feat: ✨ Add image conversion command (#21)

* Initial working version

* Fix formatting

* Run image conversion in loop

* Apply code review suggestions

* Remove unused imports

* Format, again

* Fix docstrings

* Apply code review suggestions

Author: ToothyDev

pyproject.toml

@@ -5,6 +5,7 @@ description = "Versa is a Discord user app (bot) aimed to provide helpful utilit
 readme = "README.md"
 requires-python = ">=3.13,<3.14"
 dependencies = [
+    "pillow>=12.1.0",
     "py-cord>=2.7.0",
     "python-dotenv>=1.2.1",
 ]
@@ -37,7 +38,7 @@ extend-ignore = [
     "D10", # missing docstrings is overkill
     "T201" # print used # TODO: Switch to only using logging.*
 ]
-pydocstyle.convention = "google"
+pydocstyle.convention = "numpy"
 
 [tool.ruff.lint.per-file-ignores]
 "src/cogs/*" = [

src/__main__.py

@@ -3,7 +3,10 @@
 import discord
 from dotenv import load_dotenv
 
-bot = discord.Bot(intents=discord.Intents.default())
+bot = discord.Bot(
+    intents=discord.Intents.default(),
+    default_command_integration_types={discord.IntegrationType.guild_install, discord.IntegrationType.user_install},
+)
 
 bot.load_extensions("src.cogs")
 print("Loaded cogs: " + ", ".join(bot.cogs))

src/cogs/message_commands.py

@@ -10,7 +10,6 @@ def __init__(self, bot: discord.Bot) -> None:
 
     @message_command()
     async def fxlink(self, ctx: discord.ApplicationContext, message: discord.Message) -> None:
-        """Makes certain site's links embed properly within Discord."""
         if not message.content:
             await ctx.respond("No link found!", ephemeral=True)
             return

src/cogs/slash_commands.py

@@ -1,10 +1,91 @@
+import asyncio
+import io
+from pathlib import Path
+
 import discord
+from discord import option, slash_command
+from PIL import Image, UnidentifiedImageError
+
+MAX_IMAGE_FILESIZE = 50_000_000  # 50 MB
+SUPPORTED_IMAGE_FORMATS = {"jpeg", "png", "gif", "webp", "tiff", "bmp"}
+TRANSPARENT_FORMATS = {"png", "webp", "tiff"}
 
 
 class SlashCommands(discord.Cog, name="slash_commands"):
     def __init__(self, bot: discord.Bot) -> None:
         self.bot = bot
 
+    @slash_command()
+    @option("image", discord.Attachment, description="The image to convert")
+    @option(
+        "target_filetype",
+        description="The filetype to convert to",
+        choices=SUPPORTED_IMAGE_FORMATS,
+    )
+    async def convert(
+        self,
+        ctx: discord.ApplicationContext,
+        image: discord.Attachment,
+        target_filetype: str,
+    ) -> None:
+        """Convert an image to another image format. Animated GIFs will be converted to static images."""
+        if not image.content_type or not image.content_type.startswith("image/"):
+            await ctx.respond("Attached file is not an image!", ephemeral=True)
+            return
+        if image.size > MAX_IMAGE_FILESIZE:
+            await ctx.respond(
+                f"Attached file is too large! Keep it below {MAX_IMAGE_FILESIZE // 1_000_000}MB.", ephemeral=True
+            )
+            return
+
+        await ctx.defer(ephemeral=True)
+        file_bytes = await image.read()
+        try:
+            converted = await asyncio.get_running_loop().run_in_executor(
+                None, self.convert_image, file_bytes, target_filetype
+            )
+        except (FileNotFoundError, UnidentifiedImageError):
+            await ctx.respond("Something went wrong", ephemeral=True)
+            return
+
+        await ctx.respond(
+            file=discord.File(converted, filename=self.replace_extension(image.filename, target_filetype)),
+            ephemeral=True,
+        )
+
+    @staticmethod
+    def replace_extension(filename: str, new_extension: str) -> str:
+        """Replace the file extension of a filename with the given one.
+
+        :param filename: The filename to replace the extension of
+        :param new_extension: The extension to replace the old one with
+
+        :return str: The new filename with the new extension
+        """
+        return Path(filename).stem + "." + new_extension
+
+    @staticmethod
+    def convert_image(image_bytes: bytes, target_filetype: str) -> io.BytesIO:
+        """Convert given image bytes to other image formats.
+
+        :param image_bytes: The image bytes to convert
+        :param target_filetype: The filetype to convert to
+
+        :return BytesIO: The converted image bytes
+        """
+        file = io.BytesIO(image_bytes)
+        buffer = io.BytesIO()
+        with Image.open(file) as image:
+            if target_filetype not in TRANSPARENT_FORMATS and image.mode != "RGB":
+                image.convert("RGB").save(
+                    buffer, format=target_filetype
+                )  # Cut the alpha channel to support PNG / WebP / TIFF -> X
+            else:
+                image.save(buffer, format=target_filetype)
+
+        buffer.seek(0)
+        return buffer
+
 
 def setup(bot: discord.Bot) -> None:
     bot.add_cog(SlashCommands(bot))