Make the link button do something

src/web/pug/guild.pug

@@ -205,7 +205,7 @@ block body
               p.s-description All of the above, and publicly visible in the Matrix space directory (like Server Discovery)
 
     h3.mt32.fs-category Manually link channels
-    form.d-flex.g16.ai-start(method="post" action="/api/link")
+    form.d-flex.g16.ai-start(hx-post="/api/privacy-level" hx-trigger="submit" hx-disabled-elt="this")
       .fl-grow2.s-btn-group.fd-column.w40
         each channel in unlinkedChannels
           input.s-btn--radio(type="radio" name="discord" id=channel.id value=channel.id)
@@ -220,7 +220,8 @@ block body
             +matrix(room, true)
         else
           .s-empty-state.p8 All Matrix rooms are linked.
+      input(type="hidden" name="guild_id" value=guild_id)
       div
-        button.s-btn.s-btn__icon.s-btn__filled
-          != icons.Icons.IconLink
-          = ` Connect`
+        button.s-btn.s-btn__icon.s-btn__filled.htmx-indicator
+          != icons.Icons.IconMerge
+          = ` Link`

src/web/routes/link.js

@@ -0,0 +1,63 @@
+// @ts-check
+
+const {z} = require("zod")
+const {defineEventHandler, useSession, createError, readValidatedBody} = require("h3")
+const Ty = require("../../types")
+
+const {discord, db, as, sync, select, from} = require("../../passthrough")
+/** @type {import("../../d2m/actions/create-space")} */
+const createSpace = sync.require("../../d2m/actions/create-space")
+/** @type {import("../../d2m/actions/create-room")} */
+const createRoom = sync.require("../../d2m/actions/create-room")
+const {reg} = require("../../matrix/read-registration")
+
+/** @type {import("../../matrix/api")} */
+const api = sync.require("../../matrix/api")
+
+const schema = {
+	link: z.object({
+		guild_id: z.string(),
+		matrix: z.string(),
+		discord: z.string()
+	})
+}
+
+as.router.post("/api/link", defineEventHandler(async event => {
+	const parsedBody = await readValidatedBody(event, schema.link.parse)
+	const session = await useSession(event, {password: reg.as_token})
+
+	// Check guild ID or nonce
+	const guildID = parsedBody.guild_id
+	if (!(session.data.managedGuilds || []).includes(guildID)) throw createError({status: 403, message: "Forbidden", data: "Can't edit a guild you don't have Manage Server permissions in"})
+
+	// Check guild is bridged
+	const guild = discord.guilds.get(guildID)
+	if (!guild) throw createError({status: 400, message: "Bad Request", data: "Discord guild does not exist or bot has not joined it"})
+	const spaceID = await createSpace.ensureSpace(guild)
+
+	// Check channel exists
+	const channel = discord.channels.get(parsedBody.discord)
+	if (!channel) throw createError({status: 400, message: "Bad Request", data: "Discord channel does not exist"})
+
+	// Check channel and room are not already bridged
+	const row = from("channel_room").select("channel_id", "room_id").and("WHERE channel_id = ? OR room_id = ?").get(parsedBody.discord, parsedBody.matrix)
+	if (row) throw createError({status: 400, message: "Bad Request", data: `Channel ID ${row.channel_id} and room ID ${row.room_id} are already bridged and cannot be reused`})
+
+	// Check room exists and bridge is joined and bridge has PL 100
+	const self = `@${reg.sender_localpart}:${reg.ooye.server_name}`
+	/** @type {Ty.Event.M_Room_Member} */
+	const memberEvent = await api.getStateEvent(parsedBody.matrix, "m.room.member", self)
+	if (memberEvent.membership !== "join") throw createError({status: 400, message: "Bad Request", data: "Matrix room does not exist"})
+	/** @type {Ty.Event.M_Power_Levels} */
+	const powerLevelsStateContent = await api.getStateEvent(parsedBody.matrix, "m.room.power_levels", "")
+	const selfPowerLevel = powerLevelsStateContent.users?.[self] || powerLevelsStateContent.users_default || 0
+	if (selfPowerLevel < (powerLevelsStateContent.state_default || 50) || selfPowerLevel < 100) throw createError({status: 400, message: "Bad Request", data: "OOYE needs power level 100 (admin) in the target Matrix room"})
+
+	// Insert database entry
+	db.prepare("INSERT INTO channel_room (channel_id, room_id, name, guild_id) VALUES (?, ?, ?, ?)").run(parsedBody.discord, parsedBody.matrix, channel.name, guildID)
+
+	// Sync room data and space child
+	createRoom.syncRoom(parsedBody.discord)
+
+	return null // 204
+}))

src/web/server.js

@@ -23,8 +23,9 @@ pugSync.createRoute(as.router, "/ok", "ok.pug")
 
 sync.require("./routes/download-matrix")
 sync.require("./routes/download-discord")
-sync.require("./routes/invite")
 sync.require("./routes/guild-settings")
+sync.require("./routes/invite")
+sync.require("./routes/link")
 sync.require("./routes/oauth")
 sync.require("./routes/qr")