<?php
// +----------------------------------------------------------------------
// | YwxApp [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2026-2036 http://ywxapp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Author: ywxapp<admin@ywxapp.cn>
// +----------------------------------------------------------------------
declare (strict_types = 1);

namespace addon\articles\service;

use addon\articles\model\Article;
use addon\articles\model\ArticleComment;
use addon\articles\model\ArticleLike;
use think\facade\Db;

/**
 * 点赞服务（文章 / 评论）
 *
 * 规则：
 *   - 必须登录（游客不允许点赞，避免刷量）
 *   - 同一用户对同一目标只能赞一次（唯一键保证），再次调用即取消
 *   - 计数冗余在目标表的 like_count，取消时用 dec 并保证不为负
 */
class LikeService
{
    /**
     * 文章点赞/取消
     *
     * @return array ['liked' => bool, 'count' => int]
     */
    public static function toggleArticle(int $uid, int $articleId): array
    {
        if ($uid <= 0 || $articleId <= 0) {
            return ['liked' => false, 'count' => 0];
        }

        // 文章必须存在且已发布
        $exists = Article::where('id', $articleId)->where('status', 1)->where('delete_at', 0)->count();
        if (!$exists) {
            return ['liked' => false, 'count' => 0];
        }

        return self::toggle($uid, $articleId, ArticleLike::TYPE_ARTICLE, 'articles_article', $articleId);
    }

    /**
     * 评论点赞/取消
     *
     * @return array ['liked' => bool, 'count' => int]
     */
    public static function toggleComment(int $uid, int $commentId): array
    {
        if ($uid <= 0 || $commentId <= 0) {
            return ['liked' => false, 'count' => 0];
        }

        $exists = ArticleComment::where('id', $commentId)->where('delete_at', 0)->count();
        if (!$exists) {
            return ['liked' => false, 'count' => 0];
        }

        return self::toggle($uid, $commentId, ArticleLike::TYPE_COMMENT, 'articles_comment', $commentId);
    }

    /**
     * 是否已点赞
     */
    public static function isLiked(int $uid, int $targetId, int $type): bool
    {
        if ($uid <= 0) {
            return false;
        }
        return (bool) ArticleLike::where('uid', $uid)
            ->where('target_id', $targetId)
            ->where('type', $type)
            ->count();
    }

    /**
     * 批量判断文章是否已赞（列表/详情页用，避免 N+1）
     *
     * @param array $ids 文章ID数组
     * @return array 已赞的文章ID => true
     */
    public static function likedArticleMap(int $uid, array $ids): array
    {
        if ($uid <= 0 || empty($ids)) {
            return [];
        }
        $rows = ArticleLike::where('uid', $uid)
            ->where('type', ArticleLike::TYPE_ARTICLE)
            ->whereIn('target_id', $ids)
            ->column('target_id');

        $map = [];
        foreach ($rows as $id) {
            $map[(int) $id] = true;
        }
        return $map;
    }

    /**
     * 通用切换逻辑
     */
    private static function toggle(int $uid, int $targetId, int $type, string $countTable, int $targetKey): array
    {
        $record = ArticleLike::where('uid', $uid)
            ->where('target_id', $targetId)
            ->where('type', $type)
            ->find();

        if ($record) {
            // 已赞 → 取消
            $record->delete();
            Db::name($countTable)->where('id', $targetKey)
                ->where('like_count', '>', 0)
                ->dec('like_count')
                ->update();

            return ['liked' => false, 'count' => self::count($countTable, $targetKey)];
        }

        ArticleLike::create([
            'uid'       => $uid,
            'target_id' => $targetId,
            'type'      => $type,
            'create_at' => time(),
        ]);
        Db::name($countTable)->where('id', $targetKey)->inc('like_count')->update();

        return ['liked' => true, 'count' => self::count($countTable, $targetKey)];
    }

    /**
     * 读取最新计数
     */
    private static function count(string $table, int $id): int
    {
        return (int) Db::name($table)->where('id', $id)->value('like_count');
    }
}