package metadata

import (
	"errors"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"
	"velvettear/badger/internal/config"
	"velvettear/badger/internal/database"
	"velvettear/badger/internal/database/models"
	"velvettear/badger/internal/executables"
	"velvettear/badger/internal/log"
	"velvettear/badger/internal/tools"

	"gorm.io/gorm"
)

// exported function(s)
func FromFile(file string) Metadata {
	timestamp := tools.LogTimestamp()
	metadata := Metadata{Path: file}
	executable, error := executables.GetExecutable(executables.FFPROBE)
	if error != nil {
		log.Fatal("could not get executable '"+executables.FFPROBE+"'", error.Error())
	}
	result, error := executable.Spawn("-show_format", "-show_streams", "-loglevel", "quiet", "-print_format", "flat", file)
	keys := getKeys()
	resultElements := strings.Split(result, "\n")
	for elementIndex := 0; elementIndex < len(resultElements); elementIndex++ {
		element := strings.Trim(resultElements[elementIndex], " ")
		if !strings.HasPrefix(strings.ToLower(element), METADATA_PREFIX) {
			continue
		}
		for keyIndex := 0; keyIndex < len(keys); keyIndex++ {
			key := keys[keyIndex]
			cut := strings.Index(element, "=")
			if cut == -1 {
				continue
			}
			elementKey := strings.Trim(strings.ToLower(element[0:cut]), " ")
			elementKey = elementKey[strings.LastIndex(elementKey, ".")+1:]
			if key != elementKey {
				continue
			}
			element = strings.Trim(strings.Trim(element[cut+1:], "\""), " ")
			switch key {
			case METADATA_TITLE:
				metadata.Title = element
			case METADATA_ALBUM:
				metadata.Album = element
			case METADATA_ARTIST:
				metadata.Artist = element
			case METADATA_ALBUM_ARTIST:
				separators := []string{",", ";", "|"}
				for index := 0; index < len(separators); index++ {
					element = strings.ReplaceAll(element, separators[index], "/")
				}
				parts := strings.Split(element, "/")
				for index := 0; index < len(parts); index++ {
					metadata.AlbumArtist = append(metadata.AlbumArtist, strings.Trim(parts[index], " "))
				}
			case METADATA_DATE:
				metadata.Date = element
			case METADATA_TRACK:
				metadata.TrackNo = strings.Split(element, "/")[0]
			case METADATA_DISC:
				metadata.DiscNo = strings.Split(element, "/")[0]
			case METADATA_DURATION:
				metadata.Duration = element
			case METADATA_BITRATE:
				metadata.Bitrate, _ = strconv.Atoi(element)
			}
		}
	}
	stats, error := os.Stat(metadata.Path)
	if error != nil {
		log.Error("encountered an error getting the stats for file '"+metadata.Path+"'", error.Error())
	}
	metadata.Modified = stats.ModTime()
	metadata.Size = stats.Size()
	metadata.generateFingerprint()
	metadata.generateChecksum()
	log.DebugTimed("parsed file '"+metadata.Path+"'", timestamp)
	metadata.Complete = true
	return metadata
}

func (metadata *Metadata) GenerateTargetPath() string {
	library := config.LibraryDirectory()
	artist := strings.Join(metadata.AlbumArtist, " - ")
	artist = strings.TrimRight(artist, " - ")
	if tools.IsEmpty(artist) {
		if tools.IsEmpty(metadata.Artist) {
			artist = "unknown"
		} else {
			artist = metadata.Artist
		}
	}
	library += string(os.PathSeparator) + artist
	if tools.NotEmpty(metadata.Album) {
		library += string(os.PathSeparator) + metadata.Album
	}
	return filepath.Clean(library)
}

func (metadata *Metadata) GenerateFileName() string {
	var filename string
	if tools.NotEmpty(metadata.DiscNo) {
		filename += tools.FrontFill(metadata.DiscNo, "0", 2)
	}
	if tools.NotEmpty(metadata.TrackNo) {
		if !tools.IsEmpty(filename) {
			filename += "-"
		}
		filename += tools.FrontFill(metadata.TrackNo, "0", 2)
	}
	if tools.NotEmpty(metadata.Artist) {
		if tools.NotEmpty(filename) {
			filename += " "
		}
		filename += metadata.Artist
	}
	if tools.NotEmpty(metadata.Title) {
		if tools.NotEmpty(filename) {
			filename += " - "
		}
		filename += metadata.Title
	}
	if tools.IsEmpty(filename) {
		return ""
	}
	return filename + filepath.Ext(metadata.Path)
}

// func (metadata *Metadata) ShouldBeMoved(target string) bool {
// 	if len(target) == 0 {
// 		return false
// 	}
// 	existing := tools.Exists(target)
// 	var track models.Track
// 	database.Connection().First(&track, models.Track{Path: target})
// 	if track.ID == 0 && !existing {
// 		log.Debug("file '" + metadata.Path + "' should be moved to '" + target + "', no entry in database and target does not exist")
// 		return true
// 	}
// 	if metadata.Bitrate < track.Bitrate {
// 		log.Debug("file '" + metadata.Path + "' should be moved to '" + target + "', no entry in database and target does not exist")
// 		return false
// 	}
// 	if existing {
// 		error := tools.DeleteFile(track.Path)
// 		if error != nil {
// 			log.Error("encountered an error deleting the file '" + track.Path + "' in order to replace it with '" + metadata.Path + "' ")
// 			return false
// 		}
// 	}
// 	return true
// }

func (metadata *Metadata) Store() error {
	timestamp := tools.LogTimestamp()
	if !metadata.Complete {
		return errors.New("can not store incomplete metadata")
	}
	artist := models.Artist{
		Name: metadata.Artist,
	}
	var connection *gorm.DB
	if config.DatabaseInMemory() {
		connection = database.Memory()
	} else {
		connection = database.File()
	}
	connection.FirstOrCreate(&artist, artist)
	if artist.ID <= 0 {
		return errors.New("could not find or create artist '" + artist.Name + "' in database")
	}
	album := models.Album{
		Name: metadata.Album,
	}
	connection.FirstOrCreate(&album, album)
	if album.ID <= 0 {
		return errors.New("could not find or create album '" + album.Name + "' in database")
	}
	track := models.Track{
		Path:        metadata.Path,
		Title:       metadata.Title,
		Date:        metadata.Title,
		TrackNo:     metadata.TrackNo,
		DiscNo:      metadata.DiscNo,
		Duration:    metadata.Duration,
		Bitrate:     metadata.Bitrate,
		Fingerprint: metadata.Fingerprint.RawValue,
		Checksum:    metadata.Checksum,
		Modified:    metadata.Modified.UnixMilli(),
		Size:        metadata.Size,
		ArtistID:    artist.ID,
		AlbumID:     album.ID,
	}
	connection.FirstOrCreate(&track, models.Track{Path: track.Path})
	if album.ID <= 0 {
		return errors.New("could not find or create track '" + track.Path + "' in database")
	}
	log.DebugTimed("stored parsed metadata for file '"+metadata.Path+"' in database", timestamp)
	return nil
}

// unexported function(s)
func getKeys() []string {
	return []string{
		METADATA_TITLE,
		METADATA_ALBUM,
		METADATA_ARTIST,
		METADATA_ALBUM_ARTIST,
		METADATA_DATE,
		METADATA_TRACK,
		METADATA_DISC,
		METADATA_DURATION,
		METADATA_BITRATE,
	}
}

func (metadata *Metadata) generateChecksum() {
	if !config.ChangeDetectionChecksum() {
		return
	}
	timestamp := tools.LogTimestamp()
	checksum, error := tools.XxHash(metadata.Path)
	if error != nil {
		log.Error("encountered an error generating xxhash checksum for file '"+metadata.Path+"'", error.Error())
		return
	}
	log.DebugTimed("generated xxhash checksum for file '"+metadata.Path+"'", timestamp)
	metadata.Checksum = strconv.FormatUint(checksum, 10)
}

// struct(s)
type Metadata struct {
	Title       string
	Album       string
	Artist      string
	AlbumArtist []string
	Date        string
	TrackNo     string
	DiscNo      string
	Duration    string
	Bitrate     int
	Path        string
	Fingerprint Fingerprint
	Modified    time.Time
	Size        int64
	Checksum    string
	Complete    bool
}