Rework subscribing to deleted channels

utils/constants.js

@@ -50,6 +50,7 @@ let constants = {
 		csrf_time: 4*60*60*1000,
 		seen_token_subscriptions_eligible: 40*60*60*1000,
 		subscriptions_refresh_loop_min: 5*60*1000,
+		subscriptions_refesh_fake_not_found_cooldown: 10*60*1000,
 	},
 
 	// Pattern matching.

utils/getuser.js

@@ -54,7 +54,7 @@ class User {
 
 	getSubscriptions() {
 		if (this.token) {
-			return db.prepare("SELECT ucid FROM Subscriptions WHERE token = ? AND channel_missing = 0").pluck().all(this.token)
+			return db.prepare("SELECT ucid FROM Subscriptions WHERE token = ?").pluck().all(this.token)
 		} else {
 			return []
 		}
@@ -62,7 +62,7 @@ class User {
 
 	isSubscribed(ucid) {
 		if (this.token) {
-			return !!db.prepare("SELECT * FROM Subscriptions WHERE token = ? AND ucid = ? AND channel_missing = 0").get([this.token, ucid])
+			return !!db.prepare("SELECT * FROM Subscriptions WHERE token = ? AND ucid = ?").get([this.token, ucid])
 		} else {
 			return false
 		}

utils/upgradedb.js

@@ -75,6 +75,26 @@ const deltas = [
 	function() {
 		db.prepare("ALTER TABLE Settings ADD COLUMN theme INTEGER DEFAULT 0")
 			.run()
+	},
+	// 12: Channels +missing +missing_reason, Subscriptions -
+	// Better management for missing channels
+	// We totally discard the existing Subscriptions.channel_missing since it is unreliable.
+	function() {
+		db.prepare("ALTER TABLE Channels ADD COLUMN missing INTEGER NOT NULL DEFAULT 0")
+			.run()
+		db.prepare("ALTER TABLE Channels ADD COLUMN missing_reason TEXT")
+			.run()
+		// https://www.sqlite.org/lang_altertable.html#making_other_kinds_of_table_schema_changes
+		db.transaction(() => {
+			db.prepare("CREATE TABLE NEW_Subscriptions (token TEXT NOT NULL, ucid TEXT NOT NULL, PRIMARY KEY (token, ucid))")
+				.run()
+			db.prepare("INSERT INTO NEW_Subscriptions (token, ucid) SELECT token, ucid FROM Subscriptions")
+				.run()
+			db.prepare("DROP TABLE Subscriptions")
+				.run()
+			db.prepare("ALTER TABLE NEW_Subscriptions RENAME TO Subscriptions")
+				.run()
+		})()
 	}
 ]
 

utils/youtube.js

@@ -2,14 +2,58 @@ const {request} = require("./request")
 const db = require("./db")
 
 async function fetchChannel(ucid, instance) {
+	function updateGoodData(channel) {
+		const bestIcon = channel.authorThumbnails.slice(-1)[0]
+		const iconURL = bestIcon ? bestIcon.url : null
+		db.prepare("REPLACE INTO Channels (ucid, name, icon_url, missing, missing_reason) VALUES (?, ?, ?, 0, NULL)").run(channel.authorId, channel.author, iconURL)
+	}
+
+	function updateBadData(channel) {
+		if (channel.identifier === "NOT_FOUND" || channel.identifier === "ACCOUNT_TERMINATED") {
+			db.prepare("UPDATE Channels SET missing = 1, missing_reason = ? WHERE ucid = ?").run(channel.error, channel.authorId)
+			return {
+				missing: true,
+				message: channel.error
+			}
+		} else {
+			return {
+				missing: false,
+				message: channel.error
+			}
+		}
+	}
+
 	if (!instance) throw new Error("No instance parameter provided")
-	// fetch
+
+	const row = db.prepare("SELECT * FROM Channels WHERE ucid = ?").get(ucid)
+
+	// handle the case where the channel has a known error
+	if (row && row.missing_reason) {
+		return {
+			error: true,
+			ucid,
+			row,
+			missing: true,
+			message: row.missing_reason
+		}
+	}
+
+	/** @type {any} */
 	const channel = await request(`${instance}/api/v1/channels/${ucid}`).then(res => res.json())
-	// update database
-	const bestIcon = channel.authorThumbnails.slice(-1)[0]
-	const iconURL = bestIcon ? bestIcon.url : null
-	db.prepare("REPLACE INTO Channels (ucid, name, icon_url) VALUES (?, ?, ?)").run([channel.authorId, channel.author, iconURL])
-	// return
+
+	// handle the case where the channel has a newly discovered error
+	if (channel.error) {
+		const missingData = updateBadData(channel)
+		return {
+			error: true,
+			ucid,
+			row,
+			...missingData
+		}
+	}
+
+	// handle the case where the channel returns good data (this is the only remaining scenario)
+	updateGoodData(channel)
 	return channel
 }