<?php
/**
 * Database tables and schema upgrades.
 *
 * @package CNWS\Coupons
 */

namespace CNWS\Coupons;

defined( 'ABSPATH' ) || exit;

final class Installer {

	public const SCHEMA_VERSION = '2.2.0';
	public const SCHEMA_OPTION  = 'cnwscoupons_schema_version';

	public static function install(): void {
		global $wpdb;

		require_once ABSPATH . 'wp-admin/includes/upgrade.php';

		self::drop_prerelease_schema( (string) get_option( self::SCHEMA_OPTION ) );

		$charset    = $wpdb->get_charset_collate();
		$categories = Tables::categories();
		$campaigns  = Tables::campaigns();
		$codes      = Tables::codes();
		$redeem     = Tables::redemptions();

		// dbDelta needs two spaces after PRIMARY KEY and one column per line.
		dbDelta(
			"CREATE TABLE {$categories} (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				slug varchar(100) NOT NULL,
				name varchar(190) NOT NULL,
				created_at datetime NOT NULL,
				PRIMARY KEY  (id),
				UNIQUE KEY slug (slug)
			) {$charset};
			CREATE TABLE {$campaigns} (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				slug varchar(100) NOT NULL,
				name varchar(190) NOT NULL,
				category_id bigint(20) unsigned DEFAULT NULL,
				type varchar(20) NOT NULL DEFAULT 'personal',
				discount_type varchar(20) NOT NULL DEFAULT 'percent',
				amount decimal(19,4) NOT NULL DEFAULT 0,
				starts_on date DEFAULT NULL,
				expires_on date DEFAULT NULL,
				valid_days int(10) unsigned DEFAULT NULL,
				code_prefix varchar(20) NOT NULL DEFAULT '',
				max_codes int(10) unsigned DEFAULT NULL,
				uses_per_code int(10) unsigned NOT NULL DEFAULT 1,
				max_redemptions int(10) unsigned DEFAULT NULL,
				max_per_email int(10) unsigned DEFAULT NULL,
				restrictions longtext DEFAULT NULL,
				email_restricted tinyint(1) NOT NULL DEFAULT 1,
				extensions longtext DEFAULT NULL,
				status varchar(20) NOT NULL DEFAULT 'active',
				created_at datetime NOT NULL,
				updated_at datetime NOT NULL,
				PRIMARY KEY  (id),
				UNIQUE KEY slug (slug),
				KEY category_id (category_id),
				KEY status (status)
			) {$charset};
			CREATE TABLE {$codes} (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				campaign_id bigint(20) unsigned NOT NULL,
				code varchar(40) NOT NULL,
				email varchar(190) NOT NULL DEFAULT '',
				source varchar(60) NOT NULL DEFAULT '',
				uses int(10) unsigned NOT NULL DEFAULT 0,
				expires_at datetime DEFAULT NULL,
				created_at datetime NOT NULL,
				PRIMARY KEY  (id),
				UNIQUE KEY code (code),
				UNIQUE KEY campaign_email (campaign_id,email),
				KEY created_at (created_at)
			) {$charset};
			CREATE TABLE {$redeem} (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				code_id bigint(20) unsigned NOT NULL,
				campaign_id bigint(20) unsigned NOT NULL,
				order_id bigint(20) unsigned NOT NULL,
				email varchar(190) NOT NULL DEFAULT '',
				country varchar(2) NOT NULL DEFAULT '',
				discount_amount decimal(19,4) NOT NULL DEFAULT 0,
				order_total decimal(19,4) NOT NULL DEFAULT 0,
				redeemed_at datetime NOT NULL,
				released_at datetime DEFAULT NULL,
				PRIMARY KEY  (id),
				KEY code_order (code_id,order_id),
				KEY code_email (code_id,email),
				KEY campaign_redeemed (campaign_id,redeemed_at),
				KEY redeemed_at (redeemed_at),
				KEY order_id (order_id)
			) {$charset};"
		);

		self::migrate_restrictions();

		update_option( self::SCHEMA_OPTION, self::SCHEMA_VERSION, false );
	}

	public static function maybe_upgrade(): void {
		if ( get_option( self::SCHEMA_OPTION ) !== self::SCHEMA_VERSION ) {
			self::install();
		}
	}

	/**
	 * Schema 2.0.0 kept the minimum amount and product/category limits in their own columns.
	 * From 2.1.0 they live in the restrictions JSON with the other rules; move them and drop the
	 * old columns. Safe to run again: it does nothing once the old columns are gone.
	 */
	private static function migrate_restrictions(): void {
		global $wpdb;

		$table   = Tables::campaigns();
		$columns = (array) $wpdb->get_col( $wpdb->prepare( 'SHOW COLUMNS FROM %i', $table ) ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery -- Schema check on the plugin's own table.

		if ( ! in_array( 'product_ids', $columns, true ) ) {
			return;
		}

		// phpcs:disable WordPress.DB.DirectDatabaseQuery -- One-time migration of the plugin's own table.
		$rows = (array) $wpdb->get_results( $wpdb->prepare( 'SELECT id, minimum_amount, product_ids, category_ids, restrictions FROM %i', $table ) );

		foreach ( $rows as $row ) {
			$rules = Restrictions::from_array( (string) $row->restrictions );

			$rules->lists['products']['include']   = Campaign::id_list( (string) $row->product_ids );
			$rules->lists['categories']['include'] = Campaign::id_list( (string) $row->category_ids );
			$rules->minimum_amount                 = null !== $row->minimum_amount ? (float) $row->minimum_amount : null;

			$wpdb->update( $table, array( 'restrictions' => wp_json_encode( $rules->to_array() ) ), array( 'id' => (int) $row->id ) );
		}

		$wpdb->query( $wpdb->prepare( 'ALTER TABLE %i DROP COLUMN minimum_amount, DROP COLUMN product_ids, DROP COLUMN category_ids', $table ) );
		// phpcs:enable
	}

	/**
	 * Schema 1.x only ever existed on development sites before the first release, so it is replaced
	 * rather than migrated.
	 *
	 * @param string $version Stored schema version.
	 */
	private static function drop_prerelease_schema( string $version ): void {
		global $wpdb;

		if ( 0 !== strpos( $version, '1.' ) ) {
			return;
		}

		foreach ( array( 'cnwscoupons_series', 'cnwscoupons_codes', 'cnwscoupons_redemptions' ) as $table ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery -- Pre-release tables owned by this plugin.
			$wpdb->query( $wpdb->prepare( 'DROP TABLE IF EXISTS %i', $wpdb->prefix . $table ) );
		}
	}
}