From 44b4204517ad8671065ac41a8a6c463a15ca0041 Mon Sep 17 00:00:00 2001
From: Joscha <joscha@plugh.de>
Date: Mon, 6 May 2019 11:54:36 +0000
Subject: [PATCH] Add basic Ti downloader

---
 PFERD/__init__.py |   2 +
 PFERD/ti.py       | 110 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 112 insertions(+)
 create mode 100644 PFERD/ti.py

diff --git a/PFERD/__init__.py b/PFERD/__init__.py
index 61039f4..cd7ae16 100644
--- a/PFERD/__init__.py
+++ b/PFERD/__init__.py
@@ -3,6 +3,7 @@ import logging
 from .ffm import *
 from .ilias import *
 from .norbert import *
+from .ti import *
 from .utils import *
 
 __all__ = ["STYLE", "FORMAT", "DATE_FORMAT", "FORMATTER", "enable_logging"]
@@ -10,6 +11,7 @@ __all__ = ["STYLE", "FORMAT", "DATE_FORMAT", "FORMATTER", "enable_logging"]
 __all__ += ffm.__all__
 __all__ += ilias.__all__
 __all__ += norbert.__all__
+__all__ += ti.__all__
 __all__ += utils.__all__
 
 STYLE = "{"
diff --git a/PFERD/ti.py b/PFERD/ti.py
new file mode 100644
index 0000000..f01bbd3
--- /dev/null
+++ b/PFERD/ti.py
@@ -0,0 +1,110 @@
+# Fakultät für Mathematik (FfM)
+
+import getpass
+import logging
+import pathlib
+import re
+
+import bs4
+import requests
+
+from .organizer import Organizer
+from .utils import stream_to_path
+
+__all__ = ["Ti"]
+logger = logging.getLogger(__name__)
+
+class Ti:
+    BASE_URL = "http://ti.ira.uka.de/"
+    FILE_RE = re.compile(r"^.+\.pdf$")
+
+    def __init__(self, base_path):
+        self.base_path = base_path
+
+        self._session = requests.Session()
+        self._credentials = None
+
+    def synchronize(self, urlpart, to_dir, transform=lambda x: x,
+            filter=lambda x: True):
+        logger.info(f"    Synchronizing {urlpart} to {to_dir} using the Ti synchronizer.")
+
+        sync_path = pathlib.Path(self.base_path, to_dir)
+
+        orga = Organizer(self.base_path, sync_path)
+        orga.clean_temp_dir()
+
+        self._reset_credentials()
+
+        available = self._find_available(urlpart)
+
+        if "Folien" in available:
+            path = pathlib.PurePath("Folien")
+            if filter(path):
+                self._crawl(urlpart + available["Folien"], path, orga,
+                        transform)
+            else:
+                logger.info("Skipping Folien/")
+
+        if "Blätter" in available:
+            path = pathlib.PurePath("Blätter")
+            if filter(path):
+                self._crawl(urlpart + available["Blätter"], path, orga,
+                        transform)
+            else:
+                logger.info("Skipping Blätter/")
+
+        orga.clean_sync_dir()
+        orga.clean_temp_dir()
+
+        self._reset_credentials()
+
+    def _find_available(self, urlpart):
+        url = self.BASE_URL + urlpart
+        r = self._session.get(url)
+        soup = bs4.BeautifulSoup(r.text, "html.parser")
+
+        available = {}
+
+        if soup.find(href="./Vorlesung/Vorlesung.php"):
+            logger.info("Found Folien/")
+            available["Folien"] = "/Vorlesung/"
+        if soup.find(href="./Uebungen/Uebungen.php"):
+            logger.info("Found Blätter/")
+            available["Blätter"] = "/Uebungen/"
+
+        return available
+
+    def _crawl(self, urlpart, path, orga, transform):
+        url = self.BASE_URL + urlpart
+        r = self._session.get(url)
+        soup = bs4.BeautifulSoup(r.text, "html.parser")
+
+        for filelink in soup.find_all("a", href=self.FILE_RE):
+            filepath = path / filelink["href"]
+            fileurl = url + "/" + filelink["href"]
+
+            new_path = transform(filepath)
+            if new_path is None:
+                continue
+            logger.debug(f"Transformed from {filepath} to {new_path}")
+
+            temp_path = orga.temp_file()
+            self._download(fileurl, temp_path)
+            orga.add_file(temp_path, new_path)
+
+
+    def _get_credentials(self):
+        if self._credentials is None:
+            print("Please enter Ti credentials.")
+            username = getpass.getpass(prompt="Username: ")
+            password = getpass.getpass(prompt="Password: ")
+            self._credentials = (username, password)
+        return self._credentials
+
+    def _reset_credentials(self):
+        self._credentials = None
+
+    def _download(self, url, to_path):
+        username, password = self._get_credentials()
+        with self._session.get(url, stream=True, auth=(username, password)) as r:
+            stream_to_path(r, to_path)