<?php
/**
 * AKSRT Front Submit — 前台投稿系统骨架
 *
 * 提供前台投稿、草稿保存、编辑回退能力。
 * 当前为骨架实现，后续 Phase 补充完整投稿产品线。
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Front_Submit {

    private static $instance = null;

    public static function get_instance(): self {
        if (null === self::$instance) self::$instance = new self();
        return self::$instance;
    }

    public function init(): void {
        add_action('wp_ajax_aksrt_submit_post', [$this, 'ajax_submit_post']);
        add_action('wp_ajax_aksrt_save_draft', [$this, 'ajax_save_draft']);
        add_action('wp_ajax_aksrt_update_post', [$this, 'ajax_update_post']);
        add_action('wp_ajax_aksrt_delete_draft', [$this, 'ajax_delete_draft']);
    }

    /**
     * 检查用户是否可以投稿
     *
     * @param int|null $user_id User ID (null = current user).
     * @return bool
     */
    public function can_submit(?int $user_id = null): bool {
        if ($user_id === null) {
            $user_id = get_current_user_id();
        }
        if ($user_id <= 0) return false;

        // Read submission settings
        $submit_settings = [];
        if (class_exists('AKSRT_Settings')) {
            $submit_settings = AKSRT_Settings::get_value('post_list.submit', []);
        }

        // Check if front submission is enabled (fix: was checking !empty && empty which is always false)
        if (isset($submit_settings['submit_enabled']) && !$submit_settings['submit_enabled']) {
            return false;
        }

        // Role whitelist: if configured, user must have one of the allowed roles
        $allowed_roles = $submit_settings['submit_roles'] ?? [];
        if (!empty($allowed_roles)) {
            $user = get_userdata($user_id);
            if (!$user) return false;
            $user_roles = $user->roles;
            if (empty(array_intersect($user_roles, (array) $allowed_roles))) {
                // Also allow administrators
                if (!in_array('administrator', $user_roles, true)) {
                    return false;
                }
            }
        }

        // Credits threshold: if configured, user must have enough credits
        $min_credits = (int) ($submit_settings['submit_min_credits'] ?? 0);
        if ($min_credits > 0 && class_exists('AKSRT_Credits')) {
            $balance = AKSRT_Credits::balance($user_id);
            if ($balance < $min_credits) {
                return false;
            }
        }

        // Default: allow users with edit_posts capability (or any logged-in user if submission is enabled)
        return user_can($user_id, 'edit_posts') || !empty($submit_settings['submit_enabled']);
    }

    /**
     * 提交文章
     *
     * @param array $data 投稿数据
     * @return array{success: bool, post_id?: int, message: string}
     */
    public function submit(array $data): array {
        $user_id = get_current_user_id();
        if (!$this->can_submit($user_id)) {
            return ['success' => false, 'message' => __('没有投稿权限', 'aksrt')];
        }

        $title = sanitize_text_field((string) ($data['title'] ?? ''));
        $content = wp_kses_post((string) ($data['content'] ?? ''));
        $category = (int) ($data['category'] ?? 0);
        $tags = sanitize_text_field((string) ($data['tags'] ?? ''));
        $status = sanitize_key((string) ($data['status'] ?? 'pending'));

        if ($title === '') {
            return ['success' => false, 'message' => __('标题不能为空', 'aksrt')];
        }

        $valid_statuses = ['pending', 'draft', 'publish'];
        if (!in_array($status, $valid_statuses, true)) {
            $status = 'pending';
        }

        // Determine review policy: if review is not required and user can publish, auto-publish
        if ($status === 'pending') {
            $submit_settings = [];
            if (class_exists('AKSRT_Settings')) {
                $submit_settings = AKSRT_Settings::get_value('post_list.submit', []);
            }
            $review_required = $submit_settings['review_required'] ?? true;
            $skip_moderation = false;
            if (class_exists('AKSRT_Settings')) {
                $all = AKSRT_Settings::get_all();
                $skip_moderation = !empty($all['skip_submit_moderation']);
            }

            if (!$review_required || $skip_moderation) {
                // Auto-publish if user has publish_posts capability
                if (user_can($user_id, 'publish_posts')) {
                    $status = 'publish';
                }
            }
        }

        $post_data = [
            'post_title'   => $title,
            'post_content' => $content,
            'post_status'  => $status,
            'post_author'  => $user_id,
            'post_type'    => 'post',
        ];

        $post_id = wp_insert_post($post_data, true);

        if (is_wp_error($post_id)) {
            return ['success' => false, 'message' => $post_id->get_error_message()];
        }

        // 设置分类
        if ($category > 0) {
            wp_set_post_categories($post_id, [$category]);
        }

        // 设置标签
        if ($tags !== '') {
            $tag_names = array_map('trim', explode(',', $tags));
            wp_set_post_tags($post_id, $tag_names);
        }

        // 设置封面图
        $thumbnail_url = sanitize_url((string) ($data['thumbnail'] ?? ''));
        if ($thumbnail_url !== '') {
            $this->set_thumbnail_from_url($post_id, $thumbnail_url);
        }

        // 设置专题 (topics taxonomy)
        $this->apply_topics_and_filters($post_id, $data);

        return [
            'success' => true,
            'post_id' => $post_id,
            'message' => $status === 'draft' ? __('草稿已保存', 'aksrt') : __('投稿已提交，等待审核', 'aksrt'),
        ];
    }

    /**
     * 更新文章
     */
    public function update(int $post_id, array $data): array {
        $user_id = get_current_user_id();
        if ($user_id <= 0) {
            return ['success' => false, 'message' => __('请先登录', 'aksrt')];
        }

        $post = get_post($post_id);
        if (!$post || (int) $post->post_author !== $user_id) {
            return ['success' => false, 'message' => __('没有编辑权限', 'aksrt')];
        }

        $update_data = ['ID' => $post_id];

        if (isset($data['title'])) {
            $update_data['post_title'] = sanitize_text_field($data['title']);
        }
        if (isset($data['content'])) {
            $update_data['post_content'] = wp_kses_post($data['content']);
        }
        if (isset($data['status'])) {
            $update_data['post_status'] = sanitize_key($data['status']);
        }

        $result = wp_update_post($update_data, true);

        if (is_wp_error($result)) {
            return ['success' => false, 'message' => $result->get_error_message()];
        }

        // Update category
        $category = (int) ($data['category'] ?? 0);
        if ($category > 0) {
            wp_set_post_categories($post_id, [$category]);
        }

        // Update tags
        if (isset($data['tags'])) {
            $tags = sanitize_text_field((string) $data['tags']);
            if ($tags !== '') {
                $tag_names = array_map('trim', explode(',', $tags));
                wp_set_post_tags($post_id, $tag_names);
            } else {
                wp_set_post_tags($post_id, []);
            }
        }

        // Update thumbnail
        if (isset($data['thumbnail'])) {
            $thumbnail_url = sanitize_url((string) $data['thumbnail']);
            if ($thumbnail_url !== '') {
                $this->set_thumbnail_from_url($post_id, $thumbnail_url);
            }
        }

        // Update topics + custom filter meta
        $this->apply_topics_and_filters($post_id, $data);

        return ['success' => true, 'post_id' => $post_id, 'message' => __('已更新', 'aksrt')];
    }

    /**
     * 从 URL 设置封面图
     *
     * Downloads the image from the given URL, sideloads it into the media library,
     * and sets it as the post's featured image.
     *
     * @param int    $post_id Post ID.
     * @param string $url     Image URL.
     */
    private function set_thumbnail_from_url(int $post_id, string $url): void {
        if ($url === '' || !filter_var($url, FILTER_VALIDATE_URL)) {
            return;
        }

        // Require media handling functions
        if (!function_exists('media_sideload_image')) {
            require_once ABSPATH . 'wp-admin/includes/media.php';
            require_once ABSPATH . 'wp-admin/includes/file.php';
            require_once ABSPATH . 'wp-admin/includes/image.php';
        }

        // Check if URL is an image
        $ext = strtolower(pathinfo(parse_url($url, PHP_URL_PATH) ?? '', PATHINFO_EXTENSION));
        $allowed_exts = ['jpg', 'jpeg', 'png', 'gif', 'webp', 'svg'];
        if ($ext !== '' && !in_array($ext, $allowed_exts, true)) {
            return;
        }

        // Sideload the image
        $attachment_id = media_sideload_image($url, $post_id, '', 'id');

        if (!is_wp_error($attachment_id)) {
            set_post_thumbnail($post_id, $attachment_id);
        } elseif (defined('WP_DEBUG') && WP_DEBUG) {
            error_log(sprintf('[AKSRT Front Submit] Failed to set thumbnail for post %d: %s — %s', $post_id, $url, $attachment_id->get_error_message()));
        }
    }

    /**
     * AJAX 提交投稿
     */
    public function ajax_submit_post(): void {
        check_ajax_referer('aksrt_submit', '_nonce');

        $data = $_POST;
        $result = $this->submit($data);

        if ($result['success']) {
            wp_send_json_success($result);
        }

        wp_send_json_error($result);
    }

    /**
     * AJAX 保存草稿
     */
    public function ajax_save_draft(): void {
        check_ajax_referer('aksrt_submit', '_nonce');

        $_POST['status'] = 'draft';
        $data = $_POST;
        $result = $this->submit($data);

        if ($result['success']) {
            wp_send_json_success($result);
        }

        wp_send_json_error($result);
    }

    /**
     * AJAX 更新文章
     */
    public function ajax_update_post(): void {
        check_ajax_referer('aksrt_submit', '_nonce');

        $post_id = (int) ($_POST['post_id'] ?? 0);
        if ($post_id <= 0) {
            wp_send_json_error(['message' => __('文章 ID 无效', 'aksrt')]);
        }

        $result = $this->update($post_id, $_POST);

        if ($result['success']) {
            wp_send_json_success($result);
        }

        wp_send_json_error($result);
    }

    /**
     * AJAX handler: delete draft
     */
    public function ajax_delete_draft(): void {
        check_ajax_referer('aksrt_submit', '_nonce');

        $user_id = get_current_user_id();
        if ($user_id <= 0) {
            wp_send_json_error(['message' => __('请先登录', 'aksrt')]);
        }

        // Fix: JS sends 'draft_id', not 'post_id'
        $post_id = (int) (($_POST['draft_id'] ?? $_POST['post_id']) ?? 0);
        if ($post_id <= 0) {
            wp_send_json_error(['message' => __('草稿 ID 无效', 'aksrt')]);
        }

        $post = get_post($post_id);
        if (!$post || (int) $post->post_author !== $user_id) {
            wp_send_json_error(['message' => __('没有删除权限', 'aksrt')]);
        }

        if ($post->post_status !== 'draft') {
            wp_send_json_error(['message' => __('只能删除草稿', 'aksrt')]);
        }

        $result = wp_delete_post($post_id, true);
        if ($result) {
            wp_send_json_success(['message' => __('草稿已删除', 'aksrt')]);
        }

        wp_send_json_error(['message' => __('删除失败', 'aksrt')]);
    }

    /**
     * Apply topics taxonomy terms and custom filter meta values to a post.
     *
     * Reads 'topics' array and 'cf_{dim_key}' scalar values from $data.
     * Custom filter keys are validated against the configured dimension definitions.
     *
     * @param int   $post_id Post ID.
     * @param array $data    Submission data ($_POST).
     */
    private function apply_topics_and_filters(int $post_id, array $data): void {
        // Topics taxonomy
        if (isset($data['topics']) && is_array($data['topics']) && taxonomy_exists('topics')) {
            $topic_ids = array_map('absint', $data['topics']);
            $topic_ids = array_filter($topic_ids);
            wp_set_object_terms($post_id, array_values($topic_ids), 'topics');
        }

        // Custom filter meta values (_aksrt_cf_{dim_key})
        foreach ($data as $key => $val) {
            if (strpos($key, 'cf_') !== 0) {
                continue;
            }
            $dim_key = sanitize_key(substr($key, 3));
            if ($dim_key === '') {
                continue;
            }
            $cf_val = sanitize_key((string) $val);
            $meta_key = '_aksrt_cf_' . $dim_key;
            if ($cf_val !== '') {
                update_post_meta($post_id, $meta_key, $cf_val);
            } else {
                delete_post_meta($post_id, $meta_key);
            }
        }
    }
}