feat: learn launch suggestions and preserve selection during refresh

Sources/Conjure/LauncherWindowController.swift

@@ -8,12 +8,14 @@ final class LauncherWindowController: NSWindowController, NSWindowDelegate, NSSe
     private let statusLabel = NSTextField(labelWithString: "Finding applications…")
     private let emptyLabel = NSTextField(labelWithString: "Finding applications…")
     private let openButton = NSButton(title: "Open Application", target: nil, action: nil)
+    private let history: LaunchHistory
     private var applications: [Application] = []
     private var results: [Application] = []
     private var discoveryTask: Task<Void, Never>?
     private var isLaunching = false
 
-    init() {
+    init(history: LaunchHistory = LaunchHistory()) {
+        self.history = history
         let window = LauncherPanel(
             contentRect: NSRect(x: 0, y: 0, width: 750, height: 474),
             styleMask: [.borderless],
@@ -227,16 +229,23 @@ final class LauncherWindowController: NSWindowController, NSWindowDelegate, NSSe
             guard let self else { return }
             self.applications = applications
             self.discoveryTask = nil
-            self.updateResults()
+            self.updateResults(preservingSelection: true)
         }
     }
 
-    private func updateResults() {
-        results = ApplicationSearch.results(for: searchField.stringValue, in: applications)
+    private func updateResults(preservingSelection: Bool = false) {
+        let selectedURL = preservingSelection && results.indices.contains(tableView.selectedRow)
+            ? results[tableView.selectedRow].id : nil
+        if searchField.stringValue.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
+            results = history.suggestions(in: applications)
+        } else {
+            results = ApplicationSearch.results(for: searchField.stringValue, in: applications)
+        }
         tableView.reloadData()
         if !results.isEmpty {
-            tableView.selectRowIndexes(IndexSet(integer: 0), byExtendingSelection: false)
-            tableView.scrollRowToVisible(0)
+            let row = selectedURL.flatMap { url in results.firstIndex { $0.id == url } } ?? 0
+            tableView.selectRowIndexes(IndexSet(integer: row), byExtendingSelection: false)
+            tableView.scrollRowToVisible(row)
         }
         emptyLabel.isHidden = !results.isEmpty
         if discoveryTask != nil {
@@ -350,6 +359,7 @@ final class LauncherWindowController: NSWindowController, NSWindowDelegate, NSSe
         Task {
             do {
                 try await AppLauncher.launch(application.url)
+                history.recordLaunch(of: application)
                 window?.orderOut(nil)
             } catch {
                 let alert = NSAlert(error: error)