main.py

# Copyright 2014 The Oppia Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS-IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""URL routing definitions, and some basic error/warmup handlers."""

from __future__ import annotations

import logging

from core import android_validation_constants, feconf
from core.constants import constants
from core.controllers import (
    access_validators,
    acl_decorators,
    admin,
    android,
    base,
    beam_jobs,
    blog_admin,
    blog_dashboard,
    blog_homepage,
    certificate_assessment,
    classroom,
    collection_editor,
    collection_viewer,
    concept_card_viewer,
    contributor_dashboard,
    contributor_dashboard_admin,
    creator_dashboard,
    cron,
    custom_landing_pages,
    diagnostic_test_player,
    editor,
    feature_flag,
    features,
    feedback,
    firebase,
    general_feedback,
    improvements,
    incoming_app_feedback_report,
    learner_dashboard,
    learner_goals,
    learner_group,
    library,
    machine_translation,
    moderator,
    oppia_root,
    pages,
    practice_sessions,
    profile,
    question_editor,
    questions_list,
    reader,
    recent_commits,
    release_coordinator,
    resources,
    review_tests,
    skill_editor,
    skill_mastery,
    story_editor,
    story_viewer,
    subscriptions,
    subtopic_viewer,
    suggestion,
    tasks,
    topic_editor,
    topic_viewer,
    topics_and_skills_dashboard,
    voice_artist,
    voiceover,
)
from core.platform import models
from core.platform.auth import firebase_auth_services

import google.cloud.logging
import webapp2
from typing import Dict, Optional, Type, TypeVar
from webapp2_extras import routes

MYPY = False
if MYPY:  # pragma: no cover
    from mypy_imports import datastore_services
    from mypy_imports import memory_cache_services as cache_services

T = TypeVar('T')  # pylint: disable=invalid-name

cache_services = models.Registry.import_cache_services()
datastore_services = models.Registry.import_datastore_services()

# Cloud Logging is disabled in emulator mode, since it is unnecessary and
# creates a lot of noise.
if not constants.EMULATOR_MODE:
    # Instantiates a client and retrieves a Cloud Logging handler based on the
    # environment you're running in and integrates the handler with the Python
    # logging module.
    client = google.cloud.logging.Client()
    client.setup_logging()

# Suppress debug logging for chardet. See https://stackoverflow.com/a/48581323.
# Without this, a lot of unnecessary debug logs are printed in error logs,
# which makes it tiresome to identify the actual error.
logging.getLogger(name='chardet.charsetprober').setLevel(logging.INFO)


class InternetConnectivityHandler(
    base.BaseHandler[Dict[str, str], Dict[str, str]]
):
    """Handles the get request to the server from the
    frontend to check for internet connection."""

    GET_HANDLER_ERROR_RETURN_TYPE = feconf.HANDLER_TYPE_JSON
    URL_PATH_ARGS_SCHEMAS: Dict[str, str] = {}
    HANDLER_ARGS_SCHEMAS: Dict[str, Dict[str, str]] = {'GET': {}}

    @acl_decorators.open_access
    def get(self) -> None:
        """Handles GET requests."""
        self.render_json({'is_internet_connected': True})


class FrontendErrorHandler(base.BaseHandler[Dict[str, str], Dict[str, str]]):
    """Handles errors arising from the frontend."""

    REQUIRE_PAYLOAD_CSRF_CHECK = False
    URL_PATH_ARGS_SCHEMAS: Dict[str, str] = {}
    HANDLER_ARGS_SCHEMAS = {
        'POST': {'error': {'schema': {'type': 'basestring'}}}
    }

    @acl_decorators.open_access
    def post(self) -> None:
        """Records errors reported by the frontend."""
        assert self.normalized_payload is not None
        logging.error(
            'Frontend error: %s' % self.normalized_payload.get('error')
        )
        self.render_json(self.values)


class WarmupPage(base.BaseHandler[Dict[str, str], Dict[str, str]]):
    """Handles warmup requests."""

    GET_HANDLER_ERROR_RETURN_TYPE = feconf.HANDLER_TYPE_HTML
    URL_PATH_ARGS_SCHEMAS: Dict[str, str] = {}
    HANDLER_ARGS_SCHEMAS: Dict[str, Dict[str, str]] = {'GET': {}}

    @acl_decorators.open_access
    def get(self) -> None:
        """Handles GET warmup requests."""
        pass


class SplashRedirectPage(base.BaseHandler[Dict[str, str], Dict[str, str]]):
    """Redirect the old splash URL, '/splash' to the new one, '/'."""

    GET_HANDLER_ERROR_RETURN_TYPE = feconf.HANDLER_TYPE_HTML
    URL_PATH_ARGS_SCHEMAS: Dict[str, str] = {}
    HANDLER_ARGS_SCHEMAS: Dict[str, Dict[str, str]] = {'GET': {}}

    @acl_decorators.open_access
    def get(self) -> None:
        self.redirect('/')


# Type for `defaults` is set to Dict[str, str] based on the usage in our
# backend. Should be changed in future as per the requirements.
def get_redirect_route(
    regex_route: str,
    handler: Type[webapp2.RequestHandler],
    defaults: Optional[Dict[str, str]] = None,
) -> routes.RedirectRoute:
    """Returns a route that redirects /foo/ to /foo.

    Warning: this method strips off parameters after the trailing slash. URLs
    with parameters should be formulated without the trailing slash.

    Args:
        regex_route: unicode. A raw string representing a route.
        handler: RequestHandler. A callable to handle the route.
        defaults: dict. Optional defaults parameter to be passed
            into the RedirectRoute object.

    Returns:
        RedirectRoute. A RedirectRoute object for redirects.
    """
    if defaults is None:
        defaults = {}
    name = regex_route.replace('/', '_')
    return routes.RedirectRoute(
        regex_route, handler, name, strict_slash=True, defaults=defaults
    )


# Register the URLs with the classes responsible for handling them.
URLS = [
    get_redirect_route(
        '/<firebase_path:__/auth(?:/.*)?>', firebase.FirebaseProxyPage
    ),
    get_redirect_route(r'/_ah/warmup', WarmupPage),
    get_redirect_route(
        r'%s/can_access_story_viewer_page/<classroom_url_fragment>/<topic_url_fragment>/story/<story_url_fragment>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.StoryViewerPageAccessValidationHandler,
    ),
    get_redirect_route(r'/splash', SplashRedirectPage),
    get_redirect_route(
        r'/internetconnectivityhandler', InternetConnectivityHandler
    ),
    get_redirect_route(r'/credits', pages.AboutRedirectPage),
    get_redirect_route(r'/participate', pages.TeachRedirectPage),
    get_redirect_route(r'/site_guidelines', pages.TeachRedirectPage),
    get_redirect_route(r'/forum', pages.ForumRedirectPage),
    # Access Validators.
    get_redirect_route(
        r'%s/can_access_classroom_page'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ClassroomAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_classrooms_page'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ClassroomsPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_collection_editor_page/<collection_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.CollectionEditorAccessValidationPage,
    ),
    get_redirect_route(
        r'%s/can_access_exploration_editor_page/<exploration_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ExplorationEditorAccessValidationHandlerPage,
    ),
    get_redirect_route(
        r'%s/can_access_story_editor_page/<story_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.StoryEditorAccessValidationHandlerPage,
    ),
    get_redirect_route(
        r'%s/can_access_blog_home_page'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.BlogHomePageAccessValidationHandler,
    ),
    get_redirect_route(
        '/learn/<classroom_url_fragment>/<topic_url_fragment>/revision/<subtopic_url_fragment>',  # pylint: disable=line-too-long
        access_validators.SubtopicViewerPageRevisionRedirectHandler,
    ),
    get_redirect_route(
        r'%s/can_access_subtopic_viewer_page/<classroom_url_fragment>/<topic_url_fragment>/studyguide/<subtopic_url_fragment>'  # pylint: disable=line-too-long
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.SubtopicViewerPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_blog_post_page'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.BlogPostPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_blog_author_profile_page/<author_username>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.BlogAuthorProfilePageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_manage_own_account' % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ManageOwnAccountValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_topic_editor/<topic_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.TopicEditorAccessValidationPage,
    ),
    get_redirect_route(
        r'%s/does_profile_exist/<username>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ProfileExistsValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_release_coordinator_page'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ReleaseCoordinatorAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_facilitator_dashboard_page'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.FacilitatorDashboardPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_create_learner_group_page'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.CreateLearnerGroupPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_edit_learner_group_page/<learner_group_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.EditLearnerGroupPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/does_learner_group_exist/<learner_group_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ViewLearnerGroupPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_collection_player_page/<collection_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.CollectionViewerPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_diagnostic_test_player_page'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.DiagnosticTestPlayerAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_practice_session_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>/practice/session'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.PracticeSessionAccessValidationPage,
    ),
    get_redirect_route(
        r'%s/can_access_practice_session_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>/practice/<node_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.PracticeSessionAccessValidationPage,
    ),
    get_redirect_route(
        r'%s/can_access_practice_session_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>/test/arc/<arc_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.PracticeSessionAccessValidationPage,
    ),
    get_redirect_route(
        r'%s/can_access_practice_session_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>/mastery-challenge'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.PracticeSessionAccessValidationPage,
    ),
    get_redirect_route(
        r'%s/can_access_topic_viewer_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>' % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.TopicViewerPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_topic_viewer_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>/story'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.TopicViewerPageAccessValidationHandler,
    ),
    get_redirect_route(
        '/learn/<classroom_url_fragment>/<topic_url_fragment>/revision',
        access_validators.TopicViewerPageRevisionRedirectHandler,
    ),
    get_redirect_route(
        r'%s/can_access_topic_viewer_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>/studyguide'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.TopicViewerPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_topic_viewer_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>/practice'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.TopicViewerPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/can_access_technical_feedback_dashboard'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.TechnicalFeedbackDashboardAccessValidationHandler,
    ),
    get_redirect_route(r'%s' % feconf.ADMIN_URL, oppia_root.OppiaRootPage),
    get_redirect_route(r'/adminhandler', admin.AdminHandler),
    get_redirect_route(r'/adminrolehandler', admin.AdminRoleHandler),
    get_redirect_route(r'/bannedusershandler', admin.BannedUsersHandler),
    get_redirect_route(
        r'/topicmanagerrolehandler', admin.TopicManagerRoleHandler
    ),
    get_redirect_route(
        r'/translationcoordinatorrolehandler',
        admin.TranslationCoordinatorRoleHandler,
    ),
    get_redirect_route(
        r'/adminsuperadminhandler', admin.AdminSuperAdminPrivilegesHandler
    ),
    get_redirect_route(
        r'/admintopicscsvdownloadhandler', admin.AdminTopicsCsvFileDownloader
    ),
    get_redirect_route(
        r'%s' % feconf.AUTOMATIC_VOICEOVER_ADMIN_CONTROL_URL,
        admin.AutomaticVoiceoverAdminControlHandler,
    ),
    get_redirect_route(
        r'/updateblogpostdatahandler', admin.UpdateBlogPostHandler
    ),
    get_redirect_route(
        r'%s' % feconf.REGENERATE_TOPIC_SUMMARIES_URL,
        admin.RegenerateTopicSummariesHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.GENERATE_STUDY_GUIDE_MODELS_URL,
        admin.GenerateStudyGuideModelsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.DELETE_STUDY_GUIDE_MODELS_URL,
        admin.DeleteStudyGuideModelsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.VERIFY_STUDY_GUIDE_MODELS_URL,
        admin.VerifyStudyGuideModelsHandler,
    ),
    get_redirect_route(
        r'/contributionrightshandler/<category>',
        contributor_dashboard_admin.ContributionRightsHandler,
    ),
    get_redirect_route(
        r'/getcontributorusershandler/<category>',
        contributor_dashboard_admin.ContributorUsersListHandler,
    ),
    get_redirect_route(
        r'/contributionrightsdatahandler',
        contributor_dashboard_admin.ContributionRightsDataHandler,
    ),
    get_redirect_route(
        r'%s/<contribution_type>/<contribution_subtype>'
        % (feconf.CONTRIBUTOR_DASHBOARD_ADMIN_STATS_URL_PREFIX),
        contributor_dashboard_admin.ContributorDashboardAdminStatsHandler,
    ),
    get_redirect_route(
        r'%s' % (feconf.COMMUNITY_CONTRIBUTION_STATS_URL),
        contributor_dashboard_admin.CommunityContributionStatsHandler,
    ),
    get_redirect_route(
        r'/translationcontributionstatshandler',
        contributor_dashboard_admin.TranslationContributionStatsHandler,
    ),
    get_redirect_route(
        r'%s/<contribution_type>/<contribution_subtype>/<username>'
        % (feconf.CONTRIBUTOR_STATS_SUMMARIES_URL),
        contributor_dashboard.ContributorStatsSummariesHandler,
    ),
    get_redirect_route(
        r'%s/<username>' % feconf.CONTRIBUTOR_ALL_STATS_SUMMARIES_URL,
        contributor_dashboard.ContributorAllStatsSummariesHandler,
    ),
    get_redirect_route(
        r'%s/<username>/<suggestion_type>'
        % (feconf.CONTRIBUTOR_CERTIFICATE_URL),
        contributor_dashboard.ContributorCertificateHandler,
    ),
    get_redirect_route(
        '/contributor_dashboard',
        creator_dashboard.OldContributorDashboardRedirectPage,
    ),
    get_redirect_route(
        '/creator_dashboard', creator_dashboard.OldCreatorDashboardRedirectPage
    ),
    get_redirect_route(
        r'%s' % feconf.CREATOR_DASHBOARD_DATA_URL,
        creator_dashboard.CreatorDashboardHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.NEW_EXPLORATION_URL,
        creator_dashboard.NewExplorationHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.NEW_COLLECTION_URL,
        creator_dashboard.NewCollectionHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.FRACTIONS_LANDING_PAGE_URL,
        custom_landing_pages.FractionLandingRedirectPage,
    ),
    get_redirect_route(
        r'/learn/maths/<topic>', custom_landing_pages.TopicLandingRedirectPage
    ),
    get_redirect_route(
        r'%s/<opportunity_type>' % feconf.CONTRIBUTOR_OPPORTUNITIES_DATA_URL,
        contributor_dashboard.ContributionOpportunitiesHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.CONTRIBUTOR_OPPORTUNITIES_DATA_V2_URL,
        contributor_dashboard.ContributionOpportunitiesHandlerV2,
    ),
    get_redirect_route(
        r'%s' % feconf.OPPORTUNITIES_COUNT_URL,
        contributor_dashboard.OpportunitiesCountHandler,
    ),
    get_redirect_route(
        r'/preferredtranslationlanguage',
        contributor_dashboard.TranslationPreferenceHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.REVIEWABLE_OPPORTUNITIES_URL,
        contributor_dashboard.ReviewableOpportunitiesHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.REVIEWABLE_OPPORTUNITIES_V2_URL,
        contributor_dashboard.ReviewableOpportunitiesHandlerV2,
    ),
    get_redirect_route(
        r'%s' % feconf.PINNED_OPPORTUNITIES_URL,
        contributor_dashboard.LessonsPinningHandler,
    ),
    get_redirect_route(
        r'/gettranslatabletexthandler',
        contributor_dashboard.TranslatableTextHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.TRANSLATABLE_CONTENTS_V2_URL,
        contributor_dashboard.TranslatableContentsHandlerV2,
    ),
    get_redirect_route(
        r'%s' % feconf.MACHINE_TRANSLATION_DATA_URL,
        contributor_dashboard.MachineTranslationStateTextsHandler,
    ),
    get_redirect_route(
        r'/generate-translation',
        machine_translation.MachineTranslationGenerateHandler,
    ),
    get_redirect_route(
        r'/translation-provider-mapping',
        machine_translation.TranslationProviderMappingHandler,
    ),
    get_redirect_route(
        r'/usercontributionrightsdatahandler',
        contributor_dashboard.UserContributionRightsDataHandler,
    ),
    get_redirect_route(
        r'/retrievefeaturedtranslationlanguages',
        contributor_dashboard.FeaturedTranslationLanguagesHandler,
    ),
    get_redirect_route(
        r'/gettranslatabletopicnames',
        contributor_dashboard.TranslatableTopicNamesHandler,
    ),
    get_redirect_route(
        r'/gettranslatabletopicnamesperclassroom',
        contributor_dashboard.TranslatableTopicNamesPerClassroomHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.NEW_SKILL_URL,
        topics_and_skills_dashboard.NewSkillHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.NEW_QUESTION_URL, question_editor.QuestionCreationHandler
    ),
    get_redirect_route(
        r'%s/<comma_separated_skill_ids>' % feconf.QUESTIONS_LIST_URL_PREFIX,
        questions_list.QuestionsListHandler,
    ),
    get_redirect_route(
        r'%s/<comma_separated_skill_ids>' % feconf.QUESTION_COUNT_URL_PREFIX,
        questions_list.QuestionCountDataHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>/<topic_url_fragment>'
        % feconf.PRACTICE_SESSION_DATA_URL_PREFIX,
        practice_sessions.PracticeSessionsPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>/<topic_url_fragment>'
        r'/<node_id>' % feconf.PRACTICE_SESSION_DATA_URL_PREFIX,
        practice_sessions.PracticeSessionsPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>/<topic_url_fragment>'
        r'/arc/<arc_id>' % feconf.PRACTICE_SESSION_DATA_URL_PREFIX,
        practice_sessions.PracticeSessionsPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>/<topic_url_fragment>'
        r'/<story_url_fragment>' % feconf.REVIEW_TEST_DATA_URL_PREFIX,
        review_tests.ReviewTestsPageDataHandler,
    ),
    get_redirect_route(
        r'%s/can_access_review_tests_page/<classroom_url_fragment>'
        r'/<topic_url_fragment>/<story_url_fragment>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ReviewTestsPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>/<topic_url_fragment>'
        r'/<story_url_fragment>' % feconf.STORY_DATA_HANDLER,
        story_viewer.StoryPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<story_url_fragment>' % feconf.STORY_URL_FRAGMENT_HANDLER,
        story_editor.StoryUrlFragmentHandler,
    ),
    get_redirect_route(
        r'%s/<topic_name>' % feconf.TOPIC_NAME_HANDLER,
        topic_viewer.TopicNameHandler,
    ),
    get_redirect_route(
        r'%s/<topic_url_fragment>' % feconf.TOPIC_URL_FRAGMENT_HANDLER,
        topic_editor.TopicUrlFragmentHandler,
    ),
    get_redirect_route(
        r'%s/<skill_description>' % feconf.SKILL_DESCRIPTION_HANDLER,
        skill_editor.SkillDescriptionHandler,
    ),
    get_redirect_route(
        r'%s/<skill_id>' % feconf.DIAGNOSTIC_TEST_SKILL_ASSIGNMENT_HANDLER,
        skill_editor.DiagnosticTestSkillAssignmentHandler,
    ),
    get_redirect_route(
        r'%s/' % feconf.TOPIC_ID_TO_DIAGNOSTIC_TEST_SKILL_IDS_HANDLER,
        topics_and_skills_dashboard.TopicIdToDiagnosticTestSkillIdsHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>' % feconf.DIAGNOSTIC_TEST_QUESTIONS_HANDLER_URL,
        diagnostic_test_player.DiagnosticTestQuestionsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.CLASSROOM_DISPLAY_INFO_HANDLER_URL,
        classroom.ClassroomDisplayInfoHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.UPDATE_CLASSROOMS_ORDER_HANDLER_URL,
        classroom.UpdateClassroomIndexMappingHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.UNUSED_TOPICS_HANDLER_URL, classroom.UnusedTopicsHandler
    ),
    get_redirect_route(
        r'%s' % feconf.NEW_CLASSROOM_ID_HANDLER_URL,
        classroom.NewClassroomIdHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.NEW_CLASSROOM_HANDLER_URL, classroom.NewClassroomHandler
    ),
    get_redirect_route(
        r'%s' % feconf.TOPICS_TO_CLASSROOM_RELATION_HANDLER_URL,
        classroom.TopicsToClassroomsRelationHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.ALL_CLASSROOMS_SUMMARY_HANDLER_URL,
        classroom.AllClassroomsSummaryHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_id>' % feconf.CLASSROOM_HANDLER_URL,
        classroom.ClassroomHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>' % feconf.CLASSROOM_URL_FRAGMENT_HANDLER,
        classroom.ClassroomUrlFragmentHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>' % feconf.CLASSROOM_ID_HANDLER_URL,
        classroom.ClassroomIdHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.VOICEOVER_ADMIN_DATA_HANDLER_URL,
        voiceover.VoiceoverAdminDataHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.VOICEOVER_LANGUAGE_CODES_MAPPING_HANDLER_URL,
        voiceover.VoiceoverLanguageCodesMappingHandler,
    ),
    get_redirect_route(
        r'/entity_voiceovers_bulk_handler/<entity_type>/<entity_id>/'
        r'<entity_version>/<language_code>',
        voiceover.EntityVoiceoversBulkHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.REGENERATE_AUTOMATIC_VOICEOVER_HANDLER_URL,
        voiceover.RegenerateAutomaticVoiceoverHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.REGENERATE_VOICEOVER_ON_EXP_UPDATE_URL,
        voiceover.RegenerateVoiceoverOnExpUpdateHandler,
    ),
    get_redirect_route(
        r'/exploration_voiceovers_data/<exploration_id>',
        voiceover.ExplorationDataForVoiceoverRegenerationHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.REGENERATE_VOICEOVERS_FOR_EXPLORATION_URL,
        voiceover.RegenerateVoiceoversForExplorationHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>/<topic_url_fragment>'
        r'/<story_url_fragment>/<node_id>' % feconf.STORY_PROGRESS_URL_PREFIX,
        story_viewer.StoryProgressHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>/<topic_url_fragment>'
        r'/<subtopic_url_fragment>' % feconf.SUBTOPIC_DATA_HANDLER,
        subtopic_viewer.SubtopicPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>' % feconf.TOPIC_EDITOR_STORY_URL,
        topic_editor.TopicEditorStoryHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>/<topic_url_fragment>'
        % feconf.TOPIC_DATA_HANDLER,
        topic_viewer.TopicPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<classroom_url_fragment>' % feconf.CLASSROOM_DATA_HANDLER,
        classroom.ClassroomDataHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.NEW_TOPIC_URL,
        topics_and_skills_dashboard.NewTopicHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.UPLOAD_EXPLORATION_URL,
        creator_dashboard.UploadExplorationHandler,
    ),
    get_redirect_route(
        '/learner_dashboard', learner_dashboard.OldLearnerDashboardRedirectPage
    ),
    get_redirect_route(
        r'%s' % feconf.LEARNER_DASHBOARD_TOPIC_AND_STORY_DATA_URL,
        learner_dashboard.LearnerDashboardTopicsAndStoriesProgressHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.LEARNER_COMPLETED_CHAPTERS_COUNT_DATA_URL,
        learner_dashboard.LearnerCompletedChaptersCountHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.LEARNER_DASHBOARD_COLLECTION_DATA_URL,
        learner_dashboard.LearnerDashboardCollectionsProgressHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.LEARNER_DASHBOARD_EXPLORATION_DATA_URL,
        learner_dashboard.LearnerDashboardExplorationsProgressHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.LEARNER_DASHBOARD_IDS_DATA_URL,
        learner_dashboard.LearnerDashboardIdsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.MERGE_SKILLS_URL,
        topics_and_skills_dashboard.MergeSkillHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.TOPICS_AND_SKILLS_DASHBOARD_DATA_URL,
        topics_and_skills_dashboard.TopicsAndSkillsDashboardPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<skill_id>' % feconf.UNASSIGN_SKILL_DATA_HANDLER_URL,
        topics_and_skills_dashboard.TopicAssignmentsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.SKILL_DASHBOARD_DATA_URL,
        topics_and_skills_dashboard.SkillsDashboardPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<activity_type>/<activity_id>'
        % feconf.LEARNER_INCOMPLETE_ACTIVITY_DATA_URL,
        reader.LearnerIncompleteActivityHandler,
    ),
    get_redirect_route(
        r'%s/<activity_type>/<topic_id>' % feconf.LEARNER_GOALS_DATA_URL,
        learner_goals.LearnerGoalsHandler,
    ),
    get_redirect_route(
        r'%s/<blog_post_url>' % feconf.BLOG_HOMEPAGE_DATA_URL,
        blog_homepage.BlogPostDataHandler,
    ),
    get_redirect_route(
        r'%s/<author_username>'
        % feconf.BLOG_AUTHOR_PROFILE_PAGE_DATA_URL_PREFIX,
        blog_homepage.AuthorsPageHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.BLOG_HOMEPAGE_DATA_URL,
        blog_homepage.BlogHomepageDataHandler,
    ),
    get_redirect_route(
        r'/assetsdevhandler/<page_context>/<page_identifier>/'
        'assets/<asset_type:(image|audio|thumbnail)>/<encoded_filename>',
        resources.AssetDevHandler,
    ),
    get_redirect_route(
        r'/value_generator_handler/<generator_id>',
        resources.ValueGeneratorHandler,
    ),
    get_redirect_route(r'/promo_bar_handler', resources.PromoBarHandler),
    get_redirect_route('/library', library.OldLibraryRedirectPage),
    get_redirect_route(
        r'%s' % feconf.LIBRARY_INDEX_DATA_URL, library.LibraryIndexHandler
    ),
    get_redirect_route(
        r'%s' % feconf.LIBRARY_GROUP_DATA_URL, library.LibraryGroupIndexHandler
    ),
    get_redirect_route(r'/gallery', library.LibraryRedirectPage),
    get_redirect_route(r'/contribute', library.LibraryRedirectPage),
    get_redirect_route(r'/playtest', library.LibraryRedirectPage),
    get_redirect_route(
        feconf.EXPLORATION_SUMMARIES_DATA_URL,
        library.ExplorationSummariesHandler,
    ),
    get_redirect_route(
        feconf.COLLECTION_SUMMARIES_DATA_URL, library.CollectionSummariesHandler
    ),
    get_redirect_route(
        r'/profilehandler/data/<username>', profile.ProfileHandler
    ),
    get_redirect_route(
        r'/mailinglistsubscriptionhandler',
        profile.MailingListSubscriptionHandler,
    ),
    get_redirect_route(
        r'%s/<secret>' % feconf.BULK_EMAIL_WEBHOOK_ENDPOINT,
        profile.BulkEmailWebhookEndpoint,
    ),
    get_redirect_route(feconf.PREFERENCES_DATA_URL, profile.PreferencesHandler),
    get_redirect_route(r'%s' % feconf.SIGNUP_URL, profile.SignupPage),
    get_redirect_route(r'%s' % feconf.SIGNUP_DATA_URL, profile.SignupHandler),
    get_redirect_route(
        feconf.DELETE_ACCOUNT_HANDLER_URL, profile.DeleteAccountHandler
    ),
    get_redirect_route(
        feconf.EXPORT_ACCOUNT_HANDLER_URL, profile.ExportAccountHandler
    ),
    get_redirect_route(
        r'%s' % feconf.USERNAME_CHECK_DATA_URL, profile.UsernameCheckHandler
    ),
    get_redirect_route(
        r'%s' % feconf.SITE_LANGUAGE_DATA_URL, profile.SiteLanguageHandler
    ),
    get_redirect_route(r'/userinfohandler', profile.UserInfoHandler),
    get_redirect_route(r'/userinfohandler/data', profile.UserInfoHandler),
    get_redirect_route(r'/url_handler', profile.UrlHandler),
    get_redirect_route(
        r'/moderatorhandler/featured', moderator.FeaturedActivitiesHandler
    ),
    get_redirect_route(
        r'/moderatorhandler/email_draft', moderator.EmailDraftHandler
    ),
    get_redirect_route(
        r'/memorycachehandler', release_coordinator.MemoryCacheHandler
    ),
    get_redirect_route(
        r'%s' % feconf.FEATURE_FLAGS_URL,
        release_coordinator.FeatureFlagsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.USER_GROUPS_HANDLER_URL,
        release_coordinator.UserGroupHandler,
    ),
    get_redirect_route(
        r'%s/can_access_exploration_player_page/<exploration_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.ExplorationPlayerAccessValidationPage,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.EXPLORATION_INIT_URL_PREFIX,
        reader.ExplorationHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.EXPLORATION_PRETESTS_URL_PREFIX,
        reader.PretestHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.EXPLORATION_FEATURES_PREFIX,
        features.ExplorationFeaturesHandler,
    ),
    get_redirect_route(
        '/explorehandler/exploration_start_event/<exploration_id>',
        reader.ExplorationStartEventHandler,
    ),
    get_redirect_route(
        '/explorehandler/exploration_actual_start_event/<exploration_id>',
        reader.ExplorationActualStartEventHandler,
    ),
    get_redirect_route(
        '/explorehandler/solution_hit_event/<exploration_id>',
        reader.SolutionHitEventHandler,
    ),
    get_redirect_route(
        '/sync_logged_out_and_logged_in_progress/<exploration_id>',
        reader.SyncLoggedOutLearnerProgressHandler,
    ),
    get_redirect_route(
        r'/explorehandler/state_hit_event/<exploration_id>',
        reader.StateHitEventHandler,
    ),
    get_redirect_route(
        r'/explorehandler/state_complete_event/<exploration_id>',
        reader.StateCompleteEventHandler,
    ),
    get_redirect_route(
        r'/explorehandler/checkpoint_reached_by_logged_out_user/<exploration_id>',  # pylint: disable=line-too-long
        reader.SaveTransientCheckpointProgressHandler,
    ),
    get_redirect_route(
        '/progress/<unique_progress_url_id>', reader.TransientCheckpointUrlPage
    ),
    get_redirect_route(
        r'/explorehandler/leave_for_refresher_exp_event/<exploration_id>',
        reader.LeaveForRefresherExpEventHandler,
    ),
    get_redirect_route(
        r'/explorehandler/answer_submitted_event/<exploration_id>',
        reader.AnswerSubmittedEventHandler,
    ),
    get_redirect_route(
        r'/explorehandler/checkpoint_reached/<exploration_id>',
        reader.CheckpointReachedEventHandler,
    ),
    get_redirect_route(
        r'/explorehandler/restart/<exploration_id>',
        reader.ExplorationRestartEventHandler,
    ),
    get_redirect_route(
        r'/explorehandler/give_feedback/<exploration_id>',
        reader.ReaderFeedbackHandler,
    ),
    get_redirect_route(
        r'/explorehandler/exploration_complete_event/<exploration_id>',
        reader.ExplorationCompleteEventHandler,
    ),
    get_redirect_route(
        r'/explorehandler/exploration_maybe_leave_event/<exploration_id>',
        reader.ExplorationMaybeLeaveHandler,
    ),
    get_redirect_route(
        r'/explorehandler/stats_events/<exploration_id>',
        reader.StatsEventsHandler,
    ),
    get_redirect_route(
        r'/explorehandler/store_playthrough/<exploration_id>',
        reader.StorePlaythroughHandler,
    ),
    get_redirect_route(
        r'/explorehandler/rating/<exploration_id>', reader.RatingHandler
    ),
    get_redirect_route(
        r'/explorehandler/recommendations/<exploration_id>',
        reader.RecommendationsHandler,
    ),
    get_redirect_route(
        r'%s/<entity_type>/<entity_id>'
        % (feconf.LEARNER_ANSWER_DETAILS_SUBMIT_URL),
        reader.LearnerAnswerDetailsSubmissionHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>/<state_name>/<version>'
        % (feconf.STATE_VERSION_HISTORY_URL_PREFIX),
        reader.StateVersionHistoryHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>/<version>'
        % (feconf.METADATA_VERSION_HISTORY_URL_PREFIX),
        reader.MetadataVersionHistoryHandler,
    ),
    get_redirect_route(
        r'%s/<question_id>' % feconf.QUESTION_EDITOR_DATA_URL_PREFIX,
        question_editor.EditableQuestionDataHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.EXPLORATION_DATA_PREFIX,
        editor.ExplorationHandler,
    ),
    get_redirect_route(
        r'/editsallowedhandler/<exploration_id>',
        editor.ExplorationEditsAllowedHandler,
    ),
    get_redirect_route(
        r'/createhandler/download/<exploration_id>',
        editor.ExplorationFileDownloader,
    ),
    get_redirect_route(
        r'%s/<entity_type>/<entity_id>'
        % (feconf.EXPLORATION_IMAGE_UPLOAD_PREFIX),
        editor.ImageUploadHandler,
    ),
    get_redirect_route(
        r'/createhandler/audioupload/<exploration_id>',
        voice_artist.AudioUploadHandler,
    ),
    get_redirect_route(
        r'/createhandler/state_yaml/<exploration_id>', editor.StateYamlHandler
    ),
    get_redirect_route(
        r'/createhandler/check_revert_valid/<exploration_id>/<version>',
        editor.ExplorationCheckRevertValidHandler,
    ),
    get_redirect_route(
        r'/createhandler/revert/<exploration_id>',
        editor.ExplorationRevertHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.EXPLORATION_RIGHTS_PREFIX,
        editor.ExplorationRightsHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.USER_PERMISSIONS_URL_PREFIX,
        editor.UserExplorationPermissionsHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.EXPLORATION_STATUS_PREFIX,
        editor.ExplorationStatusHandler,
    ),
    get_redirect_route(
        r'/createhandler/moderatorrights/<exploration_id>',
        editor.ExplorationModeratorRightsHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.USER_EXPLORATION_EMAILS_PREFIX,
        editor.UserExplorationEmailsHandler,
    ),
    get_redirect_route(
        r'/createhandler/snapshots/<exploration_id>',
        editor.ExplorationSnapshotsHandler,
    ),
    get_redirect_route(
        r'/createhandler/statistics/<exploration_id>',
        editor.ExplorationStatisticsHandler,
    ),
    get_redirect_route(
        r'/createhandler/state_interaction_stats/<exploration_id>/<state_name>',
        editor.StateInteractionStatsHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.EXPLORATION_STATE_ANSWER_STATS_PREFIX,
        editor.StateAnswerStatisticsHandler,
    ),
    get_redirect_route(
        r'/createhandler/started_tutorial_event/<exploration_id>',
        editor.StartedTutorialEventHandler,
    ),
    get_redirect_route(
        r'/createhandler/started_translation_tutorial_event/<exploration_id>',
        voice_artist.StartedTranslationTutorialEventHandler,
    ),
    get_redirect_route(
        r'/createhandler/autosave_draft/<exploration_id>',
        editor.EditorAutosaveHandler,
    ),
    get_redirect_route(
        r'/createhandler/get_top_unresolved_answers/<exploration_id>',
        editor.TopUnresolvedAnswersHandler,
    ),
    get_redirect_route(
        r'%s/<entity_type>/<entity_id>'
        % feconf.LEARNER_ANSWER_INFO_HANDLER_URL,
        editor.LearnerAnswerInfoHandler,
    ),
    get_redirect_route(
        r'/entity_translations_bulk_handler/<entity_type>/<entity_id>/<entity_version>',  # pylint: disable=line-too-long
        editor.EntityTranslationsBulkHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.RECENT_COMMITS_DATA_URL,
        recent_commits.RecentCommitsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.RECENT_FEEDBACK_MESSAGES_DATA_URL,
        feedback.RecentFeedbackMessagesHandler,
    ),
    get_redirect_route(
        r'%s/<thread_id>' % feconf.FEEDBACK_THREAD_VIEW_EVENT_URL,
        feedback.FeedbackThreadViewEventHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.FEEDBACK_THREADLIST_URL_PREFIX,
        feedback.ThreadListHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>' % feconf.FEEDBACK_THREADLIST_URL_PREFIX_FOR_TOPICS,
        feedback.ThreadListHandlerForTopicsHandler,
    ),
    get_redirect_route(
        r'%s/<thread_id>' % feconf.FEEDBACK_THREAD_URL_PREFIX,
        feedback.ThreadHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.FEEDBACK_STATS_URL_PREFIX,
        feedback.FeedbackStatsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.MY_FEEDBACK_URL,
        general_feedback.MyFeedbackListHandler,
    ),
    get_redirect_route(
        r'%s/unread_count' % feconf.MY_FEEDBACK_URL,
        general_feedback.MyFeedbackUnreadCountHandler,
    ),
    get_redirect_route(
        r'%s/<feedback_id>' % feconf.MY_FEEDBACK_URL,
        general_feedback.MyFeedbackDetailHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.LESSON_FEEDBACK_URL,
        general_feedback.LessonFeedbackSubmitHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>/<feedback_id>' % feconf.LESSON_FEEDBACK_URL,
        general_feedback.LessonFeedbackDetailHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.LESSON_FEEDBACK_URL,
        general_feedback.LessonFeedbackListHandler,
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.FEEDBACK_STATUS_COUNTS_URL,
        general_feedback.FeedbackStatusCountsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.PLATFORM_FEEDBACK_URL,
        general_feedback.PlatformFeedbackSubmitHandler,
    ),
    get_redirect_route(
        r'%s/<dashboard>/<dashboard_id>/<report_id>'
        % feconf.PLATFORM_FEEDBACK_URL,
        general_feedback.PlatformFeedbackDetailHandler,
    ),
    get_redirect_route(
        r'%s/<dashboard>/<dashboard_id>' % feconf.PLATFORM_FEEDBACK_URL,
        general_feedback.PlatformFeedbackListHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.GENERAL_FEEDBACK_CAPTCHA_CONFIG_URL,
        general_feedback.GeneralFeedbackCaptchaConfigHandler,
    ),
    get_redirect_route(
        r'%s/' % feconf.SUGGESTION_URL_PREFIX, suggestion.SuggestionHandler
    ),
    get_redirect_route(
        r'%s/<suggestion_id>' % feconf.UPDATE_TRANSLATION_SUGGESTION_URL_PREFIX,
        suggestion.UpdateTranslationSuggestionHandler,
    ),
    get_redirect_route(
        r'%s/<suggestion_id>' % feconf.UPDATE_QUESTION_SUGGESTION_URL_PREFIX,
        suggestion.UpdateQuestionSuggestionHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.QUESTIONS_URL_PREFIX, reader.QuestionPlayerHandler
    ),
    get_redirect_route(
        r'%s/exploration/<target_id>/<suggestion_id>'
        % feconf.SUGGESTION_ACTION_URL_PREFIX,
        suggestion.SuggestionToExplorationActionHandler,
    ),
    get_redirect_route(
        r'%s/resubmit/<suggestion_id>' % feconf.SUGGESTION_ACTION_URL_PREFIX,
        suggestion.ResubmitSuggestionHandler,
    ),
    get_redirect_route(
        r'%s/skill/<target_id>/<suggestion_id>'
        % feconf.SUGGESTION_ACTION_URL_PREFIX,
        suggestion.SuggestionToSkillActionHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.SUGGESTION_LIST_URL_PREFIX,
        suggestion.SuggestionListHandler,
    ),
    get_redirect_route(
        r'/getreviewablesuggestions/<target_type>/<suggestion_type>',
        suggestion.ReviewableSuggestionsHandler,
    ),
    get_redirect_route(
        r'/getsubmittedsuggestions/<target_type>/<suggestion_type>',
        suggestion.UserSubmittedSuggestionsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.SUBSCRIBE_URL_PREFIX, subscriptions.SubscribeHandler
    ),
    get_redirect_route(
        r'%s' % feconf.UNSUBSCRIBE_URL_PREFIX, subscriptions.UnsubscribeHandler
    ),
    get_redirect_route(
        r'%s/<exploration_id>' % feconf.FLAG_EXPLORATION_URL_PREFIX,
        reader.FlagExplorationHandler,
    ),
    get_redirect_route(
        r'%s/<collection_id>' % feconf.COLLECTION_DATA_URL_PREFIX,
        collection_viewer.CollectionDataHandler,
    ),
    get_redirect_route(
        r'%s/<collection_id>' % feconf.COLLECTION_EDITOR_DATA_URL_PREFIX,
        collection_editor.EditableCollectionDataHandler,
    ),
    get_redirect_route(
        r'%s/<collection_id>' % feconf.COLLECTION_RIGHTS_PREFIX,
        collection_editor.CollectionRightsHandler,
    ),
    get_redirect_route(
        r'%s/<collection_id>' % feconf.COLLECTION_PUBLISH_PREFIX,
        collection_editor.CollectionPublishHandler,
    ),
    get_redirect_route(
        r'%s/<collection_id>' % feconf.COLLECTION_UNPUBLISH_PREFIX,
        collection_editor.CollectionUnpublishHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>' % feconf.TOPIC_EDITOR_DATA_URL_PREFIX,
        topic_editor.EditableTopicDataHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>/<subtopic_id>'
        % feconf.SUBTOPIC_PAGE_EDITOR_DATA_URL_PREFIX,
        topic_editor.EditableSubtopicPageDataHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>/<subtopic_id>'
        % feconf.STUDY_GUIDE_EDITOR_DATA_URL_PREFIX,
        topic_editor.EditableStudyGuideDataHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>' % feconf.TOPIC_RIGHTS_URL_PREFIX,
        topic_editor.TopicRightsHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>' % feconf.TOPIC_STATUS_URL_PREFIX,
        topic_editor.TopicPublishHandler,
    ),
    get_redirect_route(
        r'%s/<topic_id>' % feconf.TOPIC_SEND_MAIL_URL_PREFIX,
        topic_editor.TopicPublishSendMailHandler,
    ),
    get_redirect_route(
        r'%s/' % feconf.TOPIC_ID_TO_TOPIC_NAME,
        topic_editor.TopicIdToTopicNameHandler,
    ),
    get_redirect_route(
        r'%s/<selected_skill_ids>' % feconf.CONCEPT_CARD_DATA_URL_PREFIX,
        concept_card_viewer.ConceptCardDataHandler,
    ),
    get_redirect_route(
        r'%s/<question_id>' % feconf.QUESTION_SKILL_LINK_URL_PREFIX,
        question_editor.QuestionSkillLinkHandler,
    ),
    get_redirect_route(
        r'%s/<comma_separated_skill_ids>' % feconf.SKILL_DATA_URL_PREFIX,
        skill_editor.SkillDataHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.FETCH_SKILLS_URL_PREFIX, skill_editor.FetchSkillsHandler
    ),
    get_redirect_route(
        r'%s/can_access_skill_editor/<skill_id>'
        % feconf.ACCESS_VALIDATION_HANDLER_PREFIX,
        access_validators.SkillEditorPageAccessValidationHandler,
    ),
    get_redirect_route(
        r'%s/<skill_id>' % feconf.SKILL_EDITOR_DATA_URL_PREFIX,
        skill_editor.EditableSkillDataHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.SKILL_MASTERY_DATA_URL,
        skill_mastery.SkillMasteryDataHandler,
    ),
    get_redirect_route(
        r'%s/<skill_id>' % feconf.SKILL_RIGHTS_URL_PREFIX,
        skill_editor.SkillRightsHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.SUBTOPIC_MASTERY_DATA_URL,
        skill_mastery.SubtopicMasteryDataHandler,
    ),
    get_redirect_route(
        r'%s/<story_id>' % feconf.STORY_EDITOR_DATA_URL_PREFIX,
        story_editor.EditableStoryDataHandler,
    ),
    get_redirect_route(
        r'%s/<story_id>' % feconf.STORY_PUBLISH_HANDLER,
        story_editor.StoryPublishHandler,
    ),
    get_redirect_route(
        r'%s/<story_id>' % feconf.VALIDATE_STORY_EXPLORATIONS_URL_PREFIX,
        story_editor.ValidateExplorationsHandler,
    ),
    get_redirect_route(
        r'/explorationdataextractionhandler', admin.DataExtractionQueryHandler
    ),
    get_redirect_route(
        r'/senddummymailtoadminhandler', admin.SendDummyMailToAdminHandler
    ),
    get_redirect_route(r'/updateusernamehandler', admin.UpdateUsernameHandler),
    get_redirect_route(
        r'/numberofdeletionrequestshandler',
        admin.NumberOfDeletionRequestsHandler,
    ),
    get_redirect_route(
        r'/verifyusermodelsdeletedhandler', admin.VerifyUserModelsDeletedHandler
    ),
    get_redirect_route(r'/deleteuserhandler', admin.DeleteUserHandler),
    get_redirect_route(
        r'/interactions', admin.InteractionsByExplorationIdHandler
    ),
    get_redirect_route(r'/frontend_errors', FrontendErrorHandler),
    get_redirect_route(r'/session_begin', base.SessionBeginHandler),
    get_redirect_route(r'/session_end', base.SessionEndHandler),
    get_redirect_route(
        r'%s/%s/<exploration_id>'
        % (
            feconf.IMPROVEMENTS_URL_PREFIX,
            constants.TASK_ENTITY_TYPE_EXPLORATION,
        ),
        improvements.ExplorationImprovementsHandler,
    ),
    get_redirect_route(
        r'%s/%s/<exploration_id>'
        % (
            feconf.IMPROVEMENTS_HISTORY_URL_PREFIX,
            constants.TASK_ENTITY_TYPE_EXPLORATION,
        ),
        improvements.ExplorationImprovementsHistoryHandler,
    ),
    get_redirect_route(
        r'%s/%s/<exploration_id>'
        % (
            feconf.IMPROVEMENTS_CONFIG_URL_PREFIX,
            constants.TASK_ENTITY_TYPE_EXPLORATION,
        ),
        improvements.ExplorationImprovementsConfigHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.BLOG_ADMIN_ROLE_HANDLER_URL,
        blog_admin.BlogAdminRolesHandler,
    ),
    get_redirect_route(r'/blogadminhandler', blog_admin.BlogAdminHandler),
    get_redirect_route('/beam_job', beam_jobs.BeamJobHandler),
    get_redirect_route('/beam_job_run', beam_jobs.BeamJobRunHandler),
    get_redirect_route(
        '/beam_job_run_result', beam_jobs.BeamJobRunResultHandler
    ),
    get_redirect_route(
        r'%s/<blog_post_id>' % feconf.BLOG_EDITOR_DATA_URL_PREFIX,
        blog_dashboard.BlogPostHandler,
    ),
    get_redirect_route(
        r'%s/<blog_post_id>' % feconf.BLOG_TITLE_HANDLER,
        blog_dashboard.BlogPostTitleHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.BLOG_DASHBOARD_DATA_URL,
        blog_dashboard.BlogDashboardDataHandler,
    ),
    get_redirect_route(
        r'/issuesdatahandler/<exploration_id>', editor.FetchIssuesHandler
    ),
    get_redirect_route(
        r'/playthroughdatahandler/<exploration_id>/<playthrough_id>',
        editor.FetchPlaythroughHandler,
    ),
    get_redirect_route(
        r'/resolveissuehandler/<exploration_id>', editor.ResolveIssueHandler
    ),
    get_redirect_route(r'%s' % feconf.CSRF_HANDLER_URL, base.CsrfTokenHandler),
    get_redirect_route(
        r'/feature_flags_evaluation_handler',
        feature_flag.FeatureFlagsEvaluationHandler,
    ),
    get_redirect_route(
        r'/feature_flag_dummy_handler', feature_flag.FeatureFlagDummyHandler
    ),
    get_redirect_route(
        r'%s'
        % (android_validation_constants.INCOMING_ANDROID_FEEDBACK_REPORT_URL),
        incoming_app_feedback_report.IncomingAndroidFeedbackReportHandler,
    ),
    get_redirect_route(
        r'/voice_artist_management_handler/<entity_type>/<entity_id>',
        voice_artist.VoiceArtistManagementHandler,
    ),
    get_redirect_route(
        r'/topics_and_skills_dashboard/categorized_and_untriaged_skills_data',
        topics_and_skills_dashboard.CategorizedAndUntriagedSkillsDataHandler,
    ),
    get_redirect_route(
        r'/entity_translations_handler/<entity_type>/<entity_id>/'
        r'<entity_version>/<language_code>',
        reader.EntityTranslationHandler,
    ),
    get_redirect_route(
        r'/create_learner_group_handler',
        learner_group.CreateLearnerGroupHandler,
    ),
    get_redirect_route(
        r'/update_learner_group_handler/<learner_group_id>',
        learner_group.LearnerGroupHandler,
    ),
    get_redirect_route(
        r'/delete_learner_group_handler/<learner_group_id>',
        learner_group.LearnerGroupHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.FACILITATOR_DASHBOARD_HANDLER,
        learner_group.FacilitatorDashboardHandler,
    ),
    get_redirect_route(
        r'%s' % feconf.LEARNER_DASHBOARD_LEARNER_GROUPS_HANDLER,
        learner_group.LearnerDashboardLearnerGroupsHandler,
    ),
    get_redirect_route(
        r'/view_learner_group_info_handler/<learner_group_id>',
        learner_group.ViewLearnerGroupInfoHandler,
    ),
    get_redirect_route(
        r'/learner_group_search_syllabus_handler',
        learner_group.LearnerGroupSearchSyllabusHandler,
    ),
    get_redirect_route(
        r'/learner_group_syllabus_handler/<learner_group_id>',
        learner_group.LearnerGroupSyllabusHandler,
    ),
    get_redirect_route(
        r'/learner_group_user_progress_handler/<learner_group_id>',
        learner_group.LearnerGroupLearnerProgressHandler,
    ),
    get_redirect_route(
        r'/learner_group_learner_specific_progress_handler/<learner_group_id>',
        learner_group.LearnerGroupLearnerSpecificProgressHandler,
    ),
    get_redirect_route(
        r'/learner_group_search_learner_handler',
        learner_group.LearnerGroupSearchLearnerHandler,
    ),
    get_redirect_route(
        r'/learner_group_learners_info_handler/<learner_group_id>',
        learner_group.LearnerGroupLearnersInfoHandler,
    ),
    get_redirect_route(
        r'/learner_group_learner_invitation_handler/<learner_group_id>',
        learner_group.LearnerGroupLearnerInvitationHandler,
    ),
    get_redirect_route(
        r'/learner_group_progress_sharing_permission_handler/<learner_group_id>',  # pylint: disable=line-too-long
        learner_group.LearnerGroupProgressSharingPermissionHandler,
    ),
    get_redirect_route(
        r'/exit_learner_group_handler/<learner_group_id>',
        learner_group.ExitLearnerGroupHandler,
    ),
    get_redirect_route(
        r'/user_progress_in_stories_chapters_handler/<username>',
        learner_group.LearnerStoriesChaptersProgressHandler,
    ),
    get_redirect_route(
        r'/android_platform_parameters',
        android.AndroidPlatformParametersHandler,
    ),
    get_redirect_route(
        r'/android_feature_flags', android.AndroidFeatureFlagsHandler
    ),
    get_redirect_route('/android_data', android.AndroidActivityHandler),
    get_redirect_route(
        '/automatic_voiceover_regeneration_record',
        voiceover.AutomaticVoiceoverRegenerationRecordHandler,
    ),
    get_redirect_route(
        r'/exploration_voiceover_regeneration_status_url/<exploration_id>',
        voiceover.VoiceoverRegenerationRequestToCloudTaskHandler,
    ),
    get_redirect_route(
        feconf.CERTIFICATE_ASSESSMENT_OFFERING_HANDLER,
        certificate_assessment.CertificateAssessmentOfferingHandler,
    ),
    get_redirect_route(
        feconf.CERTIFICATE_ASSESSMENT_OFFERING_BY_ID_HANDLER,
        certificate_assessment.CertificateAssessmentOfferingByIdHandler,
    ),
    get_redirect_route(
        feconf.VALIDATE_CERTIFICATE_ASSESSMENT_OFFERING_HANDLER,
        certificate_assessment.ValidateCertificateAssessmentOfferingHandler,
    ),
    get_redirect_route(
        feconf.CERTIFICATE_ASSESSMENT_OFFERINGS_FOR_CLASSROOM_HANDLER,
        certificate_assessment.CertificateAssessmentOfferingsForClassroomHandler,
    ),
    get_redirect_route(
        feconf.START_CERTIFICATE_ASSESSMENT_HANDLER,
        certificate_assessment.StartCertificateAssessmentHandler,
    ),
    get_redirect_route(
        feconf.SUBMIT_CERTIFICATE_ASSESSMENT_HANDLER,
        certificate_assessment.SubmitCertificateAssessmentHandler,
    ),
    get_redirect_route(
        feconf.CERTIFICATE_ASSESSMENT_RESULT_HANDLER,
        certificate_assessment.CertificateAssessmentResultHandler,
    ),
    get_redirect_route(
        feconf.CERTIFICATE_ASSESSMENT_ATTEMPTS_HANDLER,
        certificate_assessment.CertificateAssessmentAttemptsHandler,
    ),
]

# Adding redirects for topic landing pages.
for subject, topics in constants.AVAILABLE_LANDING_PAGES.items():
    for topic in topics:
        URLS.append(
            get_redirect_route(
                r'/%s/%s' % (subject, topic), oppia_root.OppiaRootPage
            )
        )

if constants.DEV_MODE:
    URLS.append(
        get_redirect_route(
            r'/initialize_android_test_data',
            android.InitializeAndroidTestDataHandler,
        )
    )

# Adding redirects for all stewards landing pages.
for stewards_route in constants.STEWARDS_LANDING_PAGE['ROUTES']:
    URLS.append(
        get_redirect_route(r'/%s' % stewards_route, oppia_root.OppiaRootPage)
    )

# Redirect all routes handled using angular router to the oppia root page.
for page in constants.PAGES_REGISTERED_WITH_FRONTEND.values():
    if not 'MANUALLY_REGISTERED_WITH_BACKEND' in page:
        URLS.append(
            get_redirect_route(r'/%s' % page['ROUTE'], oppia_root.OppiaRootPage)
        )

# Manually redirect routes with url fragments to the oppia root page.
URLS.extend(
    (
        get_redirect_route(r'/profile/<username>', oppia_root.OppiaRootPage),
        get_redirect_route(
            r'/collection/<collection_id>', oppia_root.OppiaRootPage
        ),
        get_redirect_route(
            r'%s/story/<story_url_fragment>' % feconf.TOPIC_VIEWER_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'/learn/<classroom_url_fragment>', oppia_root.OppiaRootPage
        ),
        get_redirect_route(
            r'%s/<exploration_id>' % feconf.EXPLORATION_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/<exploration_id>' % feconf.EXPLORATION_URL_EMBED_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s%s'
            % (
                feconf.TOPIC_VIEWER_URL_PREFIX,
                feconf.PRACTICE_SESSION_URL_PREFIX,
            ),
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/practice/<node_id>' % feconf.TOPIC_VIEWER_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/test/arc/<arc_id>' % feconf.TOPIC_VIEWER_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/mastery-challenge' % feconf.TOPIC_VIEWER_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/story' % feconf.TOPIC_VIEWER_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/studyguide' % feconf.TOPIC_VIEWER_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/studyguide/<subtopic_url_fragment>'
            % feconf.TOPIC_VIEWER_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/practice' % feconf.TOPIC_VIEWER_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s' % feconf.TOPIC_VIEWER_URL_PREFIX, oppia_root.OppiaRootPage
        ),
        get_redirect_route(
            r'%s/<blog_post_url>' % feconf.BLOG_HOMEPAGE_URL,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/<topic_id>' % feconf.TOPIC_EDITOR_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/<author_username>'
            % feconf.BLOG_AUTHOR_PROFILE_PAGE_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/<exploration_id>' % feconf.EDITOR_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/<skill_id>' % feconf.SKILL_EDITOR_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/<story_id>' % feconf.STORY_EDITOR_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
        get_redirect_route(
            r'%s/<exploration_id>' % feconf.LESSON_URL_PREFIX,
            oppia_root.OppiaRootPage,
        ),
    )
)

# Add cron urls. Note that cron URLs MUST start with /cron for them to work
# in production (see dispatch() in base.py).
URLS.extend(
    (
        get_redirect_route(
            r'/cron/models/cleanup', cron.CronModelsCleanupHandler
        ),
        get_redirect_route(
            r'/cron/users/user_deletion', cron.CronUserDeletionHandler
        ),
        get_redirect_route(
            r'/cron/users/fully_complete_user_deletion',
            cron.CronFullyCompleteUserDeletionHandler,
        ),
        get_redirect_route(
            r'/cron/mail/admins/contributor_dashboard_bottlenecks',
            cron.CronMailAdminContributorDashboardBottlenecksHandler,
        ),
        get_redirect_route(
            r'/cron/mail/reviewers/contributor_dashboard_suggestions',
            cron.CronMailReviewersContributorDashboardSuggestionsHandler,
        ),
        get_redirect_route(
            r'/cron/app_feedback_report/scrub_expiring_reports',
            cron.CronAppFeedbackReportsScrubberHandlerPage,
        ),
        get_redirect_route(
            r'/cron/explorations/recommendations',
            cron.CronExplorationRecommendationsHandler,
        ),
        get_redirect_route(
            r'/cron/cloud_task/mark_stale_cloud_task_run_as_failed',
            cron.CronMarkStaleCloudTaskRunModelsAsFailedHandler,
        ),
        get_redirect_route(
            r'/cron/cloud_task/mark_stale_voiceover_regeneration_content_as_failed',
            cron.CronMarkStaleVoiceoverRegenerationContentAsFailedHandler,
        ),
        get_redirect_route(
            r'/cron/users/dashboard_stats', cron.CronDashboardStatsHandler
        ),
        get_redirect_route(
            r'/cron/mail/curriculum_admins/chapter_publication_notfications',
            cron.CronMailChapterPublicationsNotificationsHandler,
        ),
        get_redirect_route(
            r'/cron/mail/reviewers/new_contributor_dashboard_suggestions',
            cron.CronMailReviewerNewSuggestionsHandler,
        ),
        get_redirect_route(
            r'/cron/feedback/lesson_feedback_cleanup',
            cron.CronLessonFeedbackCleanupHandler,
        ),
        get_redirect_route(
            r'/cron/feedback/platform_feedback_cleanup',
            cron.CronPlatformFeedbackCleanupHandler,
        ),
    )
)

# Add tasks urls.
URLS.extend(
    (
        get_redirect_route(
            r'%s' % feconf.TASK_URL_FEEDBACK_MESSAGE_EMAILS,
            tasks.UnsentFeedbackEmailHandler,
        ),
        get_redirect_route(
            r'%s'
            % (
                feconf.TASK_URL_CONTRIBUTOR_DASHBOARD_ACHIEVEMENT_NOTIFICATION_EMAILS
            ),
            tasks.ContributorDashboardAchievementEmailHandler,
        ),
        get_redirect_route(
            r'%s' % feconf.TASK_URL_FLAG_EXPLORATION_EMAILS,
            tasks.FlagExplorationEmailHandler,
        ),
        get_redirect_route(
            r'%s' % feconf.TASK_URL_INSTANT_FEEDBACK_EMAILS,
            tasks.InstantFeedbackMessageEmailHandler,
        ),
        get_redirect_route(
            r'%s' % feconf.TASK_URL_FEEDBACK_STATUS_EMAILS,
            tasks.FeedbackThreadStatusChangeEmailHandler,
        ),
        get_redirect_route(
            r'%s' % feconf.TASK_URL_RETRY_FAILED_EMAIL,
            tasks.RetryEmailHandler,
        ),
        get_redirect_route(
            r'%s' % feconf.TASK_URL_DEFERRED, tasks.DeferredTasksHandler
        ),
    )
)

# Add URLs to static resources that differ between deployments.
URLS.extend(
    (
        get_redirect_route('/favicon.ico', resources.FaviconHandler),
        get_redirect_route('/robots.txt', resources.RobotsTxtHandler),
        get_redirect_route(
            '/assets/copyrighted-images/<folder>/<filename>',
            resources.CopyrightImagesHandler,
        ),
    )
)

# 404 error handler (Needs to be at the end of the URLS list).
URLS.append(get_redirect_route(r'/<:.*>', base.Error404Handler))


class NdbWsgiMiddleware:
    """Wraps the WSGI application into the NDB client context."""

    def __init__(self, wsgi_app: webapp2.WSGIApplication) -> None:
        self.wsgi_app = wsgi_app

    def __call__(
        self, environ: Dict[str, str], start_response: webapp2.Response
    ) -> webapp2.Response:
        global_cache = datastore_services.RedisCache(
            cache_services.get_cloud_ndb_redis_client()
        )
        with datastore_services.get_ndb_context(global_cache=global_cache):
            return self.wsgi_app(environ, start_response)


app_without_context = webapp2.WSGIApplication(URLS, debug=feconf.DEBUG)
app = NdbWsgiMiddleware(app_without_context)

# Only establish Firebase connection when not running backend tests. This allows
# test discovery and collection without requiring Google Cloud credentials.
if 'pytest' not in __import__('sys').modules:
    firebase_auth_services.establish_firebase_connection()