document.addEventListener('DOMContentLoaded', () => {
    const stationInput = document.getElementById('station-input');
    const daysInput = document.getElementById('days-input');
    const fetchButton = document.getElementById('fetch-button');
    const loadingDiv = document.getElementById('loading');
    const errorDiv = document.getElementById('error');
    const resultsDiv = document.getElementById('results');
    const resultsTitle = document.getElementById('results-title');
    const analysisSummary = document.getElementById('analysis-summary');
    const rawDataContainer = document.getElementById('raw-data-container');

    // Устанавливаем значения по умолчанию
    stationInput.value = 'UIII'; // Иркутск
    daysInput.value = '14';

    const charts = {};

    const fetchAndDrawData = async () => {
        const station = stationInput.value.toUpperCase() || 'UIII';
        const days = daysInput.value || '14';

        loadingDiv.classList.remove('hidden');
        resultsDiv.classList.add('hidden');
        errorDiv.classList.add('hidden');

        try {
            const response = await fetch(`/api/metar?station=${station}&days=${days}`);
            if (!response.ok) {
                const errorData = await response.json();
                throw new Error(errorData.error || `HTTP error! status: ${response.status}`);
            }
            const apiResponse = await response.json();

            if (!apiResponse.data || apiResponse.data.length === 0) {
                throw new Error('Данные для указанной станции или периода не найдены.');
            }

            processData(apiResponse.data, station, days);

            loadingDiv.classList.add('hidden');
            resultsDiv.classList.remove('hidden');

        } catch (e) {
            loadingDiv.classList.add('hidden');
            errorDiv.textContent = `Ошибка: ${e.message}`;
            errorDiv.classList.remove('hidden');
        }
    };

    const processData = (data, station, days) => {
        resultsTitle.textContent = `Результаты для ${station} за последние ${days} дней`;

        const labels = [];
        const temperatures = [];
        const dewPoints = [];
        const pressures = [];
        const windSpeeds = [];
        const windDirections = [];

        const fToC = (f) => f !== null ? ((f - 32) * 5 / 9).toFixed(1) : null;
        const inHgToHpa = (inHg) => inHg !== null ? (inHg * 33.8639).toFixed(1) : null;
        const knotsToMs = (knots) => knots !== null ? (knots * 0.514444).toFixed(1) : null;

        data.forEach(report => {
            labels.push(new Date(report.valid).toLocaleString('ru-RU', { timeZone: 'UTC' }));
            temperatures.push(fToC(report.tmpf));
            dewPoints.push(fToC(report.dwpf));
            pressures.push(inHgToHpa(report.alti));
            windSpeeds.push(knotsToMs(report.sknt));
            if (report.drct) {
                windDirections.push(report.drct);
            }
        });

        // графики
        drawChart('temp-chart', 'line', {
            labels,
            datasets: [
                {
                    label: 'Температура (°C)',
                    data: temperatures,
                    borderColor: 'rgba(255, 99, 132, 1)',
                    backgroundColor: 'rgba(255, 99, 132, 0.2)',
                    fill: false,
                    tension: 0.1
                },
                {
                    label: 'Точка росы (°C)',
                    data: dewPoints,
                    borderColor: 'rgba(54, 162, 235, 1)',
                    backgroundColor: 'rgba(54, 162, 235, 0.2)',
                    fill: false,
                    tension: 0.1
                }
            ]
        }, 'Температура и точка росы');

        drawChart('pressure-chart', 'line', {
            labels,
            datasets: [{
                label: 'Давление (гПа)',
                data: pressures,
                borderColor: 'rgba(75, 192, 192, 1)',
                backgroundColor: 'rgba(75, 192, 192, 0.2)',
                fill: false,
                tension: 0.1
            }]
        }, 'Атмосферное давление (QNH)');

        drawChart('wind-speed-chart', 'line', {
            labels,
            datasets: [{
                label: 'Скорость ветра (м/с)',
                data: windSpeeds,
                borderColor: 'rgba(153, 102, 255, 1)',
                backgroundColor: 'rgba(153, 102, 255, 0.2)',
                fill: false,
                tension: 0.1
            }]
        }, 'Скорость ветра');

        // анализ
        performAnalysis(temperatures, windSpeeds, windDirections);

        // отображение данных тлько последние 50
        displayRawData(data.slice(-20));
    };

    const drawChart = (canvasId, type, data, title) => {
        const ctx = document.getElementById(canvasId).getContext('2d');

        if (charts[canvasId]) {
            charts[canvasId].destroy();
        }

        charts[canvasId] = new Chart(ctx, {
            type: type,
            data: data,
            options: {
                responsive: true,
                maintainAspectRatio: false,
                plugins: {
                    title: {
                        display: true,
                        text: title,
                        font: { size: 16 }
                    }
                },
                scales: {
                    x: {
                        ticks: {
                            maxTicksLimit: 15
                        }
                    }
                }
            }
        });
    };

    const performAnalysis = (temps, speeds, directions) => {
        const validTemps = temps.filter(t => t !== null).map(Number);
        const validSpeeds = speeds.filter(s => s !== null).map(Number);

        const maxTemp = Math.max(...validTemps);
        const minTemp = Math.min(...validTemps);
        const avgTemp = (validTemps.reduce((a, b) => a + b, 0) / validTemps.length).toFixed(1);

        const maxWind = Math.max(...validSpeeds);

        const getWindDirection = (deg) => {
            if (deg > 337.5 || deg <= 22.5) return 'С';
            if (deg > 22.5 && deg <= 67.5) return 'СВ';
            if (deg > 67.5 && deg <= 112.5) return 'В';
            if (deg > 112.5 && deg <= 157.5) return 'ЮВ';
            if (deg > 157.5 && deg <= 202.5) return 'Ю';
            if (deg > 202.5 && deg <= 247.5) return 'ЮЗ';
            if (deg > 247.5 && deg <= 292.5) return 'З';
            if (deg > 292.5 && deg <= 337.5) return 'СЗ';
            return null;
        };

        const dirCounts = directions.map(getWindDirection)
            .filter(d => d !== null)
            .reduce((acc, dir) => {
                acc[dir] = (acc[dir] || 0) + 1;
                return acc;
            }, {});

        const prevailingDir = Object.keys(dirCounts).length > 0 ? Object.keys(dirCounts).reduce((a, b) => dirCounts[a] > dirCounts[b] ? a : b) : 'Нет данных';

        analysisSummary.innerHTML = `
            <ul>
                <li><strong>Температура:</strong></li>
                <ul>
                    <li>Максимальная: <strong>${maxTemp}°C</strong></li>
                    <li>Минимальная: <strong>${minTemp}°C</strong></li>
                    <li>Средняя: <strong>${avgTemp}°C</strong></li>
                </ul>
                <li><strong>Ветер:</strong></li>
                <ul>
                    <li>Максимальная скорость: <strong>${maxWind} м/с</strong></li>
                    <li>Преобладающее направление: <strong>${prevailingDir}</strong></li>
                </ul>
            </ul>
        `;
    };

    const displayRawData = (data) => {
        let tableHTML = `
        <table>
            <thead>
                <tr>
                    <th>Время (UTC)</th>
                    <th>Сводка METAR</th>
                </tr>
            </thead>
            <tbody>
    `;
        data.forEach(report => {
            const date = new Date(report.valid);

            const formattedDate = date.toLocaleString('ru-RU', {
                timeZone: 'UTC',
                year: 'numeric',
                month: '2-digit',
                day: '2-digit',
                hour: '2-digit',
                minute: '2-digit'
            });

            tableHTML += `
            <tr>
                <td>${formattedDate}</td>
                <td><code>${report.metar}</code></td>
            </tr>
        `;
        });
        tableHTML += `</tbody></table>`;
        rawDataContainer.innerHTML = tableHTML;
    };


    fetchButton.addEventListener('click', fetchAndDrawData);

    fetchAndDrawData();
});