<?php
/**
 * Base Custom Database Table Schema Class.
 *
 * @since 3.5.0
 */

namespace SimplePay\Core\Database\Engine;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * A base WordPress database table class, which facilitates the creation of
 * and schema changes to individual database tables.
 *
 * This class is intended to be extended for each unique database table,
 * including global multisite tables and users tables.
 *
 * It exists to make managing database tables in WordPress as easy as possible.
 *
 * Extending this class comes with several automatic benefits:
 * - Activation hook makes it great for plugins
 * - Tables store their versions in the database independently
 * - Tables upgrade via independent upgrade abstract methods
 * - Multisite friendly - site tables switch on "switch_blog" action
 *
 * @since 3.5.0
 */
class Schema extends Engine_Base {

	/**
	 * Array of database column objects to turn into Column
	 *
	 * @since 3.5.0
	 * @access public
	 * @var array
	 */
	protected $columns = array();

	/**
	 * Invoke new column objects based on array of column data
	 *
	 * @since 3.5.0
	 * @access public
	 */
	public function __construct() {

		// Bail if no columns
		if ( empty( $this->columns ) || ! is_array( $this->columns ) ) {
			return;
		}

		// Juggle original columns array
		$columns = $this->columns;
		$this->columns = array();

		// Loop through columns and create objects from them
		foreach ( $columns as $column ) {
			if ( is_array( $column ) ) {
				$this->columns[] = new Column( $column );
			} elseif ( $column instanceof Column ) {
				$this->columns[] = $column;
			}
		}
	}

	/**
	 * Return the schema in string form
	 *
	 * @since 3.5.0
	 * @access protected
	 */
	protected function to_string() {

		// Default return value
		$retval = '';

		// Bail if no columns to convert
		if ( empty( $this->columns ) ) {
			return $retval;
		}

		// Loop through columns...
		foreach ( $this->columns as $column_info ) {
			if ( method_exists( $column_info, 'get_create_string' ) ) {
				$retval .= '\n' . $column_info->get_create_string() . ', ';
			}
		}

		// Return the string
		return $retval;
	}
}