package services

import (
	"fmt"

	cdssdk "gitlink.org.cn/cloudream/common/sdks/storage"

	stgglb "gitlink.org.cn/cloudream/storage/common/globals"
	"gitlink.org.cn/cloudream/storage/common/pkgs/db/model"
	"gitlink.org.cn/cloudream/storage/common/pkgs/iterator"
	coormq "gitlink.org.cn/cloudream/storage/common/pkgs/mq/coordinator"
)

// PackageService 提供对包相关操作的服务接口
type PackageService struct {
	*Service
}

// PackageSvc 创建并返回一个PackageService的实例
func (svc *Service) PackageSvc() *PackageService {
	return &PackageService{Service: svc}
}

// Get 获取指定用户的指定包信息
func (svc *PackageService) Get(userID cdssdk.UserID, packageID cdssdk.PackageID) (*model.Package, error) {
	// 从协调器MQ池中获取客户端
	coorCli, err := stgglb.CoordinatorMQPool.Acquire()
	if err != nil {
		return nil, fmt.Errorf("new coordinator client: %w", err)
	}
	defer stgglb.CoordinatorMQPool.Release(coorCli)

	// 向协调器请求获取包信息
	getResp, err := coorCli.GetPackage(coormq.NewGetPackage(userID, packageID))
	if err != nil {
		return nil, fmt.Errorf("requsting to coodinator: %w", err)
	}

	return &getResp.Package, nil
}

// Create 创建一个新的包
func (svc *PackageService) Create(userID cdssdk.UserID, bucketID cdssdk.BucketID, name string) (cdssdk.PackageID, error) {
	// 从协调器MQ池中获取客户端
	coorCli, err := stgglb.CoordinatorMQPool.Acquire()
	if err != nil {
		return 0, fmt.Errorf("new coordinator client: %w", err)
	}
	defer stgglb.CoordinatorMQPool.Release(coorCli)

	// 向协调器发送创建包的请求
	resp, err := coorCli.CreatePackage(coormq.NewCreatePackage(userID, bucketID, name))
	if err != nil {
		return 0, fmt.Errorf("creating package: %w", err)
	}

	return resp.PackageID, nil
}

// DownloadPackage 下载指定包的内容
func (svc *PackageService) DownloadPackage(userID cdssdk.UserID, packageID cdssdk.PackageID) (iterator.DownloadingObjectIterator, error) {
	// 从协调器MQ池中获取客户端
	coorCli, err := stgglb.CoordinatorMQPool.Acquire()
	if err != nil {
		return nil, fmt.Errorf("new coordinator client: %w", err)
	}
	defer stgglb.CoordinatorMQPool.Release(coorCli)

	// 向协调器请求获取包内对象的详情
	getObjsResp, err := coorCli.GetPackageObjectDetails(coormq.NewGetPackageObjectDetails(packageID))
	if err != nil {
		return nil, fmt.Errorf("getting package object details: %w", err)
	}

	// 创建下载对象的迭代器
	iter := iterator.NewDownloadObjectIterator(getObjsResp.Objects, &iterator.DownloadContext{
		Distlock: svc.DistLock,
	})

	return iter, nil
}

// DeletePackage 删除指定的包
func (svc *PackageService) DeletePackage(userID cdssdk.UserID, packageID cdssdk.PackageID) error {
	// 从协调器MQ池中获取客户端
	coorCli, err := stgglb.CoordinatorMQPool.Acquire()
	if err != nil {
		return fmt.Errorf("new coordinator client: %w", err)
	}
	defer stgglb.CoordinatorMQPool.Release(coorCli)

	// 向协调器发送删除包的请求
	_, err = coorCli.DeletePackage(coormq.NewDeletePackage(userID, packageID))
	if err != nil {
		return fmt.Errorf("deleting package: %w", err)
	}

	return nil
}

// GetCachedNodes 获取指定包的缓存节点信息
func (svc *PackageService) GetCachedNodes(userID cdssdk.UserID, packageID cdssdk.PackageID) (cdssdk.PackageCachingInfo, error) {
	// 从协调器MQ池中获取客户端
	coorCli, err := stgglb.CoordinatorMQPool.Acquire()
	if err != nil {
		return cdssdk.PackageCachingInfo{}, fmt.Errorf("new coordinator client: %w", err)
	}
	defer stgglb.CoordinatorMQPool.Release(coorCli)

	// 向协调器请求获取包的缓存节点信息
	resp, err := coorCli.GetPackageCachedNodes(coormq.NewGetPackageCachedNodes(userID, packageID))
	if err != nil {
		return cdssdk.PackageCachingInfo{}, fmt.Errorf("get package cached nodes: %w", err)
	}

	// 构造并返回缓存信息
	tmp := cdssdk.PackageCachingInfo{
		NodeInfos:   resp.NodeInfos,
		PackageSize: resp.PackageSize,
	}
	return tmp, nil
}

// GetLoadedNodes 获取指定包加载的节点列表
func (svc *PackageService) GetLoadedNodes(userID cdssdk.UserID, packageID cdssdk.PackageID) ([]cdssdk.NodeID, error) {
	// 从协调器MQ池中获取客户端
	coorCli, err := stgglb.CoordinatorMQPool.Acquire()
	if err != nil {
		return nil, fmt.Errorf("new coordinator client: %w", err)
	}
	defer stgglb.CoordinatorMQPool.Release(coorCli)

	// 向协调器请求获取加载指定包的节点ID列表
	resp, err := coorCli.GetPackageLoadedNodes(coormq.NewGetPackageLoadedNodes(userID, packageID))
	if err != nil {
		return nil, fmt.Errorf("get package loaded nodes: %w", err)
	}
	return resp.NodeIDs, nil
}