<?php
namespace WPDeveloper\BetterDocs\Admin;

use WPDeveloper\BetterDocs\Admin\Importer\WPImport;
use WPDeveloper\BetterDocs\Admin\BackgroundProcess\WP_Background_Process;

class HelpScoutMigration extends WP_Background_Process {
    /**
     * @var string
     */
    protected $action = 'betterdocs_helpscout_migration';

    /**
     * Task
     *
     * Override this method to perform any actions required on each
     * queue item. Return the modified item for further processing
     * in the next pass through. Or, return false to remove the
     * item from the queue.
     *
     * @param mixed $item Queue item to iterate over
     *
     * @return mixed
     */
    protected function task( $item ) {
        if ( empty( $item ) ) {
            return false;
        }

        $headers          = $item['headers'];
        $initial_response = $item['initial_response'];
        $api_key          = $item['api_key'];
        $collection_id    = $item['collection_id'];
        // Implement your migration logic here
        $this->migrateFromHelpScout( $headers, $initial_response, $api_key, $collection_id );

        return false;
    }

    /**
     * Complete
     *
     * Override if applicable, but ensure that the below actions are
     * performed, or, call parent::complete().
     */
    protected function complete() {
        parent::complete();

        // Perform any cleanup tasks after all items are processed
    }

    /**
     * Migrate articles from Help Scout to WordPress
     *
     * @param string $api_key Help Scout API key
     * @param int $collection_id Help Scout collection ID
     * @return bool True if migration is successful, false otherwise
     */
    protected function migrateFromHelpScout( $headers, $initial_response, $api_key, $collection_id ) {
        $total_pages = get_option( 'betterdocs_helpscout_total_pages' );

        if ( ! $total_pages ) {
            if ( is_wp_error( $initial_response ) ) {
                return false;
            }
            $initial_body = wp_remote_retrieve_body( $initial_response );
            $initial_data = json_decode( $initial_body, true );
            $total_pages  = $initial_data['articles']['pages'];
            update_option( 'betterdocs_helpscout_total_pages', $total_pages );
        }

        $current_page  = get_option( 'betterdocs_helpscout_current_page', 1 );
        $allArticleIds = [];

        try {
            // Fetch articles page by page
            while ( $current_page <= $total_pages ) {
                $api_endpoint = 'https://docsapi.helpscout.net/v1/collections/' . $collection_id . '/articles?pageSize=1&page=' . $current_page;

                $response = wp_remote_get( $api_endpoint, ['headers' => $headers] );

                if ( is_wp_error( $response ) ) {
                    return false;
                }

                $body = wp_remote_retrieve_body( $response );
                $data = json_decode( $body, true );

                if ( ! isset( $data['articles'] ) || ! isset( $data['articles']['items'] ) ) {
                    return false;
                }

                $articles = $data['articles']['items'];

                // Fetch detailed information for each article
                $detailedArticles = [];
                foreach ( $articles as $article ) {
                    $articleId     = $article['id'];
                    $articleNumber = $article['number'];

                    if ( ! $this->articleIdExists( $articleId ) ) {
                        $articleEndpoint = "https://docsapi.helpscout.net/v1/articles/{$articleId}";
                        $articleResponse = wp_remote_get( $articleEndpoint, ['headers' => $headers] );

                        if ( ! is_wp_error( $articleResponse ) ) {
                            $articleBody = wp_remote_retrieve_body( $articleResponse );
                            $articleData = json_decode( $articleBody, true );

                            if ( isset( $articleData['article'] ) && isset( $articleData['article']['text'] ) ) {
                                $article['text']  = $articleData['article']['text'];
                                $categories       = $articleData['article']['categories'];
                                $categoryDetails  = [];
                                $categories_cache = get_transient( 'betterdocs_helpscout_categories' );

                                // Initialize $categories_cache as an array if it's not set
                                if ( ! is_array( $categories_cache ) ) {
                                    $categories_cache = [];
                                }

                                foreach ( $categories as $categoryId ) {
                                    if ( isset( $categories_cache[$categoryId] ) ) {
                                        $categoryDetails[] = $categories_cache[$categoryId];
                                    } else {
                                        $categoryInfo = $this->fetchCategoryInfo( $categoryId, $headers );
                                        if ( $categoryInfo ) {
                                            $categoryDetails[]             = $categoryInfo;
                                            $categories_cache[$categoryId] = $categoryInfo;
                                            set_transient( 'betterdocs_helpscout_categories', $categories_cache, DAY_IN_SECONDS ); // Cache for a day
                                        }
                                    }
                                }

                                $article['categories'] = $categoryDetails;
                                $detailedArticles[]    = $article;
                                $allArticleIds[]       = $articleId;
                            }
                        }
                    }
                }

                if ( ! empty( $detailedArticles ) ) {
                    $wp_importer = new WPImport( '' );
                    $wp_importer->import_helpscout_data( $detailedArticles );
                    $existingArticleIds = get_option( 'betterdocs_helpscout_migrated_article_ids', [] );
                    $existingArticleIds = is_array( $existingArticleIds ) ? $existingArticleIds : [];
                    $allArticleIds      = array_merge( $existingArticleIds, $allArticleIds );
                    update_option( 'betterdocs_helpscout_migrated_article_ids', serialize( $allArticleIds ) );
                }

                $current_page++;

                update_option( 'betterdocs_helpscout_current_page', $current_page );

                // Check if we have processed all pages
                if ( $current_page > $total_pages ) {
                    update_option( 'betterdocs_helpscout_current_page', 1 );
                    delete_option( 'betterdocs_helpscout_total_pages' );
                }
            }
        } catch ( \WP_Error $wp_error ) {
            // Handle WP_Error exceptions
            //error_log('WP_Error occurred during migration: ' . $wp_error->get_error_message());
            return false; // Indicate failure to process the current item
        } catch ( \Exception $e ) {
            // Handle other exceptions
            //error_log('Error occurred during migration: ' . $e->getMessage());
            return false; // Indicate failure to process the current item
        }

        return true; // Indicate success
    }

    /**
     * Fetch category information from Help Scout API.
     *
     * @param string $categoryId Category ID
     * @param array $headers Headers for API requests
     * @return array|null Category information
     */
    protected function fetchCategoryInfo( $categoryId, $headers ) {
        $categoryEndpoint = "https://docsapi.helpscout.net/v1/categories/{$categoryId}";
        $categoryResponse = wp_remote_get( $categoryEndpoint, ['headers' => $headers] );

        if ( ! is_wp_error( $categoryResponse ) ) {
            $categoryBody = wp_remote_retrieve_body( $categoryResponse );
            $categoryData = json_decode( $categoryBody, true );

            if ( isset( $categoryData['category']['name'] ) && isset( $categoryData['category']['slug'] ) ) {
                return [
                    'name' => $categoryData['category']['name'],
                    'slug' => $categoryData['category']['slug']
                ];
            }
        }
        return null;
    }

    /**
     * Check if article ID exists in the option.
     *
     * @param int $articleId Article ID
     * @return bool True if article ID exists, false otherwise
     */
    protected function articleIdExists( $articleId ) {
        $existingArticleIds = get_option( 'betterdocs_helpscout_migrated_article_ids' );
        $existingArticleIds = $existingArticleIds ? unserialize( $existingArticleIds ) : [];
        return in_array( $articleId, $existingArticleIds );
    }
}