package server

import (
	"context"
	"fmt"
	"net/http"

	"music-server/internal/backend"

	"github.com/danielgtaylor/huma/v2"
	"github.com/google/uuid"
)

type uuidInput struct {
	UUID string `path:"uuid" format:"uuid" doc:"UUID of the soundtrack or song"`
}

func (in *uuidInput) id() uuid.UUID {
	// The format is validated by Huma before the handler runs.
	return uuid.MustParse(in.UUID)
}

// AlternativeNames is the body of PUT /soundtracks/{uuid}/alternative-names.
type AlternativeNames struct {
	Names []string `json:"names" maxItems:"50" doc:"The new list of alternative names. Replaces the old list; send [] to remove them all."`
}

type alternativeNamesInput struct {
	UUID string `path:"uuid" format:"uuid" doc:"UUID of the soundtrack"`
	Body AlternativeNames
}

func (in *alternativeNamesInput) id() uuid.UUID {
	return uuid.MustParse(in.UUID)
}

func (s *Server) registerLibrary(a huma.API) {
	l := s.library
	op := func(id, path, summary, description string, errs ...int) huma.Operation {
		return huma.Operation{
			OperationID: id,
			Method:      http.MethodGet,
			Path:        path,
			Summary:     summary,
			Description: description,
			Tags:        []string{"library"},
			Errors:      errs,
		}
	}

	register(s, a, route{op: op("list-soundtracks", "/soundtracks", "List soundtracks",
		"Returns all soundtracks, sorted by name.")},
		func(ctx context.Context, _ *struct{}) (*jsonBody[[]backend.Soundtrack], error) {
			return ok(l.Soundtracks(ctx))
		})
	register(s, a, route{op: op("get-soundtrack", "/soundtracks/{uuid}", "Get soundtrack",
		"Returns a soundtrack with its songs, sorted by name.", http.StatusNotFound)},
		func(ctx context.Context, in *uuidInput) (*jsonBody[backend.SoundtrackWithSongList], error) {
			return ok(l.Soundtrack(ctx, in.id()))
		})
	register(s, a, route{op: op("get-song", "/songs/{uuid}", "Get song",
		"Returns information about a song.", http.StatusNotFound)},
		func(ctx context.Context, in *uuidInput) (*jsonBody[backend.Song], error) {
			return ok(l.Song(ctx, in.id()))
		})

	names := op("set-alternative-names", "/soundtracks/{uuid}/alternative-names", "Set alternative names",
		"Replaces the soundtrack's alternative names, which search and the cover search also use. "+
			"Names are trimmed, and empty names, duplicates and the soundtrack's own name (ignoring case) are dropped.",
		http.StatusNotFound)
	names.Method = http.MethodPut
	register(s, a, route{op: names},
		func(ctx context.Context, in *alternativeNamesInput) (*jsonBody[backend.Soundtrack], error) {
			for _, name := range in.Body.Names {
				if len(name) > backend.MaxNameLength {
					return nil, huma.Error422UnprocessableEntity(
						fmt.Sprintf("names can be at most %d bytes long", backend.MaxNameLength))
				}
			}
			soundtrack, err := l.SetAlternativeNames(ctx, in.id(), in.Body.Names)
			if err != nil {
				return nil, apiError(err)
			}
			s.soundtracksChanged(ctx)
			return ok(soundtrack, nil)
		})

	file := op("get-song-file", "/songs/{uuid}/file", "Stream song",
		"Returns the audio file of a song.", http.StatusNotFound)
	file.Responses = fileResponses("The song (MP3)", audioMPEG)
	register(s, a, route{op: file, locked: true},
		func(ctx context.Context, in *uuidInput) (*huma.StreamResponse, error) {
			return streamSong(l.SongPath(ctx, in.id()))
		})
}