✨ Watch calendar for changes

Author: oschrenk

Sources/Cli/Watch.swift

@@ -0,0 +1,29 @@
+import ArgumentParser
+import Foundation
+
+/// `plan watch`
+///
+/// Watch for calendar changes
+struct Watch: ParsableCommand {
+  static var configuration = CommandConfiguration(
+    abstract: "Watch for changes",
+    shouldDisplay: false
+  )
+
+  mutating func run() {
+    let home = FileManager.default.homeDirectoryForCurrentUser
+    let dir = home.path + "/Library/Calendars"
+    let files = [
+      dir + "/Calendar.sqlitedb",
+      dir + "/Calendar.sqlitedb-wal",
+      dir + "/Extras.db",
+      dir + "/Extras.db-shm",
+      dir + "/Extras.db-wal",
+    ]
+    let sketchybar = Sketchybar(event: "calendar_changed")
+    let watcher = FileWatcher(paths: files, callback: sketchybar.trigger)
+    watcher.start()
+
+    dispatchMain()
+  }
+}

Sources/IO/FileWatcher.swift

@@ -0,0 +1,74 @@
+import Foundation
+
+class FileWatcher {
+  private let minSeconds = 2
+  private var lastChange = Int(Date().timeIntervalSince1970)
+
+  private var sources: [Int32: DispatchSourceFileSystemObject] = [:]
+  private let queue = DispatchQueue.global()
+
+  private let paths: [String]
+  private let callback: () -> Void
+
+  init(paths: [String], callback: @escaping () -> Void) {
+    self.paths = paths
+    self.callback = callback
+  }
+
+  func start() {
+    for path in paths {
+      let isMonitoring = monitorFile(path: path)
+      if !isMonitoring {
+        StdErr.print("Not monitoring \(path)")
+      }
+    }
+  }
+
+  private func monitorFile(path: String) -> Bool {
+    let fileDescriptor = open(path, O_EVTONLY)
+    guard fileDescriptor != -1 else { return false }
+
+    let source = DispatchSource.makeFileSystemObjectSource(fileDescriptor: fileDescriptor, eventMask: [.write, .delete, .rename, .extend, .attrib], queue: queue)
+
+    source.setEventHandler { [weak self] in
+      guard let self = self else { return }
+      let event = source.data
+
+      if event.contains(.delete) || event.contains(.rename) {
+        self.stopMonitoring(fileDescriptor)
+      } else if event.contains(.write) || event.contains(.extend) || event.contains(.attrib) {
+        self.handleWriteEvent(at: path)
+      }
+    }
+
+    source.setCancelHandler {
+      close(fileDescriptor)
+    }
+
+    source.resume()
+    sources[fileDescriptor] = source
+
+    return true
+  }
+
+  private func stopMonitoring(_ fd: Int32) {
+    sources[fd]?.cancel()
+    sources.removeValue(forKey: fd)
+  }
+
+  private func handleWriteEvent(at _: String) {
+    let now = Int(Date().timeIntervalSince1970)
+    if now - lastChange < minSeconds {
+    } else {
+      lastChange = now
+      callback()
+    }
+  }
+
+  deinit {
+    for (fd, source) in sources {
+      source.cancel()
+      close(fd)
+    }
+  }
+}

Sources/IO/Sketchybar.swift

@@ -0,0 +1,23 @@
+import Foundation
+
+class Sketchybar {
+  private let event: String
+
+  init(event: String) {
+    self.event = event
+  }
+
+  func trigger() {
+    let task = Process()
+    task.executableURL = URL(fileURLWithPath: "/opt/homebrew/bin/sketchybar")
+    task.arguments = ["--trigger", event]
+
+    do {
+      try task.run()
+      task.waitUntilExit()
+      print("Fired sketchybar event \(event)")
+    } catch {
+      print("Failed to execute command: \(error)")
+    }
+  }
+}

Sources/Plan.swift

@@ -12,6 +12,7 @@ struct Plan: ParsableCommand {
       Next.self,
       Today.self,
       Usage.self,
+      Watch.self,
     ],
     defaultSubcommand: Usage.self
   )