// Define the default fill and stroke colors
const defaultFill = "#dcfce7";
const defaultStroke = "#bbf7d0";

// Define the stroke width
const strokeWidth = 4;

/**
 * Draws a sparkline SVG based on the given width, height and points
 * @param {number} width - The width of the SVG element
 * @param {number} height - The height of the SVG element
 * @param {number[]} points - The array of points to plot
 * @param {string} [fill=defaultFill] - The fill color of the area under the curve
 * @param {string} [stroke=defaultStroke] - The stroke color of the curve
 * @returns {string} The SVG markup
 */
function draw(width, height, points, fill = defaultFill, stroke = defaultStroke) {
  // Calculate the viewbox dimensions based on the points
  let vbWidth = points.length - 1;
  let vbHeight = Math.max(...points);

  // Return the SVG markup with the paths and attributes
  return `
    <svg height="${height}" width="${width}" viewBox="0 0 ${vbWidth} ${vbHeight}" preserveAspectRatio="none" role="img" xmlns="http://www.w3.org/2000/svg">
      <path d="${closedPath(points, vbWidth, vbHeight)}" stroke="transparent" fill="${fill}" />
      <path d="${path(points, vbWidth, vbHeight)}" stroke-width="${strokeWidth}" vector-effect="non-scaling-stroke" stroke="${stroke}" fill="transparent" />
    </svg>
  `;
}

/**
 * Generates the path for the curve
 * @param {number[]} points - The array of points to plot
 * @param {number} vbWidth - The viewbox width
 * @param {number} vbHeight - The viewbox height
 * @returns {string} The path data
 */
const path = (points, vbWidth, vbHeight) => [
  "M",
  points
    .map((value, i) => {
      let x = i;
      let y = vbHeight - value;
      return `${x} ${y}${i < vbWidth ? " L " : ""}`;
    })
    .join("")
].join("");

/**
 * Generates the path for the area under the curve
 * @param {number[]} points - The array of points to plot
 * @param {number} vbWidth - The viewbox width
 * @param {number} vbHeight - The viewbox height
 * @returns {string} The path data
 */
const closedPath = (points, vbWidth, vbHeight) => [
  path(points, vbWidth, vbHeight),
  ` L ${vbWidth} ${vbHeight} L 0 ${vbHeight} Z`
].join("");

// Export the draw function as a module
module.exports = draw;