(moderation): tickets command and note ticket.

Add new `tickets` command for viewing moderation tickets.
Add `Note` ticket implementation, with command.
Add `offer_delete` context utility.
Add `guild_moderator` command ward.

bot/modules/moderation/tickets/Ticket.py

@@ -32,6 +32,7 @@ class TicketState(FieldEnum):
     EXPIRING = 'EXPIRING', "Active"
     EXPIRED = 'EXPIRED', "Expired"
     PARDONED = 'PARDONED', "Pardoned"
+    REVERTED = 'REVERTED', "Reverted"
 
 
 class Ticket:
@@ -200,6 +201,10 @@ class Ticket:
     def state(self):
         return TicketState(self.data.ticket_state)
 
+    @property
+    def type(self):
+        return TicketType(self.data.ticket_type)
+
     async def update(self, **kwargs):
         """
         Update ticket fields.

bot/modules/moderation/tickets/__init__.py

@@ -1,2 +1,3 @@
 from .Ticket import Ticket, TicketType, TicketState
 from .studybans import StudyBanTicket
+from .notes import NoteTicket

bot/modules/moderation/tickets/notes.py

@@ -0,0 +1,113 @@
+"""
+Note ticket implementation.
+
+Guild moderators can add a note about a user, visible in their moderation history.
+Notes appear in the moderation log and the user's ticket history, like any other ticket.
+
+This module implements the Note TicketType and the `note` moderation command.
+"""
+from cmdClient.lib import ResponseTimedOut
+
+from wards import guild_moderator
+
+from ..module import module
+from ..data import tickets
+
+from .Ticket import Ticket, TicketType, TicketState
+
+
+@Ticket.register_ticket_type
+class NoteTicket(Ticket):
+    _ticket_type = TicketType.NOTE
+
+    @classmethod
+    async def create(cls, guildid, targetid, moderatorid, content, **kwargs):
+        """
+        Create a new Note on a target.
+
+        `kwargs` are passed transparently to the table insert method.
+        """
+        ticket_row = tickets.insert(
+            guildid=guildid,
+            targetid=targetid,
+            ticket_type=cls._ticket_type,
+            ticket_state=TicketState.OPEN,
+            moderator_id=moderatorid,
+            auto=False,
+            content=content,
+            **kwargs
+        )
+
+        # Create the note ticket
+        ticket = cls(ticket_row['ticketid'])
+
+        # Post the ticket and return
+        await ticket.post()
+        return ticket
+
+
+# TODO: Remember the moderator ward!!
+@module.cmd(
+    "note",
+    group="Moderation",
+    desc="Add a Note to a member's record."
+)
+@guild_moderator()
+async def cmd_note(ctx):
+    """
+    Usage``:
+        {prefix}note @target
+        {prefix}note @target <content>
+    Description:
+        Add a note to the target's moderation record.
+        The note will appear in the moderation log and in the `tickets` command.
+
+        The `target` must be specificed by mention or user id.
+        If the `note` is not given, it will be prompted for.
+    Example:
+        {prefix}note {ctx.author.mention} Seen reading the `note` documentation.
+    """
+    if not ctx.args:
+        return await ctx.error_reply(
+            "**Usage:** `{}note @target <content>`.".format(ctx.best_prefix)
+        )
+
+    # Extract the target. We don't require them to be in the server
+    splits = ctx.args.split(maxsplit=1)
+    target_str = splits[0].strip('<@!&> ')
+    if not target_str.isdigit():
+        return await ctx.error_reply(
+            "**Usage:** `{}note @target <content>`.\n"
+            "`target` must be provided by mention or userid.".format(ctx.best_prefix)
+        )
+    targetid = int(target_str)
+
+    # Extract or prompt for the content
+    if len(splits) != 2:
+        try:
+            content = await ctx.input("What note would you like to add?", timeout=300)
+        except ResponseTimedOut:
+            raise ResponseTimedOut("Prompt timed out, no note was created.")
+    else:
+        content = splits[1].strip()
+
+    # Create the note ticket
+    ticket = await NoteTicket.create(
+        ctx.guild.id,
+        targetid,
+        ctx.author.id,
+        content
+    )
+
+    if ticket.data.log_msg_id:
+        await ctx.embed_reply(
+            "Note on <@{}> created as [Ticket #{}]({}).".format(
+                targetid,
+                ticket.data.guild_ticketid,
+                ticket.link
+            )
+        )
+    else:
+        await ctx.embed_reply(
+            "Note on <@{}> created as Ticket #{}.".format(targetid, ticket.data.guild_ticketid)
+        )