous INSERT query.
	 * @return int
	 */
	static function getGeneratedID() { 
		return DB::$globalConn->getGeneratedID();
	}
	
	/**
	 * Get the ID for the next new record for the table.
	 * @var string $table The name od the table.
	 * @return int
	 */
	static function getNextID($table) { 
		return DB::$globalConn->getNextID($table);
	}
	
	/**
	 * Check if the connection to the database is active.
	 * @return boolean
	 */
	static function isActive() {
		return DB::$globalConn->isActive();
	}
	
	/**
	 * Create the database and connect to it. This can be called if the
	 * initial database connection is not successful because the database
	 * does not exist.
	 * @return boolean Returns true if successful
	 */
	static function createDatabase() {
		return DB::$globalConn->createDatabase();
	}
	
	/**
	 * Create a new table.
	 * The table will have a single field - the integer key ID.
	 * @param string $table Name of table to create.
	 */
	static function createTable($table) {
		return DB::$globalConn->createTable($table);
	}
	
	/**
	 * Create a new field on a table.
	 * @param string $table Name of the table.
	 * @param string $field Name of the field to add.
	 * @param string $spec The field specification, eg 'INTEGER NOT NULL'
	 */
	static function createField($table, $field, $spec) {
		return DB::$globalConn->createField($table, $field, $spec);
	}
	
	/**
	 * Generate the following table in the database, modifying whatever already exists
	 * as necessary.
	 * @param string $table The name of the table
	 * @param string $fieldSchema A list of the fields to create, in the same form as DataObject::$db
	 * @param string $indexSchema A list of indexes to create.  The keys of the array are the names of the index.
	 * The values of the array can be one of:
	 *   - true: Create a single column index on the field named the same as the index.
	 *   - array('fields' => array('A','B','C'), 'type' => 'index/unique/fulltext'): This gives you full
	 *     control over the index.
	 */
	static function requireTable($table, $fieldSchema = null, $indexSchema = null) {
		return DB::$globalConn->requireTable($table, $fieldSchema, $indexSchema);
	}
	
	/**
	 * Generate the given field on the table, modifying whatever already exists as necessary.
	 * @param string $table The table name.
	 * @param string $field The field name.
	 * @param string $spec The field specification.
	 */
	static function requireField($table, $field, $spec) {
		return DB::$globalConn->requireField($table, $field, $spec);
	}
	
	/**
	 * Generate the given index in the database, modifying whatever already exists as necessary.
	 * @param string $table The table name.
	 * @param string $index The index name.
	 * @param string|boolean $spec The specification of the index. See requireTable() for more information.
	 */
	static function requireIndex($table, $index, $spec) {
		return DB::$globalConn->requireIndex($table, $index, $spec);
	}
	
	/**
	 * If the given table exists, move it out of the way by renaming it to _obsolete_(tablename).
	 * @param string $table The table name.
	 */
	static function dontRequireTable($table) {
		return DB::$globalConn->dontRequireTable($table);
	}
	
	/**
	 * Checks a table's integrity and repairs it if necessary.
	 * @var string $tableName The name of the table.
	 * @return boolean Return true if the table has integrity after the method is complete.
	 */
	static function checkAndRepairTable($table) {
		return DB::$globalConn->checkAndRepairTable($table);
	}
	
	/**
	 * Return the number of rows affected by the previous operation.
	 * @return int
	 */
	static function affectedRows() {
		return DB::$globalConn->affectedRows();
	}
	
	/**
	 * Returns a list of all tables in the database.
	 * The table names will be in lower case.
	 * @return array
	 */
	static function tableList() {
		return DB::$globalConn->tableList();
	}
	
	/**
	 * Enable supression of database messages.
	 */
	static function quiet() {
		return DB::$globalConn->quiet();
	}
}
?>