<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Forum;

defined('ABSPATH') || exit;

class ScoreService {

    /** @var Forum */
    private $forum;

    public function __construct($forum) {
        $this->forum = $forum;
    }

    // ================================================================
    // Favorite (§7.3)
    // ================================================================

    public function is_favorited(int $user_id, int $topic_id): bool {
        if ($user_id <= 0) {
            return false;
        }
        $favorites = get_user_meta($user_id, 'aksrt_favorite_forum_posts', true);
        $favorites = is_array($favorites) ? $favorites : [];
        return in_array($topic_id, $favorites, true);
    }

    public function toggle_favorite(int $user_id, int $topic_id) {
        if ($user_id <= 0) {
            return new \WP_Error('not_logged_in', __('请先登录', 'aksrt'));
        }

        $post = get_post($topic_id);
        if (!$post || $post->post_type !== 'aksrt_forum_topic') {
            return new \WP_Error('invalid_topic', __('帖子不存在', 'aksrt'));
        }

        $favorites = get_user_meta($user_id, 'aksrt_favorite_forum_posts', true);
        $favorites = is_array($favorites) ? $favorites : [];
        $was_favorited = in_array($topic_id, $favorites, true);

        if ($was_favorited) {
            $favorites = array_values(array_diff($favorites, [$topic_id]));
        } else {
            $favorites[] = $topic_id;
        }

        update_user_meta($user_id, 'aksrt_favorite_forum_posts', $favorites);

        $count = (int) get_post_meta($topic_id, '_aksrt_favorite_count', true);
        $count = $was_favorited ? max(0, $count - 1) : $count + 1;
        update_post_meta($topic_id, '_aksrt_favorite_count', $count);
        $this->refresh_recommend_score($topic_id);

        return [
            'favorited' => !$was_favorited,
            'count'     => $count,
            'message'   => $was_favorited
                ? __('已取消收藏', 'aksrt')
                : __('收藏成功', 'aksrt'),
        ];
    }

    // ================================================================
    // Score (§7.3)
    // ================================================================

    public function score_topic(int $user_id, int $topic_id, int $amount) {
        if ($user_id <= 0) {
            return new \WP_Error('not_logged_in', __('请先登录', 'aksrt'));
        }

        $post = get_post($topic_id);
        if (!$post || $post->post_type !== 'aksrt_forum_topic') {
            return new \WP_Error('invalid_topic', __('帖子不存在', 'aksrt'));
        }

        if ($amount === 0) {
            return new \WP_Error('invalid_amount', __('评分值不能为零', 'aksrt'));
        }

        $author_id = (int) $post->post_author;
        if ($author_id === $user_id) {
            return new \WP_Error('self_score', __('不能给自己的帖子评分', 'aksrt'));
        }

        $config = $this->forum->get_config();
        $max_extra = (int) ($config['post_page']['score_extra_max'] ?? 5);
        $max_deduct = (int) ($config['post_page']['score_deduct_max'] ?? 3);

        if ($amount > 0 && $amount > $max_extra) {
            $amount = $max_extra;
        }
        if ($amount < 0 && abs($amount) > $max_deduct) {
            $amount = -$max_deduct;
        }

        $detail = get_post_meta($topic_id, '_aksrt_score_detail', true);
        $detail = is_array($detail) ? $detail : [];

        $user_key = (string) $user_id;
        if (isset($detail[$user_key])) {
            return new \WP_Error('already_scored', __('你已经对该帖评过分', 'aksrt'));
        }

        $detail[$user_key] = [
            'amount' => $amount,
            'time'   => current_time('mysql'),
        ];
        update_post_meta($topic_id, '_aksrt_score_detail', $detail);

        $total = (int) get_post_meta($topic_id, '_aksrt_score', true);
        $total += $amount;
        update_post_meta($topic_id, '_aksrt_score', $total);
        do_action('aksrt_forum_topic_scored', $topic_id, (int) $author_id, (float) $amount);

        $reputation = (int) get_user_meta($author_id, 'aksrt_reputation', true);
        $reputation += $amount;
        update_user_meta($author_id, 'aksrt_reputation', $reputation);

        if ($amount > 0) {
            $credits_amount = (int) ($config['credits']['score_extra'] ?? 3);
            if ($credits_amount > 0) {
                if (class_exists('\AKSRT\Credits\PointsFree')) {
                    \AKSRT\Credits\PointsFree::grant($author_id, 'bbs_score_extra', $credits_amount, [
                        'type' => 'post',
                        'id'   => $topic_id,
                    ]);
                } elseif (class_exists('\AKSRT\Credits\Credits')) {
                    $daily = $this->today_credits_count($author_id, 'forum_score_extra');
                    $daily_max = (int) ($config['credits']['daily_max'] ?? 50);
                    if ($daily < $daily_max) {
                        \AKSRT\Credits\Credits::add($author_id, $credits_amount, 'forum_score_extra', sprintf(
                            __('帖子「%s」被加分', 'aksrt'),
                            get_the_title($topic_id)
                        ));
                    }
                }
            }
        }

        $this->refresh_recommend_score($topic_id);
        $this->notify_topic_scored($topic_id, $user_id, $amount);

        return [
            'score'   => $total,
            'message' => $amount > 0
                ? __('加分成功', 'aksrt')
                : __('减分成功', 'aksrt'),
        ];
    }

    public function get_score_detail(int $topic_id): array {
        $detail = get_post_meta($topic_id, '_aksrt_score_detail', true);
        $detail = is_array($detail) ? $detail : [];

        $entries = [];
        foreach ($detail as $uid => $entry) {
            $user = get_userdata((int) $uid);
            $entries[] = [
                'user_id'      => (int) $uid,
                'display_name' => $user ? $user->display_name : '',
                'amount'       => (int) ($entry['amount'] ?? 0),
                'time'         => (string) ($entry['time'] ?? ''),
            ];
        }

        return $entries;
    }

    // ================================================================
    // Recommend score (§7.3)
    // ================================================================

    public function calculate_recommend_score(int $topic_id): float {
        $post = get_post($topic_id);
        if (!$post || $post->post_type !== 'aksrt_forum_topic') {
            return 0.0;
        }

        $views = (int) get_post_meta($topic_id, '_aksrt_views', true);
        $favorites = (int) get_post_meta($topic_id, '_aksrt_favorite_count', true);
        $comments = (int) get_comments([
            'post_id' => $topic_id,
            'count'   => true,
            'status'  => 'approve',
        ]);
        $score = (int) get_post_meta($topic_id, '_aksrt_score', true);

        $w_views = 1.0;
        $w_favorites = 5.0;
        $w_comments = 3.0;
        $w_score = 2.0;

        $raw = ($views * $w_views)
             + ($favorites * $w_favorites)
             + ($comments * $w_comments)
             + (max(0, $score) * $w_score);

        $post_time = strtotime($post->post_date_gmt);
        $age_hours = max(1, (time() - $post_time) / 3600);
        $decay = pow($age_hours, 1.5);
        $recommend = ($raw + 1) / $decay * 10000;

        return round($recommend, 2);
    }

    public function refresh_recommend_score(int $topic_id): float {
        $score = $this->calculate_recommend_score($topic_id);
        update_post_meta($topic_id, '_aksrt_recommend_score', $score);
        $this->maybe_reward_hot_topic($topic_id, $score);
        return $score;
    }

    private function maybe_reward_hot_topic(int $topic_id, float $score): void {
        $config = $this->forum->get_config();
        $hot_threshold = (float) ($config['post_page']['hot_recommend_threshold']
            ?? $config['credits']['hot_recommend_threshold']
            ?? $config['other']['hot_topic_threshold']
            ?? 500);
        if ($hot_threshold <= 0) {
            $hot_threshold = 500.0;
        }
        if ($score < $hot_threshold) {
            return;
        }
        if (get_post_meta($topic_id, '_aksrt_hot_rewarded', true)) {
            return;
        }
        $post = get_post($topic_id);
        if (!$post || $post->post_type !== 'aksrt_forum_topic') {
            return;
        }
        $author_id = (int) $post->post_author;
        if ($author_id <= 0) {
            return;
        }
        do_action('aksrt_forum_topic_hot', $topic_id, (int) $author_id);
        update_post_meta($topic_id, '_aksrt_hot_rewarded', '1');
        $amount = (int) ($config['credits']['posts_hot'] ?? 5);
        if ($amount > 0) {
            if (class_exists('\AKSRT\Credits\PointsFree')) {
                \AKSRT\Credits\PointsFree::grant($author_id, 'bbs_posts_hot', $amount, [
                    'type' => 'post',
                    'id'   => $topic_id,
                ]);
            } elseif (class_exists('\AKSRT\Credits\Credits')) {
                \AKSRT\Credits\Credits::add($author_id, $amount, 'forum_hot_topic', [
                    'type' => 'post', 'id' => $topic_id,
                ]);
            }
        }
        $this->notify($author_id, 'hot', sprintf(
            __('你的帖子「%s」成为热帖！', 'aksrt'), get_the_title($topic_id)
        ), [
            'title'      => __('热帖通知', 'aksrt'),
            'target_url' => get_permalink($topic_id),
        ]);
    }

    public function batch_refresh_recommend_scores(int $limit = 100): int {
        $query = new \WP_Query([
            'post_type'      => 'aksrt_forum_topic',
            'post_status'    => 'publish',
            'posts_per_page' => $limit,
            'orderby'        => 'modified',
            'order'          => 'DESC',
            'fields'         => 'ids',
            'no_found_rows'  => true,
        ]);

        $count = 0;
        foreach ($query->posts as $post_id) {
            $this->refresh_recommend_score((int) $post_id);
            $count++;
        }

        return $count;
    }

    public function maybe_refresh_recommend_on_view(): void {
        if (!is_singular('aksrt_forum_topic')) {
            return;
        }
        $topic_id = get_the_ID();
        if (!$topic_id) {
            return;
        }
        $last = (int) get_post_meta($topic_id, '_aksrt_recommend_refreshed', true);
        if ((time() - $last) > 300) {
            $this->refresh_recommend_score($topic_id);
            update_post_meta($topic_id, '_aksrt_recommend_refreshed', time());
        }
    }

    private function get_bbs_type_label(string $bbs_type): string {
        $config = $this->forum->get_config();
        $names = $config['names'] ?? [];
        $map = [
            Forum::BBS_TYPE_STANDARD => $names['posts'] ?? __('帖子', 'aksrt'),
            Forum::BBS_TYPE_QUESTION => $names['question_badge'] ?? __('提问', 'aksrt'),
        ];
        return $map[$bbs_type] ?? $map[Forum::BBS_TYPE_STANDARD];
    }

    private function get_question_status_label(int $status): string {
        $config = $this->forum->get_config();
        $names = $config['names'] ?? [];
        return $status === Forum::QUESTION_SOLVED
            ? ($names['question_ok_badge'] ?? __('已解决', 'aksrt'))
            : ($names['question_badge'] ?? __('提问', 'aksrt'));
    }

    // ================================================================
    // Notifications (§7.8)
    // ================================================================

    public function notify(int $user_id, string $type, string $content, array $data = []): void {
        if ($user_id <= 0 || !class_exists('\AKSRT\Messages\Message')) {
            return;
        }
        \AKSRT\Messages\Message::get_instance()->send($user_id, $type, $content, $data);
    }

    public function notify_topic_pending(int $topic_id, int $author_id): void {
        $title = get_the_title($topic_id);
        $config = $this->forum->get_config();
        $admin_users = $config['admin_users'] ?? [];

        foreach ($admin_users as $admin_id) {
            $this->notify((int) $admin_id, 'posts', sprintf(
                __('帖子「%s」待审核', 'aksrt'), $title
            ), [
                'title'      => __('待审核帖子', 'aksrt'),
                'target_url' => get_permalink($topic_id),
            ]);
        }
    }

    public function notify_moderation_result(int $topic_id, string $action, int $operator_id): void {
        $post = get_post($topic_id);
        if (!$post) return;
        $author_id = (int) $post->post_author;
        if ($author_id <= 0 || $author_id === $operator_id) return;

        $title = get_the_title($topic_id);
        $action_labels = [
            'review'   => __('审核状态已变更', 'aksrt'),
            'sticky'   => __('置顶状态已变更', 'aksrt'),
            'featured' => __('精华状态已变更', 'aksrt'),
            'locked'   => __('锁定状态已变更', 'aksrt'),
            'close'    => __('帖子已关闭', 'aksrt'),
            'hide'     => __('帖子已隐藏', 'aksrt'),
            'delete'   => __('帖子已删除', 'aksrt'),
            'undelete' => __('帖子已恢复', 'aksrt'),
        ];

        if ($action === 'review') {
            $review_status = (string) get_post_meta($topic_id, '_aksrt_review_status', true);
            if ($review_status === Forum::REVIEW_REJECTED) {
                $action_labels['review'] = __('审核未通过', 'aksrt');
            } elseif ($review_status === Forum::REVIEW_PENDING) {
                $action_labels['review'] = __('已转为待审核', 'aksrt');
            } elseif ($review_status === Forum::REVIEW_APPROVED) {
                $action_labels['review'] = __('审核已通过', 'aksrt');
            }
        }

        $label = $action_labels[$action] ?? __('治理动作已执行', 'aksrt');
        $target_url = $action === 'delete' ? aksrt_get_forum_home_url() : get_permalink($topic_id);
        $payload = [
            'title'      => $label,
            'target_url' => $target_url,
        ];

        $note = (string) get_post_meta($topic_id, '_aksrt_moderation_note', true);
        if ($note !== '') {
            $payload['reason'] = $note;
        }

        $this->notify($author_id, 'system', sprintf(
            __('你的帖子「%1$s」%2$s', 'aksrt'), $title, $label
        ), $payload);
    }

    public function notify_topic_reply(int $topic_id, int $commenter_id): void {
        $post = get_post($topic_id);
        if (!$post) return;
        $author_id = (int) $post->post_author;
        if ($author_id <= 0 || $author_id === $commenter_id) return;

        $commenter = get_userdata($commenter_id);
        $name = $commenter ? $commenter->display_name : __('有人', 'aksrt');
        $title = get_the_title($topic_id);

        $this->notify($author_id, 'comment', sprintf(
            __('%1$s 回复了你的帖子「%2$s」', 'aksrt'), $name, $title
        ), [
            'title'      => __('新回复', 'aksrt'),
            'target_url' => get_permalink($topic_id),
        ]);
    }

    public function notify_topic_scored(int $topic_id, int $scorer_id, int $amount): void {
        $post = get_post($topic_id);
        if (!$post) return;
        $author_id = (int) $post->post_author;
        if ($author_id <= 0 || $author_id === $scorer_id) return;

        $title = get_the_title($topic_id);
        $this->notify($author_id, 'system', sprintf(
            __('你的帖子「%1$s」被%2$s %3$d 分', 'aksrt'),
            $title,
            $amount > 0 ? __('加', 'aksrt') : __('减', 'aksrt'),
            abs($amount)
        ), [
            'title'      => $amount > 0 ? __('帖子被加分', 'aksrt') : __('帖子被减分', 'aksrt'),
            'target_url' => get_permalink($topic_id),
        ]);
    }

    // ================================================================
    // Private helpers
    // ================================================================

    private function today_credits_count(int $user_id, string $reason): int {
        if (!class_exists('\AKSRT\Core\DBMigrator') || $user_id <= 0) {
            return 0;
        }

        $table = \AKSRT\Core\DBMigrator::table('credit_log');
        if (!$table) {
            return 0;
        }

        global $wpdb;
        $today = current_time('Y-m-d');
        return (int) $wpdb->get_var($wpdb->prepare(
            "SELECT COUNT(*) FROM {$table} WHERE user_id = %d AND reason = %s AND DATE(created_at) = %s",
            $user_id, $reason, $today
        ));
    }
}