<?php
/**
 * Database migration for conversations table
 *
 * @package WP_Agentic_Writer
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Create the conversations table
 *
 * @since 0.1.4
 */
function wpaw_create_conversations_table() {
	global $wpdb;

	$table_name      = $wpdb->prefix . 'wpaw_conversations';
	$charset_collate = $wpdb->get_charset_collate();

	$sql = "CREATE TABLE IF NOT EXISTS {$table_name} (
		id BIGINT AUTO_INCREMENT PRIMARY KEY,
		session_id VARCHAR(32) NOT NULL UNIQUE,
		user_id BIGINT NOT NULL,
		post_id BIGINT DEFAULT 0,
		title VARCHAR(255) DEFAULT '',
		focus_keyword VARCHAR(255) DEFAULT '',
		messages LONGTEXT,
		context LONGTEXT,
		status ENUM('active', 'completed', 'archived') DEFAULT 'active',
		created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
		updated_at DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
		INDEX idx_user_status (user_id, status),
		INDEX idx_post_id (post_id),
		INDEX idx_session_id (session_id)
	) {$charset_collate};";

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

	// Store conversation table migration version (don't override main db version)
	$existing_version = get_option( 'wpaw_conversations_db_version', '0' );
	if ( version_compare( $existing_version, '0.1.4', '<' ) ) {
		update_option( 'wpaw_conversations_db_version', '0.1.4' );
	}
}

/**
 * Drop the conversations table (for testing/reset)
 *
 * @since 0.1.4
 */
function wpaw_drop_conversations_table() {
	global $wpdb;
	$table_name = $wpdb->prefix . 'wpaw_conversations';
	$wpdb->query( "DROP TABLE IF EXISTS {$table_name}" );
	delete_option( 'wpaw_conversations_db_version' );
}

/**
 * Run migrations on plugin activation
 *
 * @since 0.1.4
 */
function wpaw_run_migrations() {
	$current_version = get_option( 'wpaw_conversations_db_version', '0' );

	if ( version_compare( $current_version, '0.1.4', '<' ) ) {
		wpaw_create_conversations_table();
	}
}

/**
 * Cleanup old orphaned sessions (cron job)
 * Archives sessions inactive for 30+ days
 *
 * @since 0.1.4
 */
function wpaw_cleanup_old_sessions() {
	global $wpdb;
	$table_name = $wpdb->prefix . 'wpaw_conversations';

	// Archive sessions with no post_id and inactive for 30 days
	$wpdb->query(
		$wpdb->prepare(
			"UPDATE {$table_name} SET status = 'archived' WHERE status = 'active' AND post_id = 0 AND updated_at < %s",
			date( 'Y-m-d H:i:s', strtotime( '-30 days' ) )
		)
	);
}

// Register cron job for cleanup
add_action( 'wpaw_cleanup_old_sessions', 'wpaw_cleanup_old_sessions' );

if ( ! wp_next_scheduled( 'wpaw_cleanup_old_sessions' ) ) {
	wp_schedule_event( time(), 'daily', 'wpaw_cleanup_old_sessions' );
}