/*
 * Licensed to the LF AI & Data foundation under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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 proxy

import (
	"context"

	"github.com/samber/lo"

	"github.com/milvus-io/milvus-proto/go-api/v3/commonpb"
	"github.com/milvus-io/milvus-proto/go-api/v3/msgpb"
	"github.com/milvus-io/milvus/internal/types"
	"github.com/milvus-io/milvus/internal/util/importutilv2"
	"github.com/milvus-io/milvus/pkg/v3/common"
	"github.com/milvus-io/milvus/pkg/v3/mlog"
	"github.com/milvus-io/milvus/pkg/v3/proto/internalpb"
	"github.com/milvus-io/milvus/pkg/v3/util/merr"
	"github.com/milvus-io/milvus/pkg/v3/util/typeutil"
)

type importTask struct {
	baseTask
	Condition
	req      *internalpb.ImportRequest
	ctx      context.Context
	node     *Proxy
	mixCoord types.MixCoordClient

	msgID        UniqueID
	taskTS       Timestamp
	vchannels    []string
	pchannels    []string
	partitionIDs []int64
	collectionID UniqueID
	schema       *schemaInfo
	resp         *internalpb.ImportResponse
}

func (it *importTask) TraceCtx() context.Context {
	return it.ctx
}

func (it *importTask) ID() UniqueID {
	return it.msgID
}

func (it *importTask) SetID(uid UniqueID) {
	it.msgID = uid
}

func (it *importTask) Name() string {
	return "ImportTask"
}

func (it *importTask) Type() commonpb.MsgType {
	return commonpb.MsgType_Import
}

func (it *importTask) BeginTs() Timestamp {
	return it.taskTS
}

func (it *importTask) EndTs() Timestamp {
	return it.taskTS
}

func (it *importTask) SetTs(ts Timestamp) {
	it.taskTS = ts
}

func (it *importTask) OnEnqueue() error {
	return nil
}

func (it *importTask) PreExecute(ctx context.Context) error {
	req := it.req
	node := it.node
	collectionID, err := globalMetaCache.GetCollectionID(ctx, req.GetDbName(), req.GetCollectionName())
	if err != nil {
		return err
	}
	it.collectionID = collectionID
	schema, err := globalMetaCache.GetCollectionSchema(ctx, req.GetDbName(), req.GetCollectionName())
	if err != nil {
		return err
	}
	if schema.CollectionSchema == nil || len(schema.GetFields()) == 0 {
		return merr.WrapErrImportSysFailed("collection schema has no fields")
	}
	if err := validateTextStorageV3Enabled(schema.CollectionSchema); err != nil {
		return err
	}
	it.schema = schema

	channels, err := node.chMgr.getVChannels(collectionID)
	if err != nil {
		return err
	}
	it.vchannels = channels

	isBackup := importutilv2.IsBackup(req.GetOptions())
	isL0Import := importutilv2.IsL0Import(req.GetOptions())
	hasPartitionKey := typeutil.HasPartitionKey(schema.CollectionSchema)

	var partitionIDs []int64
	if isBackup {
		if req.GetPartitionName() == "" {
			return merr.WrapErrParameterMissingMsg("partition not specified")
		}
		// Currently, Backup tool call import must with a partition name, each time restore a partition
		partitionID, err := globalMetaCache.GetPartitionID(ctx, req.GetDbName(), req.GetCollectionName(), req.GetPartitionName())
		if err != nil {
			return err
		}
		partitionIDs = []UniqueID{partitionID}
	} else if isL0Import {
		if req.GetPartitionName() == "" {
			partitionIDs = []UniqueID{common.AllPartitionsID}
		} else {
			partitionID, err := globalMetaCache.GetPartitionID(ctx, req.GetDbName(), req.GetCollectionName(), req.PartitionName)
			if err != nil {
				return err
			}
			partitionIDs = []UniqueID{partitionID}
		}
		// Currently, querynodes first load L0 segments and then load L1 segments.
		// Therefore, to ensure the deletes from L0 import take effect,
		// the collection needs to be in an unloaded state,
		// and then all L0 and L1 segments should be loaded at once.
		// We will remove this restriction after querynode supported to load L0 segments dynamically.
		loaded, err := isCollectionLoaded(ctx, node.mixCoord, collectionID)
		if err != nil {
			return err
		}
		if loaded {
			return merr.WrapErrImportFailed("for l0 import, collection cannot be loaded, please release it first")
		}
	} else {
		if hasPartitionKey {
			if req.GetPartitionName() != "" {
				return merr.WrapErrImportFailed("not allow to set partition name for collection with partition key")
			}
			partitions, err := globalMetaCache.GetPartitions(ctx, req.GetDbName(), req.GetCollectionName())
			if err != nil {
				return err
			}
			_, partitionIDs, err = typeutil.RearrangePartitionsForPartitionKey(partitions)
			if err != nil {
				return err
			}
		} else {
			if req.GetPartitionName() == "" {
				req.PartitionName = Params.CommonCfg.DefaultPartitionName.GetValue()
			}
			partitionID, err := globalMetaCache.GetPartitionID(ctx, req.GetDbName(), req.GetCollectionName(), req.PartitionName)
			if err != nil {
				return err
			}
			partitionIDs = []UniqueID{partitionID}
		}
	}

	req.Files = lo.Filter(req.GetFiles(), func(file *internalpb.ImportFile, _ int) bool {
		return len(file.GetPaths()) > 0
	})
	if len(req.Files) == 0 {
		return merr.WrapErrParameterInvalidMsg("import request is empty")
	}
	if len(req.Files) > Params.DataCoordCfg.MaxFilesPerImportReq.GetAsInt() {
		return merr.WrapErrImportFailedMsg("The max number of import files should not exceed %d, but got %d",
			Params.DataCoordCfg.MaxFilesPerImportReq.GetAsInt(), len(req.Files))
	}
	if !isBackup && !isL0Import {
		// check file type
		for _, file := range req.GetFiles() {
			_, err = importutilv2.GetFileType(file)
			if err != nil {
				return err
			}
		}
	}
	it.partitionIDs = partitionIDs
	return nil
}

func (it *importTask) setChannels() error {
	// import task only send message by broadcast, which didn't affect the time tick rule at proxy.
	// so we don't need to set channels here.
	return nil
}

func (it *importTask) getChannels() []pChan {
	return nil
}

func (it *importTask) Execute(ctx context.Context) error {
	// Call DataCoord's Import method directly instead of broadcasting
	// DataCoord will handle validation, broadcasting, and job creation

	// Get database ID from database name
	dbInfo, err := globalMetaCache.GetDatabaseInfo(ctx, it.req.GetDbName())
	if err != nil {
		mlog.Warn(ctx, "failed to get database info", mlog.FieldDbName(it.req.GetDbName()), mlog.Err(err))
		return err
	}

	importReq := &internalpb.ImportRequestInternal{
		DbID:           dbInfo.dbID,
		CollectionID:   it.collectionID,
		CollectionName: it.req.GetCollectionName(),
		PartitionIDs:   it.partitionIDs,
		ChannelNames:   it.vchannels,
		Schema:         it.schema.CollectionSchema,
		Files:          it.req.GetFiles(),
		Options:        it.req.GetOptions(),
		DataTimestamp:  0, // DO NOT set - used to differentiate proxy call from ack callback
		JobID:          0, // Let DataCoord allocate
	}

	resp, err := it.mixCoord.ImportV2(ctx, importReq)
	if err != nil {
		mlog.Warn(ctx, "import request to datacoord failed", mlog.Err(err))
		return err
	}
	if resp.GetStatus().GetErrorCode() != commonpb.ErrorCode_Success {
		err = merr.Error(resp.GetStatus())
		mlog.Warn(ctx, "import request rejected by datacoord", mlog.Err(err))
		return err
	}
	mlog.Info(ctx, "import request sent to datacoord successfully",
		mlog.String("jobID", resp.GetJobID()),
	)
	it.resp.JobID = resp.GetJobID()
	return nil
}

func GetImportFiles(internals []*internalpb.ImportFile) []*msgpb.ImportFile {
	return lo.Map(internals, func(internal *internalpb.ImportFile, _ int) *msgpb.ImportFile {
		return &msgpb.ImportFile{
			Id:    internal.GetId(),
			Paths: internal.GetPaths(),
		}
	})
}

func (it *importTask) PostExecute(ctx context.Context) error {
	return nil
}
