<?php
/**
 * AJAX Handler class - Handles all AJAX requests.
 *
 * @package MapleIcons
 */

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

/**
 * Class MI_Ajax_Handler
 *
 * Handles all AJAX requests for the plugin.
 */
class MI_Ajax_Handler {

    /**
     * Constructor - Register AJAX handlers.
     */
    public function __construct() {
        // Admin AJAX handlers.
        add_action( 'wp_ajax_mi_download_set', array( $this, 'handle_download_set' ) );
        add_action( 'wp_ajax_mi_delete_set', array( $this, 'handle_delete_set' ) );
        add_action( 'wp_ajax_mi_set_active', array( $this, 'handle_set_active' ) );
        add_action( 'wp_ajax_mi_get_progress', array( $this, 'handle_get_progress' ) );

        // Block editor AJAX handlers.
        add_action( 'wp_ajax_mi_search_icons', array( $this, 'handle_search_icons' ) );
        add_action( 'wp_ajax_mi_get_icon_svg', array( $this, 'handle_get_icon_svg' ) );

        // No nopriv handlers - all functionality requires login.
    }

    /**
     * Handle download set request.
     */
    public function handle_download_set() {
        // 1. Nonce verification.
        if ( ! check_ajax_referer( 'mi_admin_nonce', 'nonce', false ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Security check failed.', 'maple-icons' ) ),
                403
            );
        }

        // 2. Capability check.
        if ( ! current_user_can( 'manage_options' ) ) {
            wp_send_json_error(
                array( 'message' => __( 'You do not have permission to do this.', 'maple-icons' ) ),
                403
            );
        }

        // 3. Input validation.
        $slug = isset( $_POST['slug'] ) ? sanitize_key( $_POST['slug'] ) : '';

        if ( empty( $slug ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Icon set slug is required.', 'maple-icons' ) )
            );
        }

        if ( ! MI_Icon_Sets::is_valid_slug( $slug ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Invalid icon set.', 'maple-icons' ) )
            );
        }

        // Check if already downloaded.
        $registry = MI_Icon_Registry::get_instance();
        if ( $registry->is_downloaded( $slug ) ) {
            wp_send_json_error(
                array( 'message' => __( 'This icon set is already downloaded.', 'maple-icons' ) )
            );
        }

        // 4. Process download.
        // Increase time limit for large downloads.
        set_time_limit( 600 ); // 10 minutes.

        $downloader = new MI_Downloader();
        $result     = $downloader->download_set( $slug );

        if ( is_wp_error( $result ) ) {
            wp_send_json_error(
                array( 'message' => $result->get_error_message() )
            );
        }

        if ( ! $result['success'] ) {
            wp_send_json_error(
                array(
                    'message'    => sprintf(
                        /* translators: %1$d: downloaded count, %2$d: failed count */
                        __( 'Download completed with errors. %1$d downloaded, %2$d failed.', 'maple-icons' ),
                        $result['downloaded'],
                        $result['failed']
                    ),
                    'errors'     => array_slice( $result['errors'], 0, 10 ), // Limit errors shown.
                    'downloaded' => $result['downloaded'],
                    'failed'     => $result['failed'],
                )
            );
        }

        // Mark as downloaded.
        $registry->mark_downloaded( $slug, $result['downloaded'] );

        // If no active set, make this one active.
        if ( ! $registry->get_active_set() ) {
            $registry->set_active( $slug );
        }

        $registry->refresh();

        wp_send_json_success(
            array(
                'message'    => sprintf(
                    /* translators: %d: number of icons */
                    __( 'Successfully downloaded %d icons.', 'maple-icons' ),
                    $result['downloaded']
                ),
                'icon_count' => $result['downloaded'],
                'is_active'  => $registry->get_active_set() === $slug,
            )
        );
    }

    /**
     * Handle delete set request.
     */
    public function handle_delete_set() {
        // 1. Nonce verification.
        if ( ! check_ajax_referer( 'mi_admin_nonce', 'nonce', false ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Security check failed.', 'maple-icons' ) ),
                403
            );
        }

        // 2. Capability check.
        if ( ! current_user_can( 'manage_options' ) ) {
            wp_send_json_error(
                array( 'message' => __( 'You do not have permission to do this.', 'maple-icons' ) ),
                403
            );
        }

        // 3. Input validation.
        $slug = isset( $_POST['slug'] ) ? sanitize_key( $_POST['slug'] ) : '';

        if ( empty( $slug ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Icon set slug is required.', 'maple-icons' ) )
            );
        }

        if ( ! MI_Icon_Sets::is_valid_slug( $slug ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Invalid icon set.', 'maple-icons' ) )
            );
        }

        // 4. Delete the set.
        $registry = MI_Icon_Registry::get_instance();
        $result   = $registry->delete_set( $slug );

        if ( is_wp_error( $result ) ) {
            wp_send_json_error(
                array( 'message' => $result->get_error_message() )
            );
        }

        wp_send_json_success(
            array(
                'message' => __( 'Icon set deleted successfully.', 'maple-icons' ),
            )
        );
    }

    /**
     * Handle set active request.
     */
    public function handle_set_active() {
        // 1. Nonce verification.
        if ( ! check_ajax_referer( 'mi_admin_nonce', 'nonce', false ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Security check failed.', 'maple-icons' ) ),
                403
            );
        }

        // 2. Capability check.
        if ( ! current_user_can( 'manage_options' ) ) {
            wp_send_json_error(
                array( 'message' => __( 'You do not have permission to do this.', 'maple-icons' ) ),
                403
            );
        }

        // 3. Input validation.
        $slug = isset( $_POST['slug'] ) ? sanitize_key( $_POST['slug'] ) : '';

        // Empty slug is allowed (to deactivate).
        if ( ! empty( $slug ) && ! MI_Icon_Sets::is_valid_slug( $slug ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Invalid icon set.', 'maple-icons' ) )
            );
        }

        // 4. Set active.
        $registry = MI_Icon_Registry::get_instance();
        $result   = $registry->set_active( $slug );

        if ( is_wp_error( $result ) ) {
            wp_send_json_error(
                array( 'message' => $result->get_error_message() )
            );
        }

        wp_send_json_success(
            array(
                'message'    => empty( $slug )
                    ? __( 'No icon set is now active.', 'maple-icons' )
                    : __( 'Icon set activated.', 'maple-icons' ),
                'active_set' => $slug,
            )
        );
    }

    /**
     * Handle get progress request.
     */
    public function handle_get_progress() {
        // 1. Nonce verification.
        if ( ! check_ajax_referer( 'mi_admin_nonce', 'nonce', false ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Security check failed.', 'maple-icons' ) ),
                403
            );
        }

        // 2. Capability check.
        if ( ! current_user_can( 'manage_options' ) ) {
            wp_send_json_error(
                array( 'message' => __( 'You do not have permission to do this.', 'maple-icons' ) ),
                403
            );
        }

        // 3. Input validation.
        $slug = isset( $_POST['slug'] ) ? sanitize_key( $_POST['slug'] ) : '';

        if ( empty( $slug ) || ! MI_Icon_Sets::is_valid_slug( $slug ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Invalid icon set.', 'maple-icons' ) )
            );
        }

        // 4. Get progress.
        $downloader = new MI_Downloader();
        $progress   = $downloader->get_progress( $slug );

        if ( false === $progress ) {
            wp_send_json_success(
                array(
                    'downloading' => false,
                    'completed'   => 0,
                    'total'       => 0,
                )
            );
        }

        wp_send_json_success(
            array(
                'downloading' => true,
                'completed'   => $progress['completed'],
                'total'       => $progress['total'],
                'percentage'  => $progress['total'] > 0
                    ? round( ( $progress['completed'] / $progress['total'] ) * 100 )
                    : 0,
            )
        );
    }

    /**
     * Handle search icons request (for block editor).
     */
    public function handle_search_icons() {
        // 1. Nonce verification.
        if ( ! check_ajax_referer( 'mi_block_nonce', 'nonce', false ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Security check failed.', 'maple-icons' ) ),
                403
            );
        }

        // 2. Capability check (edit_posts for block usage).
        if ( ! current_user_can( 'edit_posts' ) ) {
            wp_send_json_error(
                array( 'message' => __( 'You do not have permission to do this.', 'maple-icons' ) ),
                403
            );
        }

        // 3. Input validation.
        $query  = isset( $_POST['query'] ) ? sanitize_text_field( $_POST['query'] ) : '';
        $style  = isset( $_POST['style'] ) ? sanitize_key( $_POST['style'] ) : '';
        $limit  = isset( $_POST['limit'] ) ? absint( $_POST['limit'] ) : MI_SEARCH_LIMIT;
        $offset = isset( $_POST['offset'] ) ? absint( $_POST['offset'] ) : 0;

        // Limit the limit.
        if ( $limit > 100 ) {
            $limit = 100;
        }

        // 4. Search.
        $registry = MI_Icon_Registry::get_instance();
        $results  = $registry->search_icons( $query, $style, $limit, $offset );

        wp_send_json_success( $results );
    }

    /**
     * Handle get icon SVG request (for block editor).
     */
    public function handle_get_icon_svg() {
        // 1. Nonce verification.
        if ( ! check_ajax_referer( 'mi_block_nonce', 'nonce', false ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Security check failed.', 'maple-icons' ) ),
                403
            );
        }

        // 2. Capability check.
        if ( ! current_user_can( 'edit_posts' ) ) {
            wp_send_json_error(
                array( 'message' => __( 'You do not have permission to do this.', 'maple-icons' ) ),
                403
            );
        }

        // 3. Input validation.
        $slug  = isset( $_POST['set'] ) ? sanitize_key( $_POST['set'] ) : '';
        $style = isset( $_POST['style'] ) ? sanitize_key( $_POST['style'] ) : '';
        $name  = isset( $_POST['name'] ) ? sanitize_file_name( $_POST['name'] ) : '';

        if ( empty( $slug ) || empty( $style ) || empty( $name ) ) {
            wp_send_json_error(
                array( 'message' => __( 'Missing required parameters.', 'maple-icons' ) )
            );
        }

        // 4. Get SVG.
        $registry = MI_Icon_Registry::get_instance();
        $svg      = $registry->get_icon_svg( $slug, $style, $name );

        if ( is_wp_error( $svg ) ) {
            wp_send_json_error(
                array( 'message' => $svg->get_error_message() )
            );
        }

        wp_send_json_success(
            array(
                'svg'   => $svg,
                'set'   => $slug,
                'style' => $style,
                'name'  => $name,
            )
        );
    }
}