import React, { useEffect, useRef, useMemo } from 'react';
import { Chart as ChartJS, CategoryScale, LinearScale, PointElement, BarElement, Title, Tooltip, Legend, Filler,} from 'chart.js';
import { Bar } from 'react-chartjs-2';
import { useVeltClient, useCommentAnnotations, useCommentModeState, VeltCommentPin } from '@veltdev/react';

// Register the necessary Chart.js components
ChartJS.register(CategoryScale, LinearScale, PointElement, BarElement, Title, Tooltip, Legend, Filler);

// Define the data for the chart
const scores = [6, 5, 5, 5, 3, 4, 6, 4, 5];
const labels = [100, 200, 300, 400, 500, 600, 700];

// Set the options for the chart
const options: any = {
// your chart options
};

const BarChart = () => {
  const chartId = 'dataAnalyticsChart'; // Unique ID for the chart
  const chartRef = useRef(null); // Reference to the chart instance
  const { client } = useVeltClient(); // Get Velt client
  const commentModeState = useCommentModeState(); // Get Velt comment mode state
  const commentAnnotations = useCommentAnnotations(); // Get Velt comment annotations
  const [chartCommentAnnotations, setChartCommentAnnotations] = React.useState([]); // State for chart comments

  // Update chart comments when annotations change
  useEffect(() => {
    // Filter comments for the current chart, using unique chart ID
    const chartCommentAnnotations = commentAnnotations?.filter((comment) => comment.context?.chartId === chartId); 
    setChartCommentAnnotations(chartCommentAnnotations as any || []);
  }, [commentAnnotations]);

  // Handle chart clicks to find nearest data point and add a comment
  const handleChartClick = (event: any) => {
    const chart: any = chartRef.current;
    if (chart) {
      // Get the nearest element to the click event
      const elements = chart.getElementsAtEventForMode(event.nativeEvent, 'nearest', { intersect: true }, false);
      if (elements.length > 0) {
        const element = elements[0];
        const datasetIndex = element.datasetIndex;
        const index = element.index;
        const dataset = chart.data.datasets[datasetIndex];
        const xValue = chart.data.labels[index];
        const yValue = dataset.data[index];
        const context = { seriesId: dataset.label, xValue, yValue, chartId };
        addManualComment(context); // Add a comment at the nearest data point with the context data
      }
    }
  };

  // Add a manual comment to the chart
  const addManualComment = (context: any) => {
    try {
      if (client && commentModeState) {
        const commentElement = client.getCommentElement();
        commentElement.addManualComment({ context }); // Add a Velt comment
      }
    } catch (error) {
      console.error('Error adding manual comment', error);
    }
  };

  // Find the exact point on the chart to place a comment pin
  const findPoint = (seriesId: any, xValue: any, yValue: any) => {
    const chart: any = chartRef.current;
    if (chart) {
      const dataset = chart.data.datasets.find((dataset: any) => dataset.label === seriesId);
      const index = chart.data.labels.indexOf(xValue);
      if (dataset && index !== -1) {
        const yValueInDataset = dataset.data[index];
        if (yValueInDataset === yValue) {
          return { x: chart.scales.x.getPixelForValue(index), y: chart.scales.y.getPixelForValue(yValue) }; // Set the x, y position for the comment pin
        }
      }
    }
    return null;
  };

  // Show the comment pin on the chart at the specified point
  const showCommentPin = (commentAnnotation: any) => {
    const context = commentAnnotation.context || {};
    const point = findPoint(context.seriesId, context.xValue, context.yValue);
    if (point) {
      const { x, y } = point;
      return (
        <div
          key={commentAnnotation.annotationId}
          style={{
            left: `${x}px`,
            top: `${y}px`,
            position: 'absolute',
            transform: 'translate(0%, -100%)',
            zIndex: 1000,
          }}
        >
          <VeltCommentPin annotationId={commentAnnotation.annotationId} /> {/* Velt comment pin component */}
        </div>
      );
    }
    return null;
  };

  // Memoize the chart data
  const data = useMemo(() => {
    return {
      datasets: [
        {
          label: 'Mis datos',
          tension: 0.3,
          data: scores,
          borderColor: 'rgb(75, 192, 192)',
          backgroundColor: 'rgba(75, 192, 192, 0.3)',
        },
      ],
      labels,
    };
  }, []);

  return (
    <div className="dashlet-card">
      <div className="dashlet-card-header">Bar Chart With Comments</div>
      {/* Keep the parent div as relative, as comment pin will be placed with absolute position */}
      {/* Set "data-velt-manual-comment-container" to true, so that comment pin will know which div to consider while positioning */}
      <div style={{ position: 'relative' }} onClick={handleChartClick} data-velt-manual-comment-container="true"> 
        <Bar data={data} options={options} ref={chartRef} /> {/* Render the Bar chart */}
        {chartCommentAnnotations.map((comment, index) => showCommentPin(comment))} {/* Show all comment pins */}
      </div>
    </div>
  );
};

export default BarChart;