import SwiftUI

struct LoginRootView: View {
    @ObservedObject var model: AppViewModel

    #if !os(macOS)
    @State private var isNFCSheetPresented = false
    #endif

    var body: some View {
        #if os(macOS)
        MacPairingView(model: model)
        #else
        NavigationStack {
            ZStack(alignment: .top) {
                LiveQRScannerView { payload in
                    model.manualPairingPayload = payload
                    Task {
                        await model.signIn(with: payload, transport: .qr)
                    }
                }
                .ignoresSafeArea()

                VStack(spacing: 0) {
                    IdPGlassCapsule {
                        VStack(alignment: .leading, spacing: 6) {
                            Text("Scan a pairing code")
                                .font(.headline)

                            Text("Turn this iPhone into your idp.global passport with QR or NFC.")
                                .font(.subheadline)
                                .foregroundStyle(.secondary)
                        }
                        .frame(maxWidth: .infinity, alignment: .leading)
                    }
                    .padding(.horizontal, 16)
                    .padding(.top, 12)

                    Spacer()

                    Button {
                        isNFCSheetPresented = true
                    } label: {
                        IdPGlassCapsule {
                            HStack(spacing: 10) {
                                Image(systemName: "wave.3.right")
                                    .foregroundStyle(IdP.tint)
                                Text("Hold near NFC tag")
                                    .font(.headline)
                                    .foregroundStyle(.primary)
                            }
                        }
                    }
                    .buttonStyle(.plain)
                    .padding(.horizontal, 16)
                    .padding(.bottom, 24)
                }
            }
            .toolbar {
                ToolbarItem(placement: .topBarTrailing) {
                    Button("Use demo payload") {
                        Task {
                            await model.signInWithSuggestedPayload()
                        }
                    }
                    .font(.footnote)
                    .disabled(model.isAuthenticating || model.suggestedPairingPayload.isEmpty)
                }
            }
        }
        .sheet(isPresented: $isNFCSheetPresented) {
            NFCSheet(actionTitle: "Approve") { request in
                await model.signIn(with: request)
            }
        }
        #endif
    }
}

#if os(macOS)
private struct MacPairingView: View {
    @ObservedObject var model: AppViewModel

    var body: some View {
        VStack(alignment: .leading, spacing: 18) {
            HStack(spacing: 12) {
                Image(systemName: "shield.lefthalf.filled")
                    .font(.title2)
                    .foregroundStyle(IdP.tint)

                VStack(alignment: .leading, spacing: 2) {
                    Text("Set up idp.global")
                        .font(.headline)
                    Text("Use the demo payload or paste a pairing link.")
                        .font(.subheadline)
                        .foregroundStyle(.secondary)
                }
            }

            TextEditor(text: $model.manualPairingPayload)
                .font(.footnote.monospaced())
                .scrollContentBackground(.hidden)
                .frame(minHeight: 140)
                .padding(10)
                .background(Color.idpSecondaryGroupedBackground, in: RoundedRectangle(cornerRadius: IdP.cardRadius, style: .continuous))

            VStack(spacing: 10) {
                Button("Use demo payload") {
                    Task {
                        await model.signInWithSuggestedPayload()
                    }
                }
                .buttonStyle(PrimaryActionStyle())

                Button("Link with payload") {
                    Task {
                        await model.signInWithManualPayload()
                    }
                }
                .buttonStyle(SecondaryActionStyle())
            }
        }
        .padding(20)
    }
}
#endif