From 75fb3fa5fbfe59e4ac87a10ba9a3966da93aca2a Mon Sep 17 00:00:00 2001
From: Maurice Parker <mo@vincode.io>
Date: Sat, 31 Oct 2020 20:14:50 -0500
Subject: [PATCH] Implement account specific drag and drop behaviors for iOS

---
 .../Cell/MasterFeedTableViewIdentifier.swift      | 15 +++++++++++++++
 .../MasterFeedViewController+Drop.swift           | 14 ++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/iOS/MasterFeed/Cell/MasterFeedTableViewIdentifier.swift b/iOS/MasterFeed/Cell/MasterFeedTableViewIdentifier.swift
index e6d8172bb..9173f70e4 100644
--- a/iOS/MasterFeed/Cell/MasterFeedTableViewIdentifier.swift
+++ b/iOS/MasterFeed/Cell/MasterFeedTableViewIdentifier.swift
@@ -18,6 +18,7 @@ final class MasterFeedTableViewIdentifier: NSObject, NSCopying {
 
 	let isEditable: Bool
 	let isPsuedoFeed: Bool
+	let isAccount: Bool
 	let isFolder: Bool
 	let isWebFeed: Bool
 	
@@ -26,6 +27,19 @@ final class MasterFeedTableViewIdentifier: NSObject, NSCopying {
 	let unreadCount: Int
 	let childCount: Int
 	
+	var account: Account? {
+		if isAccount, let containerID = containerID {
+			return AccountManager.shared.existingContainer(with: containerID) as? Account
+		}
+		if isFolder, let parentContainerID = parentContainerID {
+			return AccountManager.shared.existingContainer(with: parentContainerID) as? Account
+		}
+		if isWebFeed, let feedID = feedID {
+			return (AccountManager.shared.existingFeed(with: feedID) as? WebFeed)?.account
+		}
+		return nil
+	}
+	
 	init(node: Node, unreadCount: Int) {
 		let feed = node.representedObject as! Feed
 		self.feedID = feed.feedID
@@ -34,6 +48,7 @@ final class MasterFeedTableViewIdentifier: NSObject, NSCopying {
 		
 		self.isEditable = !(node.representedObject is PseudoFeed)
 		self.isPsuedoFeed = node.representedObject is PseudoFeed
+		self.isAccount = node.representedObject is Account
 		self.isFolder = node.representedObject is Folder
 		self.isWebFeed = node.representedObject is WebFeed
 		self.nameForDisplay = feed.nameForDisplay
diff --git a/iOS/MasterFeed/MasterFeedViewController+Drop.swift b/iOS/MasterFeed/MasterFeedViewController+Drop.swift
index 8692e3020..32fab4f7d 100644
--- a/iOS/MasterFeed/MasterFeedViewController+Drop.swift
+++ b/iOS/MasterFeed/MasterFeedViewController+Drop.swift
@@ -22,10 +22,24 @@ extension MasterFeedViewController: UITableViewDropDelegate {
 			destIndexPath.section > 0,
 			tableView.hasActiveDrag,
 			let destIdentifier = dataSource.itemIdentifier(for: destIndexPath),
+			let destAccount = destIdentifier.account,
 			let destCell = tableView.cellForRow(at: destIndexPath) else {
 				return UITableViewDropProposal(operation: .forbidden)
 		}
+
+		// Validate account specific behaviors...
+		if destAccount.behaviors.contains(.disallowFeedInRootFolder) && destIdentifier.isAccount {
+			return UITableViewDropProposal(operation: .forbidden)
+		}
 		
+		if destAccount.behaviors.contains(.disallowFeedInMultipleFolders),
+		   let sourceFeedID = (session.localDragSession?.items.first?.localObject as? MasterFeedTableViewIdentifier)?.feedID,
+		   let sourceWebFeed = AccountManager.shared.existingFeed(with: sourceFeedID) as? WebFeed,
+		   sourceWebFeed.account?.accountID != destAccount.accountID && destAccount.hasWebFeed(withURL: sourceWebFeed.url) {
+			return UITableViewDropProposal(operation: .forbidden)
+		}
+
+		// Determine the correct drop proposal
 		if destIdentifier.isFolder {
 			if session.location(in: destCell).y >= 0 {
 				return UITableViewDropProposal(operation: .move, intent: .insertIntoDestinationIndexPath)