Move everything to src folder... it had to happen

src/m2d/actions/channel-webhook.js

@@ -0,0 +1,99 @@
+// @ts-check
+
+const assert = require("assert").strict
+const DiscordTypes = require("discord-api-types/v10")
+const {Readable} = require("stream")
+const passthrough = require("../../passthrough")
+const {discord, db, select} = passthrough
+
+/**
+ * Look in the database to find webhook credentials for a channel.
+ * (Note that the credentials may be invalid and need to be re-created if the webhook was interfered with from outside.)
+ * @param {string} channelID
+ * @param {boolean} forceCreate create a new webhook no matter what the database says about the state
+ * @returns id and token for a webhook for that channel
+ */
+async function ensureWebhook(channelID, forceCreate = false) {
+	if (!forceCreate) {
+		const row = select("webhook", ["webhook_id", "webhook_token"], {channel_id: channelID}).get()
+		if (row) {
+			return {
+				id: row.webhook_id,
+				token: row.webhook_token,
+				created: false
+			}
+		}
+	}
+
+	// If we got here, we need to create a new webhook.
+	const webhook = await discord.snow.webhook.createWebhook(channelID, {name: "Out Of Your Element: Matrix Bridge"})
+	assert(webhook.token)
+	db.prepare("REPLACE INTO webhook (channel_id, webhook_id, webhook_token) VALUES (?, ?, ?)").run(channelID, webhook.id, webhook.token)
+	return {
+		id: webhook.id,
+		token: webhook.token,
+		created: true
+	}
+}
+
+/**
+ * @param {string} channelID
+ * @param {(webhook: import("../../types").WebhookCreds) => Promise<T>} callback
+ * @returns Promise<T>
+ * @template T
+ */
+async function withWebhook(channelID, callback) {
+	const webhook = await ensureWebhook(channelID, false)
+	return callback(webhook).catch(async e => {
+		if (e.message === `{"message": "Unknown Webhook", "code": 10015}`) { // pathetic error handling from SnowTransfer
+			// Our webhook is gone. Maybe somebody deleted it, or removed and re-added OOYE from the guild.
+			const newWebhook = await ensureWebhook(channelID, true)
+			return callback(newWebhook) // not caught; if the error happens again just throw it instead of looping
+		}
+
+		throw e
+	})
+}
+
+/**
+ * @param {string} channelID
+ * @param {DiscordTypes.RESTPostAPIWebhookWithTokenJSONBody & {files?: {name: string, file: Buffer | Readable}[]}} data
+ * @param {string} [threadID]
+ */
+async function sendMessageWithWebhook(channelID, data, threadID) {
+	const result = await withWebhook(channelID, async webhook => {
+		return discord.snow.webhook.executeWebhook(webhook.id, webhook.token, data, {wait: true, thread_id: threadID})
+	})
+	return result
+}
+
+/**
+ * @param {string} channelID
+ * @param {string} messageID
+ * @param {DiscordTypes.RESTPatchAPIWebhookWithTokenMessageJSONBody & {files?: {name: string, file: Buffer | Readable}[]}} data
+ * @param {string} [threadID]
+ */
+async function editMessageWithWebhook(channelID, messageID, data, threadID) {
+	const result = await withWebhook(channelID, async webhook => {
+		return discord.snow.webhook.editWebhookMessage(webhook.id, webhook.token, messageID, {...data, thread_id: threadID})
+	})
+	return result
+}
+
+/**
+ * @param {string} channelID
+ * @param {string} messageID
+ * @param {string} [threadID]
+ */
+async function deleteMessageWithWebhook(channelID, messageID, threadID) {
+	const result = await withWebhook(channelID, async webhook => {
+		return discord.snow.webhook.deleteWebhookMessage(webhook.id, webhook.token, messageID, threadID)
+	})
+	return result
+}
+
+module.exports.ensureWebhook = ensureWebhook
+module.exports.withWebhook = withWebhook
+module.exports.sendMessageWithWebhook = sendMessageWithWebhook
+module.exports.editMessageWithWebhook = editMessageWithWebhook
+module.exports.deleteMessageWithWebhook = deleteMessageWithWebhook