const status = document.querySelector("#status");
const driverCount = document.querySelector("#driver-count");
const trackName = document.querySelector("#track-name");
const sessionType = document.querySelector("#session-type");
const timeLeft = document.querySelector("#time-left");
const weather = document.querySelector("#weather");
const lastUpdate = document.querySelector("#last-update");
const leaderboardNote = document.querySelector("#leaderboard-note");
const leaderboardBody = document.querySelector("#leaderboard-body");

function escapeHtml(value) {
  return String(value ?? "")
    .replaceAll("&", "&")
    .replaceAll("<", "&lt;")
    .replaceAll(">", "&gt;")
    .replaceAll('"', "&quot;");
}

function fmt(value, fallback = "-") {
  if (value === undefined || value === null || value === "" || Number.isNaN(value)) {
    return `<span class="empty">${fallback}</span>`;
  }
  return escapeHtml(value);
}

function fmtTime(seconds) {
  if (typeof seconds !== "number" || !Number.isFinite(seconds) || seconds < 0) {
    return "-";
  }

  const minutes = Math.floor(seconds / 60);
  const remainder = seconds - minutes * 60;
  return `${minutes}:${remainder.toFixed(3).padStart(6, "0")}`;
}

function fmtSplit(split) {
  if (!split || typeof split.delta !== "number" || !Number.isFinite(split.delta)) {
    return "-";
  }

  if (split.delta === 0) {
    return "0";
  }

  const sign = split.delta > 0 ? "+" : "-";
  return `${sign}${Math.abs(split.delta).toFixed(3)}`;
}

function sectorSplitForRow(row, session) {
  const sessionType = String(session?.sessionType || "").toLowerCase();
  const usePersonalBest = sessionType === "practice" || sessionType === "qualifying";
  return usePersonalBest
    ? row?.sectorTimeSplit || row?.checkpointSplit
    : row?.checkpointSplit || row?.sectorTimeSplit;
}

function positionChange(change) {
  if (!change?.direction) {
    return '<span class="position-change-placeholder" aria-hidden="true"></span>';
  }

  const isUp = change.direction === "up";
  const label = `${isUp ? "Moved up" : "Moved down"} ${change.places ?? 1}`;
  return `
    <span class="position-change ${isUp ? "position-up" : "position-down"}" title="${escapeHtml(label)}">
      ${isUp ? "▲" : "▼"}${change.places && change.places > 1 ? escapeHtml(change.places) : ""}
    </span>
  `;
}

function nationalityBadge(nationality) {
  if (!nationality?.code) {
    return '<span class="empty">-</span>';
  }

  const title = `${nationality.country || nationality.code}${nationality.source === "override" ? " (name override)" : ""}`;
  const flag = flagSvg(nationality.code);
  return `<span class="nat-badge" title="${escapeHtml(`${title} - ${nationality.code}`)}">${flag || escapeHtml(nationality.code)}</span>`;
}

function carShortName(row) {
  if (!row?.vehicleShortName) {
    return '<span class="empty">-</span>';
  }

  return `<span title="${escapeHtml(row.vehicle || row.vehicleShortName)}">${escapeHtml(row.vehicleShortName)}</span>`;
}

function statusBadge(row) {
  const status = row?.status;
  const label = status?.label || (row?.active === false ? "Inactive" : "Active");
  const tone = status?.tone || (row?.active === false ? "warn" : "good");
  return `<span class="${tone === "warn" ? "warn" : "good"}">${escapeHtml(label)}</span>`;
}

function raceFlagDetails(row) {
  const flag = row?.flag;
  if (!flag || row.highestFlag === undefined || row.highestFlag === null) {
    return `flag ${fmt(row?.highestFlag)}`;
  }

  const label = flag.observed ? ` ${escapeHtml(flag.observed)}` : "";
  return `flag ${fmt(row.highestFlag)} c${fmt(flag.colour)} r${fmt(flag.reason)}${label}`;
}

function flagSvg(code) {
  const iso2ByIso3 = {
    DEU: "DE",
    FRA: "FR",
    GBR: "GB",
    JPN: "JP",
    USA: "US"
  };
  const iso2 = iso2ByIso3[String(code).toUpperCase()];
  if (!iso2) return "";

  const flags = {
    DE: `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 60 40"><path fill="#000" d="M0 0h60v13.333H0z"/><path fill="#dd0000" d="M0 13.333h60v13.334H0z"/><path fill="#ffce00" d="M0 26.667h60V40H0z"/></svg>`,
    FR: `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 60 40"><path fill="#002395" d="M0 0h20v40H0z"/><path fill="#fff" d="M20 0h20v40H20z"/><path fill="#ed2939" d="M40 0h20v40H40z"/></svg>`,
    GB: `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 60 40"><path fill="#012169" d="M0 0h60v40H0z"/><path stroke="#fff" stroke-width="8" d="m0 0 60 40M60 0 0 40"/><path stroke="#c8102e" stroke-width="4" d="m0 0 60 40M60 0 0 40"/><path fill="#fff" d="M25 0h10v40H25zM0 15h60v10H0z"/><path fill="#c8102e" d="M27 0h6v40h-6zM0 17h60v6H0z"/></svg>`,
    JP: `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 60 40"><path fill="#fff" d="M0 0h60v40H0z"/><circle cx="30" cy="20" r="11" fill="#bc002d"/></svg>`,
    US: `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 60 40"><path fill="#b22234" d="M0 0h60v40H0z"/><path stroke="#fff" stroke-width="3.08" d="M0 3.08h60M0 9.23h60M0 15.38h60M0 21.54h60M0 27.69h60M0 33.85h60"/><path fill="#3c3b6e" d="M0 0h24v21.54H0z"/></svg>`
  };

  const svg = flags[iso2];
  return svg ? `<img class="flag-img" alt="${escapeHtml(iso2)} flag" src="data:image/svg+xml,${encodeURIComponent(svg)}">` : "";
}

function clock(value) {
  if (!value) return "-";
  return new Date(value).toLocaleTimeString();
}

function renderLeaderboard(leaderboard) {
  const rows = leaderboard?.rows ?? [];
  const session = leaderboard?.session ?? {};

  driverCount.textContent = String(rows.length);
  leaderboardNote.textContent = leaderboard?.note ?? "Waiting for participant or timing packets";
  trackName.textContent = session.trackName || "-";
  sessionType.textContent = session.sessionType || "-";
  timeLeft.textContent = fmtTime(session.timeLeft);
  weather.textContent = session.weather || "-";
  lastUpdate.textContent = clock(session.lastUpdate);

  leaderboardBody.innerHTML = rows.length
    ? rows.map((row) => `
      ${(() => {
        const sectorSplit = sectorSplitForRow(row, session);
        return `
      <tr class="${row.active === false ? "inactive-row" : ""}">
        <td class="pos"><span class="pos-inner"><span>${fmt(row.position)}</span>${positionChange(row.positionChange)}</span></td>
        <td>
          <strong>${fmt(row.driver)}</strong>
          <span class="subtle">slot ${fmt(row.slot)} / id ${fmt(row.id)}</span>
        </td>
        <td>${nationalityBadge(row.nationality)}</td>
        <td>${carShortName(row)}</td>
        <td>${fmt(row.lap)}</td>
        <td>${fmt(row.sector)}</td>
        <td>${fmtTime(row.currentTime)}</td>
        <td>${fmtTime(row.lastLapTime)}</td>
        <td>
          ${fmtSplit(row.latestLapSplit)}
          <span class="subtle">${row.latestLapSplit?.comparedTo ? `vs ${fmt(row.latestLapSplit.comparedTo)}` : ""}</span>
        </td>
        <td>${fmtTime(row.fastestLapTime)}</td>
        <td>
          ${fmtSplit(row.bestLapSplit)}
          <span class="subtle">${row.bestLapSplit?.comparedTo ? `vs ${fmt(row.bestLapSplit.comparedTo)}` : ""}</span>
        </td>
        <td>
          ${fmtSplit(sectorSplit)}
          <span class="subtle">${fmt(sectorSplit?.checkpoint)}${sectorSplit?.comparedTo ? ` vs ${fmt(sectorSplit.comparedTo)}` : ""}</span>
        </td>
        <td>${fmtTime(sectorSplit?.time)}</td>
        <td>
          ${statusBadge(row)}
          <span class="subtle">pit ${fmt(row.pitModeSchedule)} / ${raceFlagDetails(row)}</span>
        </td>
      </tr>
    `;
      })()}
    `).join("")
    : `<tr><td colspan="14" class="empty">No leaderboard data received yet</td></tr>`;
}

fetch("/api/leaderboard")
  .then((response) => response.json())
  .then(renderLeaderboard)
  .catch(() => {
    status.textContent = "Could not load leaderboard state";
    status.className = "warn";
  });

const events = new EventSource("/events");

events.addEventListener("state", (event) => {
  const payload = JSON.parse(event.data);
  renderLeaderboard(payload.leaderboard);
});

events.addEventListener("leaderboard", (event) => {
  const leaderboard = JSON.parse(event.data);
  status.textContent = `Receiving packets. Last update ${clock(leaderboard?.session?.lastUpdate)}`;
  status.className = "good";
  renderLeaderboard(leaderboard);
});

events.onerror = () => {
  status.textContent = "Connection to local telemetry server lost";
  status.className = "warn";
};