import SwiftUI

private let WEATHER_STATUS_MAP_RU: [String: String] = [
    "Rain": "дождливо",
    "Clouds": "облачно",
    "Clear": "солнечно",
    "Thunderstorm": "гроза",
    "Snow": "снег",
    "Drizzle": "мелкий дождь",
    "Fog": "туман"
]

private let WEATHER_STATUS_MAP_ZH: [String: String] = [
    "Rain": "下雨",
    "Clouds": "多云",
    "Clear": "晴朗",
    "Thunderstorm": "雷雨",
    "Snow": "下雪",
    "Drizzle": "毛毛雨",
    "Fog": "雾"
]

private let WEATHER_STATUS_MAP_EN: [String: String] = [
    "Rain": "Rain",
    "Clouds": "Cloudy",
    "Clear": "Sunny",
    "Thunderstorm": "Thunderstorm",
    "Snow": "Snow",
    "Drizzle": "Drizzle",
    "Fog": "Fog"
]

struct FormattedWeather {
    let temperature: Int
    let statusCode: String
    let precipitation: Int?
    let windSpeed: Double?
    var dayOfWeek: String?
    let originalDate: Date?  // добавлено для пересчета дня недели
     
    func localizedStatus(language: String) -> String {
        switch language {
        case "ru": return WEATHER_STATUS_MAP_RU[statusCode] ?? statusCode
        case "zh": return WEATHER_STATUS_MAP_ZH[statusCode] ?? statusCode
        default: return WEATHER_STATUS_MAP_EN[statusCode] ?? statusCode
        }
    }
}

struct WeatherView: View {
    @EnvironmentObject var appState: AppState
    
    @State private var todayWeather: FormattedWeather?
    @State private var forecast: [FormattedWeather] = []
    
    var body: some View {
        HStack(alignment: .center, spacing: 4) {
            if let today = todayWeather {
                VStack(alignment: .center, spacing: 2) {
                    Image(getWeatherIconName(for: today.localizedStatus(language: appState.selectedLanguage)))
                        .resizable()
                        .aspectRatio(contentMode: .fit)
                        .frame(width: 36, height: 36)
                        .padding(.bottom, 5)
                    
                    Text("\(today.temperature)°")
                        .font(.system(size: 30, weight: .bold))
                        .foregroundColor(.white)
                    
                    Text(today.localizedStatus(language: appState.selectedLanguage))
                        .font(.system(size: 12))
                        .foregroundColor(.white)
                        .multilineTextAlignment(.center)
                }
                
                VStack(alignment: .leading, spacing: 6) {
                    ForEach(forecast.prefix(3).indices, id: \.self) { index in
                        let day = forecast[index]
                        HStack(spacing: 4) {
                            Image(getWeatherIconName(for: day.localizedStatus(language: appState.selectedLanguage)))
                                .resizable()
                                .aspectRatio(contentMode: .fit)
                                .frame(width: 14, height: 14)
                            
                            if let date = day.originalDate {
                                Text(getDayOfWeek(from: date))
                                    .font(.system(size: 10))
                                    .foregroundColor(.white)
                            }
                            
                            Text("\(day.temperature)°")
                                .font(.system(size: 12))
                                .foregroundColor(.white)
                                .fontWeight(.bold)
                        }
                    }
                    
                    Divider()
                        .background(Color.white.opacity(0.8))
                        .padding(.vertical, 1)
                    
                    if let precipitation = today.precipitation {
                        HStack(spacing: 4) {
                            Image("det_humidity")
                                .resizable()
                                .aspectRatio(contentMode: .fit)
                                .frame(width: 14, height: 14)
                            Text("\(precipitation)%")
                                .font(.system(size: 12))
                                .foregroundColor(.white)
                        }
                    }
                    
                    if let windSpeed = today.windSpeed {
                        HStack(spacing: 5) {
                            Image("det_wind_speed")
                                .resizable()
                                .aspectRatio(contentMode: .fit)
                                .frame(width: 14, height: 14)
                            Text(appState.selectedLanguage == "ru" ? "\(Int(windSpeed)) м/с" :
                                 appState.selectedLanguage == "zh" ? "\(Int(windSpeed)) 米/秒" :
                                 "\(Int(windSpeed)) m/s")
                                .font(.system(size: 12))
                                .foregroundColor(.white)
                        }
                    }
                }
            } else {
                Text(appState.selectedLanguage == "ru" ? "Загрузка погоды..." :
                     appState.selectedLanguage == "zh" ? "正在加载天气..." :
                     "Loading weather...")
                    .foregroundColor(.white)
                    .padding()
            }
        }
        .padding(.horizontal, 10)
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .aspectRatio(1, contentMode: .fit)
        .background(
            ZStack {
                Color(hex: 0x806C59)
                LinearGradient(
                    stops: [
                        .init(color: .white.opacity(0.0), location: 0.0871),
                        .init(color: .white.opacity(0.16), location: 0.6969)
                    ],
                    startPoint: .bottomLeading,
                    endPoint: .topTrailing
                )
            }
        )
        .cornerRadius(25)
        .shadow(color: Color.black.opacity(0.10), radius: 8, x: 0, y: 2)
        .task {
            await fetchAndFormatWeather()
        }
        .onChange(of: appState.selectedLanguage) { _ in
            // при смене языка день недели пересчитывается динамически в View
        }
    }
    
    private func fetchAndFormatWeather() async {
        let lat = 59.938784
        let lng = 30.314997
        
        guard let url = URL(string: "https://white-nights.krbl.ru/services/weather?lang=\(appState.selectedLanguage)") else { return }
        
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        
        let parameters: [String: Any] = [
            "coordinates": ["latitude": lat, "longitude": lng]
        ]
        
        do {
            request.httpBody = try JSONSerialization.data(withJSONObject: parameters)
            let (data, _) = try await URLSession.shared.data(for: request)
            let weatherResponse = try JSONDecoder().decode(WeatherResponse.self, from: data)
            formatWeatherData(data: weatherResponse)
        } catch {
            print("Ошибка загрузки погоды: \(error)")
        }
    }
    
    private func formatWeatherData(data: WeatherResponse) {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
        dateFormatter.timeZone = TimeZone(secondsFromGMT: 0)
        dateFormatter.locale = Locale(identifier: "en_US_POSIX")

        var calendar = Calendar.current
        calendar.timeZone = TimeZone(secondsFromGMT: 0)!

        let middayForecast = data.forecast.filter { item in
            guard let date = dateFormatter.date(from: item.date) else { return false }
            return calendar.component(.hour, from: date) == 12
        }

        if let today = data.currentWeather {
            todayWeather = FormattedWeather(
                temperature: Int(today.temperatureCelsius.rounded()),
                statusCode: today.description,
                precipitation: today.humidity,
                windSpeed: today.windSpeed,
                dayOfWeek: nil,
                originalDate: nil
            )
        }

        var formattedForecast: [FormattedWeather] = []

        for item in middayForecast.prefix(3) {
            guard let date = dateFormatter.date(from: item.date) else { continue }
            let averageTemp = (item.minTemperatureCelsius + item.maxTemperatureCelsius) / 2
            formattedForecast.append(FormattedWeather(
                temperature: Int(averageTemp.rounded()),
                statusCode: item.description,
                precipitation: item.humidity,
                windSpeed: item.windSpeed,
                dayOfWeek: getDayOfWeek(from: date),
                originalDate: date
            ))
        }

        let daysToFill = 3 - formattedForecast.count
        if daysToFill > 0 {
            let baseDate = Date()
            for i in 1...daysToFill {
                guard let nextDay = Calendar.current.date(byAdding: .day, value: formattedForecast.count + i, to: baseDate) else { continue }
                formattedForecast.append(FormattedWeather(
                    temperature: 0,
                    statusCode: "N/A",
                    precipitation: nil,
                    windSpeed: nil,
                    dayOfWeek: getDayOfWeek(from: nextDay),
                    originalDate: nextDay
                ))
            }
        }

        self.forecast = formattedForecast
    }
    
    private func getDayOfWeek(from date: Date) -> String {
        let formatter = DateFormatter()
        formatter.locale = appState.selectedLanguage == "ru" ? Locale(identifier: "ru_RU") :
                           appState.selectedLanguage == "zh" ? Locale(identifier: "zh_CN") :
                           Locale(identifier: "en_US")
        formatter.dateFormat = "E"
        return formatter.string(from: date).capitalized
    }
    
    private func getWeatherIconName(for status: String) -> String {
        let normalizedStatus = status.lowercased()
        switch normalizedStatus {
        case "солнечно", "晴朗", "sunny":
            return "cond_sunny"
        case "облачно", "多云", "cloudy":
            return "cond_cloudy"
        case "дождливо", "мелкий дождь", "下雨", "毛毛雨", "rainy", "drizzle":
            return "cond_rainy"
        case "снег", "下雪", "snowy":
            return "cond_snowy"
        case "гроза", "雷雨", "thunderstorm":
            return "cond_thunder"
        case "туман", "雾", "fog":
            return "det_humidity"
        default:
            return "cond_sunny"
        }
    }
}