const axios = require('axios');

const TIMEOUT = 10000;
const HEADERS = { Accept: "application/json, text/plain;q=0.9,*/*;q=0.8" };

// Parametri API
const FORECAST_PARAMS = {
    current: [
        'temperature_2m',
        'wind_speed_10m',
        'wind_direction_10m',
        'wind_gusts_10m',
        'precipitation',
        'rain',
        'relative_humidity_2m',
        'pressure_msl'
    ],
    hourly: [
        'temperature_2m',
        'precipitation_probability',
        'precipitation',
        'rain',
        'wind_speed_10m',
        'cloud_cover',
        'wind_direction_10m',
        'relative_humidity_2m',
        'pressure_msl'
    ]
};

const MARINE_PARAMS = {
    current: [
        'wave_height',
        'wave_direction',
        'wave_period',
        'wave_peak_period',
        'ocean_current_velocity',
        'ocean_current_direction'
    ],
    hourly: [
        'wave_height',
        'wave_direction',
        'wave_period',
        'wave_peak_period',
        'ocean_current_velocity',
        'ocean_current_direction'
    ]
};

// Unità di misura globali (aggiornate da OpenMeteo)
let globalUnits = {
    forecast: {
        temperature: '°C',
        humidity: '%',
        pressure: 'hPa',
        windSpeed: 'km/h',
        windDirection: '°',
        windGusts: 'km/h',
        rain: 'mm',
        precipitation: 'mm'
    },
    waves: {
        waveHeight: 'm',
        wavePeriod: 's',
        waveDirection: '°',
        wavePeakPeriod: 's'
    }
};

/**
 * Ottiene le unità di misura globali
 */
function getUnits() {
    return globalUnits;
}

/**
 * Formatta un valore con la sua unità
 */
function formatWithUnit(value, unitKey, category = 'forecast') {
    if (value === null || value === undefined) return 'n/d';
    const unit = globalUnits[category]?.[unitKey] || '';
    return `${value}${unit}`;
}

async function getForecast(location) {
    if (!location?.latitude || !location?.longitude) {
        console.warn('[OpenMeteo] Coordinate non valide per forecast');
        return null;
    }

    const currentParams = FORECAST_PARAMS.current.join(",");
    const hourlyParams = FORECAST_PARAMS.hourly.join(",");
    const api = `https://api.open-meteo.com/v1/forecast?latitude=${location.latitude}&longitude=${location.longitude}&hourly=${hourlyParams}&current=${currentParams}`;

    try {
        const response = await axios.get(api, {
            headers: HEADERS,
            timeout: TIMEOUT,
            validateStatus: (status) => status === 200
        });

        const { data } = response;

        if (!data?.current) {
            console.warn('[OpenMeteo Forecast] Risposta senza dati current');
            return null;
        }

        // Aggiorna unità globali da API response
        if (data.current_units) {
            globalUnits.forecast = {
                temperature: data.current_units.temperature_2m || '°C',
                humidity: data.current_units.relative_humidity_2m || '%',
                pressure: data.current_units.pressure_msl || 'hPa',
                windSpeed: data.current_units.wind_speed_10m || 'km/h',
                windDirection: data.current_units.wind_direction_10m || '°',
                windGusts: data.current_units.wind_gusts_10m || 'km/h',
                rain: data.current_units.rain || 'mm',
                precipitation: data.current_units.precipitation || 'mm'
            };
        }

        return {
            temperature: data.current.temperature_2m ?? null,
            humidity: data.current.relative_humidity_2m ?? null,
            pressure: data.current.pressure_msl ?? null,
            windSpeed: data.current.wind_speed_10m ?? null,
            windDirection: data.current.wind_direction_10m ?? null,
            windGusts: data.current.wind_gusts_10m ?? null,
            rain: data.current.rain ?? null,
            precipitation: data.current.precipitation ?? null,
            // Unità di misura
            units: globalUnits.forecast,
            // Dati orari per grafici
            hourly: {
                time: data.hourly?.time,
                temperature: data.hourly?.temperature_2m,
                humidity: data.hourly?.relative_humidity_2m,
                windSpeed: data.hourly?.wind_speed_10m
            },
            hourlyUnits: data.hourly_units || null
        };
    } catch (error) {
        console.error(`[OpenMeteo Forecast] Errore: ${error.message}`);
        return null;
    }
}

async function getSeaConditions(location) {
    if (!location?.latitude || !location?.longitude) {
        console.warn('[OpenMeteo] Coordinate non valide per onde');
        return null;
    }

    const currentParams = MARINE_PARAMS.current.join(",");
    const hourlyParams = MARINE_PARAMS.hourly.join(",");
    const api = `https://marine-api.open-meteo.com/v1/marine?latitude=${location.latitude}&longitude=${location.longitude}&hourly=${hourlyParams}&current=${currentParams}&models=ecmwf_wam`;

    try {
        const response = await axios.get(api, {
            headers: HEADERS,
            timeout: TIMEOUT,
            validateStatus: (status) => status === 200
        });

        const { data } = response;

        if (!data?.current) {
            console.warn('[OpenMeteo Marine] Risposta senza dati current');
            return null;
        }

        // Aggiorna unità globali da API response
        if (data.current_units) {
            globalUnits.waves = {
                waveHeight: data.current_units.wave_height || 'm',
                wavePeriod: data.current_units.wave_period || 's',
                waveDirection: data.current_units.wave_direction || '°',
                wavePeakPeriod: data.current_units.wave_peak_period || 's',
                currentVelocity: data.current_units.ocean_current_velocity || 'm/s',
                currentDirection: data.current_units.ocean_current_direction || '°'
            };
        }

        return {
            waveHeight: data.current.wave_height ?? null,
            wavePeriod: data.current.wave_period ?? null,
            waveDirection: data.current.wave_direction ?? null,
            wavePeakPeriod: data.current.wave_peak_period ?? null,
            currentDirection: data.current.ocean_current_direction ?? null,
            currentVelocity: data.current.ocean_current_velocity ?? null,
            // Unità di misura
            units: globalUnits.waves,
            // Dati orari per grafici
            hourly: {
                time: data.hourly?.time,
                waveHeight: data.hourly?.wave_height,
                wavePeriod: data.hourly?.wave_period,
                waveDirection: data.hourly?.wave_direction,
                currentDirection: data.hourly?.ocean_current_direction,
                currentVelocity: data.hourly?.ocean_current_velocity
            },
            hourlyUnits: data.hourly_units || null
        };
    } catch (error) {
        console.error(`[OpenMeteo Marine] Errore: ${error.message}`);
        return null;
    }
}

module.exports = { getSeaConditions, getForecast, getUnits, formatWithUnit };