DM listed users when deadman is armed

README.md

@@ -79,7 +79,7 @@ A member of the Scrapyard Cogworks package. A deadman switch that alerts listed
 
 Supported units: `s`, `m`, `h`, `d`, `w` (and their full names).
 
-When the switch is armed, the bot stores the expiry time and alerts users by DM. If an optional channel is provided, it also posts the alert there. If `[p]deadman disable` is not run before expiry, the listed users are DM'd and pinged that "the deadman switch has been TRIGGERED".
+When the switch is armed, each listed user is DM'd to confirm they were added. If an optional channel is provided, the trigger alert is also posted there. If `[p]deadman disable` is not run before expiry, the listed users are DM'd and pinged that "the deadman switch has been TRIGGERED".
 
 ---
 

deadman/deadman.py

@@ -194,13 +194,37 @@ class Deadman(commands.Cog):
         self._triggered = False
 
         expires_str = expires_at.strftime("%Y-%m-%d %H:%M UTC")
-        await ctx.send(
-            f"Deadman switch ARMED.\n"
-            f"Expires: **{expires_str}** (in {duration_td})\n"
-            f"Users notified: {', '.join(u.mention for u in users)}\n"
-            + (f"Alert channel: {trigger_channel.mention}\n" if trigger_channel else "\n")
-            + "Run `[p]deadman disable` before that time to cancel."
+        notified = 0
+        failed = []
+        for user in users:
+            try:
+                await user.send(
+                    f"**Deadman switch armed**\n"
+                    f"You have been added to a deadman switch.\n"
+                    f"It expires at **{expires_str}**.\n"
+                    f"If it is not disabled before then, you will receive a TRIGGERED alert.\n"
+                    f"Contact the bot owner if this is a mistake."
                 )
+                notified += 1
+            except discord.Forbidden:
+                failed.append(user)
+            except Exception:
+                failed.append(user)
+
+        status_parts = [
+            f"Deadman switch ARMED.",
+            f"Expires: **{expires_str}** (in {duration_td})",
+            f"Users notified: {', '.join(u.mention for u in users)}",
+        ]
+        if trigger_channel:
+            status_parts.append(f"Alert channel: {trigger_channel.mention}")
+        status_parts.append(f"DM'd {notified} of {len(users)} user(s).")
+        if failed:
+            status_parts.append(
+                "Could not DM: " + ", ".join(u.mention for u in failed)
+            )
+        status_parts.append("Run `[p]deadman disable` before that time to cancel.")
+        await ctx.send("\n".join(status_parts))
 
     @deadman.command(name="disable")
     async def deadman_disable(self, ctx):