<?php

namespace AcademicCrew\PageGenerator;

use AcademicCrew\Core\Loader;

/**
 * Creates and links a WP page for each published acc_collaboration post.
 *
 * On first publish: generates the page at /projects/{slug} and stores cross-references.
 * On subsequent saves: syncs post_content bidirectionally.
 * On trash/delete: mirrors the action on the linked page and cleans nav menus.
 */
class CollaborationPageGenerator extends PageGeneratorBase {

    private static bool $syncing = false;

    public function register( Loader $loader ): void {
        $loader->add_action( 'save_post_acc_collaboration', $this, 'on_collaboration_saved', 20, 2 );
        $loader->add_action( 'save_post_page',             $this, 'on_linked_page_saved',   20, 2 );
        $loader->add_action( 'trashed_post',               $this, 'on_cpt_trashed'             );
        $loader->add_action( 'untrashed_post',             $this, 'on_cpt_untrashed'            );
        $loader->add_action( 'before_delete_post',         $this, 'on_cpt_before_delete',   10, 2 );
        $loader->add_action( 'before_delete_post',         $this, 'on_page_before_delete',  10, 2 );
    }

    // ---------------------------------------------------------------
    // Save hooks
    // ---------------------------------------------------------------

    public function on_collaboration_saved( int $post_id, \WP_Post $post ): void {
        if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) return;
        if ( wp_is_post_revision( $post_id ) ) return;
        if ( 'publish' !== $post->post_status ) return;
        if ( self::$syncing ) return;

        $existing_page_id = (int) get_post_meta( $post_id, '_academiccrew_linked_page_id', true );

        if ( $existing_page_id && get_post( $existing_page_id ) ) {
            $this->sync_to_page( $post->post_content, $existing_page_id );
            return;
        }

        $this->generate_page( $post_id );
    }

    public function on_linked_page_saved( int $page_id, \WP_Post $page ): void {
        if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) return;
        if ( wp_is_post_revision( $page_id ) ) return;
        if ( self::$syncing ) return;
        if ( 'publish' !== $page->post_status && 'private' !== $page->post_status ) return;

        $collab_id = (int) get_post_meta( $page_id, '_academiccrew_collaboration_id', true );
        if ( ! $collab_id ) return;

        self::$syncing = true;
        wp_update_post( [ 'ID' => $collab_id, 'post_content' => $page->post_content ] );
        self::$syncing = false;
    }

    private function sync_to_page( string $content, int $page_id ): void {
        if ( self::$syncing ) return;
        self::$syncing = true;
        wp_update_post( [ 'ID' => $page_id, 'post_content' => $content ] );
        self::$syncing = false;
    }

    // ---------------------------------------------------------------
    // Lifecycle hooks — trash / delete
    // ---------------------------------------------------------------

    public function on_cpt_trashed( int $post_id ): void {
        if ( 'acc_collaboration' !== get_post_type( $post_id ) ) return;
        $page_id = (int) get_post_meta( $post_id, '_academiccrew_linked_page_id', true );
        if ( ! $page_id || 'publish' !== get_post_status( $page_id ) ) return;

        self::$syncing = true;
        wp_trash_post( $page_id );
        self::$syncing = false;
    }

    public function on_cpt_untrashed( int $post_id ): void {
        if ( 'acc_collaboration' !== get_post_type( $post_id ) ) return;
        $page_id = (int) get_post_meta( $post_id, '_academiccrew_linked_page_id', true );
        if ( ! $page_id || 'trash' !== get_post_status( $page_id ) ) return;

        self::$syncing = true;
        wp_untrash_post( $page_id );
        if ( 'publish' !== get_post_status( $page_id ) ) {
            wp_update_post( [ 'ID' => $page_id, 'post_status' => 'publish' ] );
        }
        self::$syncing = false;
    }

    public function on_cpt_before_delete( int $post_id, \WP_Post $post ): void {
        if ( 'acc_collaboration' !== $post->post_type ) return;
        $page_id = (int) get_post_meta( $post_id, '_academiccrew_linked_page_id', true );
        if ( ! $page_id || ! get_post( $page_id ) ) return;

        self::$syncing = true;
        $this->remove_nav_menu_items_for_page( $page_id );
        wp_delete_post( $page_id, true );
        self::$syncing = false;
    }

    public function on_page_before_delete( int $post_id, \WP_Post $post ): void {
        if ( 'page' !== $post->post_type ) return;
        if ( self::$syncing ) return;

        $collab_id = (int) get_post_meta( $post_id, '_academiccrew_collaboration_id', true );
        if ( ! $collab_id ) return;

        delete_post_meta( $collab_id, '_academiccrew_linked_page_id' );
    }

    // ---------------------------------------------------------------
    // Page generation
    // ---------------------------------------------------------------

    public function generate_page( int $collab_id ): int {
        $collab = get_post( $collab_id );
        if ( ! $collab ) {
            return 0;
        }

        // Seed the editable page body from the project (e.g. its short description);
        // an empty page would otherwise sync back and wipe it.
        $content = (string) $collab->post_content;

        $archive_page_id = (int) get_option( 'academiccrew_collaborations_archive_page_id', 0 );
        if ( ! $archive_page_id ) {
            CollaborationsArchivePageGenerator::generate_if_needed();
            $archive_page_id = (int) get_option( 'academiccrew_collaborations_archive_page_id', 0 );
        }

        $page_id = $this->create_page( [
            'post_title'   => $collab->post_title,
            'post_content' => $content,
            'post_status'  => 'publish',
            'post_type'    => 'page',
            'post_name'    => $collab->post_name,
            'post_parent'  => $archive_page_id ?: 0,
            'meta_input'   => [
                '_academiccrew_is_collaboration_page' => 1,
                '_academiccrew_collaboration_id'      => $collab_id,
                'pyre_page_title'                  => 'no',
                'pyre_sidebar_position'            => 'none',
            ],
        ] );

        if ( ! $page_id ) {
            return 0;
        }

        update_post_meta( $collab_id, '_academiccrew_linked_page_id', $page_id );

        return $page_id;
    }
}