LibreTranslate/app/app.py
2021-10-24 16:57:45 +02:00

712 lines
22 KiB
Python

import os
from functools import wraps
import pkg_resources
from flask import Flask, abort, jsonify, render_template, request
from flask_swagger import swagger
from flask_swagger_ui import get_swaggerui_blueprint
from app import flood
from app.language import detect_languages, transliterate
from .api_keys import Database
from .suggestions import Database as SuggestionsDatabase
from argostranslatefiles import get_supported_formats
from translatehtml import translate_html
def get_json_dict(request):
d = request.get_json()
if not isinstance(d, dict):
abort(400, description="Invalid JSON format")
return d
def get_remote_address():
if request.headers.getlist("X-Forwarded-For"):
ip = request.headers.getlist("X-Forwarded-For")[0].split(",")[0]
else:
ip = request.remote_addr or "127.0.0.1"
return ip
def get_req_limits(default_limit, api_keys_db, multiplier = 1):
req_limit = default_limit
if api_keys_db:
if request.is_json:
json = get_json_dict(request)
api_key = json.get("api_key")
else:
api_key = request.values.get("api_key")
if api_key:
db_req_limit = api_keys_db.lookup(api_key)
if db_req_limit is not None:
req_limit = db_req_limit * multiplier
return req_limit
def get_routes_limits(default_req_limit, daily_req_limit, api_keys_db):
if default_req_limit == -1:
# TODO: better way?
default_req_limit = 9999999999999
def minute_limits():
return "%s per minute" % get_req_limits(default_req_limit, api_keys_db)
def daily_limits():
return "%s per day" % get_req_limits(daily_req_limit, api_keys_db, 1440)
res = [minute_limits]
if daily_req_limit > 0:
res.append(daily_limits)
return res
def create_app(args):
from app.init import boot
boot(args.load_only)
from app.language import languages
app = Flask(__name__)
if args.debug:
app.config["TEMPLATES_AUTO_RELOAD"] = True
# Map userdefined frontend languages to argos language object.
if args.frontend_language_source == "auto":
frontend_argos_language_source = type(
"obj", (object,), {"code": "auto", "name": "Auto Detect"}
)
else:
frontend_argos_language_source = next(
iter([l for l in languages if l.code == args.frontend_language_source]),
None,
)
frontend_argos_language_target = next(
iter([l for l in languages if l.code == args.frontend_language_target]), None
)
frontend_argos_supported_files_format = []
for file_format in get_supported_formats():
for ff in file_format.supported_file_extensions:
frontend_argos_supported_files_format.append(ff)
# Raise AttributeError to prevent app startup if user input is not valid.
if frontend_argos_language_source is None:
raise AttributeError(
f"{args.frontend_language_source} as frontend source language is not supported."
)
if frontend_argos_language_target is None:
raise AttributeError(
f"{args.frontend_language_target} as frontend target language is not supported."
)
api_keys_db = None
if args.req_limit > 0 or args.api_keys or args.daily_req_limit > 0:
api_keys_db = Database() if args.api_keys else None
from flask_limiter import Limiter
limiter = Limiter(
app,
key_func=get_remote_address,
default_limits=get_routes_limits(
args.req_limit, args.daily_req_limit, api_keys_db
),
)
else:
from .no_limiter import Limiter
limiter = Limiter()
if args.req_flood_threshold > 0:
flood.setup(args.req_flood_threshold)
def access_check(f):
@wraps(f)
def func(*a, **kw):
if flood.is_banned(get_remote_address()):
abort(403, description="Too many request limits violations")
if args.api_keys and args.require_api_key_origin:
if request.is_json:
json = get_json_dict(request)
ak = json.get("api_key")
else:
ak = request.values.get("api_key")
if (
api_keys_db.lookup(ak) is None and request.headers.get("Origin") != args.require_api_key_origin
):
abort(
403,
description="Please contact the server operator to obtain an API key",
)
return f(*a, **kw)
return func
@app.errorhandler(400)
def invalid_api(e):
return jsonify({"error": str(e.description)}), 400
@app.errorhandler(500)
def server_error(e):
return jsonify({"error": str(e.description)}), 500
@app.errorhandler(429)
def slow_down_error(e):
flood.report(get_remote_address())
return jsonify({"error": "Slowdown: " + str(e.description)}), 429
@app.errorhandler(403)
def denied(e):
return jsonify({"error": str(e.description)}), 403
@app.route("/")
@limiter.exempt
def index():
return render_template(
"index.html",
gaId=args.ga_id,
frontendTimeout=args.frontend_timeout,
api_keys=args.api_keys,
web_version=os.environ.get("LT_WEB") is not None,
version=pkg_resources.require("LibreTranslate")[0].version
)
@app.route("/javascript-licenses", methods=["GET"])
@limiter.exempt
def javascript_licenses():
return render_template("javascript-licenses.html")
@app.route("/languages", methods=["GET", "POST"])
@limiter.exempt
def langs():
"""
Retrieve list of supported languages
---
tags:
- translate
responses:
200:
description: List of languages
schema:
id: languages
type: array
items:
type: object
properties:
code:
type: string
description: Language code
name:
type: string
description: Human-readable language name (in English)
429:
description: Slow down
schema:
id: error-slow-down
type: object
properties:
error:
type: string
description: Reason for slow down
"""
return jsonify([{"code": l.code, "name": l.name} for l in languages])
# Add cors
@app.after_request
def after_request(response):
response.headers.add("Access-Control-Allow-Origin", "*")
response.headers.add(
"Access-Control-Allow-Headers", "Authorization, Content-Type"
)
response.headers.add("Access-Control-Expose-Headers", "Authorization")
response.headers.add("Access-Control-Allow-Methods", "GET, POST")
response.headers.add("Access-Control-Allow-Credentials", "true")
response.headers.add("Access-Control-Max-Age", 60 * 60 * 24 * 20)
return response
@app.route("/translate", methods=["POST"])
@access_check
def translate():
"""
Translate text from a language to another
---
tags:
- translate
parameters:
- in: formData
name: q
schema:
oneOf:
- type: string
example: Hello world!
- type: array
example: ['Hello world!']
required: true
description: Text(s) to translate
- in: formData
name: source
schema:
type: string
example: en
required: true
description: Source language code
- in: formData
name: target
schema:
type: string
example: es
required: true
description: Target language code
- in: formData
name: format
schema:
type: string
enum: [text, html]
default: text
example: text
required: false
description: >
Format of source text:
* `text` - Plain text
* `html` - HTML markup
- in: formData
name: api_key
schema:
type: string
example: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
required: false
description: API key
responses:
200:
description: Translated text
schema:
id: translate
type: object
properties:
translatedText:
oneOf:
- type: string
- type: array
description: Translated text(s)
400:
description: Invalid request
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
500:
description: Translation error
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
429:
description: Slow down
schema:
id: error-slow-down
type: object
properties:
error:
type: string
description: Reason for slow down
403:
description: Banned
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
"""
if request.is_json:
json = get_json_dict(request)
q = json.get("q")
source_lang = json.get("source")
target_lang = json.get("target")
text_format = json.get("format")
else:
q = request.values.get("q")
source_lang = request.values.get("source")
target_lang = request.values.get("target")
text_format = request.values.get("format")
if not q:
abort(400, description="Invalid request: missing q parameter")
if not source_lang:
abort(400, description="Invalid request: missing source parameter")
if not target_lang:
abort(400, description="Invalid request: missing target parameter")
batch = isinstance(q, list)
if batch and args.batch_limit != -1:
batch_size = len(q)
if args.batch_limit < batch_size:
abort(
400,
description="Invalid request: Request (%d) exceeds text limit (%d)"
% (batch_size, args.batch_limit),
)
if args.char_limit != -1:
if batch:
chars = sum([len(text) for text in q])
else:
chars = len(q)
if args.char_limit < chars:
abort(
400,
description="Invalid request: Request (%d) exceeds character limit (%d)"
% (chars, args.char_limit),
)
if source_lang == "auto":
source_langs = []
if batch:
auto_detect_texts = q
else:
auto_detect_texts = [q]
overall_candidates = detect_languages(q)
for text_to_check in auto_detect_texts:
if len(text_to_check) > 40:
candidate_langs = detect_languages(text_to_check)
else:
# Unable to accurately detect languages for short texts
candidate_langs = overall_candidates
source_langs.append(candidate_langs[0]["language"])
if args.debug:
print(text_to_check, candidate_langs)
print("Auto detected: %s" % candidate_langs[0]["language"])
else:
if batch:
source_langs = [source_lang for text in q]
else:
source_langs = [source_lang]
src_langs = [next(iter([l for l in languages if l.code == source_lang]), None) for source_lang in source_langs]
for idx, lang in enumerate(src_langs):
if lang is None:
abort(400, description="%s is not supported" % source_langs[idx])
tgt_lang = next(iter([l for l in languages if l.code == target_lang]), None)
if tgt_lang is None:
abort(400, description="%s is not supported" % target_lang)
if not text_format:
text_format = "text"
if text_format not in ["text", "html"]:
abort(400, description="%s format is not supported" % text_format)
try:
if batch:
results = []
for idx, text in enumerate(q):
translator = src_langs[idx].get_translation(tgt_lang)
if text_format == "html":
translated_text = str(translate_html(translator, text))
else:
translated_text = translator.translate(transliterate(text, target_lang=source_langs[idx]))
results.append(translated_text)
return jsonify(
{
"translatedText": results
}
)
else:
translator = src_langs[0].get_translation(tgt_lang)
if text_format == "html":
translated_text = str(translate_html(translator, q))
else:
translated_text = translator.translate(transliterate(q, target_lang=source_langs[0]))
return jsonify(
{
"translatedText": translated_text
}
)
except Exception as e:
abort(500, description="Cannot translate text: %s" % str(e))
@app.route("/detect", methods=["POST"])
@access_check
def detect():
"""
Detect the language of a single text
---
tags:
- translate
parameters:
- in: formData
name: q
schema:
type: string
example: Hello world!
required: true
description: Text to detect
- in: formData
name: api_key
schema:
type: string
example: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
required: false
description: API key
responses:
200:
description: Detections
schema:
id: detections
type: array
items:
type: object
properties:
confidence:
type: number
format: float
minimum: 0
maximum: 1
description: Confidence value
example: 0.6
language:
type: string
description: Language code
example: en
400:
description: Invalid request
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
500:
description: Detection error
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
429:
description: Slow down
schema:
id: error-slow-down
type: object
properties:
error:
type: string
description: Reason for slow down
403:
description: Banned
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
"""
if flood.is_banned(get_remote_address()):
abort(403, description="Too many request limits violations")
if request.is_json:
json = get_json_dict(request)
q = json.get("q")
else:
q = request.values.get("q")
if not q:
abort(400, description="Invalid request: missing q parameter")
return jsonify(detect_languages(q))
@app.route("/frontend/settings")
@limiter.exempt
def frontend_settings():
"""
Retrieve frontend specific settings
---
tags:
- frontend
responses:
200:
description: frontend settings
schema:
id: frontend-settings
type: object
properties:
charLimit:
type: integer
description: Character input limit for this language (-1 indicates no limit)
frontendTimeout:
type: integer
description: Frontend translation timeout
suggestions:
type: boolean
description: Whether submitting suggestions is enabled.
supportedFilesFormat:
type: array
items:
type: string
description: Supported files format
language:
type: object
properties:
source:
type: object
properties:
code:
type: string
description: Language code
name:
type: string
description: Human-readable language name (in English)
target:
type: object
properties:
code:
type: string
description: Language code
name:
type: string
description: Human-readable language name (in English)
"""
return jsonify(
{
"charLimit": args.char_limit,
"frontendTimeout": args.frontend_timeout,
"suggestions": args.suggestions,
"supportedFilesFormat": frontend_argos_supported_files_format,
"language": {
"source": {
"code": frontend_argos_language_source.code,
"name": frontend_argos_language_source.name,
},
"target": {
"code": frontend_argos_language_target.code,
"name": frontend_argos_language_target.name,
},
},
}
)
@app.route("/suggest", methods=["POST"])
@limiter.exempt
def suggest():
"""
Submit a suggestion to improve a translation
---
tags:
- feedback
parameters:
- in: formData
name: q
schema:
type: string
example: Hello world!
required: true
description: Original text
- in: formData
name: s
schema:
type: string
example: ¡Hola mundo!
required: true
description: Suggested translation
- in: formData
name: source
schema:
type: string
example: en
required: true
description: Language of original text
- in: formData
name: target
schema:
type: string
example: es
required: true
description: Language of suggested translation
responses:
200:
description: Success
schema:
id: suggest-response
type: object
properties:
success:
type: boolean
description: Whether submission was successful
403:
description: Not authorized
schema:
id: error-response
type: object
properties:
error:
type: string
description: Error message
"""
if not args.suggestions:
abort(403, description="Suggestions are disabled on this server.")
q = request.values.get("q")
s = request.values.get("s")
source_lang = request.values.get("source")
target_lang = request.values.get("target")
SuggestionsDatabase().add(q, s, source_lang, target_lang)
return jsonify({"success": True})
swag = swagger(app)
swag["info"]["version"] = "1.2.1"
swag["info"]["title"] = "LibreTranslate"
@app.route("/spec")
@limiter.exempt
def spec():
return jsonify(swag)
SWAGGER_URL = "/docs" # URL for exposing Swagger UI (without trailing '/')
API_URL = "/spec"
# Call factory function to create our blueprint
swaggerui_blueprint = get_swaggerui_blueprint(SWAGGER_URL, API_URL)
app.register_blueprint(swaggerui_blueprint)
return app