cursepy can guess the download URL if none is provided #13

cursepy/__init__.py

@@ -9,5 +9,5 @@
 
 # Define some metadata here:
 
-__version__ = '2.1.0'
+__version__ = '2.2.0'
 __author__ = 'Owen Cochell'

cursepy/classes/base.py

@@ -543,6 +543,8 @@ class CurseFile(BaseDownloader):
     AWAITING_PUBLISHING = 14
     FAILED_PUBLISHING = 15
 
+    CDN_URL = 'https://edge.forgecdn.net/files/'
+
     INST_ID = 6
 
     @property
@@ -645,6 +647,59 @@ def good_file(self) -> bool:
 
         return self.is_available and self.release_type == CurseFile.RELEASE and self.file_status == CurseFile.RELEASED
 
+    def guess_download(self) -> str:
+        """
+        This method will attempt to guess the download URL.
+
+        Some addons do not allow distribution on 3rd party services and APIs.
+        If this is the case, then the download URL will be 'None'.
+        This method will use available info to make a best guess URL for use.
+
+        We do this by splitting up the file ID into parts of 4
+        and merging some attributes together.
+        For example, if we have an id of '1234567' and a filename of
+        'test.jar', we will get the following download URL:
+
+        https://edge.forgecdn.net/files/1234/567/test.jar
+
+        Please note, this method is experimental and might not work!
+        It is ALWAYS recommended to use the provided download URL,
+        if one is provided.
+        Also, this method will generate a URL for the official CurseForge CDN.
+
+        Once you have this guess, you can set the 'download_url' parameter to the value
+        returned from this method, and download the file from there:
+
+        .. code-block:: python
+
+            file.download_url = file.guess_download()
+            file.download(PATH)
+
+        Or, you can use this URL directly in the download operation:
+
+        .. code-block:: python
+        
+            file.low_download(file.guess_download(), PATH)
+
+        We use the 'low_download()' method, as it accepts a custom URL.
+
+        :return: The best guess download URL
+        :rtype: str
+        """
+
+        download_url = CurseFile.CDN_URL
+        id = str(self.id)
+
+        # Split up the file ID with 4 digits in each part:
+
+        for i in range(0, len(id), 4):
+
+            download_url += id[i:i+4] + '/'
+
+        # Finally, add the filename:
+
+        return download_url + self.file_name
+
 
 @dataclass
 class CurseDependency(BaseCurseInstance):
@@ -725,7 +780,7 @@ def file(self) -> CurseFile:
         :rtype: CurseFile
         """
 
-        return self.hands.file(self,addon_id, self.file_id)
+        return self.hands.file(self.addon_id, self.file_id)
 
 
 @dataclass

docs/source/basic/curse_inst.rst

@@ -598,6 +598,7 @@ Our only understanding of the file is what the backend says it is.
 Production ready files could be poorly made,
 and non-production ready experimental files could also be valid.
 
+
 To get the changelog of the file,
 you can use the 'changelog' property:
 
@@ -629,6 +630,42 @@ object representing the addon this file is attached to.
 The CurseFile class also has :ref:`download functionality<curse_download>`.
 You can use the 'download()' method to download this file.
 
+.. note:: 
+
+    This next section is only relevant to the official CurseForge API!
+
+    If you aren't using the CurseForge backend, then this information
+    (probably) won't apply to you.
+
+In the official CurseForge API, addons can specify if they
+are approved for distribution over 3rd party services.
+Any projects created before the release of the official CurseForge API (around 2020-2021)
+will have this enabled by default.
+All new projects created afterwards will have this disabled by default.
+
+If 3rd party distribution is enabled, then the CurseForge API will serve a download
+URL for each addon file.
+Otherwise, the CurseForge API will simply server 'None', and the 'download()' method will fail.
+You can get around this by using the 'guess_download()' method:
+
+.. code-block:: python 
+
+    url = inst.guess_download()
+
+This method uses some attributes to create a best guess download URL that may work 
+(more testing is required!).
+This URL will download the addon files from the official CurseForge Content Distribution Network,
+regardless of the handler that retrieved the data.
+
+It is highly recommended to use a download URL provided by the backend if possible!
+
+Once you have the URL, you can set the 'download_url' parameter and then download the file:
+
+.. code-block:: python
+
+    inst.download_url = inst.guess_download()
+    inst.download()
+
 .. _curse_dependency:
 
 CurseDependency

docs/source/changelog.rst

@@ -2,6 +2,19 @@
 Changelog
 =========
 
+2.2.0
+=====
+
+Features Added
+--------------
+
+* CurseFile can now generate a guess download URL if the backend does not serve a valid download URL
+
+Bug Fixes
+---------
+
+* Fixed a syntax error while getting the file a dependency is apart of 
+
 2.1.0
 =====