//
//  ScanVC.swift
//  QuickLocation
//
//  Created by 八条 on 2026/6/2.
//

import UIKit
import AVFoundation
import RxSwift

class ScanVC: BaseViewController {

    override var isNavigationBarHidden: Bool { true }

    fileprivate var rootView: ScanView!

    override func loadView() {
        rootView = ScanView(frame: UIScreen.main.bounds)
        view = rootView
    }

    private var captureSession: AVCaptureSession!
    private var previewLayer: AVCaptureVideoPreviewLayer!
    private var isScanning = false

    override func viewDidLoad() {
        super.viewDidLoad()
        setupCamera()
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        previewLayer?.frame = view.bounds
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        if let session = captureSession, !session.isRunning {
            DispatchQueue.global(qos: .background).async {
                session.startRunning()
            }
        }
        startScanAnimation()
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        if let session = captureSession, session.isRunning {
            session.stopRunning()
        }
        rootView.scanLineView.layer.removeAllAnimations()
    }

    private func handleScanResult(text: String) {
        guard !isScanning else { return }
        isScanning = true
        captureSession.stopRunning()
        rootView.scanLineView.alpha = 0
        rootView.scanLineView.layer.removeAllAnimations()
        requestOperateGroup(code: text)
    }
    
    // MARK: - API
    private func requestOperateGroup(code: String) {
        DLToast.showLoading()
        GroupService.operate(opType: "join", requestData: ["share_code" : code]).subscribe(onNext: { response in
            
        }, onError: { [weak self] (error) in
            DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
                self?.isScanning = false
                self?.startSession()
            }
        }).disposed(by: disposeBag)
    }
    
    private func startSession() {
        if let session = captureSession, !session.isRunning {
            DispatchQueue.global(qos: .background).async {
                session.startRunning()
            }
        }
        startScanAnimation()
    }

    // MARK: - 扫描线动画
    private func startScanAnimation() {
        rootView.scanLineView.layer.removeAllAnimations()
        rootView.scanLineView.alpha = 1
        rootView.scanLineView.frame.origin.y = 0

        let boxH = rootView.scanBoxView.bounds.height
        guard boxH > 0 else {
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) { [weak self] in
                self?.startScanAnimation()
            }
            return
        }

        UIView.animate(withDuration: 2.0, delay: 0, options: [.repeat, .curveLinear]) {
            self.rootView.scanLineView.frame.origin.y = boxH - 2
        }
    }

    // MARK: - 相机配置
    private func setupCamera() {
        let status = AVCaptureDevice.authorizationStatus(for: .video)
        switch status {
        case .authorized:
            break
        case .notDetermined:
            AVCaptureDevice.requestAccess(for: .video) { [weak self] granted in
                DispatchQueue.main.async {
                    if granted { self?.setupCamera() }
                }
            }
            return
        default:
            DLToast.show(text: "请在设置中开启相机权限")
            return
        }

        captureSession = AVCaptureSession()
        captureSession.sessionPreset = .high

        guard let videoDevice = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back) else {
            DLToast.show(text: "未检测到摄像头")
            return
        }

        do {
            let input = try AVCaptureDeviceInput(device: videoDevice)
            if captureSession.canAddInput(input) {
                captureSession.addInput(input)
            }

            let output = AVCaptureMetadataOutput()
            if captureSession.canAddOutput(output) {
                captureSession.addOutput(output)
                output.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
                output.metadataObjectTypes = [.qr, .code128, .ean13, .ean8, .upce, .code39, .code39Mod43]
            }

            previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
            previewLayer.frame = view.bounds
            previewLayer.videoGravity = .resizeAspectFill
            view.layer.insertSublayer(previewLayer, at: 0)

            DispatchQueue.global(qos: .background).async {
                self.captureSession.startRunning()
            }

        } catch {
            DLToast.show(text: "相机初始化失败：\(error.localizedDescription)")
        }
    }
}

// MARK: - AVCaptureMetadataOutputObjectsDelegate
extension ScanVC: AVCaptureMetadataOutputObjectsDelegate {
    func metadataOutput(_ output: AVCaptureMetadataOutput,
                        didOutput metadataObjects: [AVMetadataObject],
                        from connection: AVCaptureConnection) {
        guard let obj = metadataObjects.first as? AVMetadataMachineReadableCodeObject,
              let result = obj.stringValue else { return }
        handleScanResult(text: result)
    }
}