<?php
declare (strict_types = 1);

namespace app\model\api;

use library\basic\BaseModel;
use library\traits\ModelTrait;
use think\Model;

/**
 * 用户会话关系模型
 * @mixin \think\Model
 */
class ChatUserRelation extends BaseModel
{
    use ModelTrait;
    
    protected $name = 'chat_user_relation';
    
    // 未扣次数
    const NOT_DEDUCT = 0;
    // 已扣次数
    const IS_DEDUCT = 1;
    
    /**
     * 获取或创建会话关系
     * @param int $userId 用户ID
     * @param int $toUserId 对方用户ID
     * @return self|null
     */
    public static function getOrCreate(int $userId, int $toUserId): ?self
    {
        // 确保 userId < toUserId，保持一致性
        if ($userId > $toUserId) {
            [$userId, $toUserId] = [$toUserId, $userId];
        }
        
        $relation = self::where('user_id', $userId)
            ->where('to_user_id', $toUserId)
            ->find();
        
        if (!$relation) {
            $relation = self::create([
                'user_id' => $userId,
                'to_user_id' => $toUserId,
                'is_deduct' => self::NOT_DEDUCT,
                'create_time' => time(),
                'update_time' => time(),
            ]);
        }
        
        return $relation;
    }
    
    /**
     * 检查是否已扣次数
     * @param int $userId 用户ID
     * @param int $toUserId 对方用户ID
     * @return bool
     */
    public static function isDeducted(int $userId, int $toUserId): bool
    {
        // 确保 userId < toUserId
        if ($userId > $toUserId) {
            [$userId, $toUserId] = [$toUserId, $userId];
        }
        
        $relation = self::where('user_id', $userId)
            ->where('to_user_id', $toUserId)
            ->find();
        
        return $relation && $relation->is_deduct == self::IS_DEDUCT;
    }
    
    /**
     * 标记已扣次数
     * @param int $userId 用户ID
     * @param int $toUserId 对方用户ID
     * @return bool
     */
    public static function markDeducted(int $userId, int $toUserId): bool
    {
        // 确保 userId < toUserId
        if ($userId > $toUserId) {
            [$userId, $toUserId] = [$toUserId, $userId];
        }
        
        return self::where('user_id', $userId)
            ->where('to_user_id', $toUserId)
            ->update([
                'is_deduct' => self::IS_DEDUCT,
                'update_time' => time(),
            ]) !== false;
    }
    
    /**
     * 获取用户的所有会话列表
     * @param int $userId 用户ID
     * @return array
     */
    public static function getUserSessions(int $userId): array
    {
        $relations = self::where('user_id', $userId)
            ->whereOr('to_user_id', $userId)
            ->order('update_time desc')
            ->select();
        
        $sessions = [];
        foreach ($relations ?: [] as $relation) {
            // 确定对方用户ID
            $otherUserId = $relation->user_id == $userId ? $relation->to_user_id : $relation->user_id;
            
            // 获取对方用户信息
            $user = User::find($otherUserId);
            if (!$user) continue;
            
            // 获取最新一条聊天记录
            $lastRecord = self::getLastRecord($userId, $otherUserId);
            
            // 获取未读消息数
            $unreadCount = ChatRecord::getUnreadCount($userId, $otherUserId);
            
            $sessions[] = [
                'id' => $relation->id,
                'user_id' => $otherUserId,
                'nickname' => $user->nickname ?? '',
                'avatar' => $user->avatar ?? '',
                'last_message' => $lastRecord['content'] ?? '',
                'last_message_time' => $lastRecord['create_time'] ?? $relation->update_time,
                'unread_count' => $unreadCount,
                'is_deduct' => $relation->is_deduct,
            ];
        }
        
        return $sessions;
    }
    
    /**
     * 获取最新聊天记录
     * @param int $userId 用户ID
     * @param int $toUserId 对方用户ID
     * @return array|null
     */
    protected static function getLastRecord(int $userId, int $toUserId): ?array
    {
        $record = ChatRecord::where(function ($query) use ($userId, $toUserId) {
            $query->where(function ($q) use ($userId, $toUserId) {
                $q->where('user_id', $userId)->where('to_user_id', $toUserId);
            })->whereOr(function ($q) use ($userId, $toUserId) {
                $q->where('user_id', $toUserId)->where('to_user_id', $userId);
            });
        })
            ->order('create_time desc')
            ->find();
        
        return $record ? $record->toArray() : null;
    }
    
    /**
     * 删除会话关系
     * @param int $userId 用户ID
     * @param int $toUserId 对方用户ID
     * @return bool
     */
    public static function deleteSession(int $userId, int $toUserId): bool
    {
        // 确保 userId < toUserId
        if ($userId > $toUserId) {
            [$userId, $toUserId] = [$toUserId, $userId];
        }
        
        return self::where('user_id', $userId)
            ->where('to_user_id', $toUserId)
            ->delete() !== false;
    }
}