// 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"

	"git.imall.cloud/openim/open-im-server-deploy/pkg/authverify"
	"git.imall.cloud/openim/protocol/constant"
	"git.imall.cloud/openim/protocol/conversation"
	"git.imall.cloud/openim/protocol/msg"
	"git.imall.cloud/openim/protocol/sdkws"
	"github.com/openimsdk/tools/errs"
	"github.com/openimsdk/tools/log"
	"github.com/openimsdk/tools/utils/datautil"
	"github.com/openimsdk/tools/utils/timeutil"
)

func (m *msgServer) getMinSeqs(maxSeqs map[string]int64) map[string]int64 {
	minSeqs := make(map[string]int64)
	for k, v := range maxSeqs {
		minSeqs[k] = v + 1
	}
	return minSeqs
}

func (m *msgServer) validateDeleteSyncOpt(opt *msg.DeleteSyncOpt) (isSyncSelf, isSyncOther bool) {
	if opt == nil {
		return
	}
	return opt.IsSyncSelf, opt.IsSyncOther
}

func (m *msgServer) ClearConversationsMsg(ctx context.Context, req *msg.ClearConversationsMsgReq) (*msg.ClearConversationsMsgResp, error) {
	if err := authverify.CheckAccess(ctx, req.UserID); err != nil {
		return nil, err
	}
	if err := m.clearConversation(ctx, req.ConversationIDs, req.UserID, req.DeleteSyncOpt); err != nil {
		return nil, err
	}
	return &msg.ClearConversationsMsgResp{}, nil
}

func (m *msgServer) UserClearAllMsg(ctx context.Context, req *msg.UserClearAllMsgReq) (*msg.UserClearAllMsgResp, error) {
	if err := authverify.CheckAccess(ctx, req.UserID); err != nil {
		return nil, err
	}
	conversationIDs, err := m.ConversationLocalCache.GetConversationIDs(ctx, req.UserID)
	if err != nil {
		return nil, err
	}
	if err := m.clearConversation(ctx, conversationIDs, req.UserID, req.DeleteSyncOpt); err != nil {
		return nil, err
	}
	return &msg.UserClearAllMsgResp{}, nil
}

func (m *msgServer) DeleteMsgs(ctx context.Context, req *msg.DeleteMsgsReq) (*msg.DeleteMsgsResp, error) {
	if err := authverify.CheckAccess(ctx, req.UserID); err != nil {
		return nil, err
	}

	// 获取要删除的消息信息，用于权限检查
	_, _, msgs, err := m.MsgDatabase.GetMsgBySeqs(ctx, req.UserID, req.ConversationID, req.Seqs)
	if err != nil {
		return nil, err
	}
	if len(msgs) == 0 {
		return nil, errs.ErrRecordNotFound.WrapMsg("messages not found")
	}

	// 权限检查：如果不是管理员，需要检查删除权限
	if !authverify.IsAdmin(ctx) {
		// 收集所有消息的发送者ID
		sendIDs := make([]string, 0, len(msgs))
		for _, msg := range msgs {
			if msg != nil && msg.SendID != "" {
				sendIDs = append(sendIDs, msg.SendID)
			}
		}
		sendIDs = datautil.Distinct(sendIDs)

		// 检查第一条消息的会话类型（假设所有消息来自同一会话）
		sessionType := msgs[0].SessionType
		switch sessionType {
		case constant.SingleChatType:
			// 单聊：只能删除自己发送的消息
			for _, msg := range msgs {
				if msg != nil && msg.SendID != req.UserID {
					return nil, errs.ErrNoPermission.WrapMsg("can only delete own messages in single chat")
				}
			}
		case constant.ReadGroupChatType:
			// 群聊：检查权限
			groupID := msgs[0].GroupID
			if groupID == "" {
				return nil, errs.ErrArgs.WrapMsg("groupID is empty")
			}

			// 获取操作者和所有消息发送者的群成员信息
			allUserIDs := append([]string{req.UserID}, sendIDs...)
			members, err := m.GroupLocalCache.GetGroupMemberInfoMap(ctx, groupID, datautil.Distinct(allUserIDs))
			if err != nil {
				return nil, err
			}

			// 检查操作者的角色
			opMember, ok := members[req.UserID]
			if !ok {
				return nil, errs.ErrNoPermission.WrapMsg("user not in group")
			}

			// 检查每条消息的删除权限
			for _, msg := range msgs {
				if msg == nil || msg.SendID == "" {
					continue
				}

				// 如果是自己发送的消息，可以删除
				if msg.SendID == req.UserID {
					continue
				}

				// 如果不是自己发送的消息，需要检查权限
				switch opMember.RoleLevel {
				case constant.GroupOwner:
					// 群主可以删除任何人的消息
				case constant.GroupAdmin:
					// 管理员只能删除普通成员的消息
					sendMember, ok := members[msg.SendID]
					if !ok {
						return nil, errs.ErrNoPermission.WrapMsg("message sender not in group")
					}
					if sendMember.RoleLevel != constant.GroupOrdinaryUsers {
						return nil, errs.ErrNoPermission.WrapMsg("group admin can only delete messages from ordinary members")
					}
				default:
					// 普通成员只能删除自己的消息
					return nil, errs.ErrNoPermission.WrapMsg("can only delete own messages")
				}
			}
		default:
			return nil, errs.ErrInternalServer.WrapMsg("sessionType not supported", "sessionType", sessionType)
		}
	}

	isSyncSelf, isSyncOther := m.validateDeleteSyncOpt(req.DeleteSyncOpt)
	if isSyncOther {
		if err := m.MsgDatabase.DeleteMsgsPhysicalBySeqs(ctx, req.ConversationID, req.Seqs); err != nil {
			return nil, err
		}
		conv, err := m.conversationClient.GetConversationsByConversationID(ctx, req.ConversationID)
		if err != nil {
			return nil, err
		}
		tips := &sdkws.DeleteMsgsTips{UserID: req.UserID, ConversationID: req.ConversationID, Seqs: req.Seqs}
		m.notificationSender.NotificationWithSessionType(ctx, req.UserID, m.conversationAndGetRecvID(conv, req.UserID),
			constant.DeleteMsgsNotification, conv.ConversationType, tips)
	} else {
		if err := m.MsgDatabase.DeleteUserMsgsBySeqs(ctx, req.UserID, req.ConversationID, req.Seqs); err != nil {
			return nil, err
		}
		if isSyncSelf {
			tips := &sdkws.DeleteMsgsTips{UserID: req.UserID, ConversationID: req.ConversationID, Seqs: req.Seqs}
			m.notificationSender.NotificationWithSessionType(ctx, req.UserID, req.UserID, constant.DeleteMsgsNotification, constant.SingleChatType, tips)
		}
	}
	return &msg.DeleteMsgsResp{}, nil
}

func (m *msgServer) DeleteMsgPhysicalBySeq(ctx context.Context, req *msg.DeleteMsgPhysicalBySeqReq) (*msg.DeleteMsgPhysicalBySeqResp, error) {
	if err := authverify.CheckAdmin(ctx); err != nil {
		return nil, err
	}
	err := m.MsgDatabase.DeleteMsgsPhysicalBySeqs(ctx, req.ConversationID, req.Seqs)
	if err != nil {
		return nil, err
	}
	return &msg.DeleteMsgPhysicalBySeqResp{}, nil
}

func (m *msgServer) DeleteMsgPhysical(ctx context.Context, req *msg.DeleteMsgPhysicalReq) (*msg.DeleteMsgPhysicalResp, error) {
	if err := authverify.CheckAdmin(ctx); err != nil {
		return nil, err
	}
	remainTime := timeutil.GetCurrentTimestampBySecond() - req.Timestamp
	if _, err := m.DestructMsgs(ctx, &msg.DestructMsgsReq{Timestamp: remainTime, Limit: 9999}); err != nil {
		return nil, err
	}
	return &msg.DeleteMsgPhysicalResp{}, nil
}

func (m *msgServer) clearConversation(ctx context.Context, conversationIDs []string, userID string, deleteSyncOpt *msg.DeleteSyncOpt) error {
	conversations, err := m.conversationClient.GetConversationsByConversationIDs(ctx, conversationIDs)
	if err != nil {
		return err
	}
	var existConversations []*conversation.Conversation
	var existConversationIDs []string
	for _, conversation := range conversations {
		existConversations = append(existConversations, conversation)
		existConversationIDs = append(existConversationIDs, conversation.ConversationID)
	}
	log.ZDebug(ctx, "ClearConversationsMsg", "existConversationIDs", existConversationIDs)
	maxSeqs, err := m.MsgDatabase.GetMaxSeqs(ctx, existConversationIDs)
	if err != nil {
		return err
	}
	isSyncSelf, isSyncOther := m.validateDeleteSyncOpt(deleteSyncOpt)
	if !isSyncOther {
		setSeqs := m.getMinSeqs(maxSeqs)
		if err := m.MsgDatabase.SetUserConversationsMinSeqs(ctx, userID, setSeqs); err != nil {
			return err
		}
		ownerUserIDs := []string{userID}
		for conversationID, seq := range setSeqs {
			if err := m.conversationClient.SetConversationMinSeq(ctx, conversationID, ownerUserIDs, seq); err != nil {
				return err
			}
		}
		// notification 2 self
		if isSyncSelf {
			tips := &sdkws.ClearConversationTips{UserID: userID, ConversationIDs: existConversationIDs}
			m.notificationSender.NotificationWithSessionType(ctx, userID, userID, constant.ClearConversationNotification, constant.SingleChatType, tips)
		}
	} else {
		if err := m.MsgDatabase.SetMinSeqs(ctx, m.getMinSeqs(maxSeqs)); err != nil {
			return err
		}
		for _, conversation := range existConversations {
			tips := &sdkws.ClearConversationTips{UserID: userID, ConversationIDs: []string{conversation.ConversationID}}
			m.notificationSender.NotificationWithSessionType(ctx, userID, m.conversationAndGetRecvID(conversation, userID), constant.ClearConversationNotification, conversation.ConversationType, tips)
		}
	}
	if err := m.MsgDatabase.UserSetHasReadSeqs(ctx, userID, maxSeqs); err != nil {
		return err
	}
	return nil
}