// Copyright © 2023 OpenIM. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package msg

import (
	"context"
	"encoding/json"
	"math/rand"
	"regexp"
	"strconv"
	"time"

	"git.imall.cloud/openim/open-im-server-deploy/pkg/authverify"
	"git.imall.cloud/openim/open-im-server-deploy/pkg/common/servererrs"
	"github.com/openimsdk/tools/utils/datautil"
	"github.com/openimsdk/tools/utils/encrypt"
	"github.com/openimsdk/tools/utils/timeutil"

	"git.imall.cloud/openim/protocol/constant"
	"git.imall.cloud/openim/protocol/msg"
	"git.imall.cloud/openim/protocol/sdkws"
	"github.com/openimsdk/tools/errs"
	"github.com/openimsdk/tools/log"
)

var ExcludeContentType = []int{constant.HasReadReceipt}

// URL正则表达式，匹配常见的URL格式
// 匹配以下格式的链接：
// 1. http:// 或 https:// 开头的完整URL
// 2. // 开头的协议相对URL（如 //s.yam.com/MvQzr）
// 3. www. 开头的链接
// 4. 直接包含域名的链接（如 s.yam.com/MvQzr、xxx.cc/csd、t.cn/AX4fYkFZ），匹配包含至少一个点的域名格式，后面可跟路径
// 域名格式：至少包含一个点和一个2位以上的顶级域名，如 xxx.com、xxx.cn、s.yam.com、xxx.cc、t.cn 等
// 注意：匹配 // 后面必须跟着域名格式，避免误匹配其他 // 开头的文本
// 修复：支持单字符域名（如 t.cn），移除了点之前必须有两个字符的限制
var urlRegex = regexp.MustCompile(`(?i)(https?://[^\s<>"{}|\\^` + "`" + `\[\]]+|//[a-zA-Z0-9][a-zA-Z0-9\-\.]*\.[a-zA-Z]{2,}(/[^\s<>"{}|\\^` + "`" + `\[\]]*)?|www\.[^\s<>"{}|\\^` + "`" + `\[\]]+|[a-zA-Z0-9][a-zA-Z0-9\-\.]*\.[a-zA-Z]{2,}(/[^\s<>"{}|\\^` + "`" + `\[\]]*)?)`)

type Validator interface {
	validate(pb *msg.SendMsgReq) (bool, int32, string)
}

// TextElem 用于解析文本消息内容
type TextElem struct {
	Content string `json:"content"`
}

// AtElem 用于解析@消息内容
type AtElem struct {
	Text string `json:"text"`
}

// checkMessageContainsLink 检测消息内容中是否包含链接
// userType: 0-普通用户（不能发送链接），1-特殊用户（可以发送链接）
func (m *msgServer) checkMessageContainsLink(msgData *sdkws.MsgData, userType int32) error {
	// userType=1 的用户可以发送链接，不进行检测
	if userType == 1 {
		return nil
	}

	// 只检测文本类型的消息
	if msgData.ContentType != constant.Text && msgData.ContentType != constant.AtText {
		return nil
	}

	var textContent string
	var err error

	// 解析消息内容
	if msgData.ContentType == constant.Text {
		var textElem TextElem
		if err = json.Unmarshal(msgData.Content, &textElem); err != nil {
			// 如果解析失败，尝试直接使用字符串
			textContent = string(msgData.Content)
		} else {
			textContent = textElem.Content
		}
	} else if msgData.ContentType == constant.AtText {
		var atElem AtElem
		if err = json.Unmarshal(msgData.Content, &atElem); err != nil {
			// 如果解析失败，尝试直接使用字符串
			textContent = string(msgData.Content)
		} else {
			textContent = atElem.Text
		}
	}

	// 检测是否包含链接
	if urlRegex.MatchString(textContent) {
		return servererrs.ErrMessageContainsLink.WrapMsg("userType=0的用户不能发送包含链接的消息")
	}

	return nil
}

type MessageRevoked struct {
	RevokerID                   string `json:"revokerID"`
	RevokerRole                 int32  `json:"revokerRole"`
	ClientMsgID                 string `json:"clientMsgID"`
	RevokerNickname             string `json:"revokerNickname"`
	RevokeTime                  int64  `json:"revokeTime"`
	SourceMessageSendTime       int64  `json:"sourceMessageSendTime"`
	SourceMessageSendID         string `json:"sourceMessageSendID"`
	SourceMessageSenderNickname string `json:"sourceMessageSenderNickname"`
	SessionType                 int32  `json:"sessionType"`
	Seq                         uint32 `json:"seq"`
}

func (m *msgServer) messageVerification(ctx context.Context, data *msg.SendMsgReq) error {
	webhookCfg := m.webhookConfig()

	switch data.MsgData.SessionType {
	case constant.SingleChatType:
		if datautil.Contain(data.MsgData.SendID, m.adminUserIDs...) {
			return nil
		}
		if data.MsgData.ContentType <= constant.NotificationEnd &&
			data.MsgData.ContentType >= constant.NotificationBegin {
			return nil
		}
		if err := m.webhookBeforeSendSingleMsg(ctx, &webhookCfg.BeforeSendSingleMsg, data); err != nil {
			return err
		}
		u, err := m.UserLocalCache.GetUserInfo(ctx, data.MsgData.SendID)
		if err != nil {
			return err
		}
		if authverify.CheckSystemAccount(ctx, u.AppMangerLevel) {
			return nil
		}
		// userType=1 的用户可以发送链接和二维码，不进行检测
		userType := u.GetUserType()

		if userType != 1 {
			// 检测userType=0的用户是否发送了包含链接的消息
			if err := m.checkMessageContainsLink(data.MsgData, userType); err != nil {
				return err
			}
			// 检测userType=0的用户是否发送了包含二维码的图片
			if err := m.checkImageContainsQRCode(ctx, data.MsgData, userType); err != nil {
				return err
			}
		}

		// 单聊中：不限制文件发送权限，所有用户都可以发送文件

		black, err := m.FriendLocalCache.IsBlack(ctx, data.MsgData.SendID, data.MsgData.RecvID)
		if err != nil {
			return err
		}
		if black {
			return servererrs.ErrBlockedByPeer.Wrap()
		}
		if m.config.RpcConfig.FriendVerify {
			friend, err := m.FriendLocalCache.IsFriend(ctx, data.MsgData.SendID, data.MsgData.RecvID)
			if err != nil {
				return err
			}
			if !friend {
				return servererrs.ErrNotPeersFriend.Wrap()
			}
			return nil
		}
		return nil
	case constant.ReadGroupChatType:
		groupInfo, err := m.GroupLocalCache.GetGroupInfo(ctx, data.MsgData.GroupID)
		if err != nil {
			return err
		}
		if groupInfo.Status == constant.GroupStatusDismissed &&
			data.MsgData.ContentType != constant.GroupDismissedNotification {
			return servererrs.ErrDismissedAlready.Wrap()
		}
		// 检查是否为系统管理员，系统管理员跳过部分检查
		isSystemAdmin := datautil.Contain(data.MsgData.SendID, m.adminUserIDs...)

		// 通知消息类型跳过检查
		if data.MsgData.ContentType <= constant.NotificationEnd &&
			data.MsgData.ContentType >= constant.NotificationBegin {
			return nil
		}

		// SuperGroup 跳过部分检查，但仍需检查文件权限
		if groupInfo.GroupType == constant.SuperGroup {
			// SuperGroup 也需要检查文件发送权限
			if data.MsgData.ContentType == constant.File {
				if isSystemAdmin {
					// 系统管理员可以发送文件
					return nil
				}
				memberIDs, err := m.GroupLocalCache.GetGroupMemberIDMap(ctx, data.MsgData.GroupID)
				if err != nil {
					return err
				}
				if _, ok := memberIDs[data.MsgData.SendID]; !ok {
					return servererrs.ErrNotInGroupYet.Wrap()
				}
				groupMemberInfo, err := m.GroupLocalCache.GetGroupMember(ctx, data.MsgData.GroupID, data.MsgData.SendID)
				if err != nil {
					if errs.ErrRecordNotFound.Is(err) {
						return servererrs.ErrNotInGroupYet.WrapMsg(err.Error())
					}
					return err
				}
				u, err := m.UserLocalCache.GetUserInfo(ctx, data.MsgData.SendID)
				if err != nil {
					return err
				}
				isGroupOwner := groupMemberInfo.RoleLevel == constant.GroupOwner
				isGroupAdmin := groupMemberInfo.RoleLevel == constant.GroupAdmin
				canSendFile := u.GetUserType() == 1 || isGroupOwner || isGroupAdmin
				if !canSendFile {
					return servererrs.ErrNoPermission.WrapMsg("only group owner, admin, or userType=1 can send files in group chat")
				}
			}
			return nil
		}

		// 先获取用户信息，用于检查userType（系统管理员和userType=1的用户可以发送文件）
		memberIDs, err := m.GroupLocalCache.GetGroupMemberIDMap(ctx, data.MsgData.GroupID)
		if err != nil {
			return err
		}
		if _, ok := memberIDs[data.MsgData.SendID]; !ok {
			return servererrs.ErrNotInGroupYet.Wrap()
		}

		groupMemberInfo, err := m.GroupLocalCache.GetGroupMember(ctx, data.MsgData.GroupID, data.MsgData.SendID)
		if err != nil {
			if errs.ErrRecordNotFound.Is(err) {
				return servererrs.ErrNotInGroupYet.WrapMsg(err.Error())
			}
			return err
		}
		// 获取用户信息以获取userType
		u, err := m.UserLocalCache.GetUserInfo(ctx, data.MsgData.SendID)
		if err != nil {
			return err
		}

		// 群聊中：检查文件发送权限（优先检查，确保不会被其他逻辑跳过）
		// 只有群主、管理员、userType=1的用户可以发送文件
		// 系统管理员也可以发送文件
		if data.MsgData.ContentType == constant.File {
			isGroupOwner := groupMemberInfo.RoleLevel == constant.GroupOwner
			isGroupAdmin := groupMemberInfo.RoleLevel == constant.GroupAdmin
			userType := u.GetUserType()

			// 如果是文件消息且 userType=0 且不是群主/管理员，可能是缓存问题，尝试清除缓存并重新获取
			if userType == 0 && !isGroupOwner && !isGroupAdmin && !isSystemAdmin {
				// 清除本地缓存
				m.UserLocalCache.DelUserInfo(ctx, data.MsgData.SendID)
				// 重新获取用户信息
				u, err = m.UserLocalCache.GetUserInfo(ctx, data.MsgData.SendID)
				if err != nil {
					return err
				}
				userType = u.GetUserType()
			}

			canSendFile := isSystemAdmin || userType == 1 || isGroupOwner || isGroupAdmin
			if !canSendFile {
				return servererrs.ErrNoPermission.WrapMsg("only group owner, admin, or userType=1 can send files in group chat")
			}
		}

		if isSystemAdmin {
			// 系统管理员跳过大部分检查
			return nil
		}

		// 群聊中：userType=1、群主、群管理员可以发送链接
		isGroupOwner := groupMemberInfo.RoleLevel == constant.GroupOwner
		isGroupAdmin := groupMemberInfo.RoleLevel == constant.GroupAdmin
		canSendLink := u.GetUserType() == 1 || isGroupOwner || isGroupAdmin

		// 如果不符合发送链接的条件，进行链接检测
		if !canSendLink {
			if err := m.checkMessageContainsLink(data.MsgData, u.GetUserType()); err != nil {
				return err
			}
		}
		// 群聊中：检测userType=0的普通成员是否发送了包含二维码的图片
		// userType=1、群主、群管理员可以发送包含二维码的图片，不进行检测
		if !canSendLink {
			if err := m.checkImageContainsQRCode(ctx, data.MsgData, u.GetUserType()); err != nil {
				return err
			}
		}

		if isGroupOwner {
			return nil
		} else {
			nowUnixMilli := time.Now().UnixMilli()
			// 记录禁言检查信息，用于排查自动禁言问题
			if groupMemberInfo.MuteEndTime > 0 {
				muteEndTime := time.UnixMilli(groupMemberInfo.MuteEndTime)
				isMuted := groupMemberInfo.MuteEndTime >= nowUnixMilli
				log.ZInfo(ctx, "messageVerification: checking mute status",
					"groupID", data.MsgData.GroupID,
					"userID", data.MsgData.SendID,
					"muteEndTimeTimestamp", groupMemberInfo.MuteEndTime,
					"muteEndTime", muteEndTime.Format(time.RFC3339),
					"now", time.UnixMilli(nowUnixMilli).Format(time.RFC3339),
					"isMuted", isMuted,
					"mutedDurationSeconds", (groupMemberInfo.MuteEndTime-nowUnixMilli)/1000,
					"roleLevel", groupMemberInfo.RoleLevel)
			}
			if groupMemberInfo.MuteEndTime >= nowUnixMilli {
				return servererrs.ErrMutedInGroup.Wrap()
			}
			if groupInfo.Status == constant.GroupStatusMuted && !isGroupAdmin {
				return servererrs.ErrMutedGroup.Wrap()
			}
		}
		return nil
	default:
		return nil
	}
}

func (m *msgServer) encapsulateMsgData(msg *sdkws.MsgData) {
	msg.ServerMsgID = GetMsgID(msg.SendID)
	if msg.SendTime == 0 {
		msg.SendTime = timeutil.GetCurrentTimestampByMill()
	}
	switch msg.ContentType {
	case constant.Text, constant.Picture, constant.Voice, constant.Video,
		constant.File, constant.AtText, constant.Merger, constant.Card,
		constant.Location, constant.Custom, constant.Quote, constant.AdvancedText, constant.MarkdownText:
	case constant.Revoke:
		datautil.SetSwitchFromOptions(msg.Options, constant.IsUnreadCount, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsOfflinePush, false)
	case constant.HasReadReceipt:
		datautil.SetSwitchFromOptions(msg.Options, constant.IsConversationUpdate, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsSenderConversationUpdate, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsUnreadCount, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsOfflinePush, false)
	case constant.Typing:
		datautil.SetSwitchFromOptions(msg.Options, constant.IsHistory, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsPersistent, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsSenderSync, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsConversationUpdate, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsSenderConversationUpdate, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsUnreadCount, false)
		datautil.SetSwitchFromOptions(msg.Options, constant.IsOfflinePush, false)
	}
}

func GetMsgID(sendID string) string {
	t := timeutil.GetCurrentTimeFormatted()
	return encrypt.Md5(t + "-" + sendID + "-" + strconv.Itoa(rand.Int()))
}

func (m *msgServer) modifyMessageByUserMessageReceiveOpt(ctx context.Context, userID, conversationID string, sessionType int, pb *msg.SendMsgReq) (bool, error) {
	opt, err := m.UserLocalCache.GetUserGlobalMsgRecvOpt(ctx, userID)
	if err != nil {
		return false, err
	}
	switch opt {
	case constant.ReceiveMessage:
	case constant.NotReceiveMessage:
		return false, nil
	case constant.ReceiveNotNotifyMessage:
		if pb.MsgData.Options == nil {
			pb.MsgData.Options = make(map[string]bool, 10)
		}
		datautil.SetSwitchFromOptions(pb.MsgData.Options, constant.IsOfflinePush, false)
		return true, nil
	}
	singleOpt, err := m.ConversationLocalCache.GetSingleConversationRecvMsgOpt(ctx, userID, conversationID)
	if errs.ErrRecordNotFound.Is(err) {
		return true, nil
	} else if err != nil {
		return false, err
	}
	switch singleOpt {
	case constant.ReceiveMessage:
		return true, nil
	case constant.NotReceiveMessage:
		if datautil.Contain(int(pb.MsgData.ContentType), ExcludeContentType...) {
			return true, nil
		}
		return false, nil
	case constant.ReceiveNotNotifyMessage:
		if pb.MsgData.Options == nil {
			pb.MsgData.Options = make(map[string]bool, 10)
		}
		datautil.SetSwitchFromOptions(pb.MsgData.Options, constant.IsOfflinePush, false)
		return true, nil
	}
	return true, nil
}