export function flattenData(raw) {
  const result = {};
  for (const [date, repos] of Object.entries(raw)) {
    result[date] = Object.values(repos).reduce((sum, n) => sum + n, 0);
  }
  return result;
}

export function constructWeeks() {
  const today = new Date();
  today.setHours(0, 0, 0, 0);

  const start = new Date(today);
  start.setDate(today.getDate() - 52 * 7);
  start.setDate(start.getDate() - start.getDay());

  const weeks = [];
  const cur = new Date(start);
  while (cur <= today) {
    const week = [];
    for (let d = 0; d < 7; d++) {
      const day = new Date(cur);
      week.push(day <= today ? day : null);
      cur.setDate(cur.getDate() + 1);
    }
    weeks.push(week);
  }
  return weeks;
}

function getColor(count) {
  if (count === 0) return "var(--color-empty)";
  if (count <= 2) return "var(--color-l1)";
  if (count <= 5) return "var(--color-l2)";
  if (count <= 10) return "var(--color-l3)";
  return "var(--color-l4)";
}

export function render(weeks, counts) {
  const CELL = 13;
  const GAP = 2;
  const SHIFT = CELL + GAP;

  const svgNS = "http://www.w3.org/2000/svg";
  const svg = document.createElementNS(svgNS, "svg");

  const svgWidth = weeks.length * SHIFT + 30;
  const svgHeight = SHIFT * 7;
  svg.setAttribute("viewBox", `0 0 ${svgWidth} ${svgHeight}`);
  svg.setAttribute("width", "100%");

  // Place the labels first
  ["Mon", "Wed", "Fri"].forEach((label, i) => {
    const dayLabel = document.createElementNS(svgNS, "text");
    dayLabel.setAttribute("x", 0);
    dayLabel.setAttribute("y", (2 * i + 1) * SHIFT + 0.75 * CELL);
    dayLabel.setAttribute("font-size", 12);

    const text = document.createTextNode(label);
    dayLabel.appendChild(text);
    svg.appendChild(dayLabel);
  });

  weeks.forEach((week, col) => {
    week.forEach((day, row) => {
      if (day === null) {
        return;
      }
      const key = day.toISOString().slice(0, 10); // Get the key in yyyy-mm-dd format

      const count = counts[key] || 0;

      const rect = document.createElementNS(svgNS, "rect");
      rect.setAttribute("x", col * SHIFT + 30);
      rect.setAttribute("y", row * SHIFT);
      rect.setAttribute("height", CELL);
      rect.setAttribute("width", CELL);
      rect.setAttribute("fill", getColor(count));
      rect.setAttribute("rx", 2);
      rect.setAttribute("data-date", key);
      rect.setAttribute("data-count", count);

      svg.appendChild(rect);
    });
  });
  return svg;
}

export function totalCount(counts) {
  return Object.values(counts).reduce((s, v) => s + v, 0);
}

export function renderLegend() {
  const CELL = 11;
  const GAP = 3;
  const SHIFT = CELL + GAP;
  const svgNS = "http://www.w3.org/2000/svg";
  const svg = document.createElementNS(svgNS, "svg");
  svg.setAttribute("width", 5 * SHIFT - GAP);
  svg.setAttribute("height", CELL);
  svg.style.display = "inline-block";
  svg.style.verticalAlign = "middle";

  const colors = [
    "var(--color-empty)",
    "var(--color-l1)",
    "var(--color-l2)",
    "var(--color-l3)",
    "var(--color-l4)",
  ];
  colors.forEach((color, i) => {
    const rect = document.createElementNS(svgNS, "rect");
    rect.setAttribute("x", i * SHIFT);
    rect.setAttribute("y", 0);
    rect.setAttribute("width", CELL);
    rect.setAttribute("height", CELL);
    rect.setAttribute("fill", color);
    rect.setAttribute("rx", 2);
    svg.appendChild(rect);
  });

  return svg;
}

export function setupTooltips(svg) {
  const tooltip = document.getElementById("tooltip");
  document.body.appendChild(tooltip);

  svg.addEventListener("mouseover", (e) => {
    if (e.target.tagName != "rect") return;
    const date = e.target.dataset.date;
    const count = e.target.dataset.count;

    tooltip.textContent = `${date} - ${count} contribution${count == 1 ? "" : "s"}`;
    tooltip.classList.remove("hidden");
  });

  svg.addEventListener("mousemove", (e) => {
    tooltip.style.left = e.clientX + 12 + "px";
    tooltip.style.top = e.clientY - 28 + "px";
  });

  svg.addEventListener("mouseout", (e) => {
    if (e.target.tagName === "rect") tooltip.classList.add("hidden");
  });
}