mirror of
https://github.com/Garmelon/PFERD.git
synced 2023-12-21 10:23:01 +01:00
464 lines
18 KiB
Python
464 lines
18 KiB
Python
import json
|
|
import re
|
|
from dataclasses import dataclass
|
|
from datetime import date, datetime, timedelta
|
|
from enum import Enum
|
|
from typing import List, Optional, Union
|
|
from urllib.parse import urljoin, urlparse
|
|
|
|
from bs4 import BeautifulSoup, Tag
|
|
|
|
from PFERD.logging import log
|
|
from PFERD.utils import url_set_query_params
|
|
|
|
TargetType = Union[str, int]
|
|
|
|
|
|
class IliasElementType(Enum):
|
|
EXERCISE = "exercise"
|
|
FILE = "file"
|
|
FOLDER = "folder"
|
|
FORUM = "forum"
|
|
LINK = "link"
|
|
MEETING = "meeting"
|
|
VIDEO = "video"
|
|
VIDEO_PLAYER = "video_player"
|
|
VIDEO_FOLDER = "video_folder"
|
|
VIDEO_FOLDER_MAYBE_PAGINATED = "video_folder_maybe_paginated"
|
|
|
|
|
|
@dataclass
|
|
class IliasPageElement:
|
|
type: IliasElementType
|
|
url: str
|
|
name: str
|
|
mtime: Optional[datetime] = None
|
|
description: Optional[str] = None
|
|
|
|
|
|
class IliasPage:
|
|
|
|
def __init__(self, soup: BeautifulSoup, _page_url: str, source_element: Optional[IliasPageElement]):
|
|
self._soup = soup
|
|
self._page_url = _page_url
|
|
self._page_type = source_element.type if source_element else None
|
|
self._source_name = source_element.name if source_element else ""
|
|
|
|
def get_child_elements(self) -> List[IliasPageElement]:
|
|
"""
|
|
Return all child page elements you can find here.
|
|
"""
|
|
if self._is_video_player():
|
|
log.explain("Page is a video player, extracting URL")
|
|
return self._player_to_video()
|
|
if self._is_video_listing():
|
|
log.explain("Page is a video listing, finding elements")
|
|
return self._find_video_entries()
|
|
if self._is_exercise_file():
|
|
log.explain("Page is an exercise, finding elements")
|
|
return self._find_exercise_entries()
|
|
log.explain("Page is a normal folder, finding elements")
|
|
return self._find_normal_entries()
|
|
|
|
def _is_video_player(self) -> bool:
|
|
return "paella_config_file" in str(self._soup)
|
|
|
|
def _is_video_listing(self) -> bool:
|
|
# ILIAS fluff around it
|
|
if self._soup.find(id="headerimage"):
|
|
element: Tag = self._soup.find(id="headerimage")
|
|
if "opencast" in element.attrs["src"].lower():
|
|
return True
|
|
|
|
# Raw listing without ILIAS fluff
|
|
video_element_table: Tag = self._soup.find(
|
|
name="table", id=re.compile(r"tbl_xoct_.+")
|
|
)
|
|
return video_element_table is not None
|
|
|
|
def _is_exercise_file(self) -> bool:
|
|
# we know it from before
|
|
if self._page_type == IliasElementType.EXERCISE:
|
|
return True
|
|
|
|
# We have no suitable parent - let's guesss
|
|
if self._soup.find(id="headerimage"):
|
|
element: Tag = self._soup.find(id="headerimage")
|
|
if "exc" in element.attrs["src"].lower():
|
|
return True
|
|
|
|
return False
|
|
|
|
def _player_to_video(self) -> List[IliasPageElement]:
|
|
# Fetch the actual video page. This is a small wrapper page initializing a javscript
|
|
# player. Sadly we can not execute that JS. The actual video stream url is nowhere
|
|
# on the page, but defined in a JS object inside a script tag, passed to the player
|
|
# library.
|
|
# We do the impossible and RegEx the stream JSON object out of the page's HTML source
|
|
regex: re.Pattern[str] = re.compile(
|
|
r"({\"streams\"[\s\S]+?),\s*{\"paella_config_file", re.IGNORECASE
|
|
)
|
|
json_match = regex.search(str(self._soup))
|
|
|
|
if json_match is None:
|
|
log.warn("Could not find JSON stream info in video player. Ignoring video.")
|
|
return []
|
|
json_str = json_match.group(1)
|
|
|
|
# parse it
|
|
json_object = json.loads(json_str)
|
|
# and fetch the video url!
|
|
video_url = json_object["streams"][0]["sources"]["mp4"][0]["src"]
|
|
return [IliasPageElement(IliasElementType.VIDEO, video_url, self._source_name)]
|
|
|
|
def _find_video_entries(self) -> List[IliasPageElement]:
|
|
# ILIAS has three stages for video pages
|
|
# 1. The initial dummy page without any videos. This page contains the link to the listing
|
|
# 2. The video listing which might be paginated
|
|
# 3. An unpaginated video listing (or at least one that includes 800 videos)
|
|
#
|
|
# We need to figure out where we are.
|
|
|
|
video_element_table: Tag = self._soup.find(
|
|
name="table", id=re.compile(r"tbl_xoct_.+")
|
|
)
|
|
|
|
if video_element_table is None:
|
|
# We are in stage 1
|
|
# The page is actually emtpy but contains the link to stage 2
|
|
content_link: Tag = self._soup.select_one("#tab_series a")
|
|
url: str = self._abs_url_from_link(content_link)
|
|
query_params = {"limit": "800", "cmd": "asyncGetTableGUI", "cmdMode": "asynch"}
|
|
url = url_set_query_params(url, query_params)
|
|
log.explain("Found ILIAS redirection page, following it as a new entry")
|
|
return [IliasPageElement(IliasElementType.VIDEO_FOLDER_MAYBE_PAGINATED, url, "")]
|
|
|
|
is_paginated = self._soup.find(id=re.compile(r"tab_page_sel.+")) is not None
|
|
|
|
if is_paginated and not self._page_type == IliasElementType.VIDEO_FOLDER:
|
|
# We are in stage 2 - try to break pagination
|
|
return self._find_video_entries_paginated()
|
|
|
|
return self._find_video_entries_no_paging()
|
|
|
|
def _find_video_entries_paginated(self) -> List[IliasPageElement]:
|
|
table_element: Tag = self._soup.find(name="table", id=re.compile(r"tbl_xoct_.+"))
|
|
|
|
if table_element is None:
|
|
log.warn("Couldn't increase elements per page (table not found). I might miss elements.")
|
|
return self._find_video_entries_no_paging()
|
|
|
|
id_match = re.match(r"tbl_xoct_(.+)", table_element.attrs["id"])
|
|
if id_match is None:
|
|
log.warn("Couldn't increase elements per page (table id not found). I might miss elements.")
|
|
return self._find_video_entries_no_paging()
|
|
|
|
table_id = id_match.group(1)
|
|
|
|
query_params = {f"tbl_xoct_{table_id}_trows": "800",
|
|
"cmd": "asyncGetTableGUI", "cmdMode": "asynch"}
|
|
url = url_set_query_params(self._page_url, query_params)
|
|
|
|
log.explain("Disabled pagination, retrying folder as a new entry")
|
|
return [IliasPageElement(IliasElementType.VIDEO_FOLDER, url, "")]
|
|
|
|
def _find_video_entries_no_paging(self) -> List[IliasPageElement]:
|
|
"""
|
|
Crawls the "second stage" video page. This page contains the actual video urls.
|
|
"""
|
|
# Video start links are marked with an "Abspielen" link
|
|
video_links: List[Tag] = self._soup.findAll(
|
|
name="a", text=re.compile(r"\s*Abspielen\s*")
|
|
)
|
|
|
|
results: List[IliasPageElement] = []
|
|
|
|
for link in video_links:
|
|
results.append(self._listed_video_to_element(link))
|
|
|
|
return results
|
|
|
|
def _listed_video_to_element(self, link: Tag) -> IliasPageElement:
|
|
# The link is part of a table with multiple columns, describing metadata.
|
|
# 6th child (1 indexed) is the modification time string
|
|
modification_string = link.parent.parent.parent.select_one(
|
|
"td.std:nth-child(6)"
|
|
).getText().strip()
|
|
modification_time = datetime.strptime(modification_string, "%d.%m.%Y - %H:%M")
|
|
|
|
title = link.parent.parent.parent.select_one("td.std:nth-child(3)").getText().strip()
|
|
title += ".mp4"
|
|
|
|
video_name: str = _sanitize_path_name(title)
|
|
|
|
video_url = self._abs_url_from_link(link)
|
|
|
|
log.explain(f"Found video {video_name!r} at {video_url!r}")
|
|
return IliasPageElement(IliasElementType.VIDEO_PLAYER, video_url, video_name, modification_time)
|
|
|
|
def _find_exercise_entries(self) -> List[IliasPageElement]:
|
|
results: List[IliasPageElement] = []
|
|
|
|
# Each assignment is in an accordion container
|
|
assignment_containers: List[Tag] = self._soup.select(".il_VAccordionInnerContainer")
|
|
|
|
for container in assignment_containers:
|
|
# Fetch the container name out of the header to use it in the path
|
|
container_name = container.select_one(".ilAssignmentHeader").getText().strip()
|
|
# Find all download links in the container (this will contain all the files)
|
|
files: List[Tag] = container.findAll(
|
|
name="a",
|
|
# download links contain the given command class
|
|
attrs={"href": lambda x: x and "cmdClass=ilexsubmissiongui" in x},
|
|
text="Download"
|
|
)
|
|
|
|
log.explain(f"Found exercise container {container_name!r}")
|
|
|
|
# Grab each file as you now have the link
|
|
for file_link in files:
|
|
# Two divs, side by side. Left is the name, right is the link ==> get left
|
|
# sibling
|
|
file_name = file_link.parent.findPrevious(name="div").getText().strip()
|
|
file_name = _sanitize_path_name(file_name)
|
|
url = self._abs_url_from_link(file_link)
|
|
|
|
log.explain(f"Found exercise entry {file_name!r}")
|
|
results.append(IliasPageElement(
|
|
IliasElementType.FILE,
|
|
url,
|
|
container_name + "/" + file_name,
|
|
None # We do not have any timestamp
|
|
))
|
|
|
|
return results
|
|
|
|
def _find_normal_entries(self) -> List[IliasPageElement]:
|
|
result: List[IliasPageElement] = []
|
|
|
|
# Fetch all links and throw them to the general interpreter
|
|
links: List[Tag] = self._soup.select("a.il_ContainerItemTitle")
|
|
|
|
for link in links:
|
|
abs_url = self._abs_url_from_link(link)
|
|
element_name = _sanitize_path_name(link.getText())
|
|
element_type = self._find_type_from_link(element_name, link, abs_url)
|
|
description = self._find_link_description(link)
|
|
|
|
if not element_type:
|
|
continue
|
|
if element_type == IliasElementType.MEETING:
|
|
normalized = _sanitize_path_name(self._normalize_meeting_name(element_name))
|
|
log.explain(f"Normalized meeting name from {element_name!r} to {normalized!r}")
|
|
element_name = normalized
|
|
elif element_type == IliasElementType.FILE:
|
|
result.append(self._file_to_element(element_name, abs_url, link))
|
|
continue
|
|
|
|
log.explain(f"Found {element_name!r}")
|
|
result.append(IliasPageElement(element_type, abs_url, element_name, description=description))
|
|
|
|
return result
|
|
|
|
def _find_link_description(self, link: Tag) -> Optional[str]:
|
|
tile: Tag = link.findParent("div", {"class": lambda x: x and "il_ContainerListItem" in x})
|
|
if not tile:
|
|
return None
|
|
description_element: Tag = tile.find("div", {"class": lambda x: x and "il_Description" in x})
|
|
if not description_element:
|
|
return None
|
|
return description_element.getText().strip()
|
|
|
|
def _file_to_element(self, name: str, url: str, link_element: Tag) -> IliasPageElement:
|
|
# Files have a list of properties (type, modification date, size, etc.)
|
|
# In a series of divs.
|
|
# Find the parent containing all those divs, so we can filter our what we need
|
|
properties_parent: Tag = link_element.findParent(
|
|
"div", {"class": lambda x: "il_ContainerListItem" in x}
|
|
).select_one(".il_ItemProperties")
|
|
# The first one is always the filetype
|
|
file_type = properties_parent.select_one("span.il_ItemProperty").getText().strip()
|
|
|
|
# The rest does not have a stable order. Grab the whole text and reg-ex the date
|
|
# out of it
|
|
all_properties_text = properties_parent.getText().strip()
|
|
modification_date_match = re.search(
|
|
r"(((\d+\. \w+ \d+)|(Gestern|Yesterday)|(Heute|Today)|(Morgen|Tomorrow)), \d+:\d+)",
|
|
all_properties_text
|
|
)
|
|
if modification_date_match is None:
|
|
modification_date = None
|
|
# TODO: Figure out if this is expected or *always* an error.
|
|
log.explain(f"Element {name} at {url} has no date. Properties: {all_properties_text!r}")
|
|
else:
|
|
modification_date_str = modification_date_match.group(1)
|
|
modification_date = demangle_date(modification_date_str)
|
|
|
|
# Grab the name from the link text
|
|
name = _sanitize_path_name(link_element.getText())
|
|
full_path = name + "." + file_type
|
|
|
|
log.explain(f"Found file {full_path!r}")
|
|
return IliasPageElement(IliasElementType.FILE, url, full_path, modification_date)
|
|
|
|
@staticmethod
|
|
def _find_type_from_link(
|
|
element_name: str,
|
|
link_element: Tag,
|
|
url: str
|
|
) -> Optional[IliasElementType]:
|
|
"""
|
|
Decides which sub crawler to use for a given top level element.
|
|
"""
|
|
parsed_url = urlparse(url)
|
|
|
|
# file URLs contain "target=file"
|
|
if "target=file_" in parsed_url.query:
|
|
return IliasElementType.FILE
|
|
|
|
# Skip forums
|
|
if "cmd=showThreads" in parsed_url.query:
|
|
return IliasElementType.FORUM
|
|
|
|
# Everything with a ref_id can *probably* be opened to reveal nested things
|
|
# video groups, directories, exercises, etc
|
|
if "ref_id=" in parsed_url.query:
|
|
return IliasPage._find_type_from_folder_like(link_element, url)
|
|
|
|
_unexpected_html_warning()
|
|
log.warn_contd(
|
|
f"Tried to figure out element type, but failed for {str(element_name)!r} / {link_element!r})"
|
|
)
|
|
return None
|
|
|
|
@staticmethod
|
|
def _find_type_from_folder_like(link_element: Tag, url: str) -> Optional[IliasElementType]:
|
|
"""
|
|
Try crawling something that looks like a folder.
|
|
"""
|
|
# pylint: disable=too-many-return-statements
|
|
|
|
found_parent: Optional[Tag] = None
|
|
|
|
# We look for the outer div of our inner link, to find information around it
|
|
# (mostly the icon)
|
|
for parent in link_element.parents:
|
|
if "ilContainerListItemOuter" in parent["class"]:
|
|
found_parent = parent
|
|
break
|
|
|
|
if found_parent is None:
|
|
_unexpected_html_warning()
|
|
log.warn_contd(f"Tried to figure out element type, but did not find an icon for {url!r}")
|
|
return None
|
|
|
|
# Find the small descriptive icon to figure out the type
|
|
img_tag: Optional[Tag] = found_parent.select_one("img.ilListItemIcon")
|
|
|
|
if img_tag is None:
|
|
_unexpected_html_warning()
|
|
log.warn_contd(f"Tried to figure out element type, but did not find an image for {url!r}")
|
|
return None
|
|
|
|
if "opencast" in str(img_tag["alt"]).lower():
|
|
return IliasElementType.VIDEO_FOLDER
|
|
|
|
if str(img_tag["src"]).endswith("icon_exc.svg"):
|
|
return IliasElementType.EXERCISE
|
|
|
|
if str(img_tag["src"]).endswith("icon_webr.svg"):
|
|
return IliasElementType.LINK
|
|
|
|
if str(img_tag["src"]).endswith("frm.svg"):
|
|
return IliasElementType.FORUM
|
|
|
|
if str(img_tag["src"]).endswith("sess.svg"):
|
|
return IliasElementType.MEETING
|
|
|
|
return IliasElementType.FOLDER
|
|
|
|
@staticmethod
|
|
def _normalize_meeting_name(meeting_name: str) -> str:
|
|
"""
|
|
Normalizes meeting names, which have a relative time as their first part,
|
|
to their date in ISO format.
|
|
"""
|
|
date_portion_str = meeting_name.split(" - ")[0]
|
|
date_portion = demangle_date(date_portion_str)
|
|
|
|
if not date_portion:
|
|
return meeting_name
|
|
|
|
rest_of_name = meeting_name
|
|
if rest_of_name.startswith(date_portion_str):
|
|
rest_of_name = rest_of_name[len(date_portion_str):]
|
|
|
|
return datetime.strftime(date_portion, "%Y-%m-%d, %H:%M") + rest_of_name
|
|
|
|
def _abs_url_from_link(self, link_tag: Tag) -> str:
|
|
"""
|
|
Create an absolute url from an <a> tag.
|
|
"""
|
|
return urljoin(self._page_url, link_tag.get("href"))
|
|
|
|
|
|
def _unexpected_html_warning() -> None:
|
|
log.warn("Encountered unexpected HTML structure, ignoring element.")
|
|
|
|
|
|
german_months = ['Jan', 'Feb', 'Mär', 'Apr', 'Mai', 'Jun', 'Jul', 'Aug', 'Sep', 'Okt', 'Nov', 'Dez']
|
|
english_months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
|
|
|
|
|
|
def demangle_date(date_str: str) -> Optional[datetime]:
|
|
"""
|
|
Demangle a given date in one of the following formats:
|
|
"Gestern, HH:MM"
|
|
"Heute, HH:MM"
|
|
"Morgen, HH:MM"
|
|
"dd. mon yyyy, HH:MM
|
|
"""
|
|
try:
|
|
date_str = re.sub(r"\s+", " ", date_str)
|
|
date_str = re.sub("Gestern|Yesterday", _format_date_english(_yesterday()), date_str, re.I)
|
|
date_str = re.sub("Heute|Today", _format_date_english(date.today()), date_str, re.I)
|
|
date_str = re.sub("Morgen|Tomorrow", _format_date_english(_tomorrow()), date_str, re.I)
|
|
for german, english in zip(german_months, english_months):
|
|
date_str = date_str.replace(german, english)
|
|
# Remove trailing dots for abbreviations, e.g. "20. Apr. 2020" -> "20. Apr 2020"
|
|
date_str = date_str.replace(english + ".", english)
|
|
|
|
# We now have a nice english String in the format: "dd. mmm yyyy, hh:mm"
|
|
day_part, time_part = date_str.split(",")
|
|
day_str, month_str, year_str = day_part.split(" ")
|
|
|
|
day = int(day_str.strip().replace(".", ""))
|
|
month = english_months.index(month_str.strip()) + 1
|
|
year = int(year_str.strip())
|
|
|
|
hour_str, minute_str = time_part.split(":")
|
|
hour = int(hour_str)
|
|
minute = int(minute_str)
|
|
|
|
return datetime(year, month, day, hour, minute)
|
|
except Exception:
|
|
log.warn(f"Date parsing failed for {date_str!r}")
|
|
return None
|
|
|
|
|
|
def _format_date_english(date_to_format: date) -> str:
|
|
month = english_months[date_to_format.month - 1]
|
|
return f"{date_to_format.day:02d}. {month} {date_to_format.year:04d}"
|
|
|
|
|
|
def _yesterday() -> date:
|
|
return date.today() - timedelta(days=1)
|
|
|
|
|
|
def _tomorrow() -> date:
|
|
return date.today() + timedelta(days=1)
|
|
|
|
|
|
def _sanitize_path_name(name: str) -> str:
|
|
return name.replace("/", "-").replace("\\", "-").strip()
|