Restructure output system

Formats can now be loaded based on book data format and file extension
of the output file. Will also try to use the extension of the output
location instead of using the default filetype every time.

grawlix/output/__init__.py

@@ -1,5 +1,5 @@
 from grawlix.book import Book, BookData, SingleFile, ImageList, OnlineFile, HtmlFiles
-from grawlix.exceptions import GrawlixError
+from grawlix.exceptions import GrawlixError, UnsupportedOutputFormat
 from grawlix.logging import info
 
 from .output_format import OutputFormat
@@ -17,7 +17,12 @@ async def download_book(book: Book, update_func: Callable, template: str) -> Non
 
     :param book: Book to download
     """
-    output_format = get_default_format(book.data)
+    _, ext = os.path.splitext(template)
+    ext = ext[1:]
+    if ext in get_valid_extensions():
+        output_format = find_output_format(book, ext)()
+    else:
+        output_format = get_default_format(book)
     location = format_output_location(book, output_format, template)
     if not book.overwrite and os.path.exists(location):
         info("Skipping - File already exists")
@@ -25,14 +30,7 @@ async def download_book(book: Book, update_func: Callable, template: str) -> Non
     parent = Path(location).parent
     if not parent.exists():
         os.makedirs(parent)
-    if isinstance(book.data, SingleFile):
-        await output_format.dl_single_file(book, location, update_func)
-    elif isinstance(book.data, ImageList):
-        await output_format.dl_image_list(book, location, update_func)
-    elif isinstance(book.data, HtmlFiles):
-        await output_format.dl_html_files(book, location, update_func)
-    else:
-        raise NotImplementedError
+    await output_format.download(book, location, update_func)
     await output_format.close()
 
 
@@ -49,34 +47,43 @@ def format_output_location(book: Book, output_format: OutputFormat, template: st
     return template.format(**values, ext = output_format.extension)
 
 
-def get_default_format(bookdata: BookData) -> OutputFormat:
+def get_default_format(book: Book) -> OutputFormat:
     """
     Get default output format for bookdata.
     Should only be used if no format was specified by the user
 
-    :param bookdata: Content of book
+    :param book: Content of book
     :returns: OutputFormat object matching the default
     """
+    bookdata = book.data
     if isinstance(bookdata, SingleFile):
-        return output_format_from_str(bookdata.file.extension)
+        extension = bookdata.file.extension
     if isinstance(bookdata, ImageList):
-        return Cbz()
+        extension = "cbz"
     if isinstance(bookdata, HtmlFiles):
-        return Epub()
-    raise GrawlixError
+        extension = "epub"
+    output_format = find_output_format(book, extension)
+    return output_format()
 
 
-def output_format_from_str(name: str) -> OutputFormat:
+def find_output_format(book: Book, extension: str) -> type[OutputFormat]:
     """
-    Convert string to outputformat object
+    Find a compatible output format
 
-    :param name: Name of output format
-    :returns: OutputFormat object
+    :param book: Book to download
+    :param extension: Extension of output file
+    :returns: Compatible OutputFormat type
+    :raises: UnsupportedOutputFormat if nothing is found
     """
     for output_format in get_output_formats():
-        if output_format.extension == name:
-            return output_format()
-    raise GrawlixError
+        matches_extension = output_format.extension == extension
+        supports_bookdata = type(book.data) in output_format.input_types
+        if matches_extension and supports_bookdata:
+            return output_format
+    raise UnsupportedOutputFormat
+
+def get_valid_extensions() -> list[str]:
+    return [output_format.extension for output_format in get_output_formats()]
 
 
 def get_output_formats() -> list[type[OutputFormat]]:

grawlix/output/acsm.py

@@ -1,14 +1,15 @@
-from grawlix.book import Book
+from grawlix.book import Book, SingleFile
 from .output_format import OutputFormat, Update
 import shutil
 import subprocess
 
 class Acsm(OutputFormat):
     extension = "acsm"
+    input_types = [SingleFile]
 
-    async def dl_single_file(self, book: Book, location: str, update_func: Update) -> None:
+    async def download(self, book: Book, location: str, update_func: Update) -> None:
         # Download and write acsm file to disk
-        await super().dl_single_file(book, location, update_func)
+        await self._download_single_file(book, location, update_func)
         # TODO: Implement more general solution
         # Decrypt if knock is available
         # https://web.archive.org/web/20221016154220/https://github.com/BentonEdmondson/knock

grawlix/output/cbz.py

@@ -9,18 +9,21 @@ class Cbz(OutputFormat):
     """Comic book zip file"""
 
     extension: str = "cbz"
+    input_types = [ImageList]
 
-    async def dl_image_list(self, book: Book, location: str, update: Update) -> None:
+    async def download(self, book: Book, location: str, update: Update) -> None:
         if not isinstance(book.data, ImageList):
             raise UnsupportedOutputFormat
+        semaphore = asyncio.Semaphore(10)
         images = book.data.images
         image_count = len(images)
         with ZipFile(location, mode="w") as zip:
             async def download_page(index: int, file: OnlineFile):
-                content = await self._download_file(file)
-                zip.writestr(f"Image {index}.{file.extension}", content)
-                if update:
-                    update(1/image_count)
+                async with semaphore:
+                    content = await self._download_file(file)
+                    zip.writestr(f"Image {index}.{file.extension}", content)
+                    if update:
+                        update(1/image_count)
             tasks = [
                 asyncio.create_task(download_page(index, file))
                 for index, file in enumerate(images)

grawlix/output/epub.py

@@ -1,4 +1,4 @@
-from grawlix.book import HtmlFiles, HtmlFile, OnlineFile, Book
+from grawlix.book import HtmlFiles, HtmlFile, OnlineFile, Book, SingleFile, Metadata
 from grawlix.exceptions import UnsupportedOutputFormat
 from .output_format import OutputFormat, Update
 
@@ -9,14 +9,20 @@ from ebooklib import epub
 
 class Epub(OutputFormat):
     extension = "epub"
+    input_types = [SingleFile, HtmlFiles]
 
-    async def dl_html_files(self, book: Book, location: str, update: Update) -> None:
-        if not isinstance(book.data, HtmlFiles):
+    async def download(self, book: Book, location: str, update: Update) -> None:
+        if isinstance(book.data, SingleFile):
+            await self._download_single_file(book, location, update)
+        elif isinstance(book.data, HtmlFiles):
+            await self._download_html_files(book.data, book.metadata, location, update)
+        else:
             raise UnsupportedOutputFormat
-        html = book.data
+
+    async def _download_html_files(self, html: HtmlFiles, metadata: Metadata, location: str, update: Update) -> None:
         output = epub.EpubBook()
-        output.set_title(book.metadata.title)
-        for author in book.metadata.authors:
+        output.set_title(metadata.title)
+        for author in metadata.authors:
             output.add_author(author)
         file_count = len(html.htmlfiles) + 1 # Html files + cover
 

grawlix/output/output_format.py

@@ -1,4 +1,4 @@
-from grawlix.book import Book, SingleFile, OnlineFile, ImageList, HtmlFiles, Book, OfflineFile
+from grawlix.book import Book, SingleFile, OnlineFile, ImageList, HtmlFiles, Book, OfflineFile, BookData
 from grawlix.exceptions import UnsupportedOutputFormat
 from grawlix.encryption import decrypt
 
@@ -10,6 +10,7 @@ Update = Optional[Callable[[float], None]]
 class OutputFormat:
     # Extension for output files
     extension: str
+    input_types: list[type[BookData]]
 
     def __init__(self) -> None:
         self._client = httpx.AsyncClient()
@@ -20,7 +21,18 @@ class OutputFormat:
         await self._client.aclose()
 
 
-    async def dl_single_file(self, book: Book, location: str, update_func: Update) -> None:
+    async def download(self, book: Book, location: str, update_func: Update) -> None:
+        """
+        Download book
+
+        :param book: Book to download
+        :param location: Path to where the file is written
+        :param update_func: Function to update progress bar
+        """
+        raise UnsupportedOutputFormat
+
+
+    async def _download_single_file(self, book: Book, location: str, update_func: Update) -> None:
         """
         Download and write an `grawlix.SingleFile` to disk
 
@@ -38,28 +50,6 @@ class OutputFormat:
             self._write_offline_file(book.data.file, location)
 
 
-    async def dl_image_list(self, book: Book, location: str, update_func: Update) -> None:
-        """
-        Download and write an `grawlix.ImageList` to disk
-
-        :param book: Book to download
-        :param location: Path to where the file is written
-        :raises UnsupportedOutputFormat: If datatype is not supported by format
-        """
-        raise UnsupportedOutputFormat
-
-
-    async def dl_html_files(self, book: Book, location: str, update_func: Update) -> None:
-        """
-        Download and write a `grawlix.HtmlFiles` to disk
-
-        :param book: Book to download
-        :param location: Path to where the file is written
-        :raises UnsupportedOutputFormat: If datatype is not supported by format
-        """
-        raise UnsupportedOutputFormat
-
-
     async def _download_file(self, file: OnlineFile, update: Update = None) -> bytes:
         """
         Download `grawlix.OnlineFile`