Update branch

3 files changed, 172 insertions, 49 deletions

diff --git a/bot/utils/decorators.py b/bot/utils/decorators.py
index 9cdaad3f..60066dc4 100644
--- a/bot/utils/decorators.py
+++ b/bot/utils/decorators.py
@@ -11,8 +11,9 @@ from discord import Colour, Embed
 from discord.ext import commands
 from discord.ext.commands import CheckFailure, Command, Context
 
-from bot.constants import ERROR_REPLIES, Month
+from bot.constants import Channels, ERROR_REPLIES, Month, WHITELISTED_CHANNELS
 from bot.utils import human_months, resolve_current_month
+from bot.utils.checks import in_whitelist_check
 
 ONE_DAY = 24 * 60 * 60
 
@@ -186,82 +187,110 @@ def without_role(*role_ids: int) -> t.Callable:
     return commands.check(predicate)
 
 
-def in_channel_check(*channels: int, bypass_roles: t.Container[int] = None) -> t.Callable[[Context], bool]:
+def whitelist_check(**default_kwargs: t.Container[int]) -> t.Callable[[Context], bool]:
     """
-    Checks that the message is in a whitelisted channel or optionally has a bypass role.
+    Checks if a message is sent in a whitelisted context.
 
-    If `in_channel_override` is present, check if it contains channels
-    and use them in place of the global whitelist.
+    All arguments from `in_whitelist_check` are supported, with the exception of "fail_silently".
+    If `whitelist_override` is present, it is added to the global whitelist.
     """
     def predicate(ctx: Context) -> bool:
+        # Skip DM invocations
         if not ctx.guild:
             log.debug(f"{ctx.author} tried to use the '{ctx.command.name}' command from a DM.")
             return True
-        if ctx.channel.id in channels:
-            log.debug(
-                f"{ctx.author} tried to call the '{ctx.command.name}' command "
-                f"and the command was used in a whitelisted channel."
-            )
-            return True
 
-        if bypass_roles and any(r.id in bypass_roles for r in ctx.author.roles):
-            log.debug(
-                f"{ctx.author} called the '{ctx.command.name}' command and "
-                f"had a role to bypass the in_channel check."
-            )
-            return True
+        kwargs = default_kwargs.copy()
 
-        if hasattr(ctx.command.callback, "in_channel_override"):
-            override = ctx.command.callback.in_channel_override
-            if override is None:
+        # Update kwargs based on override
+        if hasattr(ctx.command.callback, "override"):
+            # Remove default kwargs if reset is True
+            if ctx.command.callback.override_reset:
+                kwargs = {}
                 log.debug(
-                    f"{ctx.author} called the '{ctx.command.name}' command "
-                    f"and the command was whitelisted to bypass the in_channel check."
+                    f"{ctx.author} called the '{ctx.command.name}' command and "
+                    f"overrode default checks."
                 )
-                return True
-            else:
-                if ctx.channel.id in override:
-                    log.debug(
-                        f"{ctx.author} tried to call the '{ctx.command.name}' command "
-                        f"and the command was used in an overridden whitelisted channel."
-                    )
-                    return True
 
-                log.debug(
-                    f"{ctx.author} tried to call the '{ctx.command.name}' command. "
-                    f"The overridden in_channel check failed."
-                )
-                channels_str = ', '.join(f"<#{c_id}>" for c_id in override)
-                raise InChannelCheckFailure(
-                    f"Sorry, but you may only use this command within {channels_str}."
-                )
+            # Merge overwrites and defaults
+            for arg in ctx.command.callback.override:
+                default_value = kwargs.get(arg)
+                new_value = ctx.command.callback.override[arg]
+
+                # Skip values that don't need merging, or can't be merged
+                if default_value is None or isinstance(arg, int):
+                    kwargs[arg] = new_value
+
+                # Merge containers
+                elif isinstance(default_value, t.Container):
+                    if isinstance(new_value, t.Container):
+                        kwargs[arg] = (*default_value, *new_value)
+                    else:
+                        kwargs[arg] = new_value
+
+            log.debug(
+                f"Updated default check arguments for '{ctx.command.name}' "
+                f"invoked by {ctx.author}."
+            )
+
+        log.trace(f"Calling whitelist check for {ctx.author} for command {ctx.command.name}.")
+        result = in_whitelist_check(ctx, fail_silently=True, **kwargs)
+
+        # Return if check passed
+        if result:
+            log.debug(
+                f"{ctx.author} tried to call the '{ctx.command.name}' command "
+                f"and the command was used in an overridden context."
+            )
+            return result
 
         log.debug(
             f"{ctx.author} tried to call the '{ctx.command.name}' command. "
-            f"The in_channel check failed."
+            f"The whitelist check failed."
         )
 
-        channels_str = ', '.join(f"<#{c_id}>" for c_id in channels)
-        raise InChannelCheckFailure(
-            f"Sorry, but you may only use this command within {channels_str}."
-        )
+        # Raise error if the check did not pass
+        channels = set(kwargs.get("channels") or {})
+        categories = kwargs.get("categories")
 
-    return predicate
+        # Only output override channels + community_bot_commands
+        if channels:
+            default_whitelist_channels = set(WHITELISTED_CHANNELS)
+            default_whitelist_channels.discard(Channels.community_bot_commands)
+            channels.difference_update(default_whitelist_channels)
 
+        # Add all whitelisted category channels
+        if categories:
+            for category_id in categories:
+                category = ctx.guild.get_channel(category_id)
+                if category is None:
+                    continue
 
-in_channel = commands.check(in_channel_check)
+                channels.update(channel.id for channel in category.text_channels)
+
+        if channels:
+            channels_str = ', '.join(f"<#{c_id}>" for c_id in channels)
+            message = f"Sorry, but you may only use this command within {channels_str}."
+        else:
+            message = "Sorry, but you may not use this command."
+
+        raise InChannelCheckFailure(message)
+
+    return predicate
 
 
-def override_in_channel(channels: t.Tuple[int] = None) -> t.Callable:
+def whitelist_override(bypass_defaults: bool = False, **kwargs: t.Container[int]) -> t.Callable:
     """
-    Set command callback attribute for detection in `in_channel_check`.
+    Override global whitelist context, with the kwargs specified.
 
-    Override global whitelist if channels are specified.
+    All arguments from `in_whitelist_check` are supported, with the exception of `fail_silently`.
+    Set `bypass_defaults` to True if you want to completely bypass global checks.
 
     This decorator has to go before (below) below the `command` decorator.
     """
     def inner(func: t.Callable) -> t.Callable:
-        func.in_channel_override = channels
+        func.override = kwargs
+        func.override_reset = bypass_defaults
         return func
 
     return inner
diff --git a/bot/utils/extensions.py b/bot/utils/extensions.py
index 50350ea8..459588a1 100644
--- a/bot/utils/extensions.py
+++ b/bot/utils/extensions.py
@@ -3,6 +3,8 @@ import inspect
 import pkgutil
 from typing import Iterator, NoReturn
 
+from discord.ext.commands import Context
+
 from bot import exts
 
 
@@ -31,4 +33,12 @@ def walk_extensions() -> Iterator[str]:
         yield module.name
 
 
+async def invoke_help_command(ctx: Context) -> None:
+    """Invoke the help command or default help command if help extensions is not loaded."""
+    if 'bot.exts.evergreen.help' in ctx.bot.extensions:
+        help_command = ctx.bot.get_command('help')
+        await ctx.invoke(help_command, ctx.command.qualified_name)
+        return
+    await ctx.send_help(ctx.command)
+
 EXTENSIONS = frozenset(walk_extensions())
diff --git a/bot/utils/time.py b/bot/utils/time.py
new file mode 100644
index 00000000..fbf2fd21
--- /dev/null
+++ b/bot/utils/time.py
@@ -0,0 +1,84 @@
+import datetime
+
+from dateutil.relativedelta import relativedelta
+
+
+# All these functions are from https://github.com/python-discord/bot/blob/main/bot/utils/time.py
+def _stringify_time_unit(value: int, unit: str) -> str:
+    """
+    Returns a string to represent a value and time unit, ensuring that it uses the right plural form of the unit.
+
+    >>> _stringify_time_unit(1, "seconds")
+    "1 second"
+    >>> _stringify_time_unit(24, "hours")
+    "24 hours"
+    >>> _stringify_time_unit(0, "minutes")
+    "less than a minute"
+    """
+    if unit == "seconds" and value == 0:
+        return "0 seconds"
+    elif value == 1:
+        return f"{value} {unit[:-1]}"
+    elif value == 0:
+        return f"less than a {unit[:-1]}"
+    else:
+        return f"{value} {unit}"
+
+
+def humanize_delta(delta: relativedelta, precision: str = "seconds", max_units: int = 6) -> str:
+    """
+    Returns a human-readable version of the relativedelta.
+
+    precision specifies the smallest unit of time to include (e.g. "seconds", "minutes").
+    max_units specifies the maximum number of units of time to include (e.g. 1 may include days but not hours).
+    """
+    if max_units <= 0:
+        raise ValueError("max_units must be positive")
+
+    units = (
+        ("years", delta.years),
+        ("months", delta.months),
+        ("days", delta.days),
+        ("hours", delta.hours),
+        ("minutes", delta.minutes),
+        ("seconds", delta.seconds),
+    )
+
+    # Add the time units that are >0, but stop at accuracy or max_units.
+    time_strings = []
+    unit_count = 0
+    for unit, value in units:
+        if value:
+            time_strings.append(_stringify_time_unit(value, unit))
+            unit_count += 1
+
+        if unit == precision or unit_count >= max_units:
+            break
+
+    # Add the 'and' between the last two units, if necessary
+    if len(time_strings) > 1:
+        time_strings[-1] = f"{time_strings[-2]} and {time_strings[-1]}"
+        del time_strings[-2]
+
+    # If nothing has been found, just make the value 0 precision, e.g. `0 days`.
+    if not time_strings:
+        humanized = _stringify_time_unit(0, precision)
+    else:
+        humanized = ", ".join(time_strings)
+
+    return humanized
+
+
+def time_since(past_datetime: datetime.datetime, precision: str = "seconds", max_units: int = 6) -> str:
+    """
+    Takes a datetime and returns a human-readable string that describes how long ago that datetime was.
+
+    precision specifies the smallest unit of time to include (e.g. "seconds", "minutes").
+    max_units specifies the maximum number of units of time to include (e.g. 1 may include days but not hours).
+    """
+    now = datetime.datetime.utcnow()
+    delta = abs(relativedelta(now, past_datetime))
+
+    humanized = humanize_delta(delta, precision, max_units)
+
+    return f"{humanized} ago"