From 55d3c32b40e60702ea5bcb86a1b6490cf2d37a19 Mon Sep 17 00:00:00 2001
From: Vincent Emonet <vincent.emonet@gmail.com>
Date: Wed, 13 Jan 2021 15:33:58 +0100
Subject: [PATCH] add support for auto language. Not perfect, it picks a
 language not supported sometimes

---
 app/app.py               | 14 +++++++++++---
 app/templates/index.html |  1 +
 requirements.txt         |  1 +
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/app/app.py b/app/app.py
index 0f098bc..f837325 100644
--- a/app/app.py
+++ b/app/app.py
@@ -1,6 +1,7 @@
 from flask import Flask, render_template, jsonify, request, abort, send_from_directory
 from flask_swagger import swagger
 from flask_swagger_ui import get_swaggerui_blueprint
+from langdetect import detect
 
 def get_remote_address():
     if request.headers.getlist("X-Forwarded-For"):
@@ -10,7 +11,7 @@ def get_remote_address():
 
     return ip
 
-def create_app(char_limit=-1, req_limit=-1, ga_id=None, debug=False, frontend_language_source="en", frontend_language_target="es"):
+def create_app(char_limit=-1, req_limit=-1, ga_id=None, debug=False, frontend_language_source="auto", frontend_language_target="en"):
     from app.init import boot
     boot()
     
@@ -21,7 +22,7 @@ def create_app(char_limit=-1, req_limit=-1, ga_id=None, debug=False, frontend_la
         app.config['TEMPLATES_AUTO_RELOAD'] = True
 
     # Map userdefined frontend languages to argos language object.
-    frontend_argos_language_source = next(iter([l for l in languages if l.code == frontend_language_source]), None)
+    frontend_argos_language_source = next(iter([l for l in languages if l.code == frontend_language_source or l.code == 'auto']), None)
     frontend_argos_language_target = next(iter([l for l in languages if l.code == frontend_language_target]), None)
     # Raise AttributeError to prevent app startup if user input is not valid.
     if frontend_argos_language_source is None:
@@ -187,9 +188,16 @@ def create_app(char_limit=-1, req_limit=-1, ga_id=None, debug=False, frontend_la
         if char_limit != -1:
             q = q[:char_limit]
 
+        original_source_lang = source_lang
+        if source_lang == 'auto':
+            source_lang = detect(q)
+
         src_lang = next(iter([l for l in languages if l.code == source_lang]), None)
         tgt_lang = next(iter([l for l in languages if l.code == target_lang]), None)
-
+        
+        if src_lang is None and original_source_lang == 'auto':
+            return jsonify({"translatedText": "Detected language not supported (" + source_lang + ")" })
+            
         if src_lang is None:
             abort(400, description="%s is not supported" % source_lang)
         if tgt_lang is None:
diff --git a/app/templates/index.html b/app/templates/index.html
index d3a9bd9..f2e9c9f 100644
--- a/app/templates/index.html
+++ b/app/templates/index.html
@@ -299,6 +299,7 @@ document.addEventListener('DOMContentLoaded', function(){
 		  if (this.status >= 200 && this.status < 400) {
 			// Success!
 			self.langs = JSON.parse(this.response);
+			self.langs.push({ name: 'Auto (experimental)', code: 'auto' })
 			if (self.langs.length === 0){
 				self.loading = false;
 				self.error = "No languages available. Did you install the models correctly?"
diff --git a/requirements.txt b/requirements.txt
index 500c95e..cf30471 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,3 +4,4 @@ flask-swagger==0.2.14
 flask-swagger-ui==3.36.0
 Flask-Limiter==1.4
 waitress==1.4.4
+langdetect