// Import Chart.js types
import type { Chart, ChartConfiguration, ChartType } from 'chart.js';
import type { WeatherChartDataset, YAxisOptions } from '../types/chart-types';
import type { HandleEventFunction } from '../types/events';

// Declare global Chart object from CDN
declare global {
    interface Window {
        Chart: typeof Chart;
        chartInstances?: Map<string, ChartHookContext>;
    }
}

// Type for LiveView hooks
interface Hook {
    mounted?: () => void;
    updated?: () => void;
    destroyed?: () => void;
    el: HTMLElement;
    handleEvent: HandleEventFunction;
}

// Define chart hook context type
interface ChartHookContext extends Hook {
    chart?: Chart;
    themeChangeHandler?: () => void;
    renderChart: () => void;
}

// Type for weather history data
interface WeatherHistoryDatum {
    timestamp: string;
    temperature?: number;
    dew_point?: number;
    humidity?: number;
    pressure?: number;
    wind_direction?: number;
    wind_speed?: number;
    wind_gust?: number;
    rain_1h?: number;
    rain_24h?: number;
    rain_since_midnight?: number;
    luminosity?: number;
}

// Type for the event payload
interface UpdateWeatherChartsPayload {
    weather_history: string;
}

// Helper function to safely parse weather history data
const parseWeatherHistory = (dataStr: string | undefined): WeatherHistoryDatum[] => {
    if (!dataStr) {
        console.warn("No weather history data provided");
        return [];
    }
    try {
        return JSON.parse(dataStr);
    } catch (error) {
        console.error("Failed to parse weather history data:", error);
        return [];
    }
};

// Helper function to get theme-aware colors
const getThemeColors = () => {
    const isDark = document.documentElement.getAttribute('data-theme') === 'dark';
    return {
        text: isDark ? '#e5e7eb' : '#111827',
        grid: isDark ? '#374151' : '#9ca3af',
        background: isDark ? 'rgba(0, 0, 0, 0.1)' : 'rgba(255, 255, 255, 0.1)'
    };
};

// Register a chart instance
const registerChartInstance = (element: HTMLElement, instance: ChartHookContext) => {
    if (!window.chartInstances) {
        window.chartInstances = new Map();
    }
    const elementId = element.id || `chart-${Date.now()}`;
    if (!element.id) element.id = elementId;
    window.chartInstances.set(elementId, instance);
};

// Unregister a chart instance
const unregisterChartInstance = (element: HTMLElement) => {
    if (window.chartInstances && element.id) {
        const instance = window.chartInstances.get(element.id);
        if (instance?.chart) {
            instance.chart.destroy();
        }
        window.chartInstances.delete(element.id);
    }
};

// Get labels from the element
const getLabels = (el: HTMLElement | null): Record<string, string> => {
    if (!el || !el.dataset.labels) return {};
    const raw = el.dataset.labels;
    if (!raw) return {};
    try {
        return JSON.parse(raw);
    } catch {
        return {};
    }
}

// Chart configurations
interface ChartConfig {
    type: ChartType;
    datasets: (data: WeatherHistoryDatum[], labels: Record<string, string>) => WeatherChartDataset[];
    title: (labels: Record<string, string>) => string;
    yAxisLabel?: (labels: Record<string, string>) => string;
    yAxisOptions?: YAxisOptions;
}

const chartConfigs: Record<string, ChartConfig> = {
    temperature: {
        type: 'line',
        datasets: (data, labels) => [
            {
                label: labels.temp_label || 'Temperature (°F)',
                data: data.map(d => d.temperature),
                borderColor: 'red',
                backgroundColor: 'rgba(255, 0, 0, 0.1)',
                tension: 0.1,
                pointRadius: 0
            },
            {
                label: labels.dew_label || 'Dew Point (°F)',
                data: data.map(d => d.dew_point),
                borderColor: 'blue',
                backgroundColor: 'rgba(0, 0, 255, 0.1)',
                tension: 0.1,
                pointRadius: 0
            }
        ],
        title: (labels) => labels.temp_title || 'Temperature & Dew Point (°F)',
        yAxisLabel: (labels) => labels.degf || '°F'
    },
    humidity: {
        type: 'line',
        datasets: (data, labels) => [{
            label: labels.hum_label || 'Humidity (%)',
            data: data.map(d => d.humidity),
            borderColor: 'green',
            backgroundColor: 'rgba(0, 255, 0, 0.1)',
            tension: 0.1,
            pointRadius: 0
        }],
        title: (labels) => labels.hum_title || 'Humidity (%)',
        yAxisLabel: (labels) => labels.percent || '%',
        yAxisOptions: { min: 0, max: 100 }
    },
    pressure: {
        type: 'line',
        datasets: (data, labels) => [{
            label: labels.prs_label || 'Pressure (mb)',
            data: data.map(d => d.pressure),
            borderColor: 'purple',
            backgroundColor: 'rgba(128, 0, 128, 0.1)',
            tension: 0.1,
            pointRadius: 0
        }],
        title: (labels) => labels.prs_title || 'Barometric Pressure (mb)',
        yAxisLabel: (labels) => labels.mb || 'mb'
    },
    wind: {
        type: 'line',
        datasets: (data, labels) => [
            {
                label: labels.spd_label || 'Wind Speed (mph)',
                data: data.map(d => d.wind_speed),
                borderColor: 'orange',
                backgroundColor: 'rgba(255, 165, 0, 0.1)',
                tension: 0.1,
                pointRadius: 0
            },
            {
                label: labels.gst_label || 'Wind Gust (mph)',
                data: data.map(d => d.wind_gust),
                borderColor: 'red',
                backgroundColor: 'rgba(255, 0, 0, 0.1)',
                tension: 0.1,
                pointRadius: 0
            }
        ],
        title: (labels) => labels.wnd_title || 'Wind Speed & Gust (mph)',
        yAxisLabel: (labels) => labels.mph || 'mph',
        yAxisOptions: { min: 0 }
    },
    rain: {
        type: 'bar',
        datasets: (data, labels) => [
            {
                label: labels.h1_label || 'Rain 1h (in)',
                data: data.map(d => d.rain_1h),
                backgroundColor: 'rgba(54, 162, 235, 0.8)',
                borderColor: 'rgba(54, 162, 235, 1)',
                borderWidth: 1
            },
            {
                label: labels.h24_label || 'Rain 24h (in)',
                data: data.map(d => d.rain_24h ? d.rain_24h / 10 : null),
                backgroundColor: 'rgba(153, 102, 255, 0.8)',
                borderColor: 'rgba(153, 102, 255, 1)',
                borderWidth: 1
            }
        ],
        title: (labels) => labels.rain_title || 'Rainfall (inches)',
        yAxisLabel: (labels) => labels.inches || 'inches',
        yAxisOptions: { min: 0 }
    },
    luminosity: {
        type: 'line',
        datasets: (data, labels) => [{
            label: labels.lum_label || 'Luminosity (W/m²)',
            data: data.map(d => d.luminosity),
            borderColor: 'gold',
            backgroundColor: 'rgba(255, 215, 0, 0.1)',
            tension: 0.1,
            pointRadius: 0
        }],
        title: (labels) => labels.lum_title || 'Solar Radiation (W/m²)',
        yAxisLabel: (labels) => labels.wm2 || 'W/m²',
        yAxisOptions: { min: 0 }
    }
};

// Create a chart hook
function createChartHook(configKey: string): Hook {
    const config = chartConfigs[configKey];
    if (!config) {
        throw new Error(`Unknown chart config: ${configKey}`);
    }

    return {
        mounted() {
            const self = this as ChartHookContext;
            registerChartInstance(self.el, self);
            self.renderChart = () => {
                if (self.chart) self.chart.destroy();
                
                const data: WeatherHistoryDatum[] = parseWeatherHistory(self.el.dataset.weatherHistory);
                if (data.length === 0) return;
                
                const canvas = self.el.querySelector('canvas') as HTMLCanvasElement | null;
                if (!canvas) {
                    console.error("Canvas element not found for chart");
                    return;
                }
                
                const labels = getLabels(self.el);
                const times = data.map(d => new Date(d.timestamp));
                const colors = getThemeColors();
                
                const chartConfig: ChartConfiguration = {
                    type: config.type,
                    data: {
                        labels: times,
                        datasets: config.datasets(data, labels)
                    },
                    options: {
                        adapters: { date: { locale: 'en-GB' } },
                        responsive: true,
                        maintainAspectRatio: false,
                        plugins: {
                            title: { 
                                display: true, 
                                text: config.title(labels), 
                                color: colors.text 
                            },
                            legend: { labels: { color: colors.text } }
                        },
                        scales: {
                            x: {
                                type: 'time',
                                time: {
                                    unit: 'minute',
                                    tooltipFormat: 'HH:mm',
                                    displayFormats: { minute: 'HH:mm', hour: 'HH:mm' },
                                    locale: 'en-GB'
                                },
                                title: { display: true, text: labels.time || 'Time', color: colors.text },
                                ticks: { color: colors.text, maxTicksLimit: 8 },
                                grid: { color: colors.grid }
                            },
                            y: {
                                title: { 
                                    display: true, 
                                    text: config.yAxisLabel ? config.yAxisLabel(labels) : '', 
                                    color: colors.text 
                                },
                                ticks: { color: colors.text },
                                grid: { color: colors.grid },
                                ...(config.yAxisOptions || {})
                            }
                        }
                    }
                };
                
                self.chart = new window.Chart(canvas, chartConfig);
            };
            
            self.renderChart();
            self.themeChangeHandler = () => self.renderChart();
            window.addEventListener('themeChanged', self.themeChangeHandler);
            self.handleEvent("update_weather_charts", ({ weather_history }: UpdateWeatherChartsPayload) => {
                self.el.dataset.weatherHistory = weather_history;
                self.renderChart();
            });
        },
        
        updated() { 
            (this as ChartHookContext).renderChart(); 
        },
        
        destroyed() {
            const self = this as ChartHookContext;
            if (self.themeChangeHandler) {
                window.removeEventListener('themeChanged', self.themeChangeHandler);
            }
            unregisterChartInstance(self.el);
        }
    };
}

// Export weather chart hooks
export const WeatherChartHooks: Record<string, Hook> = {
    ChartJSTempChart: createChartHook('temperature'),
    ChartJSHumidityChart: createChartHook('humidity'),
    ChartJSPressureChart: createChartHook('pressure'),
    ChartJSWindChart: createChartHook('wind'),
    ChartJSRainChart: createChartHook('rain'),
    ChartJSLuminosityChart: createChartHook('luminosity')
};

export default WeatherChartHooks;