[QRChecker] Cog model restructure

- Restructure `QRChecker` according to SFUAnime#608.
  No functional changes.
- Move constants to `constants.py`.
- Remove redundant type hints (e.g., those fully inferrable from the
  return types of called functions).

cogs/qrchecker/commandHandlers.py

@@ -0,0 +1,16 @@
+from redbot.core import commands
+from redbot.core.commands import Context
+
+from .commandsCore import CommandsCore
+
+
+class CommandHandlers(CommandsCore):
+    @commands.group(name="qrchecker")
+    @commands.guild_only()
+    @commands.admin_or_permissions(manage_guild=True)
+    async def _grpQrChecker(self, ctx: Context):
+        """Configure QR code checker"""
+
+    @_grpQrChecker.command(name="toggle")
+    async def _cmdQrCheckerToggle(self, ctx: Context):
+        await self.cmdQrCheckerToggle(ctx=ctx)

cogs/qrchecker/commandsCore.py

@@ -0,0 +1,21 @@
+from redbot.core.commands import Context
+
+from .constants import KEY_ENABLED
+from .core import Core
+
+
+class CommandsCore(Core):
+    async def cmdQrCheckerToggle(self, ctx: Context):
+        """Toggle QR code checking"""
+        guild = ctx.guild
+        if not guild:
+            return
+        guildConfig = self.config.guild(guild)
+
+        enabled: bool = await guildConfig.get_attr(KEY_ENABLED)()
+        if enabled:
+            await guildConfig.get_attr(KEY_ENABLED).set(False)
+            await ctx.send("QR code checking is now **disabled** for this guild.")
+        else:
+            await guildConfig.get_attr(KEY_ENABLED).set(True)
+            await ctx.send("QR code checking is now **enabled** for this guild.")

cogs/qrchecker/constants.py

@@ -0,0 +1,3 @@
+KEY_ENABLED = "enabled"
+
+BASE_GUILD = {KEY_ENABLED: False}

cogs/qrchecker/core.py

@@ -0,0 +1,14 @@
+from logging import getLogger
+
+from redbot.core import Config
+from redbot.core.bot import Red
+
+from .constants import BASE_GUILD
+
+
+class Core:
+    def __init__(self, bot: Red):
+        self.bot = bot
+        self.logger = getLogger("red.luicogs.QRChecker")
+        self.config = Config.get_conf(self, identifier=5842647, force_registration=True)
+        self.config.register_guild(**BASE_GUILD)

cogs/qrchecker/eventHandlers.py

@@ -0,0 +1,12 @@
+from discord import Message
+
+from redbot.core import commands
+
+from .eventsCore import EventsCore
+
+
+class EventHandlers(EventsCore):
+    @commands.Cog.listener("on_message")
+    async def _evtListener(self, message: Message):
+        """Find QR code in message attachments"""
+        await self.evtListener(message=message)

cogs/qrchecker/eventsCore.py

@@ -0,0 +1,121 @@
+from io import BytesIO
+from typing import List
+
+from discord import AllowedMentions, Message
+from PIL import Image
+from pyzbar.pyzbar import Decoded, decode, ZBarSymbol
+
+
+from redbot.core.commands import Context
+from redbot.core.utils.chat_formatting import box, pagify
+
+from .constants import KEY_ENABLED
+from .core import Core
+
+
+class EventsCore(Core):
+    async def evtListener(self, message: Message):
+        """Find QR code in message attachments"""
+        if not message.guild:
+            return
+        # check if enabled
+        if not await self.config.guild(message.guild).get_attr(KEY_ENABLED)():
+            self.logger.debug(
+                "QR Checker disabled for %s (%s); return early",
+                message.guild.name,
+                message.guild.id,
+            )
+            return
+        if not message.attachments:
+            self.logger.debug("No attachments, return early")
+            return
+        for attachment in message.attachments:
+            contentType = attachment.content_type
+            if not contentType:
+                self.logger.debug("Unknown content type, continue")
+                continue
+            elif contentType and "image" not in contentType:
+                self.logger.debug("Not an image, continue")
+                continue
+
+            # At this point we decern that it's an image.
+            try:
+                fp = BytesIO(await attachment.read())
+                image = Image.open(fp)
+                codes: List[Decoded] = decode(image, symbols=[ZBarSymbol.QRCODE])
+                self.logger.debug("Found %s codes", len(codes))
+            except Exception:
+                self.logger.error("Couldn't check file.", exc_info=True)
+                return
+
+            if not codes:
+                self.logger.debug("No QR codes found.")
+                return
+
+            self.logger.info(
+                "%s#%s (%s) posted some QR code(s) in #%s (%s)",
+                message.author.name,
+                message.author.discriminator,
+                message.author.id,
+                message.channel.name,
+                message.channel.id,
+            )
+
+            numQrCodes = len(codes)
+            if numQrCodes == 1:
+                code = codes[0]
+                data: str = code.data.decode()
+                if len(data) == 0:
+                    self.logger.debug("No data in QR code.")
+                    return
+                if len(data) > 1900:
+                    contents = f"{data[:1900]}..."
+                else:
+                    contents = data
+                msg = (
+                    f"Found a QR code from {message.author.mention}, "
+                    f"the contents are: {box(contents)}"
+                )
+                await message.reply(
+                    msg, mention_author=False, allowed_mentions=AllowedMentions.none()
+                )
+            else:
+                hasData: bool = False
+                pages: List[str] = []
+                pages.append(
+                    f"Found several QR codes from {message.author.mention}, their contents are:"
+                )
+                for code in codes:
+                    data: str = code.data.decode()
+                    if len(data) == 0:
+                        self.logger.debug("No data in QR code.")
+                        continue
+                    if len(data) > 1990:
+                        contents = f"{box(data[:1990])}..."
+                    else:
+                        contents = f"{box(data)}"
+                    pages.append(contents)
+                    hasData |= True
+
+                if not hasData:
+                    self.logger.debug("No data in %s QR codes.", numQrCodes)
+                    return
+
+                firstMessage: bool = True
+                sentMessages: int = 0
+
+                ctx: Context = await self.bot.get_context(message)
+                for textToSend in pagify("\n".join(pages), escape_mass_mentions=True):
+                    if firstMessage:
+                        await message.reply(
+                            textToSend,
+                            mention_author=False,
+                            allowed_mentions=AllowedMentions.none(),
+                        )
+                        firstMessage = False
+                    elif sentMessages > 10:
+                        self.logger.debug("Sent more than 10 messages, bail early")
+                        break
+                    else:
+                        await ctx.send(textToSend, allowed_mentions=AllowedMentions.none())
+                    sentMessages += 1

cogs/qrchecker/qrchecker.py

@@ -4,160 +4,12 @@
 - pyzbar from PyPI
 - libzbar0 from your distro's package repo
 """
-from io import BytesIO
-from typing import Dict, List, Optional
-from logging import Logger, getLogger
 
-from discord import AllowedMentions, Guild, Message
-from pyzbar.pyzbar import Decoded, decode, ZBarSymbol
-from PIL import Image
-from redbot.core import commands, Config
-from redbot.core.bot import Red
-from redbot.core.commands import Context
-from redbot.core.config import Group
-from redbot.core.utils.chat_formatting import box, pagify
+from redbot.core import commands
 
-KEY_ENABLED: str = "enabled"
+from .commandHandlers import CommandHandlers
+from .eventHandlers import EventHandlers
 
-BASE_GUILD: Dict = {KEY_ENABLED: False}
 
-
-class QRChecker(commands.Cog):
+class QRChecker(commands.Cog, CommandHandlers, EventHandlers):
     """A QR code checker for attachments"""
-
-    def __init__(self, bot: Red):
-        self.bot: Red = bot
-        self.logger: Logger = getLogger("red.luicogs.QRChecker")
-        self.config: Config = Config.get_conf(self, identifier=5842647, force_registration=True)
-        self.config.register_guild(**BASE_GUILD)
-
-    @commands.Cog.listener("on_message")
-    async def listener(self, message: Message):
-        """Find QR code in message attachments"""
-        if not message.guild:
-            return
-        # check if enabled
-        if not await self.config.guild(message.guild).get_attr(KEY_ENABLED)():
-            self.logger.debug(
-                "QR Checker disabled for %s (%s); return early",
-                message.guild.name,
-                message.guild.id,
-            )
-            return
-        if not message.attachments:
-            self.logger.debug("No attachments, return early")
-            return
-        for attachment in message.attachments:
-            contentType: Optional[str] = attachment.content_type
-            if not contentType:
-                self.logger.debug("Unknown content type, continue")
-                continue
-            elif contentType and "image" not in contentType:
-                self.logger.debug("Not an image, continue")
-                continue
-
-            # At this point we decern that it's an image.
-            try:
-                fp: BytesIO = BytesIO(await attachment.read())
-                image: Image = Image.open(fp)
-                codes: List[Decoded] = decode(image, symbols=[ZBarSymbol.QRCODE])
-                self.logger.debug("Found %s codes", len(codes))
-            except Exception:
-                self.logger.error("Couldn't check file.", exc_info=True)
-                return
-
-            if not codes:
-                self.logger.debug("No QR codes found.")
-                return
-
-            self.logger.info(
-                "%s#%s (%s) posted some QR code(s) in #%s (%s)",
-                message.author.name,
-                message.author.discriminator,
-                message.author.id,
-                message.channel.name,
-                message.channel.id,
-            )
-
-            numQrCodes = len(codes)
-            if numQrCodes == 1:
-                code: Decoded = codes[0]
-                data: str = code.data.decode()
-                if len(data) == 0:
-                    self.logger.debug("No data in QR code.")
-                    return
-                if len(data) > 1900:
-                    contents: str = f"{data[:1900]}..."
-                else:
-                    contents: str = data
-                msg = (
-                    f"Found a QR code from {message.author.mention}, "
-                    f"the contents are: {box(contents)}"
-                )
-                await message.reply(
-                    msg, mention_author=False, allowed_mentions=AllowedMentions.none()
-                )
-            else:
-                hasData: bool = False
-                pages: List[str] = []
-                pages.append(
-                    f"Found several QR codes from {message.author.mention}, their contents are:"
-                )
-                for code in codes:
-                    data: str = code.data.decode()
-                    if len(data) == 0:
-                        self.logger.debug("No data in QR code.")
-                        continue
-                    if len(data) > 1990:
-                        contents: str = f"{box(data[:1990])}..."
-                    else:
-                        contents: str = f"{box(data)}"
-                    pages.append(contents)
-                    hasData |= True
-
-                if not hasData:
-                    self.logger.debug("No data in %s QR codes.", numQrCodes)
-                    return
-
-                firstMessage: bool = True
-                sentMessages: int = 0
-
-                ctx: Context = await self.bot.get_context(message)
-                for textToSend in pagify("\n".join(pages), escape_mass_mentions=True):
-                    if firstMessage:
-                        await message.reply(
-                            textToSend,
-                            mention_author=False,
-                            allowed_mentions=AllowedMentions.none(),
-                        )
-                        firstMessage = False
-                    elif sentMessages > 10:
-                        self.logger.debug("Sent more than 10 messages, bail early")
-                        break
-                    else:
-                        await ctx.send(textToSend, allowed_mentions=AllowedMentions.none())
-                    sentMessages += 1
-
-    @commands.group(name="qrchecker")
-    @commands.guild_only()
-    @commands.admin_or_permissions(manage_guild=True)
-    async def qrchecker(self, ctx: Context):
-        """Configure QR code checker"""
-        pass
-
-    # toggle command
-    @qrchecker.command(name="toggle")
-    async def qrcheckerToggle(self, ctx: Context):
-        """Toggle QR code checking"""
-        guild: Guild = ctx.guild
-        if not guild:
-            return
-        guildConfig: Group = self.config.guild(guild)
-
-        enabled: bool = await guildConfig.get_attr(KEY_ENABLED)()
-        if enabled:
-            await guildConfig.get_attr(KEY_ENABLED).set(False)
-            await ctx.send("QR code checking is now **disabled** for this guild.")
-        else:
-            await guildConfig.get_attr(KEY_ENABLED).set(True)
-            await ctx.send("QR code checking is now **enabled** for this guild.")