package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
)

type SpotifyResponse struct {
	ID         string
	Name       string
	Popularity int
	Genres     []string
}

type ResponseError struct {
	StatusCode int
	Err        error
}

func (r ResponseError) Error() string {
	return fmt.Sprintf("Response error with status code: %d, error: %v", r.StatusCode, r.Err)
}

// Makes a request to spotify API to grab artist data
// And parse the results into a properly typed struct
func getSpotifyArtistData(artistID string, spotifyAuthToken string) (SpotifyResponse, error) {

	artistEndpoint := fmt.Sprintf("https://api.spotify.com/v1/artists/%s", artistID)
	req, err := http.NewRequest("GET", artistEndpoint, nil)
	if err != nil {
		respErr := &ResponseError{
			StatusCode: 500,
			Err:        errors.New("Failed to build request"),
		}
		return SpotifyResponse{}, respErr
	}
	req.Header.Add("Authorization", spotifyAuthToken)

	// Send off request
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		respErr := &ResponseError{
			StatusCode: 500,
			Err:        errors.New("Failed to send request to spotify"),
		}
		return SpotifyResponse{}, respErr
	} else if resp.StatusCode != 200 {
		respErr := &ResponseError{
			StatusCode: resp.StatusCode,
			Err:        errors.New("Failed to get artist data from spotify API"),
		}
		return SpotifyResponse{}, respErr
	}

	var spotifyResponse SpotifyResponse
	err = json.NewDecoder(resp.Body).Decode(&spotifyResponse)
	if err != nil {
		respErr := &ResponseError{
			StatusCode: 500,
			Err:        errors.New("Failed to decode response body"),
		}
		return SpotifyResponse{}, respErr
	}

	// Close this immediately since it's unused now
	resp.Body.Close()

	// After all the above checks we assume this response is populated
	// If errors arise we can do extra validation here
	return spotifyResponse, nil
}