ScanView.swift

//
//  ScanView.swift
//  NativeAppTemplate
//

import CoreNFC
import SwiftUI

enum ScanType: String {
    case completeScan
    case test

    var displayString: String {
        switch self {
        case .completeScan:
            "Complete Scan"
        case .test:
            "Test"
        }
    }
}

// MARK: - CaseIterable

extension ScanType: CaseIterable {
    var index: Self.AllCases.Index {
        get {
            Self.allCases.firstIndex(of: self)!
        }
        set {
            self = Self.allCases[newValue]
        }
    }

    var count: Int {
        Self.allCases.count
    }
}

// MARK: - Identifiable

extension ScanType: Identifiable {
    var id: Self {
        self
    }
}

struct ScanView: View {
    @Environment(\.sessionController) private var sessionController: SessionControllerProtocol
    @StateObject private var nfcManager = appSingletons.nfcManager
    @State private var viewModel: ScanViewModel

    init(viewModel: ScanViewModel) {
        _viewModel = State(initialValue: viewModel)
    }

    var body: some View {
        contentView
            .onChange(of: sessionController.didBackgroundTagReading) {
                viewModel.handleBackgroundTagReading()
            }
    }
}

// MARK: - private

private extension ScanView {
    var contentView: some View {
        @ViewBuilder var contentView: some View {
            if viewModel.isBusy {
                LoadingView()
            } else {
                scanView
                    .onChange(of: nfcManager.isScanResultChanged) {
                        viewModel.handleScanResultChanged()
                    }
                    .onChange(of: nfcManager.isScanResultChangedForTesting) {
                        viewModel.handleScanResultChangedForTesting()
                    }
            }
        }

        return contentView
    }

    var scanView: some View {
        ScrollView {
            VStack(spacing: NativeAppTemplateConstants.Spacing.xxl) {
                switch viewModel.scanType {
                case .completeScan:
                    if !viewModel.isShowingResetConfirmationDialog {
                        GroupBox(label: Label(String.completeScan, systemImage: "flag.checkered")) {
                            MainButtonView(title: String.scan, type: .coloredPrimary(withArrow: false)) {
                                viewModel.startCompleteScan()
                            }
                            .padding()

                            Text(String.completeScanHelp)
                                .font(.uiFootnote)
                                .foregroundStyle(.contentText)
                        }
                        .foregroundStyle(.accent)
                        .backgroundStyle(.ultraThinMaterial)
                    }

                    CompleteScanResultView(
                        completeScanResult: sessionController.completeScanResult
                    )
                case .test:
                    GroupBox(label: Label(String.showTagInfoScan, systemImage: "info.circle")) {
                        MainButtonView(title: String.scan, type: .coloredSecondary(withArrow: false)) {
                            viewModel.startTestScan()
                        }
                        .padding()

                        Text(String.showTagInfoScanHelp)
                            .font(.uiFootnote)
                            .foregroundStyle(.contentText)
                    }
                    .foregroundStyle(.contentText)
                    .backgroundStyle(.ultraThinMaterial)

                    ShowTagInfoScanResultView(
                        showTagInfoScanResult: sessionController.showTagInfoScanResult
                    )
                }

                Spacer()
            }
        }
        .toolbar {
            ToolbarItem(placement: .principal) {
                Picker(String("ScanType"), selection: $viewModel.scanType) {
                    Text(String.completeScan).tag(ScanType.completeScan)
                    Text(String.showTagInfoScan).tag(ScanType.test)
                }
                .pickerStyle(SegmentedPickerStyle())
            }
        }
        .padding()
        .alert(
            String.itemTagAlreadyCompleted,
            isPresented: $viewModel.isShowingResetConfirmationDialog
        ) {
            Button(String.reset, role: .destructive) {
                viewModel.resetTag()
            }
            Button(String.cancel, role: .cancel) {
                viewModel.dismissResetConfirmationDialog()
            }
        } message: {
            Text(String.areYouSure)
        }
        .accessibility(identifier: "scanView")
        .scrollContentBackground(.hidden)
    }
}