// 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 cache

import (
	"context"
	"errors"
	"math/big"
	"strings"
	"time"

	"github.com/dtm-labs/rockscache"
	"github.com/redis/go-redis/v9"

	"github.com/OpenIMSDK/tools/utils"

	"github.com/OpenIMSDK/Open-IM-Server/pkg/common/db/relation"
	relationTb "github.com/OpenIMSDK/Open-IM-Server/pkg/common/db/table/relation"
)

const (
	conversationKey                          = "CONVERSATION:"
	conversationIDsKey                       = "CONVERSATION_IDS:"
	conversationIDsHashKey                   = "CONVERSATION_IDS_HASH:"
	conversationHasReadSeqKey                = "CONVERSATION_HAS_READ_SEQ:"
	recvMsgOptKey                            = "RECV_MSG_OPT:"
	superGroupRecvMsgNotNotifyUserIDsKey     = "SUPER_GROUP_RECV_MSG_NOT_NOTIFY_USER_IDS:"
	superGroupRecvMsgNotNotifyUserIDsHashKey = "SUPER_GROUP_RECV_MSG_NOT_NOTIFY_USER_IDS_HASH:"

	conversationExpireTime = time.Second * 60 * 60 * 12
)

// arg fn will exec when no data in msgCache.
type ConversationCache interface {
	metaCache
	NewCache() ConversationCache
	// get user's conversationIDs from msgCache
	GetUserConversationIDs(ctx context.Context, ownerUserID string) ([]string, error)
	DelConversationIDs(userIDs ...string) ConversationCache

	GetUserConversationIDsHash(ctx context.Context, ownerUserID string) (hash uint64, err error)
	DelUserConversationIDsHash(ownerUserIDs ...string) ConversationCache

	// get one conversation from msgCache
	GetConversation(ctx context.Context, ownerUserID, conversationID string) (*relationTb.ConversationModel, error)
	DelConversations(ownerUserID string, conversationIDs ...string) ConversationCache
	DelUsersConversation(conversationID string, ownerUserIDs ...string) ConversationCache
	// get one conversation from msgCache
	GetConversations(
		ctx context.Context,
		ownerUserID string,
		conversationIDs []string,
	) ([]*relationTb.ConversationModel, error)
	// get one user's all conversations from msgCache
	GetUserAllConversations(ctx context.Context, ownerUserID string) ([]*relationTb.ConversationModel, error)
	// get user conversation recv msg from msgCache
	GetUserRecvMsgOpt(ctx context.Context, ownerUserID, conversationID string) (opt int, err error)
	DelUserRecvMsgOpt(ownerUserID, conversationID string) ConversationCache
	// get one super group recv msg but do not notification userID list
	GetSuperGroupRecvMsgNotNotifyUserIDs(ctx context.Context, groupID string) (userIDs []string, err error)
	DelSuperGroupRecvMsgNotNotifyUserIDs(groupID string) ConversationCache
	// get one super group recv msg but do not notification userID list hash
	GetSuperGroupRecvMsgNotNotifyUserIDsHash(ctx context.Context, groupID string) (hash uint64, err error)
	DelSuperGroupRecvMsgNotNotifyUserIDsHash(groupID string) ConversationCache

	GetUserAllHasReadSeqs(ctx context.Context, ownerUserID string) (map[string]int64, error)
	DelUserAllHasReadSeqs(ownerUserID string, conversationIDs ...string) ConversationCache

	GetConversationsByConversationID(
		ctx context.Context,
		conversationIDs []string,
	) ([]*relationTb.ConversationModel, error)
	DelConversationByConversationID(conversationIDs ...string) ConversationCache
}

func NewConversationRedis(
	rdb redis.UniversalClient,
	opts rockscache.Options,
	db relationTb.ConversationModelInterface,
) ConversationCache {
	rcClient := rockscache.NewClient(rdb, opts)
	return &ConversationRedisCache{
		rcClient:       rcClient,
		metaCache:      NewMetaCacheRedis(rcClient),
		conversationDB: db,
		expireTime:     conversationExpireTime,
	}
}

type ConversationRedisCache struct {
	metaCache
	rcClient       *rockscache.Client
	conversationDB relationTb.ConversationModelInterface
	expireTime     time.Duration
}

func NewNewConversationRedis(
	rdb redis.UniversalClient,
	conversationDB *relation.ConversationGorm,
	options rockscache.Options,
) ConversationCache {
	rcClient := rockscache.NewClient(rdb, options)
	return &ConversationRedisCache{
		rcClient:       rcClient,
		metaCache:      NewMetaCacheRedis(rcClient),
		conversationDB: conversationDB,
		expireTime:     conversationExpireTime,
	}
}

func (c *ConversationRedisCache) NewCache() ConversationCache {
	return &ConversationRedisCache{
		rcClient:       c.rcClient,
		metaCache:      NewMetaCacheRedis(c.rcClient, c.metaCache.GetPreDelKeys()...),
		conversationDB: c.conversationDB,
		expireTime:     c.expireTime,
	}
}

func (c *ConversationRedisCache) getConversationKey(ownerUserID, conversationID string) string {
	return conversationKey + ownerUserID + ":" + conversationID
}

func (c *ConversationRedisCache) getConversationIDsKey(ownerUserID string) string {
	return conversationIDsKey + ownerUserID
}

func (c *ConversationRedisCache) getSuperGroupRecvNotNotifyUserIDsKey(groupID string) string {
	return superGroupRecvMsgNotNotifyUserIDsKey + groupID
}

func (c *ConversationRedisCache) getRecvMsgOptKey(ownerUserID, conversationID string) string {
	return recvMsgOptKey + ownerUserID + ":" + conversationID
}

func (c *ConversationRedisCache) getSuperGroupRecvNotNotifyUserIDsHashKey(groupID string) string {
	return superGroupRecvMsgNotNotifyUserIDsHashKey + groupID
}

func (c *ConversationRedisCache) getConversationHasReadSeqKey(ownerUserID, conversationID string) string {
	return conversationHasReadSeqKey + ownerUserID + ":" + conversationID
}

func (c *ConversationRedisCache) GetUserConversationIDs(ctx context.Context, ownerUserID string) ([]string, error) {
	return getCache(
		ctx,
		c.rcClient,
		c.getConversationIDsKey(ownerUserID),
		c.expireTime,
		func(ctx context.Context) ([]string, error) {
			return c.conversationDB.FindUserIDAllConversationID(ctx, ownerUserID)
		},
	)
}

func (c *ConversationRedisCache) DelConversationIDs(userIDs ...string) ConversationCache {
	var keys []string
	for _, userID := range userIDs {
		keys = append(keys, c.getConversationIDsKey(userID))
	}
	cache := c.NewCache()
	cache.AddKeys(keys...)
	return cache
}

func (c *ConversationRedisCache) getUserConversationIDsHashKey(ownerUserID string) string {
	return conversationIDsHashKey + ownerUserID
}

func (c *ConversationRedisCache) GetUserConversationIDsHash(
	ctx context.Context,
	ownerUserID string,
) (hash uint64, err error) {
	return getCache(
		ctx,
		c.rcClient,
		c.getUserConversationIDsHashKey(ownerUserID),
		c.expireTime,
		func(ctx context.Context) (uint64, error) {
			conversationIDs, err := c.GetUserConversationIDs(ctx, ownerUserID)
			if err != nil {
				return 0, err
			}
			utils.Sort(conversationIDs, true)
			bi := big.NewInt(0)
			bi.SetString(utils.Md5(strings.Join(conversationIDs, ";"))[0:8], 16)
			return bi.Uint64(), nil
		},
	)
}

func (c *ConversationRedisCache) DelUserConversationIDsHash(ownerUserIDs ...string) ConversationCache {
	var keys []string
	for _, ownerUserID := range ownerUserIDs {
		keys = append(keys, c.getUserConversationIDsHashKey(ownerUserID))
	}
	cache := c.NewCache()
	cache.AddKeys(keys...)
	return cache
}

func (c *ConversationRedisCache) GetConversation(
	ctx context.Context,
	ownerUserID, conversationID string,
) (*relationTb.ConversationModel, error) {
	return getCache(
		ctx,
		c.rcClient,
		c.getConversationKey(ownerUserID, conversationID),
		c.expireTime,
		func(ctx context.Context) (*relationTb.ConversationModel, error) {
			return c.conversationDB.Take(ctx, ownerUserID, conversationID)
		},
	)
}

func (c *ConversationRedisCache) DelConversations(ownerUserID string, conversationIDs ...string) ConversationCache {
	var keys []string
	for _, conversationID := range conversationIDs {
		keys = append(keys, c.getConversationKey(ownerUserID, conversationID))
	}
	cache := c.NewCache()
	cache.AddKeys(keys...)
	return cache
}

func (c *ConversationRedisCache) getConversationIndex(
	convsation *relationTb.ConversationModel,
	keys []string,
) (int, error) {
	key := c.getConversationKey(convsation.OwnerUserID, convsation.ConversationID)
	for _i, _key := range keys {
		if _key == key {
			return _i, nil
		}
	}
	return 0, errors.New("not found key:" + key + " in keys")
}

func (c *ConversationRedisCache) GetConversations(
	ctx context.Context,
	ownerUserID string,
	conversationIDs []string,
) ([]*relationTb.ConversationModel, error) {
	var keys []string
	for _, conversarionID := range conversationIDs {
		keys = append(keys, c.getConversationKey(ownerUserID, conversarionID))
	}
	return batchGetCache(
		ctx,
		c.rcClient,
		keys,
		c.expireTime,
		c.getConversationIndex,
		func(ctx context.Context) ([]*relationTb.ConversationModel, error) {
			return c.conversationDB.Find(ctx, ownerUserID, conversationIDs)
		},
	)
}

func (c *ConversationRedisCache) GetUserAllConversations(
	ctx context.Context,
	ownerUserID string,
) ([]*relationTb.ConversationModel, error) {
	conversationIDs, err := c.GetUserConversationIDs(ctx, ownerUserID)
	if err != nil {
		return nil, err
	}
	var keys []string
	for _, conversarionID := range conversationIDs {
		keys = append(keys, c.getConversationKey(ownerUserID, conversarionID))
	}
	return batchGetCache(
		ctx,
		c.rcClient,
		keys,
		c.expireTime,
		c.getConversationIndex,
		func(ctx context.Context) ([]*relationTb.ConversationModel, error) {
			return c.conversationDB.FindUserIDAllConversations(ctx, ownerUserID)
		},
	)
}

func (c *ConversationRedisCache) GetUserRecvMsgOpt(
	ctx context.Context,
	ownerUserID, conversationID string,
) (opt int, err error) {
	return getCache(
		ctx,
		c.rcClient,
		c.getRecvMsgOptKey(ownerUserID, conversationID),
		c.expireTime,
		func(ctx context.Context) (opt int, err error) {
			return c.conversationDB.GetUserRecvMsgOpt(ctx, ownerUserID, conversationID)
		},
	)
}

func (c *ConversationRedisCache) GetSuperGroupRecvMsgNotNotifyUserIDs(
	ctx context.Context,
	groupID string,
) (userIDs []string, err error) {
	return getCache(
		ctx,
		c.rcClient,
		c.getSuperGroupRecvNotNotifyUserIDsKey(groupID),
		c.expireTime,
		func(ctx context.Context) (userIDs []string, err error) {
			return c.conversationDB.FindSuperGroupRecvMsgNotNotifyUserIDs(ctx, groupID)
		},
	)
}

func (c *ConversationRedisCache) DelUsersConversation(conversationID string, ownerUserIDs ...string) ConversationCache {
	var keys []string
	for _, ownerUserID := range ownerUserIDs {
		keys = append(keys, c.getConversationKey(ownerUserID, conversationID))
	}
	cache := c.NewCache()
	cache.AddKeys(keys...)
	return cache
}

func (c *ConversationRedisCache) DelUserRecvMsgOpt(ownerUserID, conversationID string) ConversationCache {
	cache := c.NewCache()
	cache.AddKeys(c.getRecvMsgOptKey(ownerUserID, conversationID))
	return cache
}

func (c *ConversationRedisCache) DelSuperGroupRecvMsgNotNotifyUserIDs(groupID string) ConversationCache {
	cache := c.NewCache()
	cache.AddKeys(c.getSuperGroupRecvNotNotifyUserIDsKey(groupID))
	return cache
}

func (c *ConversationRedisCache) GetSuperGroupRecvMsgNotNotifyUserIDsHash(
	ctx context.Context,
	groupID string,
) (hash uint64, err error) {
	return getCache(
		ctx,
		c.rcClient,
		c.getSuperGroupRecvNotNotifyUserIDsHashKey(groupID),
		c.expireTime,
		func(ctx context.Context) (hash uint64, err error) {
			userIDs, err := c.GetSuperGroupRecvMsgNotNotifyUserIDs(ctx, groupID)
			if err != nil {
				return 0, err
			}
			utils.Sort(userIDs, true)
			bi := big.NewInt(0)
			bi.SetString(utils.Md5(strings.Join(userIDs, ";"))[0:8], 16)
			return bi.Uint64(), nil
		},
	)
}

func (c *ConversationRedisCache) DelSuperGroupRecvMsgNotNotifyUserIDsHash(groupID string) ConversationCache {
	cache := c.NewCache()
	cache.AddKeys(c.getSuperGroupRecvNotNotifyUserIDsHashKey(groupID))
	return cache
}

func (c *ConversationRedisCache) getUserAllHasReadSeqsIndex(
	conversationID string,
	conversationIDs []string,
) (int, error) {
	for _i, _conversationID := range conversationIDs {
		if _conversationID == conversationID {
			return _i, nil
		}
	}
	return 0, errors.New("not found key:" + conversationID + " in keys")
}

func (c *ConversationRedisCache) GetUserAllHasReadSeqs(
	ctx context.Context,
	ownerUserID string,
) (map[string]int64, error) {
	conversationIDs, err := c.GetUserConversationIDs(ctx, ownerUserID)
	if err != nil {
		return nil, err
	}
	var keys []string
	for _, conversarionID := range conversationIDs {
		keys = append(keys, c.getConversationHasReadSeqKey(ownerUserID, conversarionID))
	}
	return batchGetCacheMap(
		ctx,
		c.rcClient,
		keys,
		conversationIDs,
		c.expireTime,
		c.getUserAllHasReadSeqsIndex,
		func(ctx context.Context) (map[string]int64, error) {
			return c.conversationDB.GetUserAllHasReadSeqs(ctx, ownerUserID)
		},
	)
}

func (c *ConversationRedisCache) DelUserAllHasReadSeqs(
	ownerUserID string,
	conversationIDs ...string,
) ConversationCache {
	cache := c.NewCache()
	for _, conversationID := range conversationIDs {
		cache.AddKeys(c.getConversationHasReadSeqKey(ownerUserID, conversationID))
	}
	return cache
}

func (c *ConversationRedisCache) GetConversationsByConversationID(
	ctx context.Context,
	conversationIDs []string,
) ([]*relationTb.ConversationModel, error) {
	panic("implement me")
}

func (c *ConversationRedisCache) DelConversationByConversationID(conversationIDs ...string) ConversationCache {
	panic("implement me")
}