[V3] Data Converter (#1293)

* More docstrings

* still not ready...

* push this untested pile of code.

* working, menu needs cleaning up though, modlog converter not here yet

* menu cleanup

* add note about the fact that values are overwritten

* add i18n

* User friendlier quitting

* Better naming of a function

* setup automodule for dataconverter

* More documentation

* use Config.MEMBER (etc) instead of 'MEMBER' (etc)

redbot/cogs/dataconverter/dataconverter.py

@@ -0,0 +1,82 @@
+from pathlib import Path
+import asyncio
+
+from discord.ext import commands
+
+from redbot.core import checks, RedContext
+from redbot.core.bot import Red
+from redbot.core.i18n import CogI18n
+from redbot.cogs.dataconverter.core_specs import SpecResolver
+from redbot.core.utils.chat_formatting import box
+
+_ = CogI18n('DataConverter', __file__)
+
+
+class DataConverter:
+    """
+    Cog for importing Red v2 Data
+    """
+
+    def __init__(self, bot: Red):
+        self.bot = bot
+
+    @checks.is_owner()
+    @commands.command(name="convertdata")
+    async def dataconversioncommand(self, ctx: RedContext, v2path: str):
+        """
+        Interactive prompt for importing data from Red v2
+
+        Takes the path where the v2 install is
+
+        Overwrites values which have entries in both v2 and v3,
+        use with caution.
+        """
+        resolver = SpecResolver(Path(v2path.strip()))
+
+        if not resolver.available:
+            return await ctx.send(
+                _("There don't seem to be any data files I know how to "
+                  "handle here. Are you sure you gave me the base "
+                  "installation path?")
+            )
+        while resolver.available:
+            menu = _("Please select a set of data to import by number"
+                     ", or 'exit' to exit")
+            for index, entry in enumerate(resolver.available, 1):
+                menu += "\n{}. {}".format(index, entry)
+
+            menu_message = await ctx.send(box(menu))
+
+            def pred(m):
+                return m.channel == ctx.channel and m.author == ctx.author
+
+            try:
+                message = await self.bot.wait_for(
+                    'message', check=pred, timeout=60
+                )
+            except asyncio.TimeoutError:
+                return await ctx.send(
+                    _('Try this again when you are more ready'))
+            else:
+                if message.content.strip().lower() in [
+                    'quit', 'exit', '-1', 'q', 'cancel'
+                ]:
+                    return await ctx.tick()
+                try:
+                    message = int(message.content.strip())
+                    to_conv = resolver.available[message - 1]
+                except (ValueError, IndexError):
+                    await ctx.send(
+                        _("That wasn't a valid choice.")
+                    )
+                    continue
+                else:
+                    async with ctx.typing():
+                        await resolver.convert(self.bot, to_conv)
+                    await ctx.send(_("{} converted.").format(to_conv))
+            await menu_message.delete()
+        else:
+            return await ctx.send(
+                _("There isn't anything else I know how to convert here."
+                  "\nThere might be more things I can convert in the future.")
+            )