//
//  ScanVC.swift
//  QuickLocation
//

import UIKit
import AVFoundation
import RxSwift

class ScanVC: BaseViewController {

    override var isNavigationBarHidden: Bool { true }
    override var preferredStatusBarStyle: UIStatusBarStyle { .lightContent }

    private var rootView: CameraCaptureView!
    private let scanDoneAction: ((String) -> Void)?
    private var isHandling = false

    override func loadView() {
        rootView = CameraCaptureView(mode: .scan)
        view = rootView
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        rootView.onClose = { [weak self] in
            self?.closeCapture()
        }
        rootView.onScan = { [weak self] text in
            self?.handleScanResult(text: text)
        }
        rootView.onOpenAlbum = { [weak self] in
            self?.openAlbum()
        }
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        isHandling = false
        rootView.startSession()
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        rootView.stopSession()
    }

    init(scanDoneAction: ((String) -> Void)? = nil) {
        self.scanDoneAction = scanDoneAction
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private func closeCapture() {
        if presentingViewController != nil {
            dismiss(animated: true)
        } else {
            navigationController?.popViewController(animated: true)
        }
    }

    private func handleScanResult(text: String) {
        guard !isHandling else { return }
        isHandling = true
        rootView.stopSession()
        if let scanDoneAction {
            scanDoneAction(text)
            closeCapture()
            return
        }
        requestJoinGroup(code: text)
    }

    private func requestJoinGroup(code: String) {
        DLToast.showLoading()
        GroupService.operate(opType: "join", requestData: ["share_code": code]).subscribe(onNext: { response in
            DLToast.showSuccess(text: response.message ?? "申请成功") {
                AppRouter.shared.popOrDismiss()
            }
        }, onError: { [weak self] _ in
            DLToast.showError(text: "无法识别该二维码")
            DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) {
                self?.isHandling = false
                self?.rootView.startSession()
            }
        }).disposed(by: disposeBag)
    }

    private func openAlbum() {
        guard UIImagePickerController.isSourceTypeAvailable(.photoLibrary) else { return }
        let picker = UIImagePickerController()
        picker.sourceType = .photoLibrary
        picker.delegate = self
        present(picker, animated: true)
    }

    private func decodeQR(from image: UIImage) {
        guard let ciImage = CIImage(image: image) else {
            DLToast.show(text: "无法识别二维码")
            isHandling = false
            return
        }
        let detector = CIDetector(ofType: CIDetectorTypeQRCode, context: nil, options: [CIDetectorAccuracy: CIDetectorAccuracyHigh])
        let features = detector?.features(in: ciImage) ?? []
        if let qr = features.first as? CIQRCodeFeature, let text = qr.messageString, !text.isEmpty {
            handleScanResult(text: text)
        } else {
            DLToast.show(text: "未识别到二维码")
            isHandling = false
        }
    }
}

extension ScanVC: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        picker.dismiss(animated: true)
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
        picker.dismiss(animated: true)
        if let image = info[.originalImage] as? UIImage {
            decodeQR(from: image)
        }
    }
}