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)

Sources/ConjureKit/Applications.swift

@@ -12,7 +12,8 @@ public struct Application: Identifiable, Sendable {
     }
 
     fileprivate init(canonicalURL: URL, name: String) {
-        url = canonicalURL
+        url = canonicalURL.hasDirectoryPath
+            ? canonicalURL : URL(fileURLWithPath: canonicalURL.path, isDirectory: true)
         self.name = name
         searchableName = folded(name)
         searchableCharacters = Array(searchableName)
@@ -137,7 +138,7 @@ private func folded(_ string: String) -> String {
     string.folding(options: [.caseInsensitive, .diacriticInsensitive], locale: searchLocale)
 }
 
-private func alphabetical(_ lhs: Application, _ rhs: Application) -> Bool {
+func alphabetical(_ lhs: Application, _ rhs: Application) -> Bool {
     let order = lhs.name.localizedStandardCompare(rhs.name)
     if order != .orderedSame { return order == .orderedAscending }
     if lhs.name != rhs.name { return lhs.name < rhs.name }

Sources/ConjureKit/LaunchHistory.swift

@@ -0,0 +1,55 @@
+import Foundation
+
+@MainActor
+public final class LaunchHistory {
+    private struct Usage {
+        var count: Int
+        var lastLaunch: Date
+    }
+
+    private static let storageKey = "applicationLaunchHistory"
+    private let defaults: UserDefaults
+    private let now: () -> Date
+    private var usage: [URL: Usage] = [:]
+
+    public init(defaults: UserDefaults = .standard, now: @escaping () -> Date = Date.init) {
+        self.defaults = defaults
+        self.now = now
+        for (identifier, value) in defaults.dictionary(forKey: Self.storageKey) ?? [:] {
+            guard let url = URL(string: identifier), url.isFileURL,
+                  let record = value as? [String: Any],
+                  let count = record["count"] as? Int, count > 0,
+                  let lastLaunch = record["lastLaunch"] as? Date,
+                  lastLaunch.timeIntervalSinceReferenceDate.isFinite else { continue }
+            usage[url] = Usage(count: count, lastLaunch: lastLaunch)
+        }
+    }
+
+    public func recordLaunch(of application: Application) {
+        let timestamp = now()
+        var record = usage[application.id] ?? Usage(count: 0, lastLaunch: timestamp)
+        if record.count < Int.max { record.count += 1 }
+        record.lastLaunch = timestamp
+        usage[application.id] = record
+        var saved: [String: [String: Any]] = [:]
+        saved.reserveCapacity(usage.count)
+        for (url, record) in usage {
+            saved[url.absoluteString] = ["count": record.count, "lastLaunch": record.lastLaunch]
+        }
+        defaults.set(saved, forKey: Self.storageKey)
+    }
+
+    public func suggestions(in applications: [Application]) -> [Application] {
+        applications.sorted { lhs, rhs in
+            let left = usage[lhs.id]
+            let right = usage[rhs.id]
+            let leftCount = left?.count ?? 0
+            let rightCount = right?.count ?? 0
+            if leftCount != rightCount { return leftCount > rightCount }
+            if let left, let right, left.lastLaunch != right.lastLaunch {
+                return left.lastLaunch > right.lastLaunch
+            }
+            return alphabetical(lhs, rhs)
+        }
+    }
+}