import AppKit
import Environment
import FileChangeChecker
import LaunchAgentManager
import Logger
import Preferences
import PythonHelper
import Service
import ServiceManagement
import ServiceUpdateMigration
import SwiftUI
import UpdateChecker
import UserDefaultsObserver
import UserNotifications
import XcodeInspector

let bundleIdentifierBase = Bundle.main
    .object(forInfoDictionaryKey: "BUNDLE_IDENTIFIER_BASE") as! String
let serviceIdentifier = bundleIdentifierBase + ".ExtensionService"

@main
class AppDelegate: NSObject, NSApplicationDelegate, NSWindowDelegate {
    let scheduledCleaner = ScheduledCleaner()
    private var statusBarItem: NSStatusItem!
    private var xpcListener: (NSXPCListener, ServiceDelegate)?
    private let updateChecker =
        UpdateChecker(
            hostBundle: locateHostBundleURL(url: Bundle.main.bundleURL)
                .flatMap(Bundle.init(url:))
        )

    func applicationDidFinishLaunching(_: Notification) {
        if ProcessInfo.processInfo.environment["IS_UNIT_TEST"] == "YES" { return }
        _ = GraphicalUserInterfaceController.shared
        _ = RealtimeSuggestionController.shared
        _ = XcodeInspector.shared
        AXIsProcessTrustedWithOptions([
            kAXTrustedCheckOptionPrompt.takeRetainedValue() as NSString: true,
        ] as CFDictionary)
        setupQuitOnUpdate()
        setupQuitOnUserTerminated()
        xpcListener = setupXPCListener()
        Logger.service.info("XPC Service started.")
        NSApp.setActivationPolicy(.accessory)
        buildStatusBarMenu()
        DependencyUpdater().update()
        
        Task {
            do {
                try await ServiceUpdateMigrator().migrate()
                await initializePython()
            } catch {
                Logger.service.error(error.localizedDescription)
            }
        }
    }

    @objc private func buildStatusBarMenu() {
        let statusBar = NSStatusBar.system
        statusBarItem = statusBar.statusItem(
            withLength: NSStatusItem.squareLength
        )
        statusBarItem.button?.image = NSImage(named: "MenuBarIcon")

        let statusBarMenu = NSMenu(title: "Status Bar Menu")
        statusBarItem.menu = statusBarMenu

        let hostAppName = Bundle.main.object(forInfoDictionaryKey: "HOST_APP_NAME") as? String
            ?? "Copilot for Xcode"

        let copilotName = NSMenuItem(
            title: hostAppName,
            action: nil,
            keyEquivalent: ""
        )

        let checkForUpdate = NSMenuItem(
            title: "Check for Updates",
            action: #selector(checkForUpdate),
            keyEquivalent: ""
        )

        let openCopilotForXcode = NSMenuItem(
            title: "Open \(hostAppName)",
            action: #selector(openCopilotForXcode),
            keyEquivalent: ""
        )

        let openGlobalChat = NSMenuItem(
            title: "Open Chat",
            action: #selector(openGlobalChat),
            keyEquivalent: ""
        )

        let quitItem = NSMenuItem(
            title: "Quit",
            action: #selector(quit),
            keyEquivalent: ""
        )
        quitItem.target = self

        statusBarMenu.addItem(copilotName)
        statusBarMenu.addItem(openCopilotForXcode)
        statusBarMenu.addItem(checkForUpdate)
        statusBarMenu.addItem(.separator())
        statusBarMenu.addItem(openGlobalChat)
        statusBarMenu.addItem(.separator())
        statusBarMenu.addItem(quitItem)
    }

    @objc func quit() {
        Task { @MainActor in
            await scheduledCleaner.closeAllChildProcesses()
            exit(0)
        }
    }

    @objc func openCopilotForXcode() {
        let task = Process()
        if let appPath = locateHostBundleURL(url: Bundle.main.bundleURL)?.absoluteString {
            task.launchPath = "/usr/bin/open"
            task.arguments = [appPath]
            task.launch()
            task.waitUntilExit()
        }
    }

    @objc func openGlobalChat() {
        Task { @MainActor in
            let serviceGUI = GraphicalUserInterfaceController.shared
            serviceGUI.openGlobalChat()
        }
    }

    func setupQuitOnUpdate() {
        Task {
            guard let url = Bundle.main.executableURL else { return }
            let checker = await FileChangeChecker(fileURL: url)

            // If Xcode or Copilot for Xcode is made active, check if the executable of this program
            // is changed. If changed, quit this program.

            let sequence = NSWorkspace.shared.notificationCenter
                .notifications(named: NSWorkspace.didActivateApplicationNotification)
            for await notification in sequence {
                try Task.checkCancellation()
                guard let app = notification
                    .userInfo?[NSWorkspace.applicationUserInfoKey] as? NSRunningApplication,
                    app.isUserOfService
                else { continue }
                guard await checker.checkIfChanged() else {
                    Logger.service.info("Extension Service is not updated, no need to quit.")
                    continue
                }
                Logger.service.info("Extension Service will quit.")
                #if DEBUG
                #else
                quit()
                #endif
            }
        }
    }

    func setupQuitOnUserTerminated() {
        Task {
            // Whenever Xcode or the host application quits, check if any of the two is running.
            // If none, quit the XPC service.

            let sequence = NSWorkspace.shared.notificationCenter
                .notifications(named: NSWorkspace.didTerminateApplicationNotification)
            for await notification in sequence {
                try Task.checkCancellation()
                guard UserDefaults.shared.value(for: \.quitXPCServiceOnXcodeAndAppQuit)
                else { continue }
                guard let app = notification
                    .userInfo?[NSWorkspace.applicationUserInfoKey] as? NSRunningApplication,
                    app.isUserOfService
                else { continue }
                if NSWorkspace.shared.runningApplications.contains(where: \.isUserOfService) {
                    continue
                }
                quit()
            }
        }
    }

    func setupXPCListener() -> (NSXPCListener, ServiceDelegate) {
        let listener = NSXPCListener(machServiceName: serviceIdentifier)
        let delegate = ServiceDelegate()
        listener.delegate = delegate
        listener.resume()
        return (listener, delegate)
    }

    func requestAccessoryAPIPermission() {
        AXIsProcessTrustedWithOptions([
            kAXTrustedCheckOptionPrompt.takeRetainedValue() as NSString: true,
        ] as NSDictionary)
    }

    @objc func checkForUpdate() {
        updateChecker.checkForUpdates()
    }
}

extension NSRunningApplication {
    var isUserOfService: Bool {
        [
            "com.apple.dt.Xcode",
            bundleIdentifierBase,
        ].contains(bundleIdentifier)
    }
}

func locateHostBundleURL(url: URL) -> URL? {
    var nextURL = url
    while nextURL.path != "/" {
        nextURL = nextURL.deletingLastPathComponent()
        if nextURL.lastPathComponent.hasSuffix(".app") {
            return nextURL
        }
    }
    let devAppURL = url
        .deletingLastPathComponent()
        .appendingPathComponent("Copilot for Xcode Dev.app")
    return devAppURL
}