From 26d89136b15babd46cf874e7d1eac641f686be2a Mon Sep 17 00:00:00 2001
From: Ske <voltasalt@gmail.com>
Date: Fri, 20 Jul 2018 22:56:32 +0200
Subject: [PATCH] Add a command for backdating switches

---
 bot/pluralkit/commands.py | 69 +++++++++++++++++++++++++++++++++++++--
 bot/pluralkit/db.py       |  5 +++
 bot/pluralkit/help.py     | 12 +++++++
 bot/requirements.txt      |  1 +
 4 files changed, 85 insertions(+), 2 deletions(-)

diff --git a/bot/pluralkit/commands.py b/bot/pluralkit/commands.py
index 6bc6bf42..d56a9719 100644
--- a/bot/pluralkit/commands.py
+++ b/bot/pluralkit/commands.py
@@ -1,4 +1,4 @@
-from datetime import datetime
+from datetime import datetime, timezone
 import io
 import itertools
 import json
@@ -6,6 +6,7 @@ import os
 import re
 from urllib.parse import urlparse
 
+import dateparser
 import discord
 from discord.utils import oauth_url
 import humanize
@@ -464,7 +465,7 @@ async def switch_member(conn, message, args):
         if len(members) == 1:
             return False, "{} is already fronting.".format(members[0]["name"])
         return False, "Members {} are already fronting.".format(", ".join([m["name"] for m in members]))
-    
+
     # Log the switch
     async with conn.transaction():
         switch_id = await db.add_switch(conn, system_id=system["id"])
@@ -492,6 +493,70 @@ async def switch_out(conn, message, args):
     await db.add_switch(conn, system_id=system["id"])
     return True, "Switch-out registered."
 
+@command(cmd="switch move", usage="<time>", description="Moves the most recent switch to a different point in time.", category="Switching commands")
+async def switch_move(conn, message, args):
+    system = await db.get_system_by_account(conn, message.author.id)
+
+    if system is None:
+        return False, "No system is registered to this account."
+
+    if len(args) == 0:
+        return False
+
+    # Parse the time to move to
+    new_time = dateparser.parse(" ".join(args), languages=["en"], settings={
+        "TO_TIMEZONE": "UTC",
+        "RETURN_AS_TIMEZONE_AWARE": False
+    })
+    if not new_time:
+        return False, "{} can't be parsed as a valid time.".format(" ".join(args))
+
+    # Make sure the time isn't in the future
+    if new_time > datetime.now():
+        return False, "Can't move switch to a time in the future."
+
+    # Make sure it all runs in a big transaction for atomicity
+    async with conn.transaction():
+        # Get the last two switches to make sure the switch to move isn't before the second-last switch
+        last_two_switches = await get_front_history(conn, system["id"], count=2)
+        if len(last_two_switches) == 0:
+            return False, "There are no registered switches for this system."
+
+        last_timestamp, last_fronters = last_two_switches[0]
+        if len(last_two_switches) > 1:
+            second_last_timestamp, _ = last_two_switches[1]
+
+            if new_time < second_last_timestamp:
+                time_str = humanize.naturaltime(second_last_timestamp)
+                return False, "Can't move switch to before last switch time ({}), as it would cause conflicts.".format(time_str)
+        
+        # Display the confirmation message w/ humanized times
+        members = ", ".join([member["name"] for member in last_fronters])
+        last_absolute = last_timestamp.isoformat(sep=" ", timespec="seconds")
+        last_relative = humanize.naturaltime(last_timestamp)
+        new_absolute = new_time.isoformat(sep=" ", timespec="seconds")
+        new_relative = humanize.naturaltime(new_time)
+        embed = make_default_embed("This will move the latest switch ({}) from {} ({}) to {} ({}). Is this OK?".format(members, last_absolute, last_relative, new_absolute, new_relative))
+        
+        # Await and handle confirmation reactions
+        confirm_msg = await client.send_message(message.channel, embed=embed)
+        await client.add_reaction(confirm_msg, "✅")
+        await client.add_reaction(confirm_msg, "❌")
+
+        reaction = await client.wait_for_reaction(emoji=["✅", "❌"], message=confirm_msg, user=message.author, timeout=60.0)
+        if not reaction:
+            return False, "Switch move timed out."
+
+        if reaction.reaction.emoji == "❌":
+            return False, "Switch move cancelled."
+
+        # DB requires the actual switch ID which our utility method above doesn't return, do this manually
+        switch_id = (await db.front_history(conn, system["id"], count=1))[0]["id"]
+
+        # Change the switch in the DB
+        await db.move_last_switch(conn, system["id"], switch_id, naive_new_time)
+        return True, "Switch moved."
+
 @command(cmd="mod log", usage="[channel]", description="Sets the bot to log events to a specified channel. Leave blank to disable.", category="Moderation commands")
 async def set_log(conn, message, args):
     if not message.author.server_permissions.administrator:
diff --git a/bot/pluralkit/db.py b/bot/pluralkit/db.py
index 62532ddf..9c52c790 100644
--- a/bot/pluralkit/db.py
+++ b/bot/pluralkit/db.py
@@ -214,6 +214,11 @@ async def add_switch(conn, system_id: int):
     res = await conn.fetchrow("insert into switches (system) values ($1) returning *", system_id)
     return res["id"]
 
+@db_wrap
+async def move_last_switch(conn, system_id: int, switch_id: int, new_time):
+    logger.debug("Moving latest switch (system={}, id={}, new_time={})".format(system_id, switch_id, new_time))
+    await conn.execute("update switches set timestamp = $1 where system = $2 and id = $3", new_time, system_id, switch_id)
+
 @db_wrap
 async def add_switch_member(conn, switch_id: int, member_id: int):
     logger.debug("Adding switch member (switch={}, member={})".format(switch_id, member_id))
diff --git a/bot/pluralkit/help.py b/bot/pluralkit/help.py
index d5d890fc..98904d09 100644
--- a/bot/pluralkit/help.py
+++ b/bot/pluralkit/help.py
@@ -116,6 +116,18 @@ For example:
 `pk;switch John Jill` - Registers a switch John and Jill as co-fronters."""),
         ("Switching out",
         """You can use the `pk;switch out` command to register a switch with no one in front."""),
+        ("Moving a switch",
+        """You can move the latest switch you have registered using the `pk;switch move` command.
+        
+This is useful if you log the switch a while after it happened, and you want to properly backdate it in the history.
+
+For example:
+`pk;switch move 10 minutes ago` - Moves the latest switch to 10 minutes ago
+`pk;switch move 11pm EST` - Moves the latest switch to 11pm EST
+
+Note that you can't move the switch further back than the second-last logged switch, and you can't move a switch to a time in the future.
+
+The default time zone for absolute times is UTC, but you can specify other time zones in the command itself, as given in the example."""),
         ("Viewing fronting history",
         """To view front history, you can use the `pk;system fronter` and `pk;system fronthistory` commands.
         
diff --git a/bot/requirements.txt b/bot/requirements.txt
index 4d547193..f271b53c 100644
--- a/bot/requirements.txt
+++ b/bot/requirements.txt
@@ -1,6 +1,7 @@
 aiohttp
 aioinflux
 asyncpg
+dateparser
 discord.py
 humanize
 uvloop
\ No newline at end of file