<?php
/**
 * AICP REST API endpoints for AI Content Plan communication
 *
 * @package AICP
 */

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

class AICP_REST_API {
    private $namespace = 'aicp/v1';
    private $settings;

    /**
     * Allowed post statuses for publish/update operations
     *
     * @var array
     */
    private $allowed_post_statuses = array('draft', 'pending', 'publish', 'private');

    public function __construct() {
        $this->settings = AICP_Settings::get_instance();
    }

    public function init() {
        add_action('rest_api_init', array($this, 'register_routes'));
    }

    public function register_routes() {
        // Validate consumer credentials endpoint
        register_rest_route($this->namespace, '/validate', array(
            'methods' => 'POST',
            'callback' => array($this, 'validate_credentials'),
            'permission_callback' => array($this, 'check_hmac_signature'),
        ));

        // Get site info for ManagerApp
        register_rest_route($this->namespace, '/site-info', array(
            'methods' => 'GET',
            'callback' => array($this, 'get_site_info'),
            'permission_callback' => array($this, 'check_hmac_signature'),
        ));

        // Publish blog post from AI Content Plan
        register_rest_route($this->namespace, '/publish', array(
            'methods' => 'POST',
            'callback' => array($this, 'publish_post'),
            'permission_callback' => array($this, 'check_hmac_signature'),
        ));

        // Update existing blog post from AI Content Plan
        register_rest_route($this->namespace, '/update', array(
            'methods' => 'POST',
            'callback' => array($this, 'update_post'),
            'permission_callback' => array($this, 'check_hmac_signature'),
        ));

        // Search posts and products
        register_rest_route($this->namespace, '/search', array(
            'methods' => 'GET',
            'callback' => array($this, 'search_content'),
            'permission_callback' => array($this, 'check_hmac_signature'),
        ));

        // Upload media from external URLs
        register_rest_route($this->namespace, '/upload-media', array(
            'methods' => 'POST',
            'callback' => array($this, 'upload_media'),
            'permission_callback' => array($this, 'check_hmac_signature'),
        ));

        // Fetch full content details by IDs
        register_rest_route($this->namespace, '/content', array(
            'methods' => 'POST',
            'callback' => array($this, 'get_content_by_ids'),
            'permission_callback' => array($this, 'check_hmac_signature'),
        ));
    }

    /**
     * HMAC signature verification for incoming requests
     */
    public function check_hmac_signature($request) {
        $consumer_key = $request->get_header('X-AICP-Key');
        $timestamp = $request->get_header('X-AICP-Timestamp');
        $signature = $request->get_header('X-AICP-Signature');

        if (empty($consumer_key) || empty($timestamp) || empty($signature)) {
            return new WP_Error('missing_auth', 'Missing authentication headers', array('status' => 401));
        }

        // Validate timestamp (within 5 minutes)
        $current_time = time();
        if (abs($current_time - intval($timestamp)) > 300) {
            return new WP_Error('expired_request', 'Request timestamp expired', array('status' => 401));
        }

        // Verify consumer key matches
        $stored_key = $this->settings->get_consumer_key();
        if ($consumer_key !== $stored_key) {
            return new WP_Error('invalid_key', 'Invalid consumer key', array('status' => 401));
        }

        // Compute expected signature
        $secret = $this->settings->get_consumer_secret();
        $message = $consumer_key . ':' . $timestamp;
        $expected_signature = base64_encode(hash_hmac('sha256', $message, $secret, true));

        if (!hash_equals($expected_signature, $signature)) {
            return new WP_Error('invalid_signature', 'Invalid signature', array('status' => 401));
        }

        return true;
    }

    /**
     * Validate credentials and return site info
     */
    public function validate_credentials($request) {
        return rest_ensure_response(array(
            'valid' => true,
            'site_url' => get_site_url(),
            'site_name' => get_bloginfo('name'),
            'wordpress_version' => get_bloginfo('version'),
            'plugin_version' => AICP_BRIDGE_VERSION,
        ));
    }

    /**
     * Get site info (categories, authors) for configuration
     */
    public function get_site_info($request) {
        // Get categories
        $categories = get_categories(array('hide_empty' => false));
        $category_list = array_map(function($cat) {
            return array(
                'id' => $cat->term_id,
                'name' => $cat->name,
                'slug' => $cat->slug,
            );
        }, $categories);

        // Get authors
        $authors = get_users(array('role__in' => array('administrator', 'editor', 'author')));
        $author_list = array_map(function($user) {
            return array(
                'id' => $user->ID,
                'name' => $user->display_name,
                'email' => $user->user_email,
            );
        }, $authors);

        // Check WooCommerce status
        $woocommerce_active = class_exists('WooCommerce');
        $product_categories = array();
        if ($woocommerce_active) {
            $product_cats = get_terms(array('taxonomy' => 'product_cat', 'hide_empty' => false));
            if (!is_wp_error($product_cats)) {
                $product_categories = array_map(function($cat) {
                    return array(
                        'id' => $cat->term_id,
                        'name' => $cat->name,
                        'slug' => $cat->slug,
                    );
                }, $product_cats);
            }
        }

        return rest_ensure_response(array(
            'site_url' => get_site_url(),
            'site_name' => get_bloginfo('name'),
            'categories' => $category_list,
            'authors' => $author_list,
            'woocommerce_active' => $woocommerce_active,
            'product_categories' => $product_categories,
        ));
    }

    /**
     * Validate post_status against allowed values, defaulting to 'draft'
     *
     * @param string $status The status to validate
     * @return string A valid post status
     */
    private function validate_post_status($status) {
        if (empty($status) || !in_array($status, $this->allowed_post_statuses, true)) {
            return 'draft';
        }
        return $status;
    }

    /**
     * Publish a blog post from AI Content Plan
     */
    public function publish_post($request) {
        $params = $request->get_json_params();

        // Validate required fields
        if (empty($params['title']) || empty($params['content'])) {
            return new WP_Error('missing_fields', 'Title and content are required', array('status' => 400));
        }

        // Get publishing defaults
        $defaults = $this->settings->get_publishing_defaults();

        // Determine and validate post status
        $raw_status = isset($params['status']) ? $params['status'] : $defaults['post_status'];
        $post_status = $this->validate_post_status($raw_status);

        // Prepare post data
        $post_data = array(
            'post_title' => sanitize_text_field($params['title']),
            'post_content' => wp_kses_post($params['content']),
            'post_status' => $post_status,
            'post_author' => isset($params['author_id']) ? intval($params['author_id']) : $defaults['default_author_id'],
            'post_category' => isset($params['category_ids']) ? array_map('intval', $params['category_ids']) :
                ($defaults['default_category_id'] ? array($defaults['default_category_id']) : array()),
        );

        // Add excerpt if provided
        if (!empty($params['excerpt'])) {
            $post_data['post_excerpt'] = sanitize_textarea_field($params['excerpt']);
        }

        // Add slug if provided
        if (!empty($params['slug'])) {
            $post_data['post_name'] = sanitize_title($params['slug']);
        }

        // Insert the post
        $post_id = wp_insert_post($post_data, true);

        if (is_wp_error($post_id)) {
            return new WP_Error('insert_failed', $post_id->get_error_message(), array('status' => 500));
        }

        // Handle featured image (default to true if not explicitly set)
        $set_featured = isset($defaults['set_featured_image']) ? $defaults['set_featured_image'] : true;
        if (!empty($params['featured_image_url']) && $set_featured) {
            $this->set_featured_image($post_id, $params['featured_image_url'], $params['featured_image_id'] ?? null, $params['featured_image_title'] ?? null);
        }

        // Add meta data
        if (!empty($params['meta_description'])) {
            update_post_meta($post_id, '_yoast_wpseo_metadesc', sanitize_textarea_field($params['meta_description']));
            update_post_meta($post_id, '_aioseop_description', sanitize_textarea_field($params['meta_description']));
        }

        // Mark as created by AI Content Plan
        update_post_meta($post_id, '_aicp_created', true);
        update_post_meta($post_id, '_aicp_blog_post_id', sanitize_text_field($params['blog_post_id'] ?? ''));

        return rest_ensure_response(array(
            'success' => true,
            'post_id' => $post_id,
            'post_url' => get_permalink($post_id),
            'edit_url' => get_edit_post_link($post_id, 'raw'),
        ));
    }

    /**
     * Update an existing blog post from AI Content Plan
     */
    public function update_post($request) {
        $params = $request->get_json_params();

        // Validate required fields
        if (empty($params['post_id'])) {
            return new WP_Error('missing_post_id', 'post_id is required', array('status' => 400));
        }

        $post_id = intval($params['post_id']);

        // Check if the post exists
        $existing_post = get_post($post_id);
        if (!$existing_post) {
            return new WP_Error('post_not_found', 'Post not found', array('status' => 404));
        }

        // Build update data — only include fields that were sent
        $post_data = array(
            'ID' => $post_id,
        );

        if (!empty($params['title'])) {
            $post_data['post_title'] = sanitize_text_field($params['title']);
        }

        if (isset($params['content'])) {
            $post_data['post_content'] = wp_kses_post($params['content']);
        }

        if (!empty($params['excerpt'])) {
            $post_data['post_excerpt'] = sanitize_textarea_field($params['excerpt']);
        }

        if (!empty($params['slug'])) {
            $post_data['post_name'] = sanitize_title($params['slug']);
        }

        if (!empty($params['status'])) {
            $post_data['post_status'] = $this->validate_post_status($params['status']);
        }

        if (!empty($params['category_ids'])) {
            $post_data['post_category'] = array_map('intval', $params['category_ids']);
        }

        if (!empty($params['author_id'])) {
            $post_data['post_author'] = intval($params['author_id']);
        }

        // Update the post
        $result = wp_update_post($post_data, true);

        if (is_wp_error($result)) {
            return new WP_Error('update_failed', $result->get_error_message(), array('status' => 500));
        }

        // Update featured image if provided (default to true if not explicitly set)
        $defaults = $this->settings->get_publishing_defaults();
        $set_featured = isset($defaults['set_featured_image']) ? $defaults['set_featured_image'] : true;
        if (!empty($params['featured_image_url']) && $set_featured) {
            $this->set_featured_image($post_id, $params['featured_image_url'], $params['featured_image_id'] ?? null, $params['featured_image_title'] ?? null);
        }

        // Update meta data
        if (!empty($params['meta_description'])) {
            update_post_meta($post_id, '_yoast_wpseo_metadesc', sanitize_textarea_field($params['meta_description']));
            update_post_meta($post_id, '_aioseop_description', sanitize_textarea_field($params['meta_description']));
        }

        // Mark as updated by AI Content Plan
        update_post_meta($post_id, '_aicp_updated_at', current_time('mysql'));

        return rest_ensure_response(array(
            'success' => true,
            'post_id' => $post_id,
            'post_url' => get_permalink($post_id),
            'edit_url' => get_edit_post_link($post_id, 'raw'),
        ));
    }

    /**
     * Search posts and WooCommerce products
     */
    public function search_content($request) {
        $query = sanitize_text_field($request->get_param('query') ?? '');
        $type = sanitize_text_field($request->get_param('type') ?? 'all');
        $per_page = intval($request->get_param('per_page') ?? 10);
        $per_page = max(1, min($per_page, 50));

        $posts = array();
        $products = array();

        // Search posts
        if ($type === 'all' || $type === 'posts') {
            $post_args = array(
                'post_type' => 'post',
                'post_status' => 'publish',
                'posts_per_page' => $per_page,
                's' => $query,
            );
            $found_posts = get_posts($post_args);

            foreach ($found_posts as $post) {
                $posts[] = array(
                    'id' => $post->ID,
                    'title' => $post->post_title,
                    'url' => get_permalink($post->ID),
                    'excerpt' => wp_trim_words($post->post_excerpt ?: $post->post_content, 30, '...'),
                    'date' => $post->post_date,
                    'type' => 'post',
                );
            }
        }

        // Search products (if WooCommerce is active)
        if (($type === 'all' || $type === 'products') && class_exists('WooCommerce')) {
            $product_args = array(
                's' => $query,
                'limit' => $per_page,
                'status' => 'publish',
            );
            $found_products = wc_get_products($product_args);

            foreach ($found_products as $product) {
                $image_id = $product->get_image_id();
                $image_url = $image_id ? wp_get_attachment_image_url($image_id, 'thumbnail') : null;

                $products[] = array(
                    'id' => $product->get_id(),
                    'title' => $product->get_name(),
                    'url' => $product->get_permalink(),
                    'excerpt' => wp_trim_words($product->get_short_description(), 30, '...'),
                    'price' => $product->get_price(),
                    'regularPrice' => $product->get_regular_price(),
                    'salePrice' => $product->get_sale_price(),
                    'imageUrl' => $image_url,
                    'type' => 'product',
                );
            }
        }

        return rest_ensure_response(array(
            'posts' => $posts,
            'products' => $products,
        ));
    }

    /**
     * Fetch full content details by IDs
     */
    public function get_content_by_ids($request) {
        $params = $request->get_json_params();
        $post_ids = isset($params['post_ids']) ? array_map('intval', $params['post_ids']) : array();
        $product_ids = isset($params['product_ids']) ? array_map('intval', $params['product_ids']) : array();

        $posts = array();
        $products = array();

        // Fetch posts
        foreach ($post_ids as $post_id) {
            $post = get_post($post_id);
            if (!$post || $post->post_status !== 'publish') continue;

            $categories = wp_get_post_categories($post_id, array('fields' => 'names'));
            $tags = wp_get_post_tags($post_id, array('fields' => 'names'));

            $posts[] = array(
                'id' => $post->ID,
                'title' => $post->post_title,
                'content' => $post->post_content,
                'excerpt' => $post->post_excerpt,
                'url' => get_permalink($post->ID),
                'categories' => $categories ?: array(),
                'tags' => $tags ?: array(),
            );
        }

        // Fetch products (if WooCommerce is active)
        if (!empty($product_ids) && class_exists('WooCommerce')) {
            foreach ($product_ids as $product_id) {
                $product = wc_get_product($product_id);
                if (!$product || $product->get_status() !== 'publish') continue;

                $image_id = $product->get_image_id();
                $image_url = $image_id ? wp_get_attachment_image_url($image_id, 'full') : null;
                $cat_ids = $product->get_category_ids();
                $categories = array();
                foreach ($cat_ids as $cat_id) {
                    $term = get_term($cat_id, 'product_cat');
                    if ($term && !is_wp_error($term)) {
                        $categories[] = $term->name;
                    }
                }

                $products[] = array(
                    'id' => $product->get_id(),
                    'title' => $product->get_name(),
                    'description' => $product->get_description(),
                    'shortDescription' => $product->get_short_description(),
                    'url' => $product->get_permalink(),
                    'price' => $product->get_price(),
                    'regularPrice' => $product->get_regular_price(),
                    'salePrice' => $product->get_sale_price(),
                    'sku' => $product->get_sku(),
                    'imageUrl' => $image_url,
                    'categories' => $categories,
                );
            }
        }

        return rest_ensure_response(array(
            'posts' => $posts,
            'products' => $products,
        ));
    }

    /**
     * Upload media from external URLs to WordPress media library
     */
    public function upload_media($request) {
        $params = $request->get_json_params();

        if (empty($params['images']) || !is_array($params['images'])) {
            return new WP_Error('missing_images', 'images array is required', array('status' => 400));
        }

        require_once(ABSPATH . 'wp-admin/includes/media.php');
        require_once(ABSPATH . 'wp-admin/includes/file.php');
        require_once(ABSPATH . 'wp-admin/includes/image.php');

        $media = array();

        foreach ($params['images'] as $image) {
            if (empty($image['url'])) {
                continue;
            }

            $image_id = !empty($image['image_id']) ? $image['image_id'] : null;
            $title = !empty($image['title']) ? sanitize_text_field($image['title']) : null;

            // Dedup: if this image was already uploaded, return the existing WP URL
            if ($image_id) {
                // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key, WordPress.DB.SlowDBQuery.slow_db_query_meta_value -- Required for image deduplication
                $existing = get_posts(array(
                    'post_type' => 'attachment',
                    'meta_key' => '_aicp_source_image_id',
                    'meta_value' => $image_id,
                    'posts_per_page' => 1,
                    'fields' => 'ids',
                ));
                if (!empty($existing)) {
                    $media[] = array(
                        'media_id' => $existing[0],
                        'url' => wp_get_attachment_url($existing[0]),
                    );
                    continue;
                }
            }

            $media_id = media_sideload_image($image['url'], 0, $title, 'id');

            if (is_wp_error($media_id)) {
                $media[] = array(
                    'error' => $media_id->get_error_message(),
                    'url' => $image['url'],
                );
            } else {
                // Set the attachment title to the original filename (without extension)
                if ($title) {
                    wp_update_post(array(
                        'ID' => $media_id,
                        'post_title' => $title,
                    ));
                }

                // Store source image ID for deduplication on future republishes
                if ($image_id) {
                    update_post_meta($media_id, '_aicp_source_image_id', $image_id);
                }

                update_post_meta($media_id, '_aicp_uploaded_by', 'aicontentplan.com');

                $media[] = array(
                    'media_id' => $media_id,
                    'url' => wp_get_attachment_url($media_id),
                );
            }
        }

        return rest_ensure_response(array(
            'media' => $media,
        ));
    }

    /**
     * Set featured image from URL.
     * Skips re-upload if the current thumbnail was already sideloaded from the same URL.
     */
    private function set_featured_image($post_id, $image_url, $image_id = null, $title = null) {
        // Dedup: skip re-upload if current thumbnail came from the same source image
        $current_thumbnail_id = get_post_thumbnail_id($post_id);
        if ($current_thumbnail_id && $image_id) {
            $existing_image_id = get_post_meta($current_thumbnail_id, '_aicp_source_image_id', true);
            if ($existing_image_id === $image_id) {
                return; // Same image, skip re-upload
            }
        }

        require_once(ABSPATH . 'wp-admin/includes/media.php');
        require_once(ABSPATH . 'wp-admin/includes/file.php');
        require_once(ABSPATH . 'wp-admin/includes/image.php');

        $attachment_id = media_sideload_image($image_url, $post_id, $title, 'id');

        if (is_wp_error($attachment_id)) {
            return;
        }

        // Set the attachment title to the original filename (without extension)
        if ($title) {
            wp_update_post(array(
                'ID' => $attachment_id,
                'post_title' => sanitize_text_field($title),
            ));
        }

        set_post_thumbnail($post_id, $attachment_id);

        // Store source image ID for deduplication on future updates
        if ($image_id) {
            update_post_meta($attachment_id, '_aicp_source_image_id', $image_id);
        }

        update_post_meta($attachment_id, '_aicp_uploaded_by', 'aicontentplan.com');
    }
}