BackendManager.cs

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/*
 * Adapted from https://github.com/eamonwoortman/django-unity3d-example
 */

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.IO;
using System;
using System.Security.Cryptography;
using System.Linq;
using SimpleJSON;

using UI;
using System.Net;
using System.Globalization;
using System.Text;

public enum ResponseType {
    Success,
    ErrorFromClient,
    ErrorFromServer,
    ParseError,
    BackendDisabled,
    RequestError
}

public partial class BackendManager : MonoBehaviour {
    //---- Public Delegates ----//
    public delegate void RequestResponseDelegate(ResponseType responseType, JSONNode jsonResponse, string callee);


    //---- URLS ----//
    [SerializeField]
    public bool UseProduction = true;
    [SerializeField]
    public string ProductionUrl = "https://hirerna.galaxy.ibpc.fr/api/";
    [SerializeField]
    public string DevelopmentUrl = "http://localhost:8000/api/";


    //---- Private Properties ----//
    string hostUrl {
        get {
            return UseProduction ? ProductionUrl : DevelopmentUrl;
        }
    }


    //---- Private Methods ----//
    public void PerformRequest(string command, Dictionary<string, object> fields = null, RequestResponseDelegate onResponse = null, string authToken = "") {
        string url = hostUrl + command;
        WWW request;
        WWWForm wwwForm = new WWWForm();
        Dictionary<string, string> headers = new Dictionary<string, string>();

        //make sure we get a json response
        headers.Add("Accept", "application/json");
        //also, add the authentication token, if we have one
        if (authToken != "") {
            //for more information about token authentication, see: http://www.django-rest-framework.org/api-guide/authentication/#tokenauthentication
            headers.Add("Authorization", "Token " + authToken);
        }

        if (fields != null) {
            foreach (KeyValuePair<string, object> pair in fields) {
                wwwForm.AddField(pair.Key, pair.Value.ToString());
            }
            request = new WWW(url, wwwForm.data, headers);
        } else {
            request = new WWW(url, null , headers);
        }

        System.Diagnostics.StackTrace stackTrace = new System.Diagnostics.StackTrace();
        string callee = stackTrace.GetFrame(1).GetMethod().Name;
        StartCoroutine(HandleRequest(request, onResponse, callee));
    }

    public void PerformFormRequest(string command, WWWForm wwwForm, string filename, string fileData, RequestResponseDelegate onResponse = null, string authToken = "") {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(hostUrl + command);

        request.Headers.Add("Authorization", "Token " + authToken);
        request.Method = "POST";
        request.Accept = "application/json";
        request.Headers["Accept-Encoding"] = "identity";
        request.UserAgent = "UnityMol " + UnityMolMain.getVersionString();

        string boundary = DateTime.Now.Ticks.ToString("x", NumberFormatInfo.InvariantInfo);
        request.ContentType = "multipart/form-data; boundary=" + boundary;

        string postData = "--" + boundary + "\r\nContent-Type: text/plain\r\n";
        postData += "Content-Disposition: form-data; name=\"filename\"; filename=\"" + filename + "\"\r\n\r\n";
        postData += fileData;
        postData += "\r\n--" + boundary + "--\r\n";
        byte[] data = Encoding.UTF8.GetBytes(postData);

        request.ContentLength = data.Length;

        using (Stream stream = request.GetRequestStream())
        {
            stream.Write(data, 0, data.Length);
        }

        HttpWebResponse response;
        try {
            response = (HttpWebResponse)request.GetResponse();
            StartCoroutine(HandleResponse(response, onResponse, ""));
        } catch(WebException e) {
            StartCoroutine(HandleResponse((HttpWebResponse)e.Response, onResponse, ""));
        }
    }

    IEnumerator HandleResponse(HttpWebResponse response, RequestResponseDelegate onResponse, string callee) {
        HttpStatusCode statusCode = response.StatusCode;
        Debug.Log("Http Status Code: " + response.StatusCode);
        //if any other error occurred(probably 4xx range), see http://www.django-rest-framework.org/api-guide/status-codes/
        bool responseSuccessful = (statusCode >= HttpStatusCode.OK && statusCode <= HttpStatusCode.PartialContent);
        Debug.Log("response successful: " + responseSuccessful);
        JSONNode responseObj = null;

        // Get the stream associated with the response.
        Stream receiveStream = response.GetResponseStream ();

        // Pipes the stream to a higher level stream reader with the required encoding format. 
        StreamReader readStream = new StreamReader (receiveStream, Encoding.UTF8);

        Debug.Log("Got stream");
        Debug.Log(readStream.ReadToEnd());

        try {
            responseObj = JSON.Parse(readStream.ReadToEnd());
        } catch (Exception ex) {
            if (onResponse != null) {
                if (!responseSuccessful) {
                    Debug.Log("Could not parse the response, request.text=" + readStream.ReadToEnd());
                    Debug.Log("Exception=" + ex.ToString());
                    onResponse(ResponseType.ParseError, null, callee);
                } else {
                    if (readStream.ReadToEnd() == "") {
                        onResponse(ResponseType.Success, null, callee);
                    } else {
                        Debug.Log("Could not parse the response, request.text=" + readStream.ReadToEnd());
                        Debug.Log("Exception=" + ex.ToString());
                        onResponse(ResponseType.ParseError, null, callee);
                    }
                }
            }
            yield break;
        }

        if (!responseSuccessful) {
            if (onResponse != null) {
                onResponse(ResponseType.ErrorFromServer, responseObj, callee);
            }
            yield break;
        }

        //deal with successful responses
        if (onResponse != null) {
            onResponse(ResponseType.Success, responseObj, callee);
        }
    }

    IEnumerator HandleRequest(WWW request, RequestResponseDelegate onResponse, string callee) {
        //Wait till request is done
        while (true) {
            if (request.isDone) {
                break;
            }
            yield return new WaitForEndOfFrame();
        }

        //catch proper client errors(eg. can't reach the server)
        if (!String.IsNullOrEmpty(request.error)) {
            if (onResponse != null) {
                onResponse(ResponseType.RequestError, null, callee);
            }
            yield break;
        }
        int statusCode = 200;
        
        if (request.responseHeaders.ContainsKey("REAL_STATUS")) {
            string status = request.responseHeaders["REAL_STATUS"];
            statusCode = int.Parse(status.Split(' ')[0]);
        }
        //if any other error occurred(probably 4xx range), see http://www.django-rest-framework.org/api-guide/status-codes/
        bool responseSuccessful = (statusCode >= 200 && statusCode <= 206);
        JSONNode responseObj = null;

        try {
            responseObj = JSON.Parse(request.text);
        } catch (Exception ex) {
            if (onResponse != null) {
                if (!responseSuccessful) {
                    Debug.Log("Could not parse the response, request.text=" + request.text);
                    Debug.Log("Exception=" + ex.ToString());
                    onResponse(ResponseType.ParseError, null, callee);
                } else {
                    if (request.text == "") {
                        onResponse(ResponseType.Success, null, callee);
                    } else {
                        Debug.Log("Could not parse the response, request.text=" + request.text);
                        Debug.Log("Exception=" + ex.ToString());
                        onResponse(ResponseType.ParseError, null, callee);
                    }
                }
            }
            yield break;
        }

        if (!responseSuccessful) {
            if (onResponse != null) {
                onResponse(ResponseType.ErrorFromServer, responseObj, callee);
            }
            yield break;
        }
         
        //deal with successful responses
        if (onResponse != null) {
            onResponse(ResponseType.Success, responseObj, callee);
        }
    }
}