<?php
defined( 'ABSPATH' ) || exit;

/**
 * AWBSEO Data Portability - Export & Import
 *
 * Covers:
 *  - All plugin wp_options (settings, API connections, robots.txt, etc.)
 *  - Custom DB tables: redirects, rank history, local SEO
 *  - Post meta for all SEO fields across all posts/pages
 *
 * Post meta is exported with both the post ID and the post's full URL so
 * that on import the correct post can be located even when IDs differ
 * (e.g. after a site migration).
 */
class AWBSEO_Data_Portability {

	/** Option keys managed by this plugin (mirrors uninstall.php). */
	private static $option_keys = [
		'awbseo_settings',
		'awbseo_db_version',
		'awbseo_gsc_tokens',
		'awbseo_gsc_property',
		'awbseo_ga4_tokens',
		'awbseo_ga4_property',
		'awbseo_bing_api_key',
		'awbseo_bing_property',
		'awbseo_tracked_keywords',
		'awbseo_robots_txt',
		'awbseo_woo_settings',
		'awbseo_hreflang_pairs',
		'awbseo_indexnow_key',
		'awbseo_indexnow_log',
		'awbseo_indexnow_auto',
		'awbseo_bls_auto',
	];

	/** Post meta keys managed by this plugin (mirrors uninstall.php). */
	private static $meta_keys = [
		'_awb_seo_title',
		'_awb_seo_description',
		'_awb_seo_focus_keyword',
		'_awb_seo_robots_index',
		'_awb_seo_robots_follow',
		'_awb_seo_noindex',
		'_awb_seo_nofollow',
		'_awb_seo_canonical',
		'_awb_seo_og_title',
		'_awb_seo_og_description',
		'_awb_seo_og_image',
		'_awb_seo_twitter_title',
		'_awb_seo_twitter_desc',
		'_awb_seo_twitter_image',
		'_awb_seo_schema',
		'_awb_seo_schema_type',
		'_awb_seo_schema_data',
		'_awb_seo_schema_fields',
		'_awb_seo_score',
		'_awb_seo_issues',
		'_awb_seo_failed_checks',
	];

	public static function init() {
		add_action( 'wp_ajax_awbseo_export', [ __CLASS__, 'handle_export' ] );
		add_action( 'wp_ajax_awbseo_import', [ __CLASS__, 'handle_import' ] );
	}

	// ── Export ───────────────────────────────────────────────────────────────────

	/**
	 * Build the full export payload and return it as an associative array.
	 */
	public static function build_export() {
		global $wpdb;

		$payload = [
			'awbseo_export_version' => '1.0',
			'plugin_version'        => AWBSEO_VERSION,
			'exported_at'           => gmdate( 'c' ),
			'site_url'              => get_site_url(),
			'settings'              => [],
			'redirects'             => [],
			'rank_history'          => [],
			'local_seo'             => [],
			'post_meta'             => [],
		];

		// Options.
		foreach ( self::$option_keys as $key ) {
			$value = get_option( $key, null );
			if ( null !== $value ) {
				$payload['settings'][ $key ] = $value;
			}
		}

		// Redirects table.
		$rows = $wpdb->get_results( // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			"SELECT source, target, type, hits, created_at FROM {$wpdb->prefix}awb_redirects",
			ARRAY_A
		);
		$payload['redirects'] = $rows ?: [];

		// Rank history table.
		$rows = $wpdb->get_results( // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			"SELECT * FROM {$wpdb->prefix}awb_rank_history",
			ARRAY_A
		);
		$payload['rank_history'] = $rows ?: [];

		// Local SEO table.
		$rows = $wpdb->get_results( // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			"SELECT * FROM {$wpdb->prefix}awb_local_seo",
			ARRAY_A
		);
		$payload['local_seo'] = $rows ?: [];

		// Post meta - group by post, include URL for cross-site matching.
		$placeholders = implode( ',', array_fill( 0, count( self::$meta_keys ), '%s' ) );
		$rows         = $wpdb->get_results( // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			$wpdb->prepare(
				"SELECT post_id, meta_key, meta_value
				 FROM {$wpdb->postmeta}
				 WHERE meta_key IN ( {$placeholders} )",
				...self::$meta_keys
			),
			ARRAY_A
		);

		$by_post = [];
		foreach ( $rows as $row ) {
			$by_post[ $row['post_id'] ][ $row['meta_key'] ] = $row['meta_value'];
		}

		foreach ( $by_post as $post_id => $meta ) {
			$post = get_post( $post_id );
			if ( ! $post ) {
				continue;
			}
			$payload['post_meta'][] = [
				'post_id'        => $post_id,
				'post_url'       => get_permalink( $post_id ),
				'post_slug'      => $post->post_name,
				'post_type'      => $post->post_type,
				'meta'           => $meta,
			];
		}

		return $payload;
	}

	/**
	 * AJAX handler - streams the JSON file to the browser.
	 */
	public static function handle_export() {
		check_ajax_referer( 'awbseo_portability', 'nonce' );

		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'Permission denied.', 'adworksbid-seo' ), 403 );
		}

		$payload  = self::build_export();
		$json     = wp_json_encode( $payload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES );
		$filename = 'awbseo-export-' . gmdate( 'Y-m-d' ) . '.json';

		nocache_headers();
		header( 'Content-Type: application/json; charset=utf-8' );
		header( 'Content-Disposition: attachment; filename="' . $filename . '"' );
		header( 'Content-Length: ' . strlen( $json ) );

		echo $json; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
		exit;
	}

	// ── Import ───────────────────────────────────────────────────────────────────

	/**
	 * AJAX handler - reads an uploaded JSON file and restores data.
	 *
	 * Accepts a `scope` POST param (comma-separated):
	 *   settings | redirects | rank_history | local_seo | post_meta | all
	 */
	public static function handle_import() {
		check_ajax_referer( 'awbseo_portability', 'nonce' );

		if ( ! current_user_can( 'manage_options' ) ) {
			wp_send_json_error( [ 'message' => __( 'Permission denied.', 'adworksbid-seo' ) ], 403 );
		}

		if ( empty( $_FILES['import_file']['tmp_name'] ) ) {
			wp_send_json_error( [ 'message' => __( 'No file uploaded.', 'adworksbid-seo' ) ] );
		}

		$tmp  = sanitize_text_field( wp_unslash( $_FILES['import_file']['tmp_name'] ) );
		$json = file_get_contents( $tmp ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents
		$data = json_decode( $json, true );

		if ( ! is_array( $data ) || empty( $data['awbseo_export_version'] ) ) {
			wp_send_json_error( [ 'message' => __( 'Invalid export file.', 'adworksbid-seo' ) ] );
		}

		$scope = isset( $_POST['scope'] ) ? sanitize_text_field( wp_unslash( $_POST['scope'] ) ) : 'all';
		$scopes = ( 'all' === $scope ) ? [ 'settings', 'redirects', 'rank_history', 'local_seo', 'post_meta' ] : explode( ',', $scope );

		$results = [];

		if ( in_array( 'settings', $scopes, true ) ) {
			$results['settings'] = self::import_settings( $data['settings'] ?? [] );
		}
		if ( in_array( 'redirects', $scopes, true ) ) {
			$results['redirects'] = self::import_redirects( $data['redirects'] ?? [] );
		}
		if ( in_array( 'rank_history', $scopes, true ) ) {
			$results['rank_history'] = self::import_rank_history( $data['rank_history'] ?? [] );
		}
		if ( in_array( 'local_seo', $scopes, true ) ) {
			$results['local_seo'] = self::import_local_seo( $data['local_seo'] ?? [] );
		}
		if ( in_array( 'post_meta', $scopes, true ) ) {
			$results['post_meta'] = self::import_post_meta( $data['post_meta'] ?? [] );
		}

		wp_send_json_success( [
			'message' => __( 'Import complete.', 'adworksbid-seo' ),
			'results' => $results,
			'source'  => [
				'site_url'       => $data['site_url']       ?? '',
				'exported_at'    => $data['exported_at']    ?? '',
				'plugin_version' => $data['plugin_version'] ?? '',
			],
		] );
	}

	private static function import_settings( array $settings ) {
		$count = 0;
		foreach ( $settings as $key => $value ) {
			// Only restore keys this plugin owns.
			if ( ! in_array( $key, self::$option_keys, true ) ) {
				continue;
			}
			// Never overwrite live API tokens - user must reconnect on the new site.
			if ( in_array( $key, [ 'awbseo_gsc_tokens', 'awbseo_ga4_tokens' ], true ) ) {
				continue;
			}
			update_option( $key, $value );
			$count++;
		}
		return [ 'restored' => $count ];
	}

	private static function import_redirects( array $rows ) {
		global $wpdb;
		$inserted = 0;
		$skipped  = 0;
		foreach ( $rows as $row ) {
			if ( empty( $row['source'] ) || empty( $row['target'] ) ) {
				$skipped++;
				continue;
			}
			$result = $wpdb->replace( // phpcs:ignore WordPress.DB.DirectDatabaseQuery
				$wpdb->prefix . 'awb_redirects',
				[
					'source'     => $row['source'],
					'target'     => $row['target'],
					'type'       => absint( $row['type'] ?? 301 ),
					'hits'       => absint( $row['hits'] ?? 0 ),
					'created_at' => $row['created_at'] ?? current_time( 'mysql', true ),
				]
			);
			$result ? $inserted++ : $skipped++;
		}
		return [ 'inserted' => $inserted, 'skipped' => $skipped ];
	}

	private static function import_rank_history( array $rows ) {
		global $wpdb;
		$inserted = 0;
		foreach ( $rows as $row ) {
			unset( $row['id'] ); // Let auto-increment assign a new ID.
			$result = $wpdb->insert( $wpdb->prefix . 'awb_rank_history', $row ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			if ( $result ) {
				$inserted++;
			}
		}
		return [ 'inserted' => $inserted ];
	}

	private static function import_local_seo( array $rows ) {
		global $wpdb;
		$inserted = 0;
		foreach ( $rows as $row ) {
			unset( $row['id'] );
			$result = $wpdb->replace( $wpdb->prefix . 'awb_local_seo', $row ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery
			if ( $result ) {
				$inserted++;
			}
		}
		return [ 'inserted' => $inserted ];
	}

	private static function import_post_meta( array $items ) {
		$matched   = 0;
		$unmatched = 0;

		foreach ( $items as $item ) {
			$post_id = self::resolve_post_id( $item );

			if ( ! $post_id ) {
				$unmatched++;
				continue;
			}

			foreach ( $item['meta'] as $key => $value ) {
				if ( ! in_array( $key, self::$meta_keys, true ) ) {
					continue;
				}
				update_post_meta( $post_id, $key, $value );
			}
			$matched++;
		}

		return [ 'matched' => $matched, 'unmatched' => $unmatched ];
	}

	/**
	 * Find the local post ID for an exported post.
	 *
	 * Strategy:
	 * 1. If the site URL matches (same site), trust the post ID directly.
	 * 2. Otherwise try to find by URL (handles domain changes).
	 * 3. Fall back to slug + post type.
	 */
	private static function resolve_post_id( array $item ) {
		$post_id   = absint( $item['post_id']   ?? 0 );
		$post_url  = $item['post_url']  ?? '';
		$post_slug = $item['post_slug'] ?? '';
		$post_type = $item['post_type'] ?? 'any';

		// Same-site: verify the post ID still exists.
		if ( $post_id && get_post( $post_id ) ) {
			return $post_id;
		}

		// Cross-site: match by URL path (strip the host so domain changes don't matter).
		if ( $post_url ) {
			$path = wp_parse_url( $post_url, PHP_URL_PATH );
			if ( $path ) {
				$local_id = url_to_postid( home_url( $path ) );
				if ( $local_id ) {
					return $local_id;
				}
			}
		}

		// Last resort: match by slug and post type.
		if ( $post_slug ) {
			$posts = get_posts( [
				'name'           => $post_slug,
				'post_type'      => $post_type ?: 'any',
				'post_status'    => 'any',
				'posts_per_page' => 1,
				'fields'         => 'ids',
			] );
			if ( ! empty( $posts ) ) {
				return $posts[0];
			}
		}

		return 0;
	}
}