import SwiftUI

struct ConnectView: View {
    @StateObject private var vm = ConnectViewModel()
    @State private var navigateToDashboard = false
    @State private var showPassword = false
    @FocusState private var focused: ConnectField?

    var body: some View {
        NavigationStack {
            ZStack {
                AppTheme.background.ignoresSafeArea()

                ScrollView {
                    VStack(spacing: 0) {

                        // ── Header — identical treatment to BackupView ──
                        VStack(spacing: 10) {
                            Text("kisani.")
                                .font(.system(size: 11, weight: .medium, design: .monospaced))
                                .foregroundStyle(AppTheme.ink)
                                .kerning(2)
                                .padding(.top, 52)

                            KisaniLogoMark(size: 66)

                            UGreenCompatibilityBadge(selectedProtocol: vm.selectedProtocol)
                                .padding(.top, 4)
                        }
                        .frame(maxWidth: .infinity)
                        .padding(.bottom, 28)

                        // ── Protocol picker ──
                        HStack(spacing: 0) {
                            ForEach(NASProtocol.allCases, id: \.self) { proto in
                                Button {
                                    withAnimation(.spring(response: 0.25, dampingFraction: 0.8)) {
                                        vm.selectedProtocol = proto
                                        vm.isConnected = false
                                        vm.verifyError = nil
                                    }
                                } label: {
                                    Text(proto.rawValue)
                                        .font(.system(size: 12, weight: .medium))
                                        .foregroundStyle(vm.selectedProtocol == proto ? AppTheme.ink : AppTheme.inkTertiary)
                                        .frame(maxWidth: .infinity)
                                        .padding(.vertical, 7)
                                        .background(
                                            RoundedRectangle(cornerRadius: 7, style: .continuous)
                                                .fill(vm.selectedProtocol == proto ? AppTheme.surfaceRaised : Color.clear)
                                                .shadow(
                                                    color: vm.selectedProtocol == proto ? .black.opacity(0.06) : .clear,
                                                    radius: 3, x: 0, y: 1
                                                )
                                        )
                                }
                                .buttonStyle(PlainButtonStyle())
                            }
                        }
                        .padding(3)
                        .background(AppTheme.surfaceSunken)
                        .clipShape(RoundedRectangle(cornerRadius: 10, style: .continuous))
                        .padding(.horizontal, AppTheme.hPad)
                        .padding(.bottom, 20)

                        // ── Step 1: Host ──
                        VStack(alignment: .leading, spacing: 8) {
                            HStack(spacing: 12) {
                                Image(systemName: "network")
                                    .font(.system(size: 14, weight: .regular))
                                    .foregroundStyle(AppTheme.inkSecondary)
                                    .frame(width: 20)
                                TextField("IP address or hostname", text: $vm.host)
                                    .font(AppTheme.body())
                                    .foregroundStyle(AppTheme.ink)
                                    .keyboardType(.URL)
                                    .autocorrectionDisabled()
                                    .textInputAutocapitalization(.never)
                                    .focused($focused, equals: .host)
                                    .submitLabel(.next)
                                    .onSubmit { focused = .username }
                                if !vm.host.isEmpty {
                                    Button { vm.host = "" } label: {
                                        Image(systemName: "xmark.circle.fill")
                                            .foregroundStyle(AppTheme.inkQuaternary)
                                    }
                                }
                            }
                            .padding(.horizontal, 16)
                            .padding(.vertical, 14)
                            .background(AppTheme.surfaceRaised)
                            .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
                            .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)

                            Text("e.g. 192.168.1.10  or  MY_NAS")
                                .font(AppTheme.micro(11))
                                .foregroundStyle(AppTheme.inkTertiary)
                                .padding(.leading, 4)
                        }
                        .padding(.horizontal, AppTheme.hPad)
                        .padding(.bottom, 12)

                        // ── Step 1: Credentials card ──
                        VStack(spacing: 0) {
                            HStack(spacing: 12) {
                                Image(systemName: "person")
                                    .font(.system(size: 14, weight: .regular))
                                    .foregroundStyle(AppTheme.inkSecondary)
                                    .frame(width: 20)
                                TextField("Username", text: $vm.username)
                                    .font(AppTheme.body())
                                    .foregroundStyle(AppTheme.ink)
                                    .autocorrectionDisabled()
                                    .textInputAutocapitalization(.never)
                                    .focused($focused, equals: .username)
                                    .submitLabel(.next)
                                    .onSubmit { focused = .password }
                                if !vm.username.isEmpty {
                                    Button { vm.username = "" } label: {
                                        Image(systemName: "xmark.circle.fill")
                                            .foregroundStyle(AppTheme.inkQuaternary)
                                    }
                                }
                            }
                            .padding(.horizontal, 16)
                            .padding(.vertical, 14)

                            Rectangle()
                                .fill(AppTheme.separator)
                                .frame(height: 0.5)
                                .padding(.leading, 44)

                            HStack(spacing: 12) {
                                Image(systemName: "lock")
                                    .font(.system(size: 14, weight: .regular))
                                    .foregroundStyle(AppTheme.inkSecondary)
                                    .frame(width: 20)
                                Group {
                                    if showPassword {
                                        TextField("Password", text: $vm.password)
                                    } else {
                                        SecureField("Password", text: $vm.password)
                                    }
                                }
                                .font(AppTheme.body())
                                .foregroundStyle(AppTheme.ink)
                                .focused($focused, equals: .password)
                                .submitLabel(.go)
                                .onSubmit { Task { await vm.verify() } }
                                Button {
                                    showPassword.toggle()
                                } label: {
                                    Image(systemName: showPassword ? "eye.slash" : "eye")
                                        .font(.system(size: 14))
                                        .foregroundStyle(AppTheme.inkTertiary)
                                }
                            }
                            .padding(.horizontal, 16)
                            .padding(.vertical, 14)
                        }
                        .background(AppTheme.surfaceRaised)
                        .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
                        .overlay(
                            RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous)
                                .stroke(
                                    vm.isConnected ? AppTheme.positive.opacity(0.45) :
                                    vm.verifyError != nil ? AppTheme.destructive.opacity(0.45) :
                                    Color.clear,
                                    lineWidth: 1
                                )
                        )
                        .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
                        .padding(.horizontal, AppTheme.hPad)
                        .padding(.bottom, 12)
                        .animation(.spring(response: 0.3, dampingFraction: 0.8), value: vm.isConnected)
                        .animation(.spring(response: 0.3, dampingFraction: 0.8), value: vm.verifyError != nil)

                        // ── Destination folder — always visible, active only after auth ──
                        Button(action: { if vm.isConnected { vm.showFolderBrowser = true } }) {
                            HStack(spacing: 12) {
                                Image(systemName: vm.remotePath == "/" ? "folder" : "folder.fill")
                                    .font(.system(size: 14, weight: .regular))
                                    .foregroundStyle(
                                        !vm.isConnected ? AppTheme.inkQuaternary :
                                        vm.remotePath == "/" ? AppTheme.inkSecondary : AppTheme.positive
                                    )
                                    .frame(width: 20)
                                Text(vm.remotePath == "/" ? "Destination folder" : vm.remotePath)
                                    .font(AppTheme.body())
                                    .foregroundStyle(
                                        !vm.isConnected ? AppTheme.inkQuaternary :
                                        vm.remotePath == "/" ? AppTheme.inkTertiary : AppTheme.ink
                                    )
                                    .lineLimit(2)
                                    .multilineTextAlignment(.leading)
                                    .frame(maxWidth: .infinity, alignment: .leading)
                                Image(systemName: "folder.badge.plus")
                                    .font(.system(size: 16))
                                    .foregroundStyle(vm.isConnected ? AppTheme.inkSecondary : AppTheme.inkQuaternary)
                            }
                            .padding(.horizontal, 16)
                            .padding(.vertical, 14)
                            .background(AppTheme.surfaceRaised)
                            .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
                            .overlay(
                                RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous)
                                    .stroke(
                                        vm.step == .ready ? AppTheme.positive.opacity(0.45) : Color.clear,
                                        lineWidth: 1
                                    )
                            )
                            .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
                            .opacity(vm.isConnected ? 1 : 0.45)
                            .animation(.spring(response: 0.3, dampingFraction: 0.8), value: vm.isConnected)
                        }
                        .buttonStyle(ScaleButtonStyle())
                        .padding(.horizontal, AppTheme.hPad)
                        .padding(.bottom, 12)

                        // ── Status message ──
                        HStack(spacing: 6) {
                            Image(systemName: vm.statusIsError ? "exclamationmark.circle" :
                                             vm.statusIsPositive ? "checkmark.circle" : "circle.dotted")
                                .font(.system(size: 13))
                            Text(vm.statusMessage)
                                .font(AppTheme.caption())
                        }
                        .foregroundStyle(
                            vm.statusIsError ? AppTheme.destructive :
                            vm.statusIsPositive ? AppTheme.positive :
                            AppTheme.inkTertiary
                        )
                        .padding(.horizontal, AppTheme.hPad)
                        .padding(.bottom, 20)
                        .animation(.spring(response: 0.3, dampingFraction: 0.8), value: vm.step)
                        .animation(.spring(response: 0.3, dampingFraction: 0.8), value: vm.verifyError)
                    }
                }
                .safeAreaInset(edge: .bottom) {
                    VStack(spacing: 0) {
                        Button(action: {
                            focused = nil
                            if vm.step == .ready {
                                navigateToDashboard = true
                            } else {
                                Task { await vm.proceed() }
                            }
                        }) {
                            Group {
                                if vm.isVerifying {
                                    ProgressView().tint(.white)
                                } else {
                                    Text(ctaLabel)
                                }
                            }
                            .frame(maxWidth: .infinity)
                        }
                        .buttonStyle(PrimaryButtonStyle(color: ctaColor))
                        .padding(.horizontal, AppTheme.hPad)
                        .padding(.top, 12)
                        .padding(.bottom, 32)
                        .disabled(!vm.canProceed)
                        .animation(.spring(response: 0.3, dampingFraction: 0.8), value: vm.step)
                    }
                    .background(AppTheme.background)
                }
            }
            .navigationBarHidden(true)
            .navigationDestination(isPresented: $navigateToDashboard) { MainTabView() }
            .sheet(isPresented: $vm.showFolderBrowser) {
                if let conn = ConnectionStore.shared.savedConnection {
                    BrowseView(connection: conn, selectedPath: $vm.remotePath, isPickerMode: true)
                        .onDisappear {
                            if vm.remotePath != "/", var c = ConnectionStore.shared.savedConnection {
                                c.remotePath = vm.remotePath
                                ConnectionStore.shared.savedConnection = c
                            }
                        }
                }
            }
        }
    }

    private var ctaLabel: String {
        switch vm.step {
        case .credentials: return "Connect"
        case .folder:      return "Select Destination"
        case .ready:       return "Get Started"
        }
    }

    private var ctaColor: Color {
        switch vm.step {
        case .credentials: return AppTheme.ink
        case .folder:      return AppTheme.ink
        case .ready:       return AppTheme.positive
        }
    }
}