package services

import (
	"context"
	"fmt"
	"path"

	"gitlink.org.cn/cloudream/common/pkgs/ioswitch/exec"
	cdssdk "gitlink.org.cn/cloudream/storage2/client/types"

	"gitlink.org.cn/cloudream/storage2/client/types"
	stgglb "gitlink.org.cn/cloudream/storage2/common/globals"
	stgmod "gitlink.org.cn/cloudream/storage2/common/models"
	"gitlink.org.cn/cloudream/storage2/common/pkgs/distlock/reqbuilder"
	"gitlink.org.cn/cloudream/storage2/common/pkgs/downloader/strategy"
	"gitlink.org.cn/cloudream/storage2/common/pkgs/ioswitch2"
	"gitlink.org.cn/cloudream/storage2/common/pkgs/ioswitch2/parser"
	agtmq "gitlink.org.cn/cloudream/storage2/common/pkgs/mq/agent"
	coormq "gitlink.org.cn/cloudream/storage2/common/pkgs/mq/coordinator"
	"gitlink.org.cn/cloudream/storage2/common/pkgs/storage/factory"
)

type UserSpaceService struct {
	*Service
}

func (svc *Service) UserSpaceSvc() *UserSpaceService {
	return &UserSpaceService{Service: svc}
}

func (svc *UserSpaceService) Get(userspaceID cdssdk.UserSpaceID) (types.UserSpace, error) {
	return svc.DB.UserSpace().GetByID(svc.DB.DefCtx(), userspaceID)
}

func (svc *UserSpaceService) GetByName(name string) (types.UserSpace, error) {
	return svc.DB.UserSpace().GetByName(svc.DB.DefCtx(), name)
}

func (svc *UserSpaceService) GetDetails(stgIDs []cdssdk.UserSpaceID) ([]*stgmod.UserSpaceDetail, error) {

}

func (svc *UserSpaceService) LoadPackage(packageID cdssdk.PackageID, userspaceID cdssdk.UserSpaceID, rootPath string) error {
	coorCli, err := stgglb.CoordinatorMQPool.Acquire()
	if err != nil {
		return fmt.Errorf("new coordinator client: %w", err)
	}
	defer stgglb.CoordinatorMQPool.Release(coorCli)

	destStg := svc.UserSpaceMeta.Get(userspaceID)
	if destStg == nil {
		return fmt.Errorf("userspace not found: %d", userspaceID)
	}
	if destStg.MasterHub == nil {
		return fmt.Errorf("userspace %v has no master hub", userspaceID)
	}

	details, err := coorCli.GetPackageObjectDetails(coormq.ReqGetPackageObjectDetails(packageID))
	if err != nil {
		return err
	}

	var pinned []cdssdk.ObjectID
	plans := exec.NewPlanBuilder()
	for _, obj := range details.Objects {
		strg, err := svc.StrategySelector.Select(strategy.Request{
			Detail:  obj,
			DestHub: destStg.MasterHub.HubID,
		})
		if err != nil {
			return fmt.Errorf("select download strategy: %w", err)
		}

		ft := ioswitch2.NewFromTo()
		switch strg := strg.(type) {
		case *strategy.DirectStrategy:
			ft.AddFrom(ioswitch2.NewFromShardstore(strg.Detail.Object.FileHash, *strg.UserSpace.MasterHub, strg.UserSpace, ioswitch2.RawStream()))

		case *strategy.ECReconstructStrategy:
			for i, b := range strg.Blocks {
				ft.AddFrom(ioswitch2.NewFromShardstore(b.FileHash, *strg.UserSpaces[i].MasterHub, strg.UserSpaces[i], ioswitch2.ECStream(b.Index)))
				ft.ECParam = &strg.Redundancy
			}
		default:
			return fmt.Errorf("unsupported download strategy: %T", strg)
		}

		ft.AddTo(ioswitch2.NewLoadToPublic(*destStg.MasterHub, *destStg, path.Join(rootPath, obj.Object.Path)))
		// 顺便保存到同存储服务的分片存储中
		if factory.GetBuilder(*destStg).ShardStoreDesc().Enabled() {
			ft.AddTo(ioswitch2.NewToShardStore(*destStg.MasterHub, *destStg, ioswitch2.RawStream(), ""))
			pinned = append(pinned, obj.Object.ObjectID)
		}

		err = parser.Parse(ft, plans)
		if err != nil {
			return fmt.Errorf("parse plan: %w", err)
		}
	}

	mutex, err := reqbuilder.NewBuilder().
		// 保护在userspace目录中下载的文件
		UserSpace().Buzy(userspaceID).
		// 保护下载文件时同时保存到IPFS的文件
		Shard().Buzy(userspaceID).
		MutexLock(svc.DistLock)
	if err != nil {
		return fmt.Errorf("acquire locks failed, err: %w", err)
	}

	// 记录访问统计
	for _, obj := range details.Objects {
		svc.AccessStat.AddAccessCounter(obj.Object.ObjectID, packageID, userspaceID, 1)
	}

	defer mutex.Unlock()

	drv := plans.Execute(exec.NewExecContext())
	_, err = drv.Wait(context.Background())
	if err != nil {
		return err
	}

	// 失败也没关系
	coorCli.UserSpacePackageLoaded(coormq.ReqUserSpacePackageLoaded(userID, userspaceID, packageID, rootPath, pinned))
	return nil
}

// 请求节点启动从UserSpace中上传文件的任务。会返回节点ID和任务ID
func (svc *UserSpaceService) UserSpaceCreatePackage(bucketID cdssdk.BucketID, name string, userspaceID cdssdk.UserSpaceID, path string, userspaceAffinity cdssdk.UserSpaceID) (cdssdk.Package, error) {
	coorCli, err := stgglb.CoordinatorMQPool.Acquire()
	if err != nil {
		return cdssdk.Package{}, fmt.Errorf("new coordinator client: %w", err)
	}
	defer stgglb.CoordinatorMQPool.Release(coorCli)

	stgResp, err := coorCli.GetUserSpaceDetails(coormq.ReqGetUserSpaceDetails([]cdssdk.UserSpaceID{userspaceID}))
	if err != nil {
		return cdssdk.Package{}, fmt.Errorf("getting userspace info: %w", err)
	}

	if stgResp.UserSpaces[0].UserSpace.ShardStore == nil {
		return cdssdk.Package{}, fmt.Errorf("shard userspace is not enabled")
	}

	agentCli, err := stgglb.AgentMQPool.Acquire(stgResp.UserSpaces[0].MasterHub.HubID)
	if err != nil {
		return cdssdk.Package{}, fmt.Errorf("new agent client: %w", err)
	}
	defer stgglb.AgentMQPool.Release(agentCli)

	createResp, err := agentCli.UserSpaceCreatePackage(agtmq.ReqUserSpaceCreatePackage(bucketID, name, userspaceID, path, userspaceAffinity))
	if err != nil {
		return cdssdk.Package{}, err
	}

	return createResp.Package, nil
}