package api

import (
	"encoding/json"
	"strings"
)

// ID represents an identifier that can be decoded from either a JSON string or integer.
type ID string

func (id *ID) UnmarshalJSON(b []byte) error {
	if len(b) == 0 || string(b) == "null" {
		*id = ""
		return nil
	}
	if b[0] == '"' {
		var s string
		if err := json.Unmarshal(b, &s); err != nil {
			return err
		}
		*id = ID(s)
		return nil
	}
	*id = ID(strings.TrimSpace(string(b)))
	return nil
}

func (id ID) String() string {
	return string(id)
}

// Quality represents audio streaming and download quality formats.
type Quality int

const (
	QualityMp3        Quality = 5  // MP3 320kbps
	QualityLossless   Quality = 6  // 16-bit / 44.1kHz (CD Quality)
	QualityHiRes      Quality = 7  // 24-bit / ≤96kHz
	QualityUltraHiRes Quality = 27 // 24-bit / >96kHz
)

// ID returns the numeric format identifier.
func (q Quality) ID() int {
	return int(q)
}

// Label returns a human-readable description of the quality setting.
func (q Quality) Label() string {
	switch q {
	case QualityMp3:
		return "MP3 320kbps"
	case QualityLossless:
		return "FLAC 16-bit/44.1kHz"
	case QualityHiRes:
		return "FLAC 24-bit/≤96kHz"
	case QualityUltraHiRes:
		return "FLAC 24-bit/>96kHz"
	default:
		return "Unknown"
	}
}

// IsValid reports whether the quality setting is a known format.
func (q Quality) IsValid() bool {
	switch q {
	case QualityMp3, QualityLossless, QualityHiRes, QualityUltraHiRes:
		return true
	default:
		return false
	}
}

// Image holds artwork URLs across various resolutions.
type Image struct {
	Small      string `json:"small,omitempty"`
	Thumbnail  string `json:"thumbnail,omitempty"`
	Medium     string `json:"medium,omitempty"`
	Large      string `json:"large,omitempty"`
	ExtraLarge string `json:"extralarge,omitempty"`
	Mega       string `json:"mega,omitempty"`
	Back       string `json:"back,omitempty"`
}

// Best returns the highest-resolution image URL available.
func (img Image) Best() string {
	if img.Mega != "" {
		return img.Mega
	}
	if img.ExtraLarge != "" {
		return img.ExtraLarge
	}
	if img.Large != "" {
		return img.Large
	}
	if img.Thumbnail != "" {
		return img.Thumbnail
	}
	return img.Small
}

// Smallest returns the lowest-resolution image URL available.
func (img Image) Smallest() string {
	if img.Small != "" {
		return img.Small
	}
	if img.Thumbnail != "" {
		return img.Thumbnail
	}
	if img.Large != "" {
		return img.Large
	}
	if img.ExtraLarge != "" {
		return img.ExtraLarge
	}
	return img.Mega
}

// Label represents record label metadata.
type Label struct {
	ID          ID     `json:"id"`
	Name        string `json:"name"`
	AlbumsCount int    `json:"albums_count,omitempty"`
	Slug        string `json:"slug,omitempty"`
	SupplierID  int    `json:"supplier_id,omitempty"`
}

// Genre represents musical genre classification.
type Genre struct {
	ID    int    `json:"id"`
	Name  string `json:"name"`
	Path  []int  `json:"path,omitempty"`
	Slug  string `json:"slug,omitempty"`
	Color string `json:"color,omitempty"`
}

// AlbumAward represents press and catalog accolades.
type AlbumAward struct {
	ID        ID     `json:"id"`
	AwardID   ID     `json:"award_id,omitempty"`
	Name      string `json:"name"`
	AwardedAt ID     `json:"awarded_at,omitempty"`
}

func (a *AlbumAward) UnmarshalJSON(b []byte) error {
	var raw struct {
		ID             ID     `json:"id"`
		AwardID        ID     `json:"award_id"`
		AwardIDCamel   ID     `json:"awardId"`
		Name           string `json:"name"`
		AwardedAt      ID     `json:"awarded_at"`
		AwardedAtCamel ID     `json:"awardedAt"`
	}
	if err := json.Unmarshal(b, &raw); err != nil {
		return err
	}
	a.Name = raw.Name
	if raw.ID != "" {
		a.ID = raw.ID
	} else if raw.AwardID != "" {
		a.ID = raw.AwardID
	} else {
		a.ID = raw.AwardIDCamel
	}
	a.AwardID = a.ID

	if raw.AwardedAt != "" {
		a.AwardedAt = raw.AwardedAt
	} else {
		a.AwardedAt = raw.AwardedAtCamel
	}
	return nil
}

// Dates contains release date timestamps.
type Dates struct {
	Original string `json:"original,omitempty"`
	Download string `json:"download,omitempty"`
	Stream   string `json:"stream,omitempty"`
}

// AudioInfo describes audio resolution and replaygain metadata.
type AudioInfo struct {
	MaximumSamplingRate float64 `json:"maximum_sampling_rate,omitempty"`
	MaximumBitDepth     int     `json:"maximum_bit_depth,omitempty"`
	MaximumChannelCount int     `json:"maximum_channel_count,omitempty"`
	ReplayGainTrackGain float64 `json:"replaygain_track_gain,omitempty"`
	ReplayGainTrackPeak float64 `json:"replaygain_track_peak,omitempty"`
}

// Rights specifies streaming, purchase, and download availability.
type Rights struct {
	Streamable       *bool `json:"streamable,omitempty"`
	HiResStreamable  *bool `json:"hires_streamable,omitempty"`
	HiResPurchasable *bool `json:"hires_purchasable,omitempty"`
	Purchasable      *bool `json:"purchasable,omitempty"`
	Downloadable     *bool `json:"downloadable,omitempty"`
	Previewable      *bool `json:"previewable,omitempty"`
	Sampleable       *bool `json:"sampleable,omitempty"`
}

// Goodie represents supplementary media such as digital booklets.
type Goodie struct {
	ID           ID     `json:"id"`
	Name         string `json:"name"`
	URL          string `json:"url"`
	OriginalURL  string `json:"original_url,omitempty"`
	FileURL      string `json:"file_url,omitempty"`
	FileFormatID int    `json:"file_format_id,omitempty"`
	Description  string `json:"description,omitempty"`
}

// Restriction describes playback or streaming limitations.
type Restriction struct {
	Code string `json:"code"`
	Msg  string `json:"msg,omitempty"`
}