import SwiftUI
import SwiftData
import Cocoa
import Combine
import AVFoundation

@main
struct CapturaApp: App {
  
    @NSApplicationDelegateAdaptor(CapturaAppDelegate.self) var appDelegate

    var body: some Scene {
        WindowGroup {
          PreferencesScreen()
              .handlesExternalEvents(preferring: Set(arrayLiteral: "PreferencesScreen"), allowing: Set(arrayLiteral: "*"))
              .frame(width: 650, height: 450)
        }
        .handlesExternalEvents(matching: Set(arrayLiteral: "PreferencesScreen"))
        //.modelContainer(for: CapturaRemoteFile.self)
      }
}

class CapturaAppDelegate: NSObject, NSApplicationDelegate, NSMenuDelegate {
    
  @Environment(\.openURL) var openURL
  var statusItem: NSStatusItem!
  var captureState: CaptureState = .idle
  var recordingWindow: RecordingWindow? = nil
  var preferencesWindow: PreferencesWindow? = nil
  var boxListener: AnyCancellable? = nil
  var popover: NSPopover? = nil
  var helpShown = false
  var captureSession: CapturaCaptureSession? = nil
  var images: [CGImage] = []
  var outputFile: CapturaFile? = nil
  var gifCallbackTimer = ContinuousClock.now
  var pixelDensity: CGFloat = 1.0
  var stopTimer: DispatchWorkItem?
  var remoteFiles: [CapturaRemoteFile] = []
  var captureSessionConfiguration: CaptureSessionConfiguration = CaptureSessionConfiguration()
  
  @objc var scriptedPreferences: ScriptedPreferences?
  
  func applicationDidFinishLaunching(_ notification: Notification) {
    setupStatusBar()
    NotificationCenter.default.addObserver(
      self,
      selector: #selector(self.didReceiveNotification(_:)),
      name: nil,
      object: nil)
    closeWindow()
    fetchRemoteItems()
    
    scriptedPreferences = ScriptedPreferences()
  }
  
  // MARK: - Setup Functions
  
  
  private func setupStatusBar() {
    statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)
    
    if let button = statusItem.button {
      button.image = NSImage(systemSymbolName: "rectangle.dashed.badge.record", accessibilityDescription: "Captura")
    }
    
    statusItem.isVisible = true
    statusItem.menu = NSMenu()
    statusItem.menu?.delegate = self
    
    // Create the Popover
    popover = NSPopover()
    popover?.contentViewController = HelpPopoverViewController()
    popover?.behavior = .transient
    
    setupMenu()
  }
  
  private func setupMenu() {
    
    statusItem.menu?.removeAllItems()
    
    statusItem.menu?.addItem(NSMenuItem(title: "Record", action: #selector(CapturaAppDelegate.onClickStartRecording), keyEquivalent: ""))
    if (remoteFiles.count > 0) {
      statusItem.menu?.addItem(NSMenuItem.separator())
      for remoteFile in remoteFiles {
        let remoteFileItem = NSMenuItem(title: remoteFile.name, action: #selector(CapturaAppDelegate.onClickRemoteFile), keyEquivalent: "")
        remoteFileItem.representedObject = remoteFile
        statusItem.menu?.addItem(remoteFileItem)
      }
    }
    statusItem.menu?.addItem(NSMenuItem.separator())
    statusItem.menu?.addItem(NSMenuItem(title: "Open Local Folder", action: #selector(CapturaAppDelegate.onOpenFolder), keyEquivalent: ""))
    statusItem.menu?.addItem(NSMenuItem.separator())
    statusItem.menu?.addItem(NSMenuItem(title: "Preferences", action: #selector(CapturaAppDelegate.onOpenPreferences), keyEquivalent: ""))
    statusItem.menu?.addItem(NSMenuItem(title: "Quit", action: #selector(CapturaAppDelegate.onQuit), keyEquivalent: ""))
  }
  
  private func closeWindow() {
    if let window = NSApplication.shared.windows.first {
      window.close()
    }
  }
  
  // MARK: - URL Event Handler
  
  func application(_ application: NSApplication, open urls: [URL]) {
    if (CapturaSettings.shouldAllowURLAutomation) {
      for url in urls {
        if let action = CapturaURLDecoder.decodeParams(url: url) {
          switch action {
            case let .configure(config):
              CapturaSettings.apply(config)
            case let .record(config):
              let config = CaptureSessionConfiguration(from: config)
            NotificationCenter.default.post(name: .startAreaSelection, object: nil, userInfo: [
              "config": config
            ])
              NotificationCenter.default.post(name: .startAreaSelection, object: nil, userInfo: nil)
          }
        }
      }
    } else {
      let alert = NSAlert()
      alert.messageText = "URL Automation Prevented"
              alert.informativeText = "A website or application attempted to record your screen using URL Automation. If you want to allow this, enable it in Preferences."
              alert.alertStyle = .warning
              alert.addButton(withTitle: "OK")
              alert.runModal()
    }
  }
  
  // MARK: - UI Event Handlers
  
  func menuWillOpen(_ menu: NSMenu) {
    if captureState != .idle {
      menu.cancelTracking()
      if captureState == .recording {
        NotificationCenter.default.post(name: .stopRecording, object: nil, userInfo: nil)
      }
    }
  }
  
  @objc private func onClickStartRecording() {
    NotificationCenter.default.post(name: .startAreaSelection, object: nil, userInfo: nil)
  }
  
  @objc private func onOpenPreferences() {
    NSApp.activate(ignoringOtherApps: true)
    if preferencesWindow == nil {
      preferencesWindow =  PreferencesWindow()
    } else {
      preferencesWindow?.makeKeyAndOrderFront(nil)
      preferencesWindow?.orderFrontRegardless()
    }
  }
  
  @objc private func onOpenFolder() {
    if let directory = FileManager.default.urls(for: .picturesDirectory, in: .userDomainMask).first?.appendingPathComponent("captura") {
      NSWorkspace.shared.open(directory)
    }
  }
  
  @objc private func onClickRemoteFile(_ sender: NSMenuItem) {
    if let remoteFile = sender.representedObject as? CapturaRemoteFile {
      if let urlString = remoteFile.url {
        if let url = URL(string: urlString) {
          NSWorkspace.shared.open(url)
        }
      }
    }
  }
  
  @objc private func onQuit() {
    NSApplication.shared.terminate(self)
  }
  
  // MARK: - App State Event Listeners
  
  @objc func didReceiveNotification(_ notification: Notification) {
    switch(notification.name) {
    case .startAreaSelection:
      startAreaSelection()
    case .startRecording:
      startRecording()
    case .stopRecording:
      stopRecording()
    case .finalizeRecording:
      DispatchQueue.main.async {
        self.finalizeRecording()
      }
    case .reset:
      reset()
    case .failedToStart:
      DispatchQueue.main.async {
        self.failed(true)
      }
    case .failedtoUpload:
      DispatchQueue.main.async {
        self.failed()
      }
    case .receivedFrame:
      if let frame = notification.userInfo?["frame"] {
        receivedFrame(frame as! CVImageBuffer)
      }
    case .reloadConfiguration:
      reloadConfiguration()
    case .setCaptureSessionConfiguration:
      if let userInfo = notification.userInfo {
        if let config = userInfo["config"] as? RecordAction {
          setCaptureSessionConfiguration(config)
        }
      }
    case .NSManagedObjectContextObjectsDidChange:
      DispatchQueue.main.async {
        self.fetchRemoteItems()
        self.setupMenu()
      }
    default:
      return
    }
  }
  
  
  func startAreaSelection() {
    helpShown = false
    if captureState != .selectingArea {
      captureState = .selectingArea
      if let button = statusItem.button {
        let rectInWindow = button.convert(button.bounds, to: nil)
        let rectInScreen = button.window?.convertToScreen(rectInWindow)
        NSApp.activate(ignoringOtherApps: true)
        recordingWindow = RecordingWindow(captureSessionConfiguration, rectInScreen)
        recordingWindow?.makeKeyAndOrderFront(nil)
        recordingWindow?.orderFrontRegardless()
        boxListener = recordingWindow?.recordingContentView.$box
          .debounce(for: .seconds(0.3), scheduler: RunLoop.main)
          .sink { newValue in
            if newValue != nil {
              self.updateImage()
              if !self.helpShown {
                self.helpShown = true
                self.showPopoverWithMessage("Click here when you're ready to record.")
              }
            }
          }
      }
    }
  }
  
  func startRecording() {
    captureState = .recording
    updateImage()
    outputFile = nil
    images = [];
    pixelDensity = recordingWindow?.pixelDensity ?? 1.0
    recordingWindow?.recordingContentView.startRecording()
    if let box = recordingWindow?.recordingContentView.box {
      if let screen = recordingWindow?.screen {
        captureSession = CapturaCaptureSession(screen, box: box)
        
        if let captureSession {

          stopTimer = DispatchWorkItem {
            self.stopRecording()
          }
          DispatchQueue.main.asyncAfter(deadline: .now() + Double(captureSessionConfiguration.maxLength), execute: stopTimer!)
          
          outputFile = CapturaFile()
          if captureSessionConfiguration.shouldSaveMp4 {
            captureSession.startRecording(to: outputFile!.mp4URL)
          } else {
            captureSession.startRunning()
          }
          return
        }
      }
    }
    NotificationCenter.default.post(name: .failedToStart, object: nil, userInfo: nil)
  }
  
  func stopRecording() {
    captureState = .uploading
    updateImage()
    stop()
    
    Task.detached {
      if self.captureSessionConfiguration.shouldSaveGif {
        if let outputFile = self.outputFile {
          await GifRenderer.render(self.images, at: self.captureSessionConfiguration.frameRate, to: outputFile.gifURL)
        }
      }
      let wasSuccessful = await self.uploadOrCopy()
      if wasSuccessful {
        NotificationCenter.default.post(name: .finalizeRecording, object: nil, userInfo: nil)
      } else {
        NotificationCenter.default.post(name: .failedtoUpload, object: nil, userInfo: nil)
      }
    }
  }
  
  func finalizeRecording() {
    captureState = .uploaded
    updateImage()
    DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
      NotificationCenter.default.post(name: .reset, object: nil, userInfo: nil)
    }
  }
  
  func reset() {
    captureState = .idle
    updateImage()
    captureSessionConfiguration = CaptureSessionConfiguration()
    stop()
  }
  
  func receivedFrame(_ frame: CVImageBuffer) {
    let now = ContinuousClock.now
    
    if now - gifCallbackTimer > .nanoseconds(1_000_000_000 / UInt64(captureSessionConfiguration.frameRate)) {
      gifCallbackTimer = now
      DispatchQueue.main.async {
        if let cgImage = frame.cgImage?.resize(by: self.pixelDensity) {
          self.images.append(cgImage)
        }
      }
    }
  }
  
  func failed(_ requestPermission: Bool = false) {
    captureState = .error
    updateImage()
    if requestPermission {
      requestPermissionToRecord()
    }
    stop()
    DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
      NotificationCenter.default.post(name: .reset, object: nil, userInfo: nil)
    }
  }
  
  func reloadConfiguration() {
    self.captureSessionConfiguration = CaptureSessionConfiguration()
  }
  
  func setCaptureSessionConfiguration(_ config: RecordAction) {
    self.captureSessionConfiguration = CaptureSessionConfiguration(from: config)
  }
  
  // MARK: - CoreData
  
  private func fetchRemoteItems() {
    let viewContext = PersistenceController.shared.container.viewContext
    let fetchRequest = NSFetchRequest<CapturaRemoteFile>(entityName: "CapturaRemoteFile")
    fetchRequest.fetchLimit = 5
    fetchRequest.sortDescriptors = [NSSortDescriptor(key: "timestamp", ascending: false)]
    
    let results = try? viewContext.fetch(fetchRequest)
    remoteFiles = results ?? []
  }
  
  // MARK: - Presentation Helpers
  
  
  private func requestPermissionToRecord() {
    showPopoverWithMessage("Please grant Captura permission to record")
    if let url = URL(string: "x-apple.systempreferences:com.apple.preference.security?Privacy_ScreenRecording") {
      NSWorkspace.shared.open(url)
    }
  }
  
  private func showPopoverWithMessage(_ message: String) {
    if let button = statusItem.button {
      (self.popover?.contentViewController as? HelpPopoverViewController)?.updateLabel(message)
      self.popover?.show(relativeTo: button.bounds, of: button, preferredEdge: NSRectEdge.minY)
      DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
        self.popover?.performClose(nil)
      }
    }
  }
  
  private func updateImage() {
    if let button = statusItem.button {
      let image: String = switch captureState {
      case .idle:
        "rectangle.dashed.badge.record"
      case .selectingArea:
        "circle.rectangle.dashed"
      case .recording:
        "checkmark.rectangle"
      case .uploading:
        "dock.arrow.up.rectangle"
      case .uploaded:
        "checkmark.rectangle.fill"
      case .error:
        "xmark.rectangle.fill"
      }
      button.image = NSImage(systemSymbolName: image, accessibilityDescription: "Captura")
    }
  }
  
  private func stop() {
    stopTimer?.cancel()
    captureSession?.stopRunning()
    captureSession = nil
    boxListener?.cancel()
    recordingWindow?.close()
    recordingWindow = nil
  }
  
  private func uploadOrCopy() async -> Bool {
    if captureSessionConfiguration.shouldUseBackend {
      let result = await uploadToBackend()
      if result && !captureSessionConfiguration.shouldKeepLocalFiles {
        deleteLocalFiles()
      }
      return result
    } else {
      copyLocalToClipboard()
      return true
    }
  }
  
  private func copyLocalToClipboard() {
    let fileType: NSPasteboard.PasteboardType = .init(rawValue: captureSessionConfiguration.shouldSaveGif ? "com.compuserve.gif" : "public.mpeg-4")
    if let url = captureSessionConfiguration.shouldSaveGif ? outputFile?.gifURL : outputFile?.mp4URL {
      if let data = try? Data(contentsOf: url) {
        let pasteboard = NSPasteboard.general
        pasteboard.declareTypes([fileType], owner: nil)
        pasteboard.setData(data, forType: fileType)
      }
    }
  }
  
  private func uploadToBackend() async -> Bool {
    let contentType = captureSessionConfiguration.shouldUploadGif ? "image/gif" : "video/mp4"
    if let url = captureSessionConfiguration.shouldUploadGif ? outputFile?.gifURL : outputFile?.mp4URL {
      if let data = try? Data(contentsOf: url) {
        if let remoteUrl = captureSessionConfiguration.backend {
          var request = URLRequest(url: remoteUrl)
          request.httpMethod = "POST"
          request.httpBody = data
          request.setValue(contentType, forHTTPHeaderField: "Content-Type")
          request.setValue("Captura/1.0", forHTTPHeaderField: "User-Agent")
          
          do {
            let (data, response) = try await URLSession.shared.data(for: request)
            
            if let httpResponse = response as? HTTPURLResponse {
              if httpResponse.statusCode == 201 {
                let answer = try JSONDecoder().decode(BackendResponse.self, from: data)
                createRemoteFile(answer.url)
                return true
              }
            }
          } catch {}
        }
      }
    }
    return false
  }
  
  private func createRemoteFile(_ url: URL) {
    let viewContext = PersistenceController.shared.container.viewContext
    let remoteFile = CapturaRemoteFile(context: viewContext)
    remoteFile.url = url.absoluteString
    remoteFile.timestamp = Date()
    try? viewContext.save()
    let pasteboard = NSPasteboard.general
    pasteboard.declareTypes([.URL], owner: nil)
    pasteboard.setString(url.absoluteString, forType: .string)
  }
  
  private func deleteLocalFiles() {
    if captureSessionConfiguration.shouldSaveGif {
      if let url = outputFile?.gifURL {
          try? FileManager.default.removeItem(at: url)
      }
    }
    if captureSessionConfiguration.shouldSaveMp4 {
      if let url = outputFile?.mp4URL {
        try? FileManager.default.removeItem(at: url)
      }
    }
  }
}