<?php
/**
 * AI Answer Toolkit Migration Script
 *
 * Handles one-time migration of options from inconsistent naming to standardized snake_case.
 * This script runs once on plugin update to migrate existing installations.
 *
 * @package AI_Answer_Toolkit
 * @since 1.0.2
 */

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

/**
 * AI_Answer_Toolkit_Migration Class.
 *
 * Handles migration of options and settings to new standardized naming convention.
 */
class AI_Answer_Toolkit_Migration {

	/**
	 * Migration version.
	 *
	 * @var string
	 */
	const MIGRATION_VERSION = '1.0.2';

	/**
	 * Option name for tracking migration status.
	 *
	 * @var string
	 */
	const MIGRATION_STATUS_KEY = 'ai_answer_toolkit_migration_status';

	/**
	 * Initialize migration.
	 */
	public static function init() {
		add_action( 'admin_init', array( __CLASS__, 'maybe_run_migration' ) );
	}

	/**
	 * Check if migration needs to run and execute if needed.
	 */
	public static function maybe_run_migration() {
		$migration_status = get_option( self::MIGRATION_STATUS_KEY, array() );
		$current_version = isset( $migration_status['version'] ) ? $migration_status['version'] : '0';

		// Check if migration has already been completed
		if ( version_compare( $current_version, self::MIGRATION_VERSION, '>=' ) ) {
			return;
		}

		// Run migration
		self::run_migration();

		// Update migration status
		update_option(
			self::MIGRATION_STATUS_KEY,
			array(
				'version'   => self::MIGRATION_VERSION,
				'completed' => current_time( 'mysql' ),
			)
		);
	}

	/**
	 * Run the migration process.
	 */
	private static function run_migration() {
		// Migrate options from PascalCase to snake_case
		self::migrate_options();

		// Log migration completion
		if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
			error_log( 'AI Answer Toolkit: Migration to v' . self::MIGRATION_VERSION . ' completed successfully.' );
		}
	}

	/**
	 * Migrate options from PascalCase to snake_case.
	 */
	private static function migrate_options() {
		$option_mappings = array(
			// API Keys
			'AI_Answer_Toolkit_api_key'         => 'ai_answer_toolkit_api_key',
			'AI_Answer_Toolkit_openai_api_key'  => 'ai_answer_toolkit_openai_api_key',
			
			// Webhook Settings
			'AI_Answer_Toolkit_webhook_enabled' => 'ai_answer_toolkit_webhook_enabled',
			'AI_Answer_Toolkit_webhook_url'     => 'ai_answer_toolkit_webhook_url',
			'AI_Answer_Toolkit_webhook_api_key' => 'ai_answer_toolkit_webhook_api_key',
			
			// Export Settings
			'AI_Answer_Toolkit_last_export'     => 'ai_answer_toolkit_last_export',
			'AI_Answer_Toolkit_last_export_file' => 'ai_answer_toolkit_last_export_file',
		);

		foreach ( $option_mappings as $old_name => $new_name ) {
			$old_value = get_option( $old_name, null );

			// Only migrate if old option exists and new option doesn't
			if ( null !== $old_value && false === get_option( $new_name, false ) ) {
				// Copy to new option name
				add_option( $new_name, $old_value );

				// Delete old option
				delete_option( $old_name );

				if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
					error_log( sprintf( 'AI Answer Toolkit: Migrated option %s to %s', $old_name, $new_name ) );
				}
			}
		}
	}

	/**
	 * Rollback migration (for testing purposes only).
	 * DO NOT USE IN PRODUCTION.
	 */
	public static function rollback_migration() {
		if ( ! defined( 'WP_DEBUG' ) || ! WP_DEBUG ) {
			return;
		}

		$option_mappings = array(
			'ai_answer_toolkit_api_key'         => 'AI_Answer_Toolkit_api_key',
			'ai_answer_toolkit_openai_api_key'  => 'AI_Answer_Toolkit_openai_api_key',
			'ai_answer_toolkit_webhook_enabled' => 'AI_Answer_Toolkit_webhook_enabled',
			'ai_answer_toolkit_webhook_url'     => 'AI_Answer_Toolkit_webhook_url',
			'ai_answer_toolkit_webhook_api_key' => 'AI_Answer_Toolkit_webhook_api_key',
			'ai_answer_toolkit_last_export'     => 'AI_Answer_Toolkit_last_export',
			'ai_answer_toolkit_last_export_file' => 'AI_Answer_Toolkit_last_export_file',
		);

		foreach ( $option_mappings as $new_name => $old_name ) {
			$new_value = get_option( $new_name, null );

			if ( null !== $new_value ) {
				add_option( $old_name, $new_value );
				delete_option( $new_name );
			}
		}

		delete_option( self::MIGRATION_STATUS_KEY );
	}
}

// Initialize migration
AI_Answer_Toolkit_Migration::init();