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class DoublyLinkedList {
  constructor() {
    this.nodes = [];
  }

  get size() {
    return this.nodes.length;
  }

  get head() {
    return this.size ? this.nodes[0] : null;
  }

  get tail() {
    return this.size ? this.nodes[this.size - 1] : null;
  }

  insertAt(index, value) {
    const previousNode = this.nodes[index - 1] || null;
    const nextNode = this.nodes[index] || null;
    const node = { value, next: nextNode, previous: previousNode };

    if (previousNode) previousNode.next = node;
    if (nextNode) nextNode.previous = node;
    this.nodes.splice(index, 0, node);
  }

  insertFirst(value) {
    this.insertAt(0, value);
  }

  insertLast(value) {
    this.insertAt(this.size, value);
  }

  getAt(index) {
    return this.nodes[index];
  }

  removeAt(index) {
    const previousNode = this.nodes[index - 1] || null;
    const nextNode = this.nodes[index + 1] || null;

    if (previousNode) previousNode.next = nextNode;
    if (nextNode) nextNode.previous = previousNode;

    return this.nodes.splice(index, 1);
  }

  clear() {
    this.nodes = [];
  }

  reverse() {
    this.nodes = this.nodes.reduce((acc, { value }) => {
      const nextNode = acc[0] || null;
      const node = { value, next: nextNode, previous: null };
      if (nextNode) nextNode.previous = node;
      return [node, ...acc];
    }, []);
  }

  *[Symbol.iterator]() {
    yield* this.nodes;
  }
}

const list = new DoublyLinkedList();

list.insertFirst(1);
list.insertFirst(2);
list.insertFirst(3);
list.insertLast(4);
list.insertAt(3, 5);

list.size;                      // 5
list.head.value;                // 3
list.head.next.value;           // 2
list.tail.value;                // 4
list.tail.previous.value;       // 5
[...list.map(e => e.value)];    // [3, 2, 1, 5, 4]

list.removeAt(1);               // 2
list.getAt(1).value;            // 1
list.head.next.value;           // 1
[...list.map(e => e.value)];    // [3, 1, 5, 4]

list.reverse();
[...list.map(e => e.value)];    // [4, 5, 1, 3]

list.clear();
list.size;                      // 0
const rectSize = 15; // Size of the color box
        const spacing = 5; // Space between legend items
        let legend = canvas.append('g').attr('class','chart-legend')
        .attr('transform', `translate(${0}, ${height + 3})`);

        // Sample data for the legend
        const legendData = [
            { label: 'low', color: '#1f77b4' },
            { label: 'medium', color: '#ff7f0e' },
            { label: 'high', color: '#2ca02c' },
            { label: 'very high', color: '#2ca02c' }
        ];


        legend.selectAll('g')
            .data(legendData)
            .join('g')
            .attr('class', 'legend-item')
            
            .each(function (d, i) {
                const legendItem = d3.select(this);
                console.log(d.label)
                console.log(d.label?.length)
                let labelWidth = (d.label.length * 5) + 7 + 15
                

                var bbox = legendItem.node().getBBox()
                var width = bbox.width
                console.log(width)
                
                // Add rectangle for color
                legendItem.append('rect')
                    .attr('width', rectSize)
                    .attr('height', rectSize)
                    .attr('fill', d.color);
                    
                    // Add label
                    legendItem.append('text')
                    .attr('x', rectSize + spacing) // Position text to the right of the rectangle
                    .attr('y', rectSize / 2) // Align text vertically with the rectangle
                    .attr('dy', '.35em') // Adjust vertical alignment
                    .attr('text-anchor', 'start') // Align text to the start
                    .text(d.label)
                    .attr('fill', 'black'); // Optional: Text color
                // legendItem.attr('transform', `translate(${i * (rectSize + spacing + labelWidth)}, 0)`) // Position each item horizontally
            });

            const legendItems_spacing = 12
            var legendLength = 0
            legend.selectAll('.legend-item').each(function(d,i) {
              d3.select(this).attr('transform',function() {
                var bbox = d3.select(this).node().getBBox()
                var width = bbox.width
                // if (width == 0) width = (d.text.length * 5) +15  // not in dom yet
                let startingPosition = 0 
                if (i > 0) {
                    startingPosition = legendLength
                }
                legendLength += width + legendItems_spacing
                
                // return `translate(${xx - (width + 30)},0$)`
                return `translate(${startingPosition},0)`
            })
            })