package morningalarm

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

	"github.com/zmb3/spotify/v2"
)

type headerTransport struct {
	baseTransport http.RoundTripper
	headers       map[string]string
}

func (t *headerTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	for key, value := range t.headers {
		req.Header.Set(key, value)
	}

	return t.baseTransport.RoundTrip(req)
}

func (ma *MorningAlarm) setupSpotifyWithProxy() {
	client := &http.Client{
		Transport: &headerTransport{
			baseTransport: http.DefaultTransport,
			headers: map[string]string{
				"X-API-KEY": ma.config.OAuthProxyAPIKey,
			},
		},
	}

	ma.sp = spotify.New(client, spotify.WithBaseURL(ma.config.OAuthProxyURL))
}

// playWakeUpMusic plays the playlist specified in the config at the specified device.
// Returns true if the playback was started successfully.
// Returns error if any error occurred.
// Can still return an error even if the playback was started successfully.
func (ma *MorningAlarm) playWakeUpMusic() (bool, error) {
	playContextURI := spotify.URI("spotify:playlist:" + ma.config.PlaylistID)

	devID, err := ma.getDeviceIDFromName(ma.config.DeviceName)

	if err != nil {
		return false, err
	}

	deviceID := spotify.ID(devID)

	playlist, err := ma.sp.GetPlaylistItems(context.Background(), spotify.ID(ma.config.PlaylistID))

	if err != nil {
		return true, err
	}

	randomTrackIndex := rand.Intn(playlist.Total)

	err = ma.sp.PlayOpt(context.Background(), &spotify.PlayOptions{
		PlaybackContext: &playContextURI,
		DeviceID:        &deviceID,
		PlaybackOffset:  &spotify.PlaybackOffset{Position: randomTrackIndex},
	})

	if err != nil {
		return true, err
	}

	err = ma.sp.ShuffleOpt(context.Background(), true, &spotify.PlayOptions{
		DeviceID: &deviceID,
	})

	return true, err
}

func (ma *MorningAlarm) getAvailableDevices() ([]Device, error) {
	devices, err := ma.sp.PlayerDevices(context.Background())

	if err != nil {
		return nil, err
	}

	var availableDevices []Device
	for _, device := range devices {
		if !device.Restricted {
			availableDevices = append(availableDevices, Device{
				ID:   string(device.ID),
				Name: device.Name,
			})
		}
	}

	return availableDevices, nil
}

func (ma *MorningAlarm) getDeviceIDFromName(name string) (string, error) {
	dev, err := ma.getAvailableDevices()

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

	for _, device := range dev {
		if device.Name == name {
			return device.ID, nil
		}
	}

	return "", fmt.Errorf("device with name %s not found", name)
}