package storageproviders

import (
	"os"
	"path/filepath"
	"sort"

	"github.com/pkg/errors"
	log "github.com/sirupsen/logrus"

	"github.com/owncast/owncast/config"
	"github.com/owncast/owncast/core/data"
	"github.com/owncast/owncast/utils"
)

// LocalStorage represents an instance of the local storage provider for HLS video.
type LocalStorage struct {
	streamID string
}

// NewLocalStorage returns a new LocalStorage instance.
func NewLocalStorage() *LocalStorage {
	return &LocalStorage{}
}

// SetStreamId sets the stream id for this storage provider.
func (s *LocalStorage) SetStreamId(streamID string) {
	s.streamID = streamID
}

// Setup configures this storage provider.
func (s *LocalStorage) Setup() error {
	return nil
}

// SegmentWritten is called when a single segment of video is written.
func (s *LocalStorage) SegmentWritten(localFilePath string) (string, int, error) {
	if s.streamID == "" {
		log.Fatalln("stream id must be set when handling video segments")
	}

	destinationPath, err := s.Save(localFilePath, localFilePath, 0)
	if err != nil {
		log.Warnln(err)
		return "", 0, err
	}

	return destinationPath, 0, nil
}

// VariantPlaylistWritten is called when a variant hls playlist is written.
func (s *LocalStorage) VariantPlaylistWritten(localFilePath string) {
	if s.streamID == "" {
		log.Fatalln("stream id must be set when handling video playlists")
	}

	if _, err := s.Save(localFilePath, localFilePath, 0); err != nil {
		log.Errorln(err)
		return
	}
}

// MasterPlaylistWritten is called when the master hls playlist is written.
func (s *LocalStorage) MasterPlaylistWritten(localFilePath string) {
	if s.streamID == "" {
		log.Fatalln("stream id must be set when handling video playlists")
	}

	masterPlaylistDestinationLocation := filepath.Join(config.HLSStoragePath, "/stream.m3u8")
	if err := rewriteLocalPlaylist(localFilePath, s.streamID, masterPlaylistDestinationLocation); err != nil {
		log.Errorln(err)
		return
	}
}

// Save will save a local filepath using the storage provider.
func (s *LocalStorage) Save(filePath, destinationPath string, retryCount int) (string, error) {
	if filePath != destinationPath {
		if err := utils.Move(filePath, destinationPath); err != nil {
			return "", errors.Wrap(err, "unable to move file")
		}
	}

	return destinationPath, nil
}

func (s *LocalStorage) Cleanup() error {
	// If we're recording, don't perform the cleanup.
	if config.EnableReplayFeatures {
		return nil
	}

	// Determine how many files we should keep on disk
	maxNumber := data.GetStreamLatencyLevel().SegmentCount
	buffer := 10
	baseDirectory := config.HLSStoragePath

	files, err := getAllFilesRecursive(baseDirectory)
	if err != nil {
		return errors.Wrap(err, "unable find old video files for cleanup")
	}

	// Delete old private HLS files on disk
	for directory := range files {
		files := files[directory]
		if len(files) < maxNumber+buffer {
			continue
		}

		filesToDelete := files[maxNumber+buffer:]
		log.Traceln("Deleting", len(filesToDelete), "old files from", baseDirectory, "for video variant", directory)

		for _, file := range filesToDelete {
			fileToDelete := filepath.Join(baseDirectory, directory, file.Name())
			err := os.Remove(fileToDelete)
			if err != nil {
				return errors.Wrap(err, "unable to delete old video files")
			}
		}
	}
	return nil
}

func (s *LocalStorage) GetRemoteDestinationPathFromLocalFilePath(localFilePath string) string {
	return localFilePath
}

func getAllFilesRecursive(baseDirectory string) (map[string][]os.FileInfo, error) {
	files := make(map[string][]os.FileInfo)

	var directory string
	err := filepath.Walk(baseDirectory, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		if info.IsDir() {
			directory = info.Name()
		}

		if filepath.Ext(info.Name()) == ".ts" {
			files[directory] = append(files[directory], info)
		}

		return nil
	})
	if err != nil {
		return nil, err
	}

	// Sort by date so we can delete old files
	for directory := range files {
		sort.Slice(files[directory], func(i, j int) bool {
			return files[directory][i].ModTime().UnixNano() > files[directory][j].ModTime().UnixNano()
		})
	}

	return files, nil
}