feat: Enhanced the usability of the Google Translate engine. #158

engines/__init__.py

@@ -1,5 +1,6 @@
 from .google import (
-    GoogleFreeTranslate, GoogleBasicTranslate, GoogleAdvancedTranslate)
+    GoogleFreeTranslate, GoogleBasicTranslate, GoogleBasicTranslateADC,
+    GoogleAdvancedTranslate)
 from .chatgpt import ChatgptTranslate, AzureChatgptTranslate
 from .deepl import DeeplTranslate, DeeplProTranslate, DeeplFreeTranslate
 from .youdao import YoudaoTranslate
@@ -8,7 +9,7 @@
 
 
 builtin_engines = (
-    GoogleFreeTranslate, GoogleBasicTranslate, GoogleAdvancedTranslate,
-    ChatgptTranslate, AzureChatgptTranslate, DeeplTranslate, DeeplProTranslate,
-    DeeplFreeTranslate, MicrosoftEdgeTranslate, YoudaoTranslate,
-    BaiduTranslate)
+    GoogleFreeTranslate, GoogleBasicTranslate, GoogleBasicTranslateADC,
+    GoogleAdvancedTranslate, ChatgptTranslate, AzureChatgptTranslate,
+    DeeplTranslate, DeeplProTranslate, DeeplFreeTranslate,
+    MicrosoftEdgeTranslate, YoudaoTranslate, BaiduTranslate)

engines/base.py

@@ -1,4 +1,5 @@
 import ssl
+import os.path
 import traceback
 
 from mechanize import Browser, Request
@@ -21,6 +22,7 @@ class Base:
     api_key_errors = ['401']
     separator = '\n\n'
     placeholder = ('{{{{id_{}}}}}', r'({{\s*)+id\s*_\s*{}\s*(\s*}})+')
+    using_tip = None
 
     concurrency_limit = 0
     request_interval = 0.0
@@ -32,6 +34,7 @@ def __init__(self):
         self.source_lang = None
         self.target_lang = None
         self.proxy_uri = None
+        self.search_paths = []
 
         self.merge_enabled = False
 
@@ -108,6 +111,17 @@ def need_change_api_key(self, error_message):
                     return True
         return False
 
+    def set_search_paths(self, paths):
+        self.search_paths = paths
+
+    def get_external_program(self, name, paths=[]):
+        for path in paths + self.search_paths:
+            if not path.endswith('%s%s' % (os.path.sep, name)):
+                path = os.path.join(path, name)
+            if os.path.isfile(path):
+                return path
+        return None
+
     def set_endpoint(self, endpoint):
         self.endpoint = endpoint
 

engines/google.py

@@ -1,8 +1,10 @@
 import re
 import os
+import sys
 import time
 import json
 import os.path
+import traceback
 from subprocess import Popen, PIPE
 
 from ..lib.exception import BadApiKeyFormat
@@ -53,90 +55,164 @@ def _parse(self, data):
 
 
 class GoogleTranslate:
-    def _get_credential(self, key_file_path):
-        """Default lifetime of api key is 3600 seconds."""
+    api_key_errors = ['429']
+    api_key_cache = []
+    gcloud = None
+    project_id = None
+    using_tip = _(
+        'This plugin uses Application Default Credentials (ADC) in your local '
+        'environment to access your Google Translate service. To set up the '
+        'ADC, follow these steps:\n'
+        '1. Install the gcloud CLI by checking out its instructions {}.\n'
+        '2. Run the command: gcloud auth application-default login.\n'
+        '3. Sign in to your Google account and grant needed privileges.') \
+        .format('<sup><a href="https://cloud.google.com/sdk/docs/install">[^]'
+                '</a></sup>').replace('\n', '<br />')
+
+    def _run_command(self, command, silence=False):
+        message = _('Cannot run the command "{}".')
+        try:
+            startupinfo = None
+            # Prevent the popping console window on Windows.
+            if sys.platform == 'win32':
+                from subprocess import STARTUPINFO, STARTF_USESHOWWINDOW
+                startupinfo = STARTUPINFO()
+                startupinfo.dwFlags |= STARTF_USESHOWWINDOW
+            process = Popen(
+                command, stdout=PIPE, stderr=PIPE, universal_newlines=True,
+                startupinfo=startupinfo)
+        except Exception:
+            if silence:
+                return None
+            raise Exception(
+                message.format(command, '\n\n%s' % traceback.format_exc()))
+        if process.wait() != 0:
+            if silence:
+                return None
+            raise Exception(
+                message.format(command, '\n\n%s' % process.stderr.read()))
+        return process.stdout.read().strip()
+
+    def _get_gcloud_command(self):
+        if self.gcloud is not None:
+            return self.gcloud
+        if sys.platform == 'win32':
+            name = 'gcloud.cmd'
+            which = 'where'
+            base = r'google-cloud-sdk\bin\%s' % name
+            paths = [
+                r'"%s\Google\Cloud SDK\%s"'
+                % (os.environ.get('programfiles(x86)'), base),
+                r'"%s\AppData\Local\Google\Cloud SDK\%s"'
+                % (os.environ.get('userprofile'), base)]
+        else:
+            name = 'gcloud'
+            which = 'which'
+            paths = ['/usr/local/bin/%s' % name]
+        gcloud = self.get_external_program(name, paths)
+        if gcloud is None:
+            gcloud = self._run_command([which, name], silence=True)
+            if gcloud is not None:
+                gcloud = gcloud.split('\n')[0]
+        if gcloud is None:
+            raise Exception(_('Cannot find the command "{}".').format(name))
+        self.gcloud = gcloud
+        return gcloud
+
+    def _get_project_id(self):
+        if self.project_id is not None:
+            return self.project_id
+        self.project_id = self._run_command(
+            [self._get_gcloud_command(), 'config', 'get', 'project'])
+        return self.project_id
+
+    def _get_credential(self):
+        """The default lifetime of the API key is 3600 seconds. Once an
+        available key is generated, it will be cached until it expired.
+        """
         timestamp, old_api_key = self.api_key_cache or (None, None)
         if old_api_key is not None and time.time() - timestamp < 3600:
             return old_api_key
-        os.environ.update(GOOGLE_APPLICATION_CREDENTIALS=key_file_path)
+        # Temporarily add existing proxies.
         self.proxy_uri and os.environ.update(
             http_proxy=self.proxy_uri, https_proxy=self.proxy_uri)
-        process = Popen(
-            ['gcloud', 'auth', 'application-default', 'print-access-token'],
-            stdout=PIPE, stderr=PIPE)
-        if process.wait() != 0:
-            raise Exception(_('Can not obtain Google API key. Reason: {}')
-                            .format(process.stderr.read().decode('utf-8')))
+        new_api_key = self._run_command([
+            self._get_gcloud_command(), 'auth', 'application-default',
+            'print-access-token'])
+        # Cleanse the proxies after use.
         for proxy in ('http_proxy', 'https_proxy'):
             if proxy in os.environ:
                 del os.environ[proxy]
-        new_api_key = process.stdout.read().decode('utf-8').strip()
         self.api_key_cache[:] = [time.time(), new_api_key]
         return new_api_key
 
 
-class GoogleBasicTranslate(Base, GoogleTranslate):
-    name = 'Google(Basic)'
-    alias = 'Google (Basic)'
+class GoogleBasicTranslateADC(GoogleTranslate, Base):
+    name = 'Google(Basic)ADC'
+    alias = 'Google (Basic) ADC'
     lang_codes = Base.load_lang_codes(google)
     endpoint = 'https://translation.googleapis.com/language/translate/v2'
-    api_key_hint = 'API key or KEY_PATH'
-    api_key_errors = ['429']
-    api_key_cache = []
+    api_key_hint = 'API key'
+    need_api_key = False
+
+    def get_headers(self):
+        return {
+            'Content-Type': 'application/json',
+            'Authorization': 'Bearer %s' % self._get_credential(),
+            'x-goog-user-project': self._get_project_id(),
+        }
+
+    def get_data(self, data):
+        return json.dumps(data)
 
     def translate(self, text):
-        headers = {'Content-Type': 'application/x-www-form-urlencoded'}
         data = {
             'format': 'html',
             'model': 'nmt',
             'target': self._get_target_code(),
             'q': text
         }
 
-        if self.api_key:
-            if os.path.sep not in self.api_key:
-                data.update(key=self.api_key)
-            else:
-                api_key = self._get_credential(self.api_key)
-                headers = {
-                    'Content-Type': 'application/json',
-                    'Authorization': 'Bearer %s' % api_key
-                }
-                data = json.dumps(data)
-
         if not self._is_auto_lang():
             data.update(source=self._get_source_code())
-
         return self.get_result(
-            self.endpoint, data, headers, method='POST', callback=self._parse)
+            self.endpoint, self.get_data(data), self.get_headers(),
+            method='POST', callback=self._parse)
 
     def _parse(self, data):
         translations = json.loads(data)['data']['translations']
         return ''.join(i['translatedText'] for i in translations)
 
 
-class GoogleAdvancedTranslate(Base, GoogleTranslate):
+class GoogleBasicTranslate(GoogleBasicTranslateADC):
+    name = 'Google(Basic)'
+    alias = 'Google (Basic)'
+    need_api_key = True
+    using_tip = None
+
+    def get_headers(self):
+        return {'Content-Type': 'application/x-www-form-urlencoded'}
+
+    def get_data(self, data):
+        data.update(key=self.api_key)
+        return data
+
+
+class GoogleAdvancedTranslate(GoogleTranslate, Base):
     name = 'Google(Advanced)'
-    alias = 'Google (Advanced)'
+    alias = 'Google (Advanced) ADC'
     lang_codes = Base.load_lang_codes(google)
     endpoint = 'https://translation.googleapis.com/v3/projects/{}'
-    api_key_hint = 'PROJECT_NUMBER_OR_ID|KEY_PATH'
-    api_key_pattern = r'^[^\s\|]+?\|.+$'
-    api_key_errors = ['429']
-    api_key_cache = []
+    api_key_hint = 'PROJECT_ID'
+    need_api_key = False
 
     def translate(self, text):
-        try:
-            project_id, key_file_path = re.split(r'\|', self.api_key)
-        except Exception:
-            raise BadApiKeyFormat(self.api_key_error_message())
-
+        project_id = self._get_project_id()
         endpoint = self.endpoint.format('%s:translateText' % project_id)
-        api_key = self._get_credential(key_file_path)
-
         headers = {
             'Content-Type': 'application/json',
-            'Authorization': 'Bearer %s' % api_key
+            'Authorization': 'Bearer %s' % self._get_credential(),
+            'x-goog-user-project': project_id,
         }
 
         data = {

lib/config.py

@@ -28,6 +28,7 @@
     'merge_enabled': False,
     'merge_length': 1800,
     'ebook_metadata': {},
+    'search_paths': [],
 }
 
 

lib/translation.py

@@ -276,6 +276,7 @@ def get_translator(engine_class=None):
     config = get_config()
     engine_class = engine_class or get_engine_class()
     translator = engine_class()
+    translator.set_search_paths(config.get('search_paths'))
     if config.get('proxy_enabled'):
         translator.set_proxy(config.get('proxy_setting'))
     translator.set_merge_enabled(config.get('merge_enabled'))