<?php
/**
 * Metadata Importer Wizard.
 *
 * Non-destructively imports existing post metadata (`_yoast_wpseo_*`, `rank_math_*`,
 * `_aioseo_*`, `_seopress_*`) into the `wp_modulustools_meta` custom table.
 *
 * @package ModulusTools\SEO\Modules
 */

namespace ModulusTools\SEO\Modules;

use ModulusTools\SEO\Core;

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

/**
 * Class Migrator
 */
class Migrator {

	/**
	 * Constructor.
	 */
	public function __construct() {
		// Batch operations are triggered via REST_Controller.
	}

	/**
	 * Mapping of postmeta keys to `wp_modulustools_meta` columns.
	 *
	 * @return array<string, array<string, string>>
	 */
	public static function get_competitor_maps(): array {
		return array(
			'yoast'    => array(
				'label'         => 'Yoast SEO Metadata (_yoast_wpseo_*)',
				'title'         => '_yoast_wpseo_title',
				'description'   => '_yoast_wpseo_metadesc',
				'focus_keyword' => '_yoast_wpseo_focuskw',
				'canonical_url' => '_yoast_wpseo_canonical',
				'noindex'       => '_yoast_wpseo_meta-robots-noindex',
				'nofollow'      => '_yoast_wpseo_meta-robots-nofollow',
				'og_title'      => '_yoast_wpseo_opengraph-title',
				'og_desc'       => '_yoast_wpseo_opengraph-description',
				'og_image'      => '_yoast_wpseo_opengraph-image',
			),
			'rankmath' => array(
				'label'         => 'Rank Math Metadata (rank_math_*)',
				'title'         => 'rank_math_title',
				'description'   => 'rank_math_description',
				'focus_keyword' => 'rank_math_focus_keyword',
				'canonical_url' => 'rank_math_canonical_url',
				'robots'        => 'rank_math_robots',
				'og_title'      => 'rank_math_facebook_title',
				'og_desc'       => 'rank_math_facebook_description',
				'og_image'      => 'rank_math_facebook_image',
			),
			'aioseo'   => array(
				'label'         => 'AIOSEO Metadata (_aioseo_*)',
				'title'         => '_aioseo_title',
				'description'   => '_aioseo_description',
				'focus_keyword' => '_aioseo_keywords',
				'canonical_url' => '_aioseo_canonical_url',
				'og_title'      => '_aioseo_og_title',
				'og_desc'       => '_aioseo_og_description',
			),
			'seopress' => array(
				'label'         => 'SEOPress Metadata (_seopress_*)',
				'title'         => '_seopress_titles_title',
				'description'   => '_seopress_titles_desc',
				'focus_keyword' => '_seopress_analysis_target_kw',
				'canonical_url' => '_seopress_robots_canonical',
				'noindex'       => '_seopress_robots_index',
				'nofollow'      => '_seopress_robots_follow',
				'og_title'      => '_seopress_social_fb_title',
				'og_desc'       => '_seopress_social_fb_desc',
				'og_image'      => '_seopress_social_fb_img',
			),
		);
	}

	/**
	 * Processes a batch of posts to migrate existing SEO metadata into `wp_modulustools_meta`.
	 *
	 * @param string $source 'yoast', 'rankmath', 'aioseo', or 'seopress'.
	 * @param int    $offset Batch offset.
	 * @param int    $limit  Batch size.
	 * @return array<string, mixed>
	 */
	public static function process_batch( string $source, int $offset = 0, int $limit = 50 ): array {
		global $wpdb;

		$maps = self::get_competitor_maps();
		if ( ! isset( $maps[ $source ] ) ) {
			return array(
				'success' => false,
				'message' => __( 'Unsupported metadata source selected.', 'modulustools-seo-suite' ),
			);
		}

		$map = $maps[ $source ];

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
		$post_ids = $wpdb->get_col(
			$wpdb->prepare(
				'SELECT ID FROM %i WHERE post_status IN (%s, %s, %s, %s) AND post_type NOT IN (%s, %s, %s) ORDER BY ID ASC LIMIT %d OFFSET %d',
				$wpdb->posts,
				'publish',
				'draft',
				'private',
				'future',
				'revision',
				'nav_menu_item',
				'attachment',
				$limit,
				$offset
			)
		);

		$migrated_count = 0;
		if ( is_array( $post_ids ) ) {
			foreach ( $post_ids as $post_id ) {
				$post_id = (int) $post_id;
				$title   = (string) get_post_meta( $post_id, $map['title'], true );
				$desc    = (string) get_post_meta( $post_id, $map['description'], true );
				$kw      = (string) get_post_meta( $post_id, $map['focus_keyword'], true );
				$canon   = isset( $map['canonical_url'] ) ? (string) get_post_meta( $post_id, $map['canonical_url'], true ) : '';

				$title = self::normalize_variables( $title );
				$desc  = self::normalize_variables( $desc );

				$focus_kw     = $kw;
				$secondary_kw = '';
				if ( false !== strpos( $kw, ',' ) ) {
					$parts        = array_map( 'trim', explode( ',', $kw ) );
					$focus_kw     = (string) array_shift( $parts );
					$secondary_kw = implode( ', ', $parts );
				}

				$robots_index  = 'index';
				$robots_follow = 'follow';

				if ( 'rankmath' === $source && isset( $map['robots'] ) ) {
					$rm_robots = get_post_meta( $post_id, $map['robots'], true );
					if ( is_array( $rm_robots ) ) {
						if ( in_array( 'noindex', $rm_robots, true ) ) {
							$robots_index = 'noindex';
						}
						if ( in_array( 'nofollow', $rm_robots, true ) ) {
							$robots_follow = 'nofollow';
						}
					}
				} else {
					$raw_noindex  = isset( $map['noindex'] ) ? (string) get_post_meta( $post_id, $map['noindex'], true ) : '';
					$raw_nofollow = isset( $map['nofollow'] ) ? (string) get_post_meta( $post_id, $map['nofollow'], true ) : '';
					if ( in_array( $raw_noindex, array( '1', 'yes', 'noindex' ), true ) ) {
						$robots_index = 'noindex';
					}
					if ( in_array( $raw_nofollow, array( '1', 'yes', 'nofollow' ), true ) ) {
						$robots_follow = 'nofollow';
					}
				}

				$og_title = isset( $map['og_title'] ) ? (string) get_post_meta( $post_id, $map['og_title'], true ) : '';
				$og_desc  = isset( $map['og_desc'] ) ? (string) get_post_meta( $post_id, $map['og_desc'], true ) : '';
				$og_image = isset( $map['og_image'] ) ? (string) get_post_meta( $post_id, $map['og_image'], true ) : '';

				if ( '' !== $title || '' !== $desc || '' !== $focus_kw || '' !== $canon || 'noindex' === $robots_index ) {
					Core::save_meta(
						$post_id,
						'post',
						array(
							'title'              => $title,
							'description'        => $desc,
							'focus_keyword'      => $focus_kw,
							'secondary_keywords' => $secondary_kw,
							'canonical_url'      => $canon,
							'robots_index'       => $robots_index,
							'robots_follow'      => $robots_follow,
							'og_title'           => $og_title,
							'og_description'     => $og_desc,
							'og_image'           => $og_image,
						)
					);
					++$migrated_count;
				}
			}
		}

		$has_more = is_array( $post_ids ) && count( $post_ids ) === $limit;

		return array(
			'success'        => true,
			'source'         => $source,
			'processed'      => is_array( $post_ids ) ? count( $post_ids ) : 0,
			'migrated_count' => $migrated_count,
			'next_offset'    => $offset + $limit,
			'has_more'       => $has_more,
		);
	}

	/**
	 * Normalizes template variables to `%post_title%`, `%site_name%`, and `%sep%`.
	 *
	 * @param string $raw Raw template string.
	 * @return string
	 */
	private static function normalize_variables( string $raw ): string {
		if ( '' === $raw ) {
			return '';
		}
		$search  = array( '%%title%%', '%title%', '#post_title', '%%sitename%%', '%sitename%', '#site_title', '%%sep%%', '%sep%', '#separator_sa' );
		$replace = array( '%post_title%', '%post_title%', '%post_title%', '%site_name%', '%site_name%', '%site_name%', '%sep%', '%sep%', '%sep%' );
		return str_replace( $search, $replace, $raw );
	}

	/**
	 * Renders the Metadata Importer Wizard in the Admin Dashboard.
	 *
	 * @return void
	 */
	public static function render_migration_wizard(): void {
		$maps = self::get_competitor_maps();
		?>
		<div class="modulustools-migrator-view">
			<div class="modulustools-card">
				<h2><?php esc_html_e( 'Metadata Importer Wizard', 'modulustools-seo-suite' ); ?></h2>
				<p><?php esc_html_e( 'Import existing post SEO titles, meta descriptions, focus keywords, canonical URLs, OpenGraph tags, and robots directives into custom tables. Original wp_postmeta keys remain untouched.', 'modulustools-seo-suite' ); ?></p>

				<div class="modulustools-inline-form" style="margin-top:16px;">
					<label for="modulustools-migrate-source"><strong><?php esc_html_e( 'Select Metadata Format:', 'modulustools-seo-suite' ); ?></strong></label>
					<select id="modulustools-migrate-source">
						<?php foreach ( $maps as $key => $info ) : ?>
							<option value="<?php echo esc_attr( $key ); ?>"><?php echo esc_html( $info['label'] ); ?></option>
						<?php endforeach; ?>
					</select>
					<button type="button" id="modulustools-start-migration-btn" class="button button-primary"><?php esc_html_e( 'Start Batch Import', 'modulustools-seo-suite' ); ?></button>
				</div>

				<div id="modulustools-migration-progress-wrap" style="display:none; margin-top:20px;">
					<div class="modulustools-progress-bar-outer">
						<div id="modulustools-migration-progress-bar" class="modulustools-progress-bar-inner" style="width:0%;"></div>
					</div>
					<p id="modulustools-migration-status-text"><?php esc_html_e( 'Initializing batch importer...', 'modulustools-seo-suite' ); ?></p>
				</div>
			</div>
		</div>
		<?php
	}
}