import SwiftUI

// MARK: - Data Models

struct Hotel: Identifiable {
    let id = UUID()
    let name: String
    let rating: Double
    let ratingName: String
    let address: String
    let minimalPrice: Int
    let priceForIt: String
    let imageUrls: [String] // Use image names from Assets or URLs
    let description: String
    let peculiarities: [String] // Like "3-я линия", "Платный Wi-Fi в фойе"
}

struct Room: Identifiable {
    let id = UUID()
    let name: String
    let price: Int
    let pricePer: String
    let peculiarities: [String] // Like "Все включено", "Кондиционер"
    let imageUrls: [String]
}


// MARK: - Content View (Root)

struct ContentView: View {
    // --- MOCK DATA ---
    // In a real app, this would come from a ViewModel/API
    let sampleHotel = Hotel(
        name: "Steigenberger Makadi", // Updated name based on screenshot 4
        rating: 5.0,
        ratingName: "Превосходно",
        address: "Madinat Makadi, Safaga Road, Makadi Bay, Египет",
        minimalPrice: 134673,
        priceForIt: "за тур с перелётом",
        imageUrls: ["hotel_placeholder_1", "hotel_placeholder_2", "hotel_placeholder_3", "hotel_placeholder_4", "hotel_placeholder_5", "hotel_placeholder_6", "hotel_placeholder_7"], // Add your image names
        description: "Отель VIP-класса с собственными гольф полями. Высокий уровень сервиса. Рекомендуем для респектабельного отдыха.",
        peculiarities: ["3-я линия", "Платный Wi-Fi в фойе", "30 км до аэропорта", "1 км до пляжа"]
    )

     let sampleRooms = [
        Room(name: "Стандартный с видом на бассейн или сад", price: 186600, pricePer: "за 7 ночей с перелётом", peculiarities: ["Все включено", "Кондиционер"], imageUrls: ["room1_image1", "room1_image2","room1_image3","room1_image4"]),
        Room(name: "Люкс с видом на море", price: 250000, pricePer: "за 7 ночей с перелётом", peculiarities: ["Все включено", "Кондиционер", "Мини-бар"], imageUrls: ["suite1_image1", "suite1_image2", "suite1_image3"])
        // Add more rooms
    ]
    // --- ---

    var body: some View {
        NavigationView {
            HotelDetailView(hotel: sampleHotel, rooms: sampleRooms)
        }
        // Optional: Use .accentColor for global tint if needed
        // .accentColor(.blue)
    }
}

// MARK: - Hotel Detail View

struct HotelDetailView: View {
    let hotel: Hotel
    let rooms: [Room] // Pass rooms data for navigation

    @State private var selectedImageIndex = 0

    var body: some View {
        ScrollView {
            VStack(alignment: .leading, spacing: 8) {
                // --- Section 1: Image Carousel, Basic Info ---
                VStack(alignment: .leading, spacing: 16) {
                    ImageCarouselView(imageUrls: hotel.imageUrls, 
                                      selectedIndex: $selectedImageIndex)
                        .frame(height: 250) // Adjust height as needed
                        .clipShape(RoundedRectangle(cornerRadius: 15)) // Rounded corners

                    HStack(spacing: 4) {
                        Image(systemName: "star.fill")
                            .foregroundColor(.orange)
                        Text("\(hotel.rating, specifier: "%.1f") \(hotel.ratingName)")
                            .foregroundColor(.orange)
                            .font(.system(size: 16, weight: .medium))
                    }

                    Text(hotel.name)
                        .font(.system(size: 22, weight: .medium))

                    Button {
                        // Action for address tap if needed (e.g., open map)
                        print("Address tapped")
                    } label: {
                        Text(hotel.address)
                            .font(.system(size: 14, weight: .medium))
                            .foregroundColor(.blue) // Link-like appearance
                    }

                    HStack(alignment: .bottom, spacing: 8) {
                         Text("от \(hotel.minimalPrice) ₽")
                            .font(.system(size: 30, weight: .semibold))
                         Text(hotel.priceForIt.lowercased())
                            .font(.system(size: 16, weight: .regular))
                            .foregroundColor(.secondary)
                            .padding(.bottom, 4) // Align baseline better
                    }

                }
                .padding(.horizontal)
                .padding(.vertical, 8) // Add some vertical padding
                .background(Color.white) // White background for this section
                .cornerRadius(15) // Rounded corners for the section


                 // --- Section 2: About the Hotel ---
                 VStack(alignment: .leading, spacing: 16) {
                    Text("Об отеле")
                        .font(.system(size: 22, weight: .medium))

                    // Peculiarities (Tags)
                    FlexibleGridView(data: hotel.peculiarities) { item in
                        Text(item)
                            .font(.system(size: 16, weight: .medium))
                            .foregroundColor(.gray)
                            .padding(.horizontal, 10)
                            .padding(.vertical, 5)
                            .background(Color(UIColor.systemGray6)) // Tag background
                            .cornerRadius(5)
                    }


                    Text(hotel.description)
                         .font(.system(size: 16, weight: .regular))

                    // --- Detail Buttons ---
                    VStack(spacing: 0) {
                         NavigationLink(destination: AmenitiesView()) { // Navigate to Amenities
                             SectionRow(iconName: "face.smiling",
                                        title: "Удобства",
                                        subtitle: "Самое необходимое")
                         }
                         Divider().padding(.leading, 45) // Indent divider
                         SectionRow(iconName: "checkmark.circle",
                                    title: "Что включено", 
                                    subtitle: "Основные услуги")
                         Divider().padding(.leading, 45)
                         SectionRow(iconName: "xmark.circle", 
                                    title: "Что не включено", 
                                    subtitle: "Дополнительные услуги")
                    }
                    .background(Color(UIColor.systemGray6))
                    .cornerRadius(15)
                    .padding(.top) // Add space before buttons


                 }
                 .padding(.horizontal)
                 .padding(.vertical, 8)
                 .background(Color.white)
                 .cornerRadius(15)
                 .padding(.top, 8) // Space between sections


            } // End Main VStack
        } // End ScrollView
        .background(Color(UIColor.systemGray6).ignoresSafeArea()) // Background for the whole screen
        .navigationBarTitleDisplayMode(.inline) // Keep title small
       .toolbar { // Hide the default back button text
            ToolbarItem(placement: .principal) {
                 Text(hotel.name) // Or just "Отель"
                    .font(.system(size: 18, weight: .medium))
            }
        }
        .safeAreaInset(edge: .bottom) {
             // --- Bottom Button ---
             NavigationLink(destination: 
                  RoomSelectionView(hotelName: hotel.name, rooms: rooms)) {
                  Text("К выбору номера")
                     .font(.system(size: 16, weight: .medium))
                     .foregroundColor(.white)
                     .frame(maxWidth: .infinity)
                     .padding()
                     .background(Color.blue)
                     .cornerRadius(15)
             }
             .padding(.horizontal)
             .padding(.top, 8) // Add space above button
             .background( // Add a white background behind the button area
                 Color.white
                    .ignoresSafeArea(edges: .bottom) // Extend white to screen bottom edge
             )
         }
    }
}

// MARK: - Image Carousel View

struct ImageCarouselView: View {
    let imageUrls: [String]
    @Binding var selectedIndex: Int

    var body: some View {
        TabView(selection: $selectedIndex) {
            ForEach(0..<imageUrls.count, id: \.self) { index in
                Image(imageUrls[index]) // Assumes images are in Assets
                    .resizable()
                    .scaledToFill()
                    // .aspectRatio(contentMode: .fill) // Alternative scaling
                    .tag(index)
                    // Add error handling/placeholder if needed
                    .overlay{
                        VStack {
                            Spacer()
                            HStack {
                                Spacer()
                                Text("\(index + 1) / \(imageUrls.count)")
                                    .bold()
                                    .foregroundStyle(Color.white)
                                    .padding(.horizontal, 45)
                            }
                            .padding()
                        }
                    }
            }
        }
        .tabViewStyle(.page(indexDisplayMode: .never)) // Hide default dots
        .overlay(
            // Custom Pagination Dots
            HStack(spacing: 8) {
                ForEach(0..<imageUrls.count, id: \.self) { index in
                    Circle()
                        .fill(selectedIndex == index ? Color.black : Color.gray.opacity(0.7))
                        .frame(width: 7, height: 7)
                }
            }
            .padding(.horizontal, 12)
            .padding(.vertical, 8)
            .background(Color.white.opacity(0.9))
            .cornerRadius(5)
            .padding(.bottom, 10) // Position dots from bottom
            , alignment: .bottom // Align dots at the bottom
        )
    }
}

// MARK: - Section Row Helper View

struct SectionRow: View {
    let iconName: String
    let title: String
    let subtitle: String

    var body: some View {
        HStack(spacing: 12) {
            Image(systemName: iconName)
                .resizable()
                .scaledToFit()
                .frame(width: 24, height: 24)
                .foregroundColor(.primary.opacity(0.9))

            VStack(alignment: .leading) {
                Text(title)
                    .font(.system(size: 16, weight: .medium))
                    .foregroundColor(.primary)
                Text(subtitle)
                    .font(.system(size: 14, weight: .regular))
                    .foregroundColor(.secondary)
            }
            Spacer()
            Image(systemName: "chevron.right")
                .foregroundColor(.secondary)
        }
        .padding(.horizontal)
        .padding(.vertical, 10)
    }
}


// MARK: - Amenities View (Placeholder)

struct AmenitiesView: View {
    var body: some View {
        ScrollView { // Make it scrollable in case content grows
            VStack {
                 Text("Details about Удобства")
                     .padding()
                 // Add actual amenity details here (Lists, Grids, etc.)
                 Spacer()
            }
        }
        .navigationTitle("Удобства") // Standard navigation title
        .navigationBarTitleDisplayMode(.inline)
    }
}

// MARK: - Room Selection View

struct RoomSelectionView: View {
    let hotelName: String
    let rooms: [Room]

    var body: some View {
        ScrollView {
            VStack(spacing: 8) {
                ForEach(rooms) { room in
                    RoomCardView(room: room)
                }
            }
            .padding(.vertical) // Add padding top/bottom inside scrollview
        }
        .navigationTitle(hotelName) // Use hotel name as title
        .navigationBarTitleDisplayMode(.inline)
        .background(Color(UIColor.systemGray6).ignoresSafeArea()) // Match background
    }
}

// MARK: - Room Card View

struct RoomCardView: View {
    let room: Room
    @State private var selectedImageIndex = 0 // Each card manages its own carousel state

    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            ImageCarouselView(imageUrls: room.imageUrls, 
                              selectedIndex: $selectedImageIndex)
                 .frame(height: 200) // Adjust height
                 .clipShape(RoundedRectangle(cornerRadius: 15))

            Text(room.name)
                 .font(.system(size: 22, weight: .medium))

             // Peculiarities (Tags)
            FlexibleGridView(data: room.peculiarities) { item in
                Text(item)
                    .font(.system(size: 16, weight: .medium))
                    .foregroundColor(.gray)
                    .padding(.horizontal, 10)
                    .padding(.vertical, 5)
                    .background(Color(UIColor.systemGray6))
                    .cornerRadius(5)
            }

             // Room Price
             HStack(alignment: .bottom, spacing: 8) {
                  Text("\(room.price) ₽")
                     .font(.system(size: 30, weight: .semibold))
                  Text(room.pricePer.lowercased())
                     .font(.system(size: 16, weight: .regular))
                     .foregroundColor(.secondary)
                     .padding(.bottom, 4)
             }

             // Choose Room Button
             Button {
                 // Action for selecting THIS specific room
                 print("Selected room: \(room.name)")
             } label: {
                   Text("Выбрать номер")
                      .font(.system(size: 16, weight: .medium))
                      .foregroundColor(.white)
                      .frame(maxWidth: .infinity)
                      .padding()
                      .background(Color.blue)
                      .cornerRadius(15)
             }

        }
        .padding()
        .background(Color.white)
        .cornerRadius(15)
        .padding(.horizontal) // Add horizontal space between cards and screen edge
    }
}


// MARK: - Flexible Grid View (Helper for Tags)

struct FlexibleGridView<Data: Collection, Content: View>: View where Data.Element: Hashable {
    let data: Data
    let spacing: CGFloat
    let alignment: HorizontalAlignment
    let content: (Data.Element) -> Content
    @State private var availableWidth: CGFloat = 0

    init(data: Data, spacing: CGFloat = 8, alignment: HorizontalAlignment = .leading, @ViewBuilder content: @escaping (Data.Element) -> Content) {
        self.data = data
        self.spacing = spacing
        self.alignment = alignment
        self.content = content
    }

    var body: some View {
    ZStack(alignment: Alignment(horizontal: alignment, vertical: .center)) {
            Color.clear
                .frame(height: 1)
                .readSize { size in
                    availableWidth = size.width
                }

            _FlexibleGrid(
                availableWidth: availableWidth,
                data: data,
                spacing: spacing,
                alignment: alignment,
                content: content
            )
        }
    }
}

struct _FlexibleGrid<Data: Collection, Content: View>: View where Data.Element: Hashable {
    let availableWidth: CGFloat
    let data: Data
    let spacing: CGFloat
    let alignment: HorizontalAlignment
    let content: (Data.Element) -> Content
    @State var elementsSize: [Data.Element: CGSize] = [:]

    var body: some View {
        VStack(alignment: alignment, spacing: spacing) {
            ForEach(computeRows(), id: \.self) { rowElements in
                HStack(spacing: spacing) {
                    ForEach(rowElements, id: \.self) { element in
                        content(element)
                            .fixedSize()
                            .readSize { size in
                                elementsSize[element] = size
                            }
                    }
                }
            }
        }
    }

    func computeRows() -> [[Data.Element]] {
        var rows: [[Data.Element]] = [[]]
        var currentRow = 0
        var remainingWidth = availableWidth

        for element in data {
            let elementSize = elementsSize[element, default: CGSize(width: availableWidth, height: 1)]

            if remainingWidth - (elementSize.width + spacing) >= 0 {
                rows[currentRow].append(element)
            } else {
                currentRow += 1
                rows.append([element])
                remainingWidth = availableWidth
            }
            remainingWidth -= (elementSize.width + spacing)
        }
        return rows
    }
}

// Helper to read view size
struct SizePreferenceKey: PreferenceKey {
    static var defaultValue: CGSize = .zero
    static func reduce(value: inout CGSize, nextValue: () -> CGSize) {}
}
extension View {
    func readSize(onChange: @escaping (CGSize) -> Void) -> some View {
        background(
            GeometryReader { geometryProxy in
                Color.clear
                    .preference(key: SizePreferenceKey.self, value: geometryProxy.size)
            }
        )
        .onPreferenceChange(SizePreferenceKey.self, perform: onChange)
    }
}

#Preview {
    ContentView()
}

import SwiftUI
import Combine // Needed for keyboard observers if we wanted more advanced focus handling

// MARK: - Data Models (Simple representations for the example)

struct HotelBookingInfo {
    let ratingValue: Int = 5
    let ratingName: String = "Превосходно"
    let hotelName: String = "Steigenberger Makadi"
    let hotelAddress: String = "Madinat Makadi, Safaga Road, Makadi Bay, Египет"
}

struct BookingDetails {
    let departureCity: String = "Санкт-Петербург"
    let countryCity: String = "Египет, Хургада"
    let dates: String = "19.09.2023 - 27.09.2023"
    let nights: String = "7 ночей"
    let hotelName: String = "Steigenberger Makadi"
    let roomType: String = "Стандартный с видом на бассейн или сад"
    let mealPlan: String = "Все включено"
}

// MARK: - Main Booking Info View

struct BookingInfoView: View {
    // --- State Variables ---
    @State private var phoneNumber: String = "" // Stores the RAW digits (max 10)
  //  @State private var displayedPhoneNumber: String = "+7 " // What the user sees/edits
    @State private var email: String = ""
    @State private var isEmailValid: Bool = true // Assume valid initially or until typed

    // --- Data ---
    let hotelInfo = HotelBookingInfo()
    let bookingDetails = BookingDetails()

    // --- Environment ---
    @Environment(\.presentationMode) var presentationMode

    var body: some View {
        NavigationView {
            ScrollView {
                VStack(spacing: 8) { // Spacing between blocks
                    HotelInfoBlock(info: hotelInfo)
                    BookingDetailsBlock(details: bookingDetails)
                    BuyerInfoBlock(
                        phoneNumber: $phoneNumber,
                        email: $email,
                        isEmailValid: $isEmailValid
                    )

                    Spacer() // Pushes content up if screen is tall
                }
                .padding(.horizontal) // Padding for the whole content stack
                .padding(.top)      // Padding from the navigation bar
            }
            .background(Color(UIColor.systemGray6)) // Background for the whole screen
            .navigationTitle("Бронирование")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button {
                        presentationMode.wrappedValue.dismiss()
                    } label: {
                        Image(systemName: "chevron.left")
                    }
                    .tint(.primary) // Ensure back button has default color
                }
            }
        }
    }
}

// MARK: - Block Views

struct HotelInfoBlock: View {
    let info: HotelBookingInfo

    var body: some View {
        VStack(alignment: .leading, spacing: 8) {
            HStack(spacing: 4) {
                Image(systemName: "star.fill")
                Text("\(info.ratingValue) \(info.ratingName)")
            }
            .font(.system(size: 16, weight: .medium))
            .foregroundColor(.orange)
            .padding(.horizontal, 10)
            .padding(.vertical, 5)
            .background(Color.orange.opacity(0.15))
            .cornerRadius(5)

            Text(info.hotelName)
                .font(.system(size: 22, weight: .medium))

            Text(info.hotelAddress)
                .font(.system(size: 14, weight: .regular))
                .foregroundColor(.blue) // Link-like appearance
        }
        .padding()
        .frame(maxWidth: .infinity, alignment: .leading) // Take full width
        .background(Color.white)
        .cornerRadius(12)
    }
}

struct BookingDetailsBlock: View {
    let details: BookingDetails

    var body: some View {
        VStack(alignment: .leading, spacing: 16) { // Increased spacing between rows
            BookingDetailRow(label: "Вылет из", value: details.departureCity)
            BookingDetailRow(label: "Страна, город", value: details.countryCity)
            BookingDetailRow(label: "Даты", value: details.dates)
            BookingDetailRow(label: "Кол-во ночей", value: details.nights)
            BookingDetailRow(label: "Отель", value: details.hotelName)
            BookingDetailRow(label: "Номер", value: details.roomType)
            BookingDetailRow(label: "Питание", value: details.mealPlan)
        }
        .padding()
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(Color.white)
        .cornerRadius(12)
    }
}

// Helper for Booking Details rows
struct BookingDetailRow: View {
    let label: String
    let value: String

    var body: some View {
        HStack(alignment: .top) { // Align top for potentially multi-line values
            Text(label)
                .font(.system(size: 16))
                .foregroundColor(.secondary)
                .frame(width: 110, alignment: .leading) // Fixed width for labels

            Text(value)
                .font(.system(size: 16))
                .foregroundColor(.primary)
                .frame(maxWidth: .infinity, alignment: .leading) // Take remaining space
        }
    }
}

struct BuyerInfoBlock: View {
    @Binding var phoneNumber: String // Raw digits
  //  @Binding var displayedPhoneNumber: String // Formatted for display/edit
    @Binding var email: String
    @Binding var isEmailValid: Bool
    
    @State var isValid: Bool = false
    let phoneRegex = try! NSRegularExpression(pattern: #"^\+7 \(\d{3}\) \d{3}-\d{2}-\d{2}$"#)

    var body: some View {
        VStack(alignment: .leading, spacing: 20) { // Space between title and fields
            Text("Информация о покупателе")
                .font(.system(size: 22, weight: .medium))

            VStack(alignment: .leading, spacing: 8) { // Space within the fields group
                Text("Номер телефона")
                    .font(.system(size: 12))
                    .foregroundColor(.secondary)
                    .padding(.leading, 12) // Indent label slightly

                TextField("", text: $phoneNumber, prompt: Text("+7 (***) *** - ** - **").foregroundColor(.gray))
                    .keyboardType(.numberPad)
                    .onReceive(Just(phoneNumber)) { newValue in
                        if !phoneNumber.isEmpty {
                            phoneNumber = formatPhoneNumber(newValue)
                            validatePhoneNumber(newValue)
                        }
                    }
                    .onAppear{
                        UITextField.appearance().clearButtonMode = .whileEditing
                    }
                    .padding()
                    .background(Color(.systemGray6))
                    .cornerRadius(8)
                
                if !isValid {
                    Text("Invalid format. Example: +7 (901) 555-66-77")
                        .foregroundColor(.red)
                        .font(.caption)
                }

                Text("Почта")
                    .font(.system(size: 12))
                    .foregroundColor(.secondary)
                    .padding(.leading, 12)

                TextField("example@mail.ru", text: $email)
                    .keyboardType(.emailAddress)
                    .autocapitalization(.none)
                    .disableAutocorrection(true)
                    .padding(.horizontal, 12)
                    .padding(.vertical, 10)
                    .background(isEmailValid ? Color(UIColor.systemGray6) : Color.red.opacity(0.15)) // Visual validation feedback
                    .cornerRadius(10)
                    .overlay( // Optional: Add border for invalid state
                        RoundedRectangle(cornerRadius: 10)
                            .stroke(isEmailValid ? Color.clear : Color.red, lineWidth: 1)
                    )
                    .onChange(of: email) { _, newValue in
                        // Validate only if email is not empty
                        if !newValue.isEmpty {
                             isEmailValid = isValidEmail(newValue)
                        } else {
                            isEmailValid = true // Consider empty as valid or neutral
                        }
                    }
            }

            Text("Эти данные никому не передаются. После оплаты мы вышли чек на указанный вами номер и почту")
                .font(.system(size: 14))
                .foregroundColor(.secondary)

        }
        .padding()
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(Color.white)
        .cornerRadius(12)
    }

    // MARK: Phone Masking Logic
    // Formats the input string to the template: +7 (XXX) XXX-XX-XX.
    private  func formatPhoneNumber(_ number: String) -> String {
            // Remove any non-digit characters.
            let digitsOnly = number.filter { $0.isNumber }
            var cleanedNumber = digitsOnly
            
            // If the first digit is 7 or 8, remove it.
            if let first = cleanedNumber.first, first == "7" || first == "8" {
                cleanedNumber.removeFirst()
            }
            
            // Limit to 10 digits.
            if cleanedNumber.count > 10 {
                cleanedNumber = String(cleanedNumber.prefix(10))
            }
            
            // Start with the fixed +7 prefix.
            var formatted = "+7 "
            
            // Create the area code part.
            if !cleanedNumber.isEmpty {
                formatted += "("
                let areaCodeEnd = min(3, cleanedNumber.count)
                let areaCode = cleanedNumber.prefix(areaCodeEnd)
                formatted += areaCode
                if areaCode.count == 3 {
                    formatted += ") "
                }
            }
            
            // Next 3 digits.
            if cleanedNumber.count > 3 {
                let startIndex = cleanedNumber.index(cleanedNumber.startIndex, offsetBy: 3)
                let endIndex = cleanedNumber.index(startIndex, offsetBy: min(3, cleanedNumber.count - 3))
                let firstThree = cleanedNumber[startIndex..<endIndex]
                formatted += firstThree
                if firstThree.count == 3 {
                    formatted += "-"
                }
            }
            
            // Next 2 digits.
            if cleanedNumber.count > 6 {
                let startIndex = cleanedNumber.index(cleanedNumber.startIndex, offsetBy: 6)
                let endIndex = cleanedNumber.index(startIndex, offsetBy: min(2, cleanedNumber.count - 6))
                let nextTwo = cleanedNumber[startIndex..<endIndex]
                formatted += nextTwo
                if nextTwo.count == 2 {
                    formatted += "-"
                }
            }
            
            // Last 2 digits.
            if cleanedNumber.count > 8 {
                let startIndex = cleanedNumber.index(cleanedNumber.startIndex, offsetBy: 8)
                let endIndex = cleanedNumber.index(startIndex, offsetBy: min(2, cleanedNumber.count - 8))
                let lastTwo = cleanedNumber[startIndex..<endIndex]
                formatted += lastTwo
            }
            
            return formatted
        }
    
    private func validatePhoneNumber(_ number: String) {
        let range = NSRange(location: 0, length: number.utf16.count)
        // Check if the entire string matches the regular expression
        isValid = phoneRegex.firstMatch(in: number, options: [], range: range) != nil
    }

     // MARK: Email Validation Logic
     private func isValidEmail(_ email: String) -> Bool {
         // Simple regex for basic email format validation
         let emailFormat = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
         let emailPredicate = NSPredicate(format:"SELF MATCHES %@", emailFormat)
         return emailPredicate.evaluate(with: email)
     }
}


// MARK: - Preview

#Preview {
        BookingInfoView()
}

import SwiftUI

// MARK: - Data Models

struct Tourist: Identifiable {
    let id = UUID() // Necessary for ForEach
    var isExpanded: Bool = true // State for collapsing/expanding

    // Form fields
    var firstName: String = ""
    var lastName: String = ""
    var dateOfBirth: String = "" // Could use Date type later
    var citizenship: String = ""
    var passportNumber: String = ""
    var passportExpiry: String = "" // Could use Date type later
}

struct PricingInfo {
    let tourPrice: Int
    let fuelSurcharge: Int
    let serviceCharge: Int

    var totalPrice: Int {
        tourPrice + fuelSurcharge + serviceCharge
    }
}

// MARK: - Main View

struct TouristInfoView: View {
    // --- State Variables ---
    @State private var tourists: [Tourist] = [Tourist()] // Start with one tourist
    @State private var pricing = PricingInfo(
        tourPrice: 186600,
        fuelSurcharge: 9300,
        serviceCharge: 2136
    )

    var body: some View {
    
        VStack {
            ScrollView {
                VStack(spacing: 8) { // Spacing between blocks

                    // --- Tourist Information Block ---
                    TouristListBlock(tourists: $tourists)

                    // --- Add Tourist Button ---
                    AddTouristButton {
                        addNewTourist()
                    }

                    // --- Price Summary Block ---
                    PriceSummaryBlock(pricing: pricing)
                    PaymentButton(totalAmount: pricing.totalPrice) {
                        // Action for payment
                        print("Proceeding to pay \(formattedPrice(pricing.totalPrice))")
                    }

                }
                .padding(.horizontal) // Padding for the whole content stack
                .padding(.top)
            }
            .background(Color(UIColor.systemGray6).ignoresSafeArea()) // Background for the whole screen
        }
    }

    // --- Helper Functions ---

    private func addNewTourist() {
        withAnimation { // Animate the addition
             tourists.append(Tourist())
        }
    }

     private func formattedPrice(_ price: Int) -> String {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.groupingSeparator = " " // Use space as separator
        return (formatter.string(from: NSNumber(value: price)) ?? "\(price)") + " ₽"
    }
}

// MARK: - Child Views / Blocks

struct TouristListBlock: View {
    @Binding var tourists: [Tourist]

    var body: some View {
        VStack(spacing: 8) { // Consistent spacing
             ForEach($tourists) { $tourist in // Use $ for bindings
                // Find the index for displaying the correct number
                 if let index = tourists.firstIndex(where: { $0.id == tourist.id }) {
                    TouristEntryView(
                        tourist: $tourist,
                        touristNumber: index + 1 // Pass the 1-based index
                    )
                 }
            }
        }
        // No background/cornerRadius here, apply it to TouristEntryView itself
    }
}

struct TouristEntryView: View {
    @Binding var tourist: Tourist
    let touristNumber: Int

    // Helper to get ordinal string ("Первый", "Второй", etc.)
    private func ordinal(number: Int) -> String {
        // Basic implementation, expand for more numbers if needed
        switch number {
        case 1: return "Первый"
        case 2: return "Второй"
        case 3: return "Третий"
        case 4: return "Четвертый"
        case 5: return "Пятый"
        default: return "\(number)-й"
        }
    }

    var body: some View {
        VStack(alignment: .leading, spacing: 0) { // No spacing for header/content separation
            // --- Header ---
            HStack {
                Text("\(ordinal(number: touristNumber)) турист")
                    .font(.system(size: 22, weight: .medium))
                Spacer()
                Button {
                    withAnimation(.easeInOut(duration: 0.2)) { // Animate expand/collapse
                        tourist.isExpanded.toggle()
                    }
                } label: {
                    Image(systemName: tourist.isExpanded ? "chevron.up" : "chevron.down")
                        .foregroundColor(.blue)
                        .padding(8) // Increase tappable area
                        .background(Color.blue.opacity(0.1))
                        .clipShape(RoundedRectangle(cornerRadius: 6))
                }
            }
            .padding() // Padding for the header itself

            // --- Form Fields (Conditional) ---
            if tourist.isExpanded {
                VStack { // Spacing between fields
                    StylizedTextField(placeholder: "Имя", 
                             text: $tourist.firstName)
                    StylizedTextField(placeholder: "Фамилия", 
                             text: $tourist.lastName)
                    StylizedTextField( placeholder: "Дата рождения", 
                             text: $tourist.dateOfBirth)
                    StylizedTextField( placeholder: "Гражданство", 
                             text: $tourist.citizenship)
                    StylizedTextField(placeholder: "Номер загранпаспорта", 
                             text: $tourist.passportNumber)
                    StylizedTextField(
                        placeholder: "Срок действия загранпаспорта", 
                        text: $tourist.passportExpiry)
                }
                .padding(.horizontal) // Padding for the form fields container
                .padding(.bottom)    // Add padding at the bottom of the form
                // Smooth transition for appearing fields
                .transition(.opacity.combined(with: .move(edge: .top)))
            }
        }
        .background(Color.white)
        .cornerRadius(12)
    }
}

// Reusable TextField with placeholder label
struct StylizedTextField: View {
    let placeholder: String
    @Binding var text: String

    var body: some View {
            TextField(placeholder, text: $text)
                .padding()
                .background(Color.gray.opacity(0.1))
                .cornerRadius(10)
                .overlay (alignment: .top) {
                if !text.isEmpty {
                    Text(placeholder)
                        .font(.system(size: 12))
                        .foregroundColor(.gray)
                        .padding(.leading, 12) // Indent title slightly
                        .padding(.bottom, -2) // Pull textfield up a bit
                        .zIndex(1) // Ensure title is above TextField background
                }
            }
    }
}

struct AddTouristButton: View {
    let action: () -> Void

    var body: some View {
        HStack {
            Text("Добавить туриста")
                .font(.system(size: 22, weight: .medium))
            Spacer()
            Button(action: action) {
                Image(systemName: "plus")
                    .foregroundColor(.white)
                    .padding()
                    .background(Color.blue)
                    .clipShape(RoundedRectangle(cornerRadius: 6))
            }
        }
        .padding()
        .background(Color.white)
        .cornerRadius(12)
    }
}

struct PriceSummaryBlock: View {
    let pricing: PricingInfo

    private func formattedPrice(_ price: Int) -> String {
        // Duplicated formatting logic for self-containment, could be centralized
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.groupingSeparator = " "
        return (formatter.string(from: NSNumber(value: price)) ?? "\(price)") + " ₽"
    }

    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            PriceRow(label: "Тур", amount: pricing.tourPrice)
            PriceRow(label: "Топливный сбор", amount: pricing.fuelSurcharge)
            PriceRow(label: "Сервисный сбор", amount: pricing.serviceCharge)
            PriceRow(label: "К оплате", amount: pricing.totalPrice,
                                                             isTotal: true)
        }
        .padding()
        .background(Color.white)
        .cornerRadius(12)
    }
}

// Helper for rows in the price summary
struct PriceRow: View {
    let label: String
    let amount: Int
    var isTotal: Bool = false

    private func formattedPrice(_ price: Int) -> String {
         let formatter = NumberFormatter()
         formatter.numberStyle = .decimal
         formatter.groupingSeparator = " "
         return (formatter.string(from: NSNumber(value: price)) ?? "\(price)") + " ₽"
     }

    var body: some View {
        HStack {
            Text(label)
                .font(.system(size: 16))
                .foregroundColor(.secondary)

            Spacer()

            Text(formattedPrice(amount))
            .font(.system(size: 16, weight: isTotal ? .semibold : .regular))
            .foregroundColor(isTotal ? .blue : .primary) // Highlight total price
        }
    }
}


struct PaymentButton: View {
    let totalAmount: Int
    let action: () -> Void

    private func formattedPrice(_ price: Int) -> String {
         let formatter = NumberFormatter()
         formatter.numberStyle = .decimal
         formatter.groupingSeparator = " "
         return (formatter.string(from: NSNumber(value: price)) ?? "\(price)") + " ₽"
     }

    var body: some View {
        Button(action: action) {
            Text("Оплатить \(formattedPrice(totalAmount))")
                .font(.system(size: 16, weight: .medium))
                .foregroundColor(.white)
                .frame(maxWidth: .infinity)
                .padding()
                .background(Color.blue)
                .cornerRadius(15)
        }
        .padding(.horizontal)
        .padding(.vertical, 8) // Add some vertical padding
        .background( // Add a white background behind the button area
            Color.white
              .ignoresSafeArea(edges: .bottom) // Extend white to screen bottom edge
              .shadow(radius: 1) // Optional subtle shadow above button
        )
    }
}


// MARK: - Preview

#Preview {
        TouristInfoView()
}