From 0aa05050094cdc8ffd1115917d99d40cf122d824 Mon Sep 17 00:00:00 2001
From: Cadence Ember <cadence@disroot.org>
Date: Mon, 23 Aug 2021 23:43:23 +1200
Subject: [PATCH] Keep subscriptions in database if channel deleted

---
 api/formapi.js            | 5 ++++-
 background/feed-update.js | 4 ++--
 utils/getuser.js          | 4 ++--
 utils/upgradedb.js        | 5 +++++
 4 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/api/formapi.js b/api/formapi.js
index 70d1b28..14f10d0 100644
--- a/api/formapi.js
+++ b/api/formapi.js
@@ -24,7 +24,10 @@ module.exports = [
 
 					if (add) {
 						await fetchChannel(ucid, settings.instance)
-						db.prepare("INSERT OR IGNORE INTO Subscriptions (token, ucid) VALUES (?, ?)").run(token, ucid)
+						db.prepare(
+							"INSERT INTO Subscriptions (token, ucid) VALUES (?, ?)"
+								+ " ON CONFLICT (token, ucid) DO UPDATE SET channel_missing = 0"
+						).run(token, ucid)
 					} else {
 						db.prepare("DELETE FROM Subscriptions WHERE token = ? AND ucid = ?").run(token, ucid)
 					}
diff --git a/background/feed-update.js b/background/feed-update.js
index daaa9fa..069ee0d 100644
--- a/background/feed-update.js
+++ b/background/feed-update.js
@@ -16,7 +16,7 @@ const prepared = {
 		"UPDATE Channels SET refreshed = ? WHERE ucid = ?"
 	),
 	unsubscribe_all_from_channel: db.prepare(
-		"DELETE FROM Subscriptions WHERE ucid = ?"
+		"UPDATE Subscriptions SET channel_missing = 1 WHERE ucid = ?"
 	)
 }
 
@@ -35,7 +35,7 @@ class RefreshQueue {
 		// get the next set of scheduled channels to refresh
 		const afterTime = Date.now() - constants.caching.seen_token_subscriptions_eligible
 		const channels = db.prepare(
-			"SELECT DISTINCT Subscriptions.ucid FROM SeenTokens INNER JOIN Subscriptions ON SeenTokens.token = Subscriptions.token AND SeenTokens.seen > ? ORDER BY SeenTokens.seen DESC"
+			"SELECT DISTINCT Subscriptions.ucid FROM SeenTokens INNER JOIN Subscriptions ON SeenTokens.token = Subscriptions.token AND SeenTokens.seen > ? WHERE Subscriptions.channel_missing = 0 ORDER BY SeenTokens.seen DESC"
 		).pluck().all(afterTime)
 		this.addLast(channels)
 		this.lastLoadTime = Date.now()
diff --git a/utils/getuser.js b/utils/getuser.js
index cc819fe..7cbb7ef 100644
--- a/utils/getuser.js
+++ b/utils/getuser.js
@@ -51,7 +51,7 @@ class User {
 
 	getSubscriptions() {
 		if (this.token) {
-			return db.prepare("SELECT ucid FROM Subscriptions WHERE token = ?").pluck().all(this.token)
+			return db.prepare("SELECT ucid FROM Subscriptions WHERE token = ? AND channel_missing = 0").pluck().all(this.token)
 		} else {
 			return []
 		}
@@ -59,7 +59,7 @@ class User {
 
 	isSubscribed(ucid) {
 		if (this.token) {
-			return !!db.prepare("SELECT * FROM Subscriptions WHERE token = ? AND ucid = ?").get([this.token, ucid])
+			return !!db.prepare("SELECT * FROM Subscriptions WHERE token = ? AND ucid = ? AND channel_missing = 0").get([this.token, ucid])
 		} else {
 			return false
 		}
diff --git a/utils/upgradedb.js b/utils/upgradedb.js
index 33642ab..78a7696 100644
--- a/utils/upgradedb.js
+++ b/utils/upgradedb.js
@@ -53,6 +53,11 @@ const deltas = [
 	function() {
 		db.prepare("ALTER TABLE Settings ADD COLUMN recommended_mode INTEGER DEFAULT 0")
 			.run()
+	},
+	// 8: Subscriptions +channel_missing
+	function() {
+		db.prepare("ALTER TABLE Subscriptions ADD COLUMN channel_missing INTEGER DEFAULT 0")
+			.run()
 	}
 ]