SessionZero/SessionZeroClient/sessionzero/Assets/Scripts/API/ApiHandler.cs

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using Godot;
using HttpClient = System.Net.Http.HttpClient;

namespace SessionZeroClient.API;

public class ApiHandler : IApiHandler
{
    private readonly HttpClient _httpClient;
    
    public ApiHandler()
    {
        var handler = new HttpClientHandler
        {
            UseDefaultCredentials = true,
        };

        _httpClient = new HttpClient(handler)
        {
            Timeout = TimeSpan.FromSeconds(5),
        };
    }

    /// <summary>
    /// Returns true if the server URL is reachable valid, false otherwise.
    /// </summary>
    /// <param name="url"></param>
    /// <returns></returns>
    public async Task<bool> ValidateServerUrl(string url)
    {
        try
        {
            var apiString = $"{url}/api/Database/validate-server";
        
            using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
            var response = await  _httpClient.GetAsync(apiString, cts.Token);

            if (!response.IsSuccessStatusCode)
            {
                return false;
            }

            var responseString = await response.Content.ReadAsStringAsync(cts.Token);

            var options = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
            var validationResponse = JsonSerializer.Deserialize<ServerUrlValidationResponse>(responseString, options);
        
            return validationResponse?.IsValid ?? false;
        }
        catch
        {
            throw new HttpRequestException($"Server {url} is invalid or not reachable.");
            return false;
        }
    }
    
    /// <summary>
    /// Register a new user with the server.
    /// </summary>
    /// <param name="url"></param>
    /// <param name="username"></param>
    /// <param name="email"></param>
    /// <param name="password"></param>
    /// <returns></returns>
    /// <exception cref="HttpRequestException"></exception>
    public async Task<string> Register(string url, string username, string email, string password)
    {
        bool isValidServer = await ValidateServerUrl(url);
        if (!isValidServer)
        {
            throw new HttpRequestException($"Could not Register User, Server {url} is invalid or not reachable.");
        }
        
        var apiString = $"{url}/api/Auth/register";
        var requestBody = new Dictionary<string, string>
        {
            {"username", username},
            {"email", email},
            {"password", password}
        };
        
        var jsonBody = JsonSerializer.Serialize(requestBody);
        var content = new StringContent(jsonBody, System.Text.Encoding.UTF8, "application/json");
        var response = await _httpClient.PostAsync(apiString, content);
        
        if (!response.IsSuccessStatusCode)
        {
            throw new HttpRequestException($"Register failed: {response.StatusCode}");
            
        }
        
        var responseString = await response.Content.ReadAsStringAsync();
        return responseString;
    }

    /// <summary>
    /// Login to the server with the given username and password. Returns the JWT token if successful.
    /// </summary>
    /// <param name="url"></param>
    /// <param name="username"></param>
    /// <param name="password"></param>
    /// <returns></returns>
    /// <exception cref="HttpRequestException"></exception>
    public async Task<string> Login(string url, string username, string password)
    {
        
        bool isValidServer = await ValidateServerUrl(url);
        if (!isValidServer)
        {
            throw new HttpRequestException($"Could not Login, Server {url} is invalid or not reachable.");
        }
        
        var apiString = $"{url}/api/Auth/login";
        var requestBody = new Dictionary<string, string>
        {
            {"username", username},
            {"password", password}
        };
        
        var jsonBody = JsonSerializer.Serialize(requestBody);
        var content = new StringContent(jsonBody, System.Text.Encoding.UTF8, "application/json");
        var response = await _httpClient.PostAsync(apiString, content);
        
        if (!response.IsSuccessStatusCode)
        {
            throw new HttpRequestException($"Login failed: {response.StatusCode}");
        }
        
        var responseString = await response.Content.ReadAsStringAsync();
        return responseString;
    }
    
    public class ServerUrlValidationResponse
    {
        public bool IsValid { get; set; }
        public string Message { get; set; }
    }
}