package uploader

import (
	"context"
	"fmt"
	"io"
	"math"
	"time"

	"github.com/samber/lo"
	"gitlink.org.cn/cloudream/jcs-pub/client/internal/db"
	stgglb "gitlink.org.cn/cloudream/jcs-pub/common/globals"
	"gitlink.org.cn/cloudream/jcs-pub/common/pkgs/ioswitch/exec"
	"gitlink.org.cn/cloudream/jcs-pub/common/pkgs/ioswitch2"
	"gitlink.org.cn/cloudream/jcs-pub/common/pkgs/ioswitch2/ops2"
	"gitlink.org.cn/cloudream/jcs-pub/common/pkgs/ioswitch2/parser"
	"gitlink.org.cn/cloudream/jcs-pub/common/pkgs/publock/reqbuilder"
	corrpc "gitlink.org.cn/cloudream/jcs-pub/common/pkgs/rpc/coordinator"
	stgtypes "gitlink.org.cn/cloudream/jcs-pub/common/pkgs/storage/types"
	jcstypes "gitlink.org.cn/cloudream/jcs-pub/common/types"
)

func (u *Uploader) UserSpaceUpload(userSpaceID jcstypes.UserSpaceID, rootPath jcstypes.JPath, targetBktID jcstypes.BucketID, newPkgName string, uploadAffinity jcstypes.UserSpaceID) (*jcstypes.Package, error) {
	srcSpace := u.spaceMeta.Get(userSpaceID)
	if srcSpace == nil {
		return nil, fmt.Errorf("user space %d not found", userSpaceID)
	}

	pkg, err := db.DoTx01(u.db, func(tx db.SQLContext) (jcstypes.Package, error) {
		_, err := u.db.Bucket().GetByID(tx, targetBktID)
		if err != nil {
			return jcstypes.Package{}, err
		}

		return u.db.Package().Create(tx, targetBktID, newPkgName, time.Now())
	})
	if err != nil {
		return nil, fmt.Errorf("creating package: %w", err)
	}
	delPkg := func() {
		u.db.Package().Delete(u.db.DefCtx(), pkg.PackageID)
	}

	spaceIDs, err := u.db.UserSpace().GetAllIDs(u.db.DefCtx())
	if err != nil {
		delPkg()
		return nil, fmt.Errorf("getting user space ids: %w", err)
	}

	spaceDetails := u.spaceMeta.GetMany(spaceIDs)
	spaceDetails = lo.Filter(spaceDetails, func(e *jcstypes.UserSpaceDetail, i int) bool {
		return e != nil && e.UserSpace.ShardStore != nil
	})

	var uploadSpaces []UploadSpaceInfo
	// TODO 应该要分离Standalone模式和RecommendHub为nil的情况
	if !stgglb.StandaloneMode && srcSpace.RecommendHub != nil {
		coorCli := stgglb.CoordinatorRPCPool.Get()
		defer coorCli.Release()

		resp, cerr := coorCli.GetHubConnectivities(context.Background(), corrpc.ReqGetHubConnectivities([]jcstypes.HubID{srcSpace.RecommendHub.HubID}))
		if cerr != nil {
			delPkg()
			return nil, fmt.Errorf("getting hub connectivities: %w", cerr.ToError())
		}

		cons := make(map[jcstypes.HubID]jcstypes.HubConnectivity)
		for _, c := range resp.Connectivities {
			cons[c.ToHubID] = c
		}

		for _, space := range spaceDetails {
			latency := time.Duration(math.MaxInt64)

			con, ok := cons[space.RecommendHub.HubID]
			if ok && con.Latency != nil {
				latency = time.Duration(*con.Latency * float32(time.Millisecond))
			}

			uploadSpaces = append(uploadSpaces, UploadSpaceInfo{
				Space:          *space,
				Delay:          latency,
				IsSameLocation: space.UserSpace.Storage.GetLocation() == srcSpace.UserSpace.Storage.GetLocation(),
			})
		}
	} else {
		for _, space := range spaceDetails {
			uploadSpaces = append(uploadSpaces, UploadSpaceInfo{
				Space:          *space,
				IsSameLocation: space.UserSpace.Storage.GetLocation() == srcSpace.UserSpace.Storage.GetLocation(),
			})
		}
	}

	if len(uploadSpaces) == 0 {
		delPkg()
		return nil, fmt.Errorf("user no available userspaces")
	}

	targetSapce := u.chooseUploadStorage(uploadSpaces, uploadAffinity)

	store, err := u.stgPool.GetBaseStore(srcSpace)
	if err != nil {
		delPkg()
		return nil, fmt.Errorf("getting base store: %w", err)
	}

	mutex, err := reqbuilder.NewBuilder().UserSpace().Buzy(srcSpace.UserSpace.UserSpaceID).Buzy(targetSapce.Space.UserSpace.UserSpaceID).MutexLock(u.pubLock)
	if err != nil {
		delPkg()
		return nil, fmt.Errorf("acquire lock: %w", err)
	}
	defer mutex.Unlock()

	dirReader := store.ReadDir(rootPath)
	var adds []db.AddObjectEntry
	entries := make([]stgtypes.DirEntry, 0, 50)
	for {
		eof := false
		for len(entries) < 50 {
			entry, err := dirReader.Next()
			if err == io.EOF {
				eof = true
				break
			}
			if err != nil {
				delPkg()
				return nil, fmt.Errorf("reading dir: %w", err)
			}

			entries = append(entries, entry)
		}

		as, err := u.uploadFromBaseStore(srcSpace, &targetSapce.Space, entries, rootPath)
		if err != nil {
			delPkg()
			return nil, fmt.Errorf("uploading from base store: %w", err)
		}
		adds = append(adds, as...)
		entries = entries[:0]
		if eof {
			break
		}
	}

	_, err = db.DoTx21(u.db, u.db.Object().BatchAdd, pkg.PackageID, adds)
	if err != nil {
		delPkg()
		return nil, fmt.Errorf("adding objects: %w", err)
	}

	return &pkg, nil
}

func (u *Uploader) uploadFromBaseStore(srcSpace *jcstypes.UserSpaceDetail, targetSpace *jcstypes.UserSpaceDetail, entries []stgtypes.DirEntry, rootPath jcstypes.JPath) ([]db.AddObjectEntry, error) {
	ft := ioswitch2.FromTo{}

	for _, e := range entries {
		// 可以考虑增加一个配置项来控制是否上传空目录
		if e.IsDir {
			continue
		}

		ft.AddFrom(ioswitch2.NewFromBaseStore(*srcSpace, e.Path))
		ft.AddTo(ioswitch2.NewToShardStore(*targetSpace, ioswitch2.RawStream(), e.Path.String()))
	}

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

	exeCtx := exec.NewExecContext()
	exec.SetValueByType(exeCtx, u.stgPool)
	ret, err := plans.Execute(exeCtx).Wait(context.Background())
	if err != nil {
		return nil, fmt.Errorf("executing plan: %w", err)
	}

	adds := make([]db.AddObjectEntry, 0, len(ret.Stored))
	for _, e := range entries {
		if e.IsDir {
			continue
		}

		pat := e.Path.Clone()
		pat.PopFrontN(rootPath.Len() - 1)
		// 如果对象路径和RootPath相同（即RootPath是一个文件），则用文件名作为对象Path
		if pat.Len() > 1 {
			pat.PopFrontN(1)
		}

		info := ret.Get(e.Path.String()).(*ops2.FileInfoValue)
		adds = append(adds, db.AddObjectEntry{
			Path:         pat.String(),
			Size:         info.Size,
			FileHash:     info.Hash,
			CreateTime:   time.Now(),
			UserSpaceIDs: []jcstypes.UserSpaceID{targetSpace.UserSpace.UserSpaceID},
		})
	}

	return adds, nil
}