//
//  SceneDelegate.swift
//  Note
//
//  Created by fish on 2026/7/12.
//

import UIKit

class SceneDelegate: UIResponder, UIWindowSceneDelegate {

    var window: UIWindow?


    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
        guard let windowScene = (scene as? UIWindowScene) else { return }

        window = UIWindow(windowScene: windowScene)
        let rootViewController = ViewController()
        let navigationController = UINavigationController(rootViewController: rootViewController)
        window?.rootViewController = navigationController
        window?.makeKeyAndVisible()

        if let url = connectionOptions.urlContexts.first?.url {
            handleSharedFile(url)
        }
    }

    func sceneDidDisconnect(_ scene: UIScene) {
        // Called as the scene is being released by the system.
        // This occurs shortly after the scene enters the background, or when its session is discarded.
        // Release any resources associated with this scene that can be re-created the next time the scene connects.
        // The scene may re-connect later, as its session was not necessarily discarded (see `application:didDiscardSceneSessions` instead).
    }

    func sceneDidBecomeActive(_ scene: UIScene) {
        // Called when the scene has moved from an inactive state to an active state.
        // Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
    }

    func sceneWillResignActive(_ scene: UIScene) {
        // Called when the scene will move from an active state to an inactive state.
        // This may occur due to temporary interruptions (ex. an incoming phone call).
    }

    func sceneWillEnterForeground(_ scene: UIScene) {
        // Called as the scene transitions from the background to the foreground.
        // Use this method to undo the changes made on entering the background.
    }

    func sceneDidEnterBackground(_ scene: UIScene) {
        // Called as the scene transitions from the foreground to the background.
        // Use this method to save data, release shared resources, and store enough scene-specific state information
        // to restore the scene back to its current state.
    }

    func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
        guard let url = URLContexts.first?.url else { return }
        handleSharedFile(url)
    }

    private func handleSharedFile(_ url: URL) {
        guard let navigationController = window?.rootViewController as? UINavigationController else {
            return
        }

        if url.scheme == "noteapp", url.host == "share" {
            handleShareURL(url, navigationController: navigationController)
            return
        }

        guard url.isFileURL else { return }

        let shouldStopAccessing = url.startAccessingSecurityScopedResource()
        defer {
            if shouldStopAccessing {
                url.stopAccessingSecurityScopedResource()
            }
        }

        do {
            let content = try String(contentsOf: url, encoding: .utf8)
            DispatchQueue.main.async {
                let viewController = PreviewViewController()
                viewController.initialText = content
                viewController.fileName = url.lastPathComponent
                viewController.title = url.lastPathComponent
                navigationController.pushViewController(viewController, animated: true)
            }
        } catch {
            print("Failed to read shared file: \(error)")
        }
    }

    private func handleShareURL(_ url: URL, navigationController: UINavigationController) {
        guard let components = URLComponents(url: url, resolvingAgainstBaseURL: false),
              let queryItems = components.queryItems else { return }

        let fileManager = FileManager.default
        let containerURL = fileManager.containerURL(forSecurityApplicationGroupIdentifier: "group.com.fishestlife.note")
        let sharedDir = containerURL?.appendingPathComponent("SharedFiles", isDirectory: true)

        var contents: [(text: String, fileName: String)] = []

        for item in queryItems {
            if item.name.hasPrefix("text"), let text = item.value, !text.isEmpty {
                contents.append((text: text, fileName: "shared.md"))
            } else if item.name.hasPrefix("file"), let fileName = item.value, !fileName.isEmpty {
                if let sharedDir = sharedDir {
                    let fileURL = sharedDir.appendingPathComponent(fileName)
                    if let text = try? String(contentsOf: fileURL, encoding: .utf8) {
                        contents.append((text: text, fileName: fileName))
                    }
                }
            }
        }

        guard let first = contents.first else { return }

        DispatchQueue.main.async {
            let viewController = PreviewViewController()
            viewController.initialText = first.text
            viewController.fileName = first.fileName
            viewController.title = first.fileName
            navigationController.pushViewController(viewController, animated: true)
        }
    }


}