UnityObjectRecognition/Assets/Scripts/Unity-API-connection/Server/libs/HttpRequests/HttpClient.cs

using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using UnityEditor;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.Networking;

public class HttpClient
{
    public static string latestServerResponse;
    private readonly ISerializeOption _serializationOption;

    public HttpClient(ISerializeOption serializationOption)
    {
        _serializationOption = serializationOption;
    }

    /// <summary>
    /// Async method that handles communication with REST server.
    /// </summary>
    /// <returns>The coroutine.</returns>
    /// <param name="url">API url.</param>
    /// <param name="callbackOnSuccess">Callback on success.</param>
    /// <param name="callbackOnFail">Callback on fail.</param>
    /// <typeparam name="T">Data Model Type.</typeparam>
    public async Task<T> Get<T>(string url, UnityAction<T> callbackOnSuccess, UnityAction<string> callbackOnFail, string authorizationToken = null)
    {
        // Empty request to be able to reference it in the `except` block
        UnityWebRequest webRequest = new UnityWebRequest();
        try
        {
            Debug.Log($"Requesting from URL {url}");
            //webRequest = UnityWebRequest.Get(url);
            webRequest = new UnityWebRequest(url, UnityWebRequest.kHttpVerbGET);

            webRequest.uploadHandler = new UploadHandlerRaw(null);
            webRequest.uploadHandler.contentType = _serializationOption.ContentType;

            webRequest.downloadHandler = new DownloadHandlerBuffer();
            webRequest.SetRequestHeader(_serializationOption.ContentTypeHeader, _serializationOption.ContentType);

            if (authorizationToken != null)
                webRequest.SetRequestHeader("Authorization", $"Bearer {authorizationToken}");

            UnityWebRequestAsyncOperation asyncOp = webRequest.SendWebRequest();
            while (!asyncOp.isDone)
                await Task.Yield();

            // Process results
            if (webRequest.result == UnityWebRequest.Result.Success)
            {
                latestServerResponse = webRequest.downloadHandler.text;
                //Debug.Log(latestServerResponse);

                // Parse response to specific class
                T result = _serializationOption.ParseResponse<T>(latestServerResponse);
                callbackOnSuccess?.Invoke(result);
                return result;
            }
            else
            {
                Debug.LogError(webRequest.error);
                callbackOnFail?.Invoke(webRequest.error);
                return default;
            }
        }
        catch (System.Exception ex)
        {
            Debug.LogWarning($"{nameof(Get)} could not parse json response. {ex.Message}");
            callbackOnFail?.Invoke(ex.Message);
            return default;
        }
    }


    /// <summary>
    /// Async method that handles communication with REST server.
    /// </summary>
    /// <returns>The coroutine.</returns>
    /// <param name="url">API url.</param>
    /// <param name="callbackOnSuccess">Callback on success.</param>
    /// <param name="callbackOnFail">Callback on fail.</param>
    /// <typeparam name="T">Data Model Type.</typeparam>
    public async Task<T> Post<T>(string url, string data, UnityAction<T> callbackOnSuccess, UnityAction<string> callbackOnFail, string authorizationToken = null, string requestType = UnityWebRequest.kHttpVerbPOST)
    {
        try
        {
            if (data == null)
            {
                Debug.LogError("POST: `data` is null");
                return default;
            }

            // Initialize webrequest
            UnityWebRequest webRequest = new UnityWebRequest(url, requestType);

            byte[] dataBytes = Encoding.UTF8.GetBytes(data);
            webRequest.uploadHandler = new UploadHandlerRaw(dataBytes);
            //UnityWebRequest webRequest = UnityWebRequest.Post(url, data); // Not working, it should be sent as bytes
            webRequest.uploadHandler.contentType = _serializationOption.ContentType;

            webRequest.downloadHandler = new DownloadHandlerBuffer();
            webRequest.SetRequestHeader(_serializationOption.ContentTypeHeader, _serializationOption.ContentType);

            if (authorizationToken != null)
                webRequest.SetRequestHeader("Authorization", $"Bearer {authorizationToken}");

            UnityWebRequestAsyncOperation asyncOp = webRequest.SendWebRequest();
            while (!asyncOp.isDone)
                await Task.Yield();

            // Fetch response regardless result
            latestServerResponse = webRequest.downloadHandler.text;

            // Process results
            if (webRequest.result == UnityWebRequest.Result.Success)
            {
                // Parse response to specific class
                T result = _serializationOption.ParseResponse<T>(latestServerResponse);
                callbackOnSuccess?.Invoke(result);
                return result;
            }
            else
            {
                callbackOnFail?.Invoke(webRequest.error + "\n" + webRequest.downloadHandler.text);
                return default;
            }
        }
        catch (System.Exception ex)
        {
            Debug.LogWarning($"{nameof(Get)} could not parse json response. {ex.Message}");
            callbackOnFail?.Invoke(ex.Message);
            return default;
        }
    }

    /// <summary>
    /// Async method that handles communication with REST server.
    /// </summary>
    /// <returns>The coroutine.</returns>
    /// <param name="url">API url.</param>
    /// <param name="callbackOnSuccess">Callback on success.</param>
    /// <param name="callbackOnFail">Callback on fail.</param>
    /// <typeparam name="T">Data Model Type.</typeparam>
    public async Task<T> Update<T>(string url, string data, UnityAction<T> callbackOnSuccess, UnityAction<string> callbackOnFail, string authorizationToken = null)
    {
        return await Post<T>(url, data, callbackOnSuccess, callbackOnFail, authorizationToken, requestType: UnityWebRequest.kHttpVerbPUT);
    }
}