135 lines
3.7 KiB
Python
135 lines
3.7 KiB
Python
# The core application of the Mia project.
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# by imacat <imacat@mail.imacat.idv.tw>, 2020/7/24
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# Copyright (c) 2020 imacat.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""The session-based status management of the Mia core application.
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"""
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import random
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from django.http import HttpResponseRedirect
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from .utils import UrlBuilder
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def error_redirect(request, url, form):
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"""Redirects to a specific URL on error, with the status ID appended
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as the query parameter "s". The status will be loaded with the
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retrieve_status template tag.
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Args:
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request (HttpRequest): The request.
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url (str): The destination URL.
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form (dict[str]): The received POSTed form.
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Returns:
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HttpResponseRedirect: The redirect response.
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"""
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status_id = _store(request, {"form": form})
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return HttpResponseRedirect(str(UrlBuilder(url).query(s=status_id)))
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def get_previous_post(request):
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"""Retrieves the previously-stored status.
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Args:
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request (HttpRequest): The request.
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Returns:
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dict: The previously-stored status.
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"""
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if "s" not in request.GET:
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return None
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status = _retrieve(request, request.GET["s"])
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if "form" not in status:
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return None
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return status["form"]
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def retrieve_status(request):
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"""Retrieves the previously-stored status.
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Args:
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request (HttpRequest): The request.
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Returns:
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dict: The previously-stored status.
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"""
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if "s" not in request.GET:
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return None
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return _retrieve(request, request.GET["s"])
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def _store(request, status):
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"""Stores the status into the session, and returns the status ID that can
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be used to retrieve the status later with retrieve().
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Args:
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request (HttpRequest): The request.
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status (dict): The dict of the status.
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Returns:
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str: The status ID
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"""
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if "stored_status" not in request.session:
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request.session["stored_status"] = {}
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id = _new_status_id(request.session["stored_status"])
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request.session["stored_status"][id] = status
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return id
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def _retrieve(request, id):
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"""Stores the status into the session, and returns the status ID that can
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be used to retrieve the status later with retrieve().
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Args:
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request (HttpRequest): The request.
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id (str): The status ID.
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Returns:
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dict: The status, or None if the status does not exist.
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"""
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if "stored_status" not in request.session:
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return None
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if id not in request.session["stored_status"]:
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return None
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return request.session["stored_status"][id]
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def _new_status_id(status_store):
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"""Generates and returns a new status ID that does not exist yet.
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Args:
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status_store (dict): The status storage.
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Returns:
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str: The newly-generated status ID.
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"""
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while True:
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id = ""
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while len(id) < 16:
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n = random.randint(1, 64)
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if n < 26:
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id = id + chr(ord("a") + n)
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elif n < 52:
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id = id + chr(ord("a") + (n - 26))
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elif n < 62:
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id = id + chr(ord("0") + (n - 52))
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else:
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id = id + "-_."[n - 62]
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if id not in status_store:
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return id
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