package arr

import (
	"regexp"
	"strings"
)

// MediaFile is a downloaded file as Radarr (movieFile) and Sonarr
// (episodeFile) describe it.
type MediaFile struct {
	Size         int64  `json:"size"`
	SceneName    string `json:"sceneName,omitempty"`
	RelativePath string `json:"relativePath,omitempty"`
	Quality      struct {
		Quality struct {
			Name       string `json:"name"`
			Resolution int    `json:"resolution"`
		} `json:"quality"`
	} `json:"quality"`
	MediaInfo struct {
		VideoCodec            string `json:"videoCodec"`
		VideoDynamicRange     string `json:"videoDynamicRange"`
		VideoDynamicRangeType string `json:"videoDynamicRangeType"`
		AudioCodec            string `json:"audioCodec"`
		AudioAdditional       string `json:"audioAdditionalFeatures"`
	} `json:"mediaInfo"`
	Languages []struct {
		Name string `json:"name"`
	} `json:"languages"`
}

// Codec names used for filtering.
const (
	CodecX265 = "x265"
	CodecX264 = "x264"
	CodecAV1  = "AV1"
)

// FileAttrs are the properties of a file the library can be filtered by.
type FileAttrs struct {
	Resolution int      // 2160, 1080, 720, 480 ... or 0 if unknown
	Codec      string   // CodecX265, CodecX264, CodecAV1 or ""
	HDR        bool     // HDR10, HDR10+, HLG, PQ (also with Dolby Vision on top)
	DV         bool     // Dolby Vision
	Audio      []string // audio formats, see the Audio* constants
	Languages  []string // audio languages
}

// Audio formats offered as filters. Atmos and the DTS flavours overlap with
// their carrier format: a "TrueHD Atmos" track is both Atmos and TrueHD, and
// every DTS flavour also counts as plain DTS.
const (
	AudioAtmos  = "Atmos"
	AudioTrueHD = "TrueHD"
	AudioDTSX   = "DTS:X"
	AudioDTSHD  = "DTS-HD"
	AudioDTS    = "DTS"
	AudioDDPlus = "DD+"
	AudioDD     = "DD"
	AudioAAC    = "AAC"
	AudioFLAC   = "FLAC"
	AudioOpus   = "Opus"
)

var (
	reRes    = regexp.MustCompile(`(?i)\b(2160|1080|720|576|480)p\b`)
	re265    = regexp.MustCompile(`(?i)(x\.?265|h\.?265|hevc)`)
	re264    = regexp.MustCompile(`(?i)(x\.?264|h\.?264|\bavc\b)`)
	reAV1    = regexp.MustCompile(`(?i)\bav1\b`)
	reDV     = regexp.MustCompile(`(?i)(\bdv\b|dovi|dolby[ .]?vision)`)
	reAtmos  = regexp.MustCompile(`(?i)(atmos|\bddpa\b)`)
	reTrueHD = regexp.MustCompile(`(?i)true[ .-]?hd`)
	reDTSX   = regexp.MustCompile(`(?i)\bdts[ .:-]?x\b`)
	reDTSHD  = regexp.MustCompile(`(?i)dts[ .-]?(hd|ma|hra|es)`)
	reDTS    = regexp.MustCompile(`(?i)\bdts([^a-z]|$)`)
	reDDPlus = regexp.MustCompile(`(?i)(e[ .-]?ac[ .-]?3|\bddp|dd\+|dolby digital plus)`)
	reDD     = regexp.MustCompile(`(?i)(\bac[ .-]?3\b|\bdd[ .]?[0-9]|dolby digital\b)`)
	reAAC    = regexp.MustCompile(`(?i)\baac`)
	reFLAC   = regexp.MustCompile(`(?i)\bflac\b`)
	reOpus   = regexp.MustCompile(`(?i)\bopus\b`)
	reHDR    = regexp.MustCompile(`(?i)\b(hdr(10(\+|plus)?)?|hlg|pq)\b`)
)

// Attrs derives the filterable properties. Radarr/Sonarr's media info is used
// when present, otherwise the names (scene name, path, quality) are searched.
func (f MediaFile) Attrs() FileAttrs {
	names := strings.Join([]string{f.SceneName, f.RelativePath, f.Quality.Quality.Name}, " ")
	a := FileAttrs{Resolution: f.Quality.Quality.Resolution}
	if a.Resolution == 0 {
		if m := reRes.FindStringSubmatch(names); m != nil {
			a.Resolution = atoi(m[1])
		}
	}

	if f.MediaInfo.VideoCodec != "" {
		// A codec we do not offer as a filter (VC-1, MPEG-2...) stays empty
		// rather than being guessed from the name.
		a.Codec = codecOf(f.MediaInfo.VideoCodec)
	} else {
		a.Codec = codecOf(names)
	}

	dr := f.MediaInfo.VideoDynamicRangeType + " " + f.MediaInfo.VideoDynamicRange
	if strings.TrimSpace(dr) == "" {
		dr = names
	}
	a.DV = reDV.MatchString(dr)
	a.HDR = reHDR.MatchString(dr)
	audio := f.MediaInfo.AudioCodec + " " + f.MediaInfo.AudioAdditional
	if strings.TrimSpace(audio) == "" {
		audio = names
	}
	a.Audio = audioTags(audio)
	for _, l := range f.Languages {
		if l.Name != "" {
			a.Languages = append(a.Languages, l.Name)
		}
	}
	return a
}

// audioTags finds the audio formats we offer as filters in free text.
func audioTags(s string) []string {
	var tags []string
	add := func(re *regexp.Regexp, tag string) {
		if re.MatchString(s) {
			tags = append(tags, tag)
		}
	}
	add(reAtmos, AudioAtmos)
	add(reTrueHD, AudioTrueHD)
	dtsx, dtshd := reDTSX.MatchString(s), reDTSHD.MatchString(s)
	if dtsx {
		tags = append(tags, AudioDTSX)
	}
	if dtshd {
		tags = append(tags, AudioDTSHD)
	}
	if dtsx || dtshd || reDTS.MatchString(s) {
		tags = append(tags, AudioDTS)
	}
	if reDDPlus.MatchString(s) {
		tags = append(tags, AudioDDPlus)
	} else {
		add(reDD, AudioDD)
	}
	add(reAAC, AudioAAC)
	add(reFLAC, AudioFLAC)
	add(reOpus, AudioOpus)
	return tags
}

func atoi(s string) (n int) {
	for _, c := range s {
		n = n*10 + int(c-'0')
	}
	return n
}

// codecOf finds a codec we offer as a filter in free text ("x265", "H.264", "HEVC"...).
func codecOf(s string) string {
	switch {
	case re265.MatchString(s):
		return CodecX265
	case re264.MatchString(s):
		return CodecX264
	case reAV1.MatchString(s):
		return CodecAV1
	}
	return ""
}