From 75d2158163a5eb6be74d109d9ef316c7fa53805a Mon Sep 17 00:00:00 2001
From: Brent Simmons <brent@ranchero.com>
Date: Sun, 19 Apr 2020 14:10:12 -0700
Subject: [PATCH] =?UTF-8?q?Perform=20a=20one-time=20(per=20local=20account?=
 =?UTF-8?q?)=20cleanup=20made=20necessary=20by=20the=20retention=20policy?=
 =?UTF-8?q?=20change=20=E2=80=94=C2=A0mark=20articles=20older=20than=20the?=
 =?UTF-8?q?=2090-day=20window=20as=20read.=20This=20way=20users=20won?=
 =?UTF-8?q?=E2=80=99t=20get=20a=20flood=20of=20old,=20unread=20articles=20?=
 =?UTF-8?q?when=20they=20run=20this=20new=20version.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Frameworks/Account/Account.swift               | 12 ++++++++++++
 Frameworks/Account/AccountMetadata.swift       |  9 +++++++++
 .../ArticlesDatabase/ArticlesDatabase.swift    | 18 ++++++++++++++++++
 .../ArticlesDatabase/ArticlesTable.swift       | 16 ++++++++++++++++
 4 files changed, 55 insertions(+)

diff --git a/Frameworks/Account/Account.swift b/Frameworks/Account/Account.swift
index 812ad9693..9824386d4 100644
--- a/Frameworks/Account/Account.swift
+++ b/Frameworks/Account/Account.swift
@@ -279,7 +279,19 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 		webFeedMetadataFile.load()
 		opmlFile.load()
 
+		var shouldHandleRetentionPolicyChange = false
+		if type == .onMyMac {
+			let didHandlePolicyChange = metadata.performedApril2020RetentionPolicyChange ?? false
+			shouldHandleRetentionPolicyChange = !didHandlePolicyChange
+		}
+
 		DispatchQueue.main.async {
+			if shouldHandleRetentionPolicyChange {
+				// Handle one-time database changes made necessary by April 2020 retention policy change.
+				self.database.performApril2020RetentionPolicyChange()
+				self.metadata.performedApril2020RetentionPolicyChange = true
+			}
+
 			self.database.cleanupDatabaseAtStartup(subscribedToWebFeedIDs: self.flattenedWebFeeds().webFeedIDs())
 			self.fetchAllUnreadCounts()
 		}
diff --git a/Frameworks/Account/AccountMetadata.swift b/Frameworks/Account/AccountMetadata.swift
index f4c50ab44..9f5845a64 100644
--- a/Frameworks/Account/AccountMetadata.swift
+++ b/Frameworks/Account/AccountMetadata.swift
@@ -24,6 +24,7 @@ final class AccountMetadata: Codable {
 		case lastArticleFetchEndTime
 		case endpointURL
 		case lastCredentialRenewTime = "lastCredentialRenewTime"
+		case performedApril2020RetentionPolicyChange
 	}
 
 	var name: String? {
@@ -92,6 +93,14 @@ final class AccountMetadata: Codable {
 		}
 	}
 
+	var performedApril2020RetentionPolicyChange: Bool? {
+		didSet {
+			if performedApril2020RetentionPolicyChange != oldValue {
+				valueDidChange(.performedApril2020RetentionPolicyChange)
+			}
+		}
+	}
+
 	weak var delegate: AccountMetadataDelegate?
 	
 	func valueDidChange(_ key: CodingKeys) {
diff --git a/Frameworks/ArticlesDatabase/ArticlesDatabase.swift b/Frameworks/ArticlesDatabase/ArticlesDatabase.swift
index d0f3c424c..0ee215866 100644
--- a/Frameworks/ArticlesDatabase/ArticlesDatabase.swift
+++ b/Frameworks/ArticlesDatabase/ArticlesDatabase.swift
@@ -277,6 +277,24 @@ public final class ArticlesDatabase {
 		articlesTable.deleteArticlesNotInSubscribedToFeedIDs(subscribedToWebFeedIDs)
 		articlesTable.deleteOldStatuses()
 	}
+
+	/// Do database cleanups made necessary by the retention policy change in April 2020.
+	///
+	/// The retention policy for feed-based systems changed in April 2020:
+	/// we keep articles only for as long as they’re in the feed.
+	/// This change could result in a bunch of older articles suddenly
+	/// appearing as unread articles.
+	///
+	/// These are articles that were in the database,
+	/// but weren’t appearing in the UI because they were beyond the 90-day window.
+	/// (The previous retention policy used a 90-day window.)
+	///
+	/// This function marks everything as read that’s beyond that 90-day window.
+	/// It’s intended to be called only once on an account.
+	public func performApril2020RetentionPolicyChange() {
+		precondition(retentionStyle == .feedBased)
+		articlesTable.markOlderStatusesAsRead()
+	}
 }
 
 // MARK: - Private
diff --git a/Frameworks/ArticlesDatabase/ArticlesTable.swift b/Frameworks/ArticlesDatabase/ArticlesTable.swift
index 635d1d9b3..ff36a8f9b 100644
--- a/Frameworks/ArticlesDatabase/ArticlesTable.swift
+++ b/Frameworks/ArticlesDatabase/ArticlesTable.swift
@@ -580,6 +580,22 @@ final class ArticlesTable: DatabaseTable {
 			}
 		}
 	}
+
+	/// Mark statuses beyond the 90-day window as read.
+	///
+	/// This is not intended for wide use: this is part of implementing
+	/// the April 2020 retention policy change for feed-based accounts.
+	func markOlderStatusesAsRead() {
+		queue.runInDatabase { databaseResult in
+			guard let database = databaseResult.database else {
+				return
+			}
+
+			let sql = "update statuses set read = true where dateArrived<?;"
+			let parameters = [self.articleCutoffDate] as [Any]
+			database.executeUpdate(sql, withArgumentsIn: parameters)
+		}
+	}
 }
 
 // MARK: - Private