<?php
namespace Aisentic\Database;

/**
 * Class Migration_Table_Manager
 *
 * Responsible for managing the migrations history table in the database.
 */
class Migration_Table_Manager {
    /**
     * Table name for storing migration history.
     *
     * @var string
     */
    protected static $table_name = 'aisentic_migrations';

    /**
     * Ensure the migration table exists.
     *
     * @return void
     */
    public static function ensure_table_exists() {
        global $wpdb;

        $table           = $wpdb->prefix . self::$table_name;
        $charset_collate = $wpdb->get_charset_collate();

        $sql = "CREATE TABLE IF NOT EXISTS {$table} (
            id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            migration VARCHAR(255) NOT NULL,
            batch INT NOT NULL,
            migrated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
        ) $charset_collate;";

        require_once ABSPATH . 'wp-admin/includes/upgrade.php';
        dbDelta( $sql );
    }

    /**
     * Check if a given migration has already been applied.
     *
     * @param string $migration_name
     * @return bool
     */
    public static function is_migrated( $migration_name ) {
        global $wpdb;
        // Table name is safe - $wpdb->prefix is controlled by WordPress core
        $table = $wpdb->prefix . self::$table_name; // phpcs:ignore PluginCheck.Security.DirectDB.UnescapedDBParameter -- $wpdb->prefix is trusted

        return (bool) $wpdb->get_var( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $wpdb->prepare(
                "SELECT COUNT(*) FROM {$table} WHERE migration = %s", // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter -- $table uses $wpdb->prefix
                $migration_name
            )
        );
    }

    /**
     * Record a migration as applied.
     *
     * @param string $migration_name
     * @param int    $batch
     * @return void
     */
    public static function mark_as_migrated( $migration_name, $batch = 1 ) {
        global $wpdb;
        $table = $wpdb->prefix . self::$table_name;

        $wpdb->insert( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
            $table,
            [
				'migration'   => $migration_name,
				'batch'       => $batch,
				'migrated_at' => current_time( 'mysql' ),
			]
        );
    }

    /**
     * Remove a migration record (used for rollback).
     *
     * @param string $migration_name
     * @return void
     */
    public static function remove_migration( $migration_name ) {
        global $wpdb;
        $table = $wpdb->prefix . self::$table_name;

        $wpdb->delete( $table, [ 'migration' => $migration_name ] ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
    }

    /**
     * Get the latest batch number.
     *
     * @return int
     */
    public static function get_latest_batch() {
        global $wpdb;
        // Table name is safe - $wpdb->prefix is controlled by WordPress core
        $table = $wpdb->prefix . self::$table_name; // phpcs:ignore PluginCheck.Security.DirectDB.UnescapedDBParameter -- $wpdb->prefix is trusted

        return (int) $wpdb->get_var( "SELECT MAX(batch) FROM {$table}" ) ?: 1; // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
    }

    /**
     * Get all migrations in the latest batch.
     *
     * @return array
     */
    public static function get_latest_batch_migrations() {
        global $wpdb;
        // Table name is safe - $wpdb->prefix is controlled by WordPress core
        $table        = $wpdb->prefix . self::$table_name; // phpcs:ignore PluginCheck.Security.DirectDB.UnescapedDBParameter -- $wpdb->prefix is trusted
        $latest_batch = self::get_latest_batch();

        return $wpdb->get_results( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
            $wpdb->prepare(
                "SELECT * FROM {$table} WHERE batch = %d ORDER BY id DESC", // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter -- $table uses $wpdb->prefix
                $latest_batch
            )
        );
    }
}