package storage

import (
	"encoding/xml"
	"errors"
	"path"
	"sort"
	"strconv"
	"strings"
	"sync"
	"time"

	"code.gitea.io/gitea/modules/log"
	"code.gitea.io/gitea/modules/minio_ext"
	"code.gitea.io/gitea/modules/setting"

	miniov6 "github.com/minio/minio-go/v6"
)

const (
	PresignedUploadPartUrlExpireTime = time.Hour * 24 * 7
)

type ComplPart struct {
	PartNumber int    `json:"partNumber"`
	ETag       string `json:"eTag"`
}

type CompleteParts struct {
	Data []ComplPart `json:"completedParts"`
}

// completedParts is a collection of parts sortable by their part numbers.
// used for sorting the uploaded parts before completing the multipart request.
type completedParts []miniov6.CompletePart

func (a completedParts) Len() int           { return len(a) }
func (a completedParts) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a completedParts) Less(i, j int) bool { return a[i].PartNumber < a[j].PartNumber }

// completeMultipartUpload container for completing multipart upload.
type completeMultipartUpload struct {
	XMLName xml.Name               `xml:"http://s3.amazonaws.com/doc/2006-03-01/ CompleteMultipartUpload" json:"-"`
	Parts   []miniov6.CompletePart `xml:"Part"`
}

var (
	adminClient *minio_ext.Client = nil
	coreClient  *miniov6.Core     = nil
)

var mutex *sync.Mutex

func init() {
	mutex = new(sync.Mutex)
}

func getClients() (*minio_ext.Client, *miniov6.Core, error) {
	var client *minio_ext.Client
	var core *miniov6.Core
	mutex.Lock()

	defer mutex.Unlock()

	if nil != adminClient && nil != coreClient {
		client = adminClient
		core = coreClient
		return client, core, nil
	}

	var err error
	minio := setting.Attachment.Minio
	if nil == adminClient {
		adminClient, err = minio_ext.New(
			minio.Endpoint,
			minio.AccessKeyID,
			minio.SecretAccessKey,
			minio.UseSSL,
		)
		if nil != err {
			return nil, nil, err
		}
	}

	client = adminClient

	if nil == coreClient {
		coreClient, err = miniov6.NewCore(
			minio.Endpoint,
			minio.AccessKeyID,
			minio.SecretAccessKey,
			minio.UseSSL,
		)
		if nil != err {
			return nil, nil, err
		}
	}

	core = coreClient

	return client, core, nil
}

func GenMultiPartSignedUrl(uuid string, uploadId string, partNumber int, partSize int64) (string, error) {
	minioClient, _, err := getClients()
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return "", err
	}

	minio := setting.Attachment.Minio
	bucketName := minio.Bucket
	objectName := strings.TrimPrefix(path.Join(minio.BasePath, path.Join(uuid[0:1], uuid[1:2], uuid)), "/")

	return minioClient.GenUploadPartSignedUrl(uploadId, bucketName, objectName, partNumber, partSize, PresignedUploadPartUrlExpireTime, setting.Attachment.Minio.Location)
}

func GetAllObjectByBucketAndPrefixMinio(bucket string, prefix string) ([]FileInfo, error) {
	_, core, err := getClients()
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return nil, err
	}
	prefixLen := len(prefix)
	delimiter := ""
	marker := ""
	index := 1
	fileInfoList := FileInfoList{}
	for {
		output, err := core.ListObjects(bucket, prefix, marker, delimiter, 1000)
		if err == nil {
			log.Info("Page:%d\n", index)
			index++
			for _, val := range output.Contents {
				var isDir bool
				if prefixLen == len(val.Key) {
					continue
				}
				if strings.HasSuffix(val.Key, "/") {
					isDir = true
				} else {
					isDir = false
				}
				fileInfo := FileInfo{
					ModTime:  val.LastModified.Format("2006-01-02 15:04:05"),
					FileName: val.Key[prefixLen:],
					Size:     val.Size,
					IsDir:    isDir,
					ParenDir: "",
				}
				fileInfoList = append(fileInfoList, fileInfo)
			}
			if output.IsTruncated {
				marker = output.NextMarker
			} else {
				break
			}
		} else {
			log.Info("list error." + err.Error())
			return nil, err
		}
	}
	sort.Sort(fileInfoList)
	return fileInfoList, nil
}

func GetOneLevelAllObjectUnderDirMinio(bucket string, prefixRootPath string, relativePath string) ([]FileInfo, error) {
	_, core, err := getClients()
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return nil, err
	}

	Prefix := prefixRootPath + relativePath
	if !strings.HasSuffix(Prefix, "/") {
		Prefix += "/"
	}
	log.Info("bucket=" + bucket + " Prefix=" + Prefix)
	output, err := core.ListObjects(bucket, Prefix, "", "", 1000)
	fileInfos := make([]FileInfo, 0)
	prefixLen := len(Prefix)
	fileMap := make(map[string]bool, 0)
	if err == nil {
		for _, val := range output.Contents {

			log.Info("val key=" + val.Key)
			var isDir bool
			var fileName string
			if val.Key == Prefix {
				continue
			}
			fileName = val.Key[prefixLen:]
			log.Info("fileName =" + fileName)
			files := strings.Split(fileName, "/")
			if fileMap[files[0]] {
				continue
			} else {
				fileMap[files[0]] = true
			}
			ParenDir := relativePath
			fileName = files[0]
			if len(files) > 1 {
				isDir = true
				ParenDir += fileName + "/"
			} else {
				isDir = false
			}

			fileInfo := FileInfo{
				ModTime:  val.LastModified.Local().Format("2006-01-02 15:04:05"),
				FileName: fileName,
				Size:     val.Size,
				IsDir:    isDir,
				ParenDir: ParenDir,
			}
			fileInfos = append(fileInfos, fileInfo)
		}
		return fileInfos, err
	} else {

		log.Error("Message:%s", err.Error())

		return nil, err
	}

}

func MinioGetFilesSize(bucketName string, Files []string) int64 {
	_, core, err := getClients()
	var fileTotalSize int64
	fileTotalSize = 0
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return fileTotalSize
	}
	for _, file := range Files {
		log.Info("file=" + file)
		meta, err := core.StatObject(bucketName, file, miniov6.StatObjectOptions{})
		if err != nil {
			log.Info("Get file error:" + err.Error())
		}
		fileTotalSize += meta.Size
	}
	return fileTotalSize
}

func MinioCopyFiles(bucketName string, srcPath string, destPath string, Files []string) (int64, error) {
	_, core, err := getClients()
	var fileTotalSize int64
	fileTotalSize = 0
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return fileTotalSize, err
	}

	for _, file := range Files {
		srcObjectName := srcPath + file
		destObjectName := destPath + file
		log.Info("srcObjectName=" + srcObjectName + " destObjectName=" + destObjectName)
		meta, err := core.StatObject(bucketName, srcObjectName, miniov6.StatObjectOptions{})
		if err != nil {
			log.Info("Get file error:" + err.Error())
		}
		core.CopyObject(bucketName, srcObjectName, bucketName, destObjectName, meta.UserMetadata)
		fileTotalSize += meta.Size
	}

	return fileTotalSize, nil
}

func MinioPathCopy(bucketName string, srcPath string, destPath string) (int64, error) {
	_, core, err := getClients()
	var fileTotalSize int64
	fileTotalSize = 0
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return fileTotalSize, err
	}
	delimiter := ""
	marker := ""
	for {
		output, err := core.ListObjects(bucketName, srcPath, marker, delimiter, 1000)
		if err == nil {
			for _, val := range output.Contents {
				srcObjectName := val.Key
				destObjectName := destPath + srcObjectName[len(srcPath):]
				log.Info("srcObjectName=" + srcObjectName + " destObjectName=" + destObjectName)
				core.CopyObject(bucketName, srcObjectName, bucketName, destObjectName, val.UserMetadata)
				fileTotalSize += val.Size
			}
			if output.IsTruncated {
				marker = output.NextMarker
			} else {
				break
			}
		} else {
			log.Info("list error." + err.Error())
			return 0, err
		}
	}
	return fileTotalSize, nil
}

func NewMultiPartUpload(uuid string) (string, error) {
	_, core, err := getClients()
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return "", err
	}

	minio := setting.Attachment.Minio
	bucketName := minio.Bucket
	objectName := strings.TrimPrefix(path.Join(minio.BasePath, path.Join(uuid[0:1], uuid[1:2], uuid)), "/")

	return core.NewMultipartUpload(bucketName, objectName, miniov6.PutObjectOptions{})
}

func CompleteMultiPartUpload(uuid string, uploadID string, totalChunks int) (string, error) {
	client, core, err := getClients()
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return "", err
	}

	minio := setting.Attachment.Minio
	bucketName := minio.Bucket
	objectName := strings.TrimPrefix(path.Join(minio.BasePath, path.Join(uuid[0:1], uuid[1:2], uuid)), "/")

	partInfos, err := client.ListObjectParts(bucketName, objectName, uploadID)
	if err != nil {
		log.Error("ListObjectParts failed:", err.Error())
		return "", err
	}

	if len(partInfos) != totalChunks {
		log.Error("ListObjectParts number(%d) is not equal the set total chunk number(%d)", len(partInfos), totalChunks)
		return "", errors.New("the parts is not complete")
	}

	var complMultipartUpload completeMultipartUpload
	for _, partInfo := range partInfos {
		complMultipartUpload.Parts = append(complMultipartUpload.Parts, miniov6.CompletePart{
			PartNumber: partInfo.PartNumber,
			ETag:       partInfo.ETag,
		})
	}

	// Sort all completed parts.
	sort.Sort(completedParts(complMultipartUpload.Parts))

	return core.CompleteMultipartUpload(bucketName, objectName, uploadID, complMultipartUpload.Parts)
}

func GetPartInfos(uuid string, uploadID string) (string, error) {
	minioClient, _, err := getClients()
	if err != nil {
		log.Error("getClients failed:", err.Error())
		return "", err
	}

	minio := setting.Attachment.Minio
	bucketName := minio.Bucket
	objectName := strings.TrimPrefix(path.Join(minio.BasePath, path.Join(uuid[0:1], uuid[1:2], uuid)), "/")

	partInfos, err := minioClient.ListObjectParts(bucketName, objectName, uploadID)
	if err != nil {
		log.Error("ListObjectParts failed:", err.Error())
		return "", err
	}

	var chunks string
	for _, partInfo := range partInfos {
		chunks += strconv.Itoa(partInfo.PartNumber) + "-" + partInfo.ETag + ","
	}

	return chunks, nil
}