SpotiParty/SpotiParty.Web/Services/AuthorizationHandler.cs

using Microsoft.AspNetCore.Components;
using Microsoft.EntityFrameworkCore;
using SpotifyAPI.Web;
using SpotiParty.Web.Models;

namespace SpotiParty.Web.Services;

public sealed class AuthorizationHandler(NavigationManager navigator, DatabaseContext context, ClientSideStorage storage) {

    private async Task<(string clientId, string clientSecret)> GetClientSecrets() {
        var fileLines = await File.ReadAllLinesAsync(Path.Combine(Environment.CurrentDirectory, ".dev-token"));
        return (fileLines[0], fileLines[1]);
    }

    public async Task<SpotifyClient?> ConfigureClient(Guid userId) {
        var user = await context.Users.FindAsync(userId);
        if (user is null) return null;
        
        var (clientId, clientSecret) = await GetClientSecrets();
        var request = new AuthorizationCodeRefreshRequest(clientId, clientSecret, user.RefreshToken);
        var response = await new OAuthClient().RequestToken(request);
        
        return new SpotifyClient(response.AccessToken);
    }

    public async Task<Uri> ConstructLoginUri() {
        var (clientId, _) = await GetClientSecrets();
        var request = new LoginRequest(
            new Uri(navigator.BaseUri + "callback"),
            clientId,
            LoginRequest.ResponseType.Code) {
            Scope = [Scopes.UserReadPlaybackState, Scopes.UserModifyPlaybackState, Scopes.UserReadPrivate, Scopes.UserReadEmail]
        };

        return request.ToUri();
    }

    public async Task HandleCallback(string code) {
        var (clientId, clientSecret) = await GetClientSecrets();
        var response = await new OAuthClient().RequestToken(
            new AuthorizationCodeTokenRequest(
                clientId,
                clientSecret,
                code,
                new Uri(navigator.BaseUri + "callback")));

        var client = new SpotifyClient(response.AccessToken);
        var spotiUser = await client.UserProfile.Current();

        var user = await context.Users.FirstOrDefaultAsync(u => u.SpotifyUserId == spotiUser.Id);
        if (user is null) {
            user = new User {
                DisplayName = spotiUser.DisplayName,
                RefreshToken = response.RefreshToken,
                SpotifyUserId = spotiUser.Id,
                IsAdmin = await context.Users.CountAsync() == 0
            };

            await context.Users.AddAsync(user);
            await context.SaveChangesAsync();
        }
        else {
            user.RefreshToken = response.RefreshToken;
            await context.SaveChangesAsync();
        }
        
        storage.SaveUserToken(response.RefreshToken);
    }
    
}