<?php
namespace QWSpeedCache\Preload;

defined( 'ABSPATH' ) || exit;

/**
 * Preload orchestrator: manual run, after-purge, URL collection.
 */
class Manager {

	public function __construct() {
		new Bot();
		add_action( 'admin_post_qwsc_run_preload', array( $this, 'manual_run' ) );
		add_action( 'admin_post_qwsc_clear_preload_queue', array( $this, 'clear_queue' ) );
	}


	public function manual_run() {
		check_admin_referer( 'qwsc_run_preload' );
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'Unauthorized', 'qw-optimize' ), '', array( 'response' => 403 ) );
		}
		Queue::enqueue( self::collect_urls() );
		$bot = new Bot();
		$bot->schedule_process( 1 );
		$bot->process_batch();
		wp_safe_redirect(
			add_query_arg(
				array(
					'page'      => 'qw-speed-cache-media',
					'preloaded' => '1',
				),
				admin_url( 'admin.php' )
			)
		);
		exit;
	}

	public function clear_queue() {
		check_admin_referer( 'qwsc_clear_preload_queue' );
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'Unauthorized', 'qw-optimize' ), '', array( 'response' => 403 ) );
		}
		Queue::clear();
		self::reset_progress();
		wp_safe_redirect(
			add_query_arg(
				array(
					'page'          => 'qw-speed-cache-media',
					'queue_cleared' => '1',
				),
				admin_url( 'admin.php' )
			)
		);
		exit;
	}


	/**
	 * Collect homepage, menus, recent content, homepage links (Free). Sitemap is Pro.
	 *
	 * @return string[]
	 */
	public static function collect_urls() {
		$settings = \QWSpeedCache\Plugin::instance()->get_all_settings();
		$max      = (int) apply_filters( 'qwsc_preload_url_limit', 500 );
		$max      = max( 10, min( 2000, $max ) );

		$urls = array( home_url( '/' ) );

		// Nav menus.
		$urls = array_merge( $urls, self::urls_from_menus() );

		// Recent posts / pages / products (more coverage for G-09).
		foreach ( array( 'post' => 50, 'page' => 30, 'product' => 30 ) as $pt => $n ) {
			if ( 'product' === $pt && ! post_type_exists( 'product' ) ) {
				continue;
			}
			$posts = get_posts(
				array(
					'numberposts' => $n,
					'post_status' => 'publish',
					'post_type'   => $pt,
				)
			);
			foreach ( $posts as $p ) {
				$urls[] = get_permalink( $p );
			}
		}

		// Homepage HTML internal links.
		$urls = array_merge( $urls, self::urls_from_homepage_html() );


		// Sitemap preload is Pro-only — not collected in Free.

		$host = wp_parse_url( home_url(), PHP_URL_HOST );
		$out  = array();
		foreach ( $urls as $url ) {
			$url = Queue::normalize_url( is_string( $url ) ? $url : '' );
			if ( '' === $url ) {
				continue;
			}
			$u_host = wp_parse_url( $url, PHP_URL_HOST );
			if ( $u_host && strtolower( (string) $u_host ) === strtolower( (string) $host ) ) {
				$out[] = $url;
			}
		}
		$out = \QWSpeedCache\Cache\Warmup::filter_safe( $out );
		// Neutral extension point: Pro may supply traffic-aware ordering.
		$out = apply_filters( 'qwsc_preload_order_urls', $out );
		if ( ! is_array( $out ) ) {
			$out = array();
		}
		$out = \QWSpeedCache\Cache\Warmup::filter_safe( $out );
		$out = array_values( array_unique( $out ) );
		if ( count( $out ) > $max ) {
			$out = array_slice( $out, 0, $max );
		}

		self::bump_progress_on_seed( count( $out ) );
		return $out;
	}

	/**
	 * @return string[]
	 */
	public static function urls_from_menus() {
		$urls = array();
		if ( ! function_exists( 'wp_get_nav_menus' ) ) {
			return $urls;
		}
		$menus = wp_get_nav_menus();
		if ( empty( $menus ) || is_wp_error( $menus ) ) {
			return $urls;
		}
		foreach ( $menus as $menu ) {
			$items = wp_get_nav_menu_items( $menu->term_id );
			if ( empty( $items ) || is_wp_error( $items ) ) {
				continue;
			}
			foreach ( $items as $item ) {
				if ( ! empty( $item->url ) ) {
					$urls[] = $item->url;
				}
			}
		}
		return $urls;
	}

	/**
	 * Extract same-site hrefs from homepage HTML.
	 *
	 * @return string[]
	 */
	public static function urls_from_homepage_html() {
		$response = wp_safe_remote_get(
			home_url( '/' ),
			array(
				'timeout'   => 8,
				'sslverify' => true,
			)
		);
		if ( is_wp_error( $response ) || 200 !== (int) wp_remote_retrieve_response_code( $response ) ) {
			return array();
		}
		$body = (string) wp_remote_retrieve_body( $response );
		return self::extract_hrefs( $body, home_url( '/' ) );
	}

	/**
	 * Pure-ish: extract absolute URLs from HTML href attributes.
	 *
	 * @param string $html HTML.
	 * @param string $base Base URL for relative links.
	 * @return string[]
	 */
	public static function extract_hrefs( $html, $base ) {
		$out = array();
		if ( ! is_string( $html ) || '' === $html ) {
			return $out;
		}
		if ( ! preg_match_all( '/href\s*=\s*[\'"]([^\'"#]+)[\'"]/i', $html, $m ) ) {
			return $out;
		}
		$base_host = wp_parse_url( $base, PHP_URL_HOST );
		foreach ( $m[1] as $href ) {
			$href = trim( $href );
			if ( '' === $href || 0 === strpos( $href, 'mailto:' ) || 0 === strpos( $href, 'tel:' ) || 0 === strpos( $href, 'javascript:' ) ) {
				continue;
			}
			if ( 0 === strpos( $href, '//' ) ) {
				$href = ( is_ssl() ? 'https:' : 'http:' ) . $href;
			} elseif ( 0 === strpos( $href, '/' ) ) {
				$href = home_url( $href );
			} elseif ( ! preg_match( '#^https?://#i', $href ) ) {
				continue;
			}
			$h = wp_parse_url( $href, PHP_URL_HOST );
			if ( $h && $base_host && strtolower( (string) $h ) === strtolower( (string) $base_host ) ) {
				$out[] = $href;
			}
		}
		return $out;
	}

	
	/**
	 * @param int $seeded Count seeded.
	 */
	public static function bump_progress_on_seed( $seeded ) {
		$stats = array(
			'seeded'  => (int) $seeded,
			'done'    => 0,
			'failed'  => 0,
			'updated' => time(),
			'status'  => $seeded > 0 ? 'running' : 'idle',
		);
		update_option( 'qwsc_preload_stats', $stats, false );
	}

	/**
	 * @param int $done    Success count delta.
	 * @param int $failed  Fail count delta.
	 * @param int $remaining Queue remaining.
	 */
	public static function bump_progress( $done, $failed, $remaining ) {
		$stats = get_option( 'qwsc_preload_stats', array() );
		if ( ! is_array( $stats ) ) {
			$stats = array();
		}
		$stats['done']    = (int) ( $stats['done'] ?? 0 ) + (int) $done;
		$stats['failed']  = (int) ( $stats['failed'] ?? 0 ) + (int) $failed;
		$stats['updated'] = time();
		$stats['status']  = $remaining > 0 ? 'running' : 'done';
		update_option( 'qwsc_preload_stats', $stats, false );
	}

	public static function reset_progress() {
		update_option(
			'qwsc_preload_stats',
			array(
				'seeded'  => 0,
				'done'    => 0,
				'failed'  => 0,
				'updated' => time(),
				'status'  => 'idle',
			),
			false
		);
	}

	/**
	 * @return array{seeded:int,done:int,failed:int,status:string,updated:int}
	 */
	public static function progress() {
		$stats = get_option( 'qwsc_preload_stats', array() );
		if ( ! is_array( $stats ) ) {
			$stats = array();
		}
		return array(
			'seeded'  => (int) ( $stats['seeded'] ?? 0 ),
			'done'    => (int) ( $stats['done'] ?? 0 ),
			'failed'  => (int) ( $stats['failed'] ?? 0 ),
			'status'  => (string) ( $stats['status'] ?? 'idle' ),
			'updated' => (int) ( $stats['updated'] ?? 0 ),
			'queue'   => Queue::count(),
		);
	}
}