feat(bot): announce mission modlists in the ops channel

src/bot/services/missionEmbeds.ts

@@ -1,13 +1,16 @@
 import {
   ActionRowBuilder,
+  AttachmentBuilder,
   ButtonBuilder,
   ButtonStyle,
   type Client,
   EmbedBuilder,
   type TextBasedChannelFields,
 } from "discord.js";
+import fsPromises from "fs/promises";
+import path from "path";
 import type { Payload } from "payload";
-import type { Mission, MissionAttendance, User } from "@/payload-types";
+import type { Mission, MissionAttendance, ModList, User } from "@/payload-types";
 import { getMissionAttendance, type MissionAttendanceSummary } from "@/lib/attendance";
 import { ATTENDANCE_CHANGED_CHANNEL } from "@/lib/attendance/realtime";
 import { botConfig } from "@/bot/config";
@@ -16,6 +19,11 @@ const EMBED_COLOR = 0x3b82f6;
 const CANCELLED_COLOR = 0x6b7280;
 const MAX_ELIGIBLE_MISSIONS = 10;
 const ROLL_CALL_LEAD_TIME_MS = 3 * 24 * 60 * 60 * 1000;
+// Discord attachment cap (8 MiB) — larger modlists fall back to a link.
+const MAX_ATTACHMENT_BYTES = 8 * 1024 * 1024;
+// Payload's default staticDir for an upload collection is its slug, resolved
+// against the process cwd — the bot shares the web app's filesystem.
+const MODLIST_STATIC_DIR = "mod-lists";
 
 let opsChannelWarned = false;
 let reconcileRunning = false;
@@ -223,6 +231,141 @@ const postEmbed = async (
   payload.logger.info(
     `[Bot] Posted attendance embed for mission #${mission.id} (${mission.name}).`,
   );
+  await syncModlistMessage(client, payload, opsChannelId, {
+    ...mission,
+    discordAttendanceSentAt: new Date().toISOString(),
+  });
+};
+
+interface ModlistInfo {
+  id: number;
+  name: string;
+  filename: string;
+  url: string | null;
+  filesize: number | null;
+  updatedAt: string;
+}
+
+const resolveModlist = async (
+  payload: Payload,
+  mission: Mission,
+): Promise<ModlistInfo | null> => {
+  const raw = mission.gameDetails.gameSetup?.requiredMods;
+  if (raw == null || typeof raw === "number") return null;
+  const modlist = raw as ModList;
+  if (!modlist.filename) return null;
+  return {
+    id: modlist.id,
+    name: modlist.modlistName,
+    filename: modlist.filename,
+    url: modlist.url ?? null,
+    filesize: modlist.filesize ?? null,
+    updatedAt: modlist.updatedAt,
+  };
+};
+
+/**
+ * Fingerprint of the attached modlist so reconcile can detect changes and
+ * announce re-downloads without looping (same pattern as attendanceHash).
+ */
+const modlistHash = (modlist: ModlistInfo): string =>
+  JSON.stringify({
+    id: modlist.id,
+    filename: modlist.filename,
+    filesize: modlist.filesize,
+    updatedAt: modlist.updatedAt,
+  });
+
+const renderModlistEmbed = (
+  mission: Mission,
+  modlist: ModlistInfo,
+  kind: "new" | "updated",
+): EmbedBuilder => {
+  const embed = new EmbedBuilder()
+    .setTitle(kind === "new" ? `Modlist — ${modlist.name}` : `Modlist updated — ${modlist.name}`)
+    .setColor(EMBED_COLOR)
+    .setTimestamp();
+  embed.setDescription(
+    kind === "new"
+      ? `The modlist for **${missionTitle(mission)}** is attached. Please download it before the operation.`
+      : `The modlist for **${missionTitle(mission)}** has changed. Please re-download the attached file before the operation.`,
+  );
+  return embed;
+};
+
+const postModlistMessage = async (
+  client: Client,
+  payload: Payload,
+  opsChannelId: string,
+  mission: Mission,
+  modlist: ModlistInfo,
+  kind: "new" | "updated",
+): Promise<void> => {
+  const channel = await getOpsChannel(client, opsChannelId);
+  const embed = renderModlistEmbed(mission, modlist, kind);
+
+  let files: AttachmentBuilder[] | undefined;
+  const tooBig = modlist.filesize != null && modlist.filesize > MAX_ATTACHMENT_BYTES;
+  if (!tooBig) {
+    try {
+      const dir = path.resolve(process.cwd(), MODLIST_STATIC_DIR);
+      const filePath = path.resolve(dir, modlist.filename);
+      if (!filePath.startsWith(dir + path.sep)) throw new Error("invalid modlist filename");
+      files = [
+        new AttachmentBuilder(await fsPromises.readFile(filePath), { name: modlist.filename }),
+      ];
+    } catch (error) {
+      payload.logger.warn(
+        `[Bot] Could not read modlist file for mission #${mission.id}: ${errorMessage(error)}; falling back to a link.`,
+      );
+    }
+  } else {
+    payload.logger.warn(
+      `[Bot] Modlist for mission #${mission.id} exceeds the attachment size cap; linking instead.`,
+    );
+  }
+  if (!files && modlist.url) {
+    embed.addFields({ name: "Download", value: `${botConfig.appUrl}${modlist.url}` });
+  }
+
+  await channel.send({ embeds: [embed], files });
+};
+
+/**
+ * Runs once a roll call has been sent: announces a newly attached modlist,
+ * announces changes with a re-download reminder, and clears the marker when
+ * the modlist is removed. The hash marker keeps this idempotent.
+ */
+const syncModlistMessage = async (
+  client: Client,
+  payload: Payload,
+  opsChannelId: string,
+  mission: Mission,
+): Promise<void> => {
+  if (!mission.discordAttendanceSentAt) return;
+
+  const modlist = await resolveModlist(payload, mission);
+  const currentHash = modlist ? modlistHash(modlist) : null;
+  const storedHash = mission.discordModlistHash ?? null;
+  if (currentHash === storedHash) return;
+
+  if (modlist) {
+    const kind = storedHash ? "updated" : "new";
+    await postModlistMessage(client, payload, opsChannelId, mission, modlist, kind);
+    payload.logger.info(
+      `[Bot] Posted ${kind} modlist message for mission #${mission.id} (${mission.name}).`,
+    );
+  } else if (storedHash) {
+    payload.logger.info(
+      `[Bot] Modlist removed from mission #${mission.id} (${mission.name}); marker cleared.`,
+    );
+  }
+  await payload.update({
+    collection: "missions",
+    id: mission.id,
+    data: { discordModlistHash: currentHash },
+    overrideAccess: true,
+  });
 };
 
 const manageMission = async (
@@ -231,9 +374,12 @@ const manageMission = async (
   opsChannelId: string,
   mission: Mission,
 ): Promise<void> => {
-  if (!isRollCallDue(mission)) {
-    // A sent roll call may still need its existing message reconciled.
-    if (!mission.discordAttendanceSentAt) return;
+  if (!isRollCallDue(mission) && !mission.discordAttendanceSentAt) {
+    return;
+  }
+
+  if (mission.discordAttendanceSentAt) {
+    await syncModlistMessage(client, payload, opsChannelId, mission);
   }
 
   if (!mission.discordMessageId) {
@@ -304,7 +450,7 @@ export const reconcileMission = async (
   if (
     mission.ownershipAndStatus.visibility !== "unit" ||
     !["Ready", "Scheduled"].includes(mission.ownershipAndStatus.status) ||
-    (!isRollCallDue(mission) && !mission.discordMessageId)
+    (!isRollCallDue(mission) && !mission.discordMessageId && !mission.discordAttendanceSentAt)
   ) {
     return;
   }
@@ -359,7 +505,7 @@ export const reconcile = async (client: Client, payload: Payload): Promise<void>
     }
 
     const eligible = (await getEligibleMissions(payload)).filter(
-      (mission) => isRollCallDue(mission) || !!mission.discordMessageId,
+      (mission) => isRollCallDue(mission) || !!mission.discordMessageId || !!mission.discordAttendanceSentAt,
     );
     for (const mission of eligible) {
       try {