// Captures README screenshots (docs/screenshots/*.jpg) against a real, isolated instance
// of the app - own temp SQLite dir, own headless Chrome profile, exactly like the
// tests/browser_*.js suite and scripts/record-video-guides.mjs. Nothing here ever touches
// a real installation's data.
//
// Usage: node scripts/capture-screenshots.mjs [shot-name ...]
//   With no arguments, captures every shot below. Pass one or more names (e.g. "guide")
//   to capture only those. Output overwrites docs/screenshots/<name>.jpg.
//
// Captured at 1600x900 CSS with deviceScaleFactor 2 (3200x1800 JPEG), matching every
// existing screenshot in that folder - a plain viewport capture, not a full-page stitch,
// so a shot's setup should scroll to whatever should be visible before capturing.

import { spawn, execFileSync } from "node:child_process";
import { existsSync, mkdtempSync, rmSync, mkdirSync, writeFileSync } from "node:fs";
import { createServer } from "node:net";
import { tmpdir } from "node:os";
import { dirname, join } from "node:path";
import { fileURLToPath } from "node:url";
import { startFakeDecoder } from "../tests/browser_fake_decoder.js";

const projectDir = dirname(dirname(fileURLToPath(import.meta.url)));
const outputDir = join(projectDir, "docs", "screenshots");
const chrome = [process.env.CHROME_PATH, "/usr/bin/google-chrome", "/usr/bin/chromium", "/usr/bin/chromium-browser"].find((p) => p && existsSync(p));
if (!chrome) throw new Error("Chrome/Chromium not found. Set CHROME_PATH to the browser executable.");

const pause = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function waitFor(check, label, timeout = 15000) {
  const until = Date.now() + timeout;
  while (Date.now() < until) {
    try { if (await check()) return; } catch {}
    await pause(100);
  }
  throw new Error("Timed out: " + label);
}

async function freePort() {
  const server = createServer();
  await new Promise((resolve, reject) => { server.once("error", reject); server.listen(0, "127.0.0.1", resolve); });
  const port = server.address().port;
  await new Promise((resolve) => server.close(resolve));
  return port;
}

// Demo data shared by every shot, so screenshots taken at different times still look like
// one consistent club/session - matching the existing screenshots' "JMK RB" branding and
// active-session header.
function seedDemoState(state, decoderPort) {
  state.settings.wsUrl = `ws://127.0.0.1:${decoderPort}`;
  state.settings.autoReconnect = true;
  const classId = "shot_class";
  const driverA = { id: "shot_driver_a", name: "Alex Karlsson", classId, transponder: "7960001" };
  const driverB = { id: "shot_driver_b", name: "Sam Nilsson", classId, transponder: "7960002" };
  const driverC = { id: "shot_driver_c", name: "Jamie Lee", classId, transponder: "7960003" };
  const driverD = { id: "shot_driver_d", name: "Robin Berg", classId, transponder: "7960004" };
  const raceEvent = {
    id: "shot_event", name: "Klubbmästare Race 4", classId, mode: "race",
    raceConfig: { participantsConfigured: true, driverIds: [driverA.id, driverB.id, driverC.id, driverD.id], teams: [], minLapMs: 3000, maxLapMs: 60000 },
  };
  const practice = { id: "shot_practice", eventId: raceEvent.id, name: "Practice 1", type: "practice", durationMin: 10, status: "finished", startedAt: Date.now() - 3600000, endedAt: Date.now() - 3000000 };
  const qualifying = { id: "shot_quali", eventId: raceEvent.id, name: "Qualification 1", type: "qualification", startMode: "position", durationMin: 5, status: "finished", startedAt: Date.now() - 2400000, endedAt: Date.now() - 2100000 };
  state.classes.push({ id: classId, name: "2WD Buggy" });
  state.drivers.push(driverA, driverB, driverC, driverD);
  state.events.push(raceEvent);
  state.sessions.push(practice, qualifying);
  state.activeSessionId = qualifying.id;
  state.settings.theme = "light";
  state.settings.clubName = "JMK RB";
  state.settings.clubTagline = "Live Timing & Race Control";
}

async function captureShot(name, { setup }) {
  const temporary = mkdtempSync(join(tmpdir(), "racecore-shot-"));
  const children = [];
  let socket;
  const decoder = await startFakeDecoder();
  const launch = (command, args, options = {}) => {
    const child = spawn(command, args, { cwd: projectDir, stdio: "ignore", ...options });
    children.push(child);
    child.on("error", (e) => console.error(e.message));
    return child;
  };
  try {
    const port = await freePort();
    const debugPort = await freePort();
    const base = `http://127.0.0.1:${port}`;
    launch(process.execPath, ["server.js"], { env: { ...process.env, HOST: "127.0.0.1", PORT: String(port), RC_TIMING_DATA_DIR: join(temporary, "data"), RC_TIMING_PID_FILE: "" } });
    await waitFor(async () => (await fetch(base + "/api/health")).ok, "isolated server");

    const initial = {
      classes: [], drivers: [], cars: [], events: [], sessions: [], resultsBySession: {},
      settings: { language: "en", autoReconnect: false, backendUrl: base, raceAudio: { enabled: false } },
      training: {},
    };
    seedDemoState(initial, decoder.port);
    await fetch(base + "/api/state", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify(initial) });

    launch(chrome, [
      "--headless", "--disable-gpu", "--no-first-run", "--no-default-browser-check", "--disable-background-networking",
      ...(process.env.RC_BROWSER_NO_SANDBOX === "1" ? ["--no-sandbox"] : []),
      "--window-size=1600,900", `--user-data-dir=${join(temporary, "browser")}`, `--remote-debugging-port=${debugPort}`, "about:blank",
    ]);
    let target;
    await waitFor(async () => {
      target = (await (await fetch(`http://127.0.0.1:${debugPort}/json/list`)).json()).find((p) => p.type === "page");
      return target;
    }, "headless browser");

    socket = new WebSocket(target.webSocketDebuggerUrl);
    await new Promise((resolve, reject) => { socket.addEventListener("open", resolve, { once: true }); socket.addEventListener("error", reject, { once: true }); });
    let nextId = 0;
    const requests = new Map();
    socket.addEventListener("message", (event) => {
      const message = JSON.parse(event.data);
      if (message.id) {
        const request = requests.get(message.id);
        requests.delete(message.id);
        if (message.error) request?.reject(new Error(message.error.message)); else request?.resolve(message.result);
      }
    });
    function send(method, params = {}) {
      return new Promise((resolve, reject) => { const id = ++nextId; requests.set(id, { resolve, reject }); socket.send(JSON.stringify({ id, method, params })); });
    }
    async function evaluate(expression) {
      const result = await send("Runtime.evaluate", { expression, returnByValue: true, awaitPromise: true });
      if (result.exceptionDetails) throw new Error(result.exceptionDetails.exception?.description || JSON.stringify(result.exceptionDetails));
      return result.result.value;
    }
    async function navigate(view, readySelector) {
      await send("Page.navigate", { url: base + "/?view=" + view });
      await waitFor(async () =>
        Boolean(await evaluate(`document.querySelector(${JSON.stringify(readySelector)})`)) &&
        (await evaluate(`document.getElementById("syncStatusDetail")?.textContent`) || "").includes("Data loaded"),
        view + " hydrated");
      // Match the "Decoder Online" state every other screenshot already shows, and let any
      // save the connection triggers finish so the sidebar doesn't show a stray "Changes
      // waiting to save" banner in the capture.
      await waitFor(async () => await evaluate('document.getElementById("connectionBadge")?.classList.contains("badge-online")'), "decoder connected");
      await waitFor(async () => (await evaluate('document.getElementById("syncStatus")?.dataset.state')) === "saved", "settings saved");
    }
    const click = (selector) => evaluate(`document.querySelector(${JSON.stringify(selector)}).click()`);
    const scrollTo = (selector, block = "start") => evaluate(`document.querySelector(${JSON.stringify(selector)})?.scrollIntoView({block: ${JSON.stringify(block)}})`);

    await send("Runtime.enable");
    await send("Page.enable");
    await send("Emulation.setDeviceMetricsOverride", { width: 1600, height: 900, deviceScaleFactor: 2, mobile: false });

    await setup({ evaluate, navigate, click, scrollTo, pause, waitFor });
    await pause(300); // let any final CSS transition/re-render settle

    const { data } = await send("Page.captureScreenshot", { format: "jpeg", quality: 90 });
    mkdirSync(outputDir, { recursive: true });
    const outputPath = join(outputDir, `${name}.jpg`);
    writeFileSync(outputPath, Buffer.from(data, "base64"));
    console.log(`[${name}] wrote ${outputPath}`);
  } finally {
    try { socket?.close(); } catch {}
    for (const child of children.reverse()) { try { child.kill(); } catch {} }
    await pause(300);
    try { await decoder.close(); } catch {}
    rmSync(temporary, { recursive: true, force: true, maxRetries: 5, retryDelay: 200 });
  }
}

const shots = {
  guide: {
    async setup({ navigate }) {
      await navigate("guide", ".guide-list");
    },
  },
  "race-manage-tabs": {
    async setup({ navigate, click, scrollTo, waitFor: waitForFn, evaluate, pause: pauseFn }) {
      await navigate("race_setup", "#raceWizardStepForm");
      await click("#event-manage-shot_event");
      await waitForFn(async () => Boolean(await evaluate('document.querySelector(".manage-tabs")')), "manage tabs rendered");
      await click('[data-manage-tab="live"]');
      await scrollTo(".manage-tabs");
      await pauseFn(200);
    },
  },
};

const requested = process.argv.slice(2);
const names = requested.length ? requested : Object.keys(shots);
for (const name of names) {
  const shot = shots[name];
  if (!shot) { console.error(`Unknown shot "${name}". Available: ${Object.keys(shots).join(", ")}`); process.exitCode = 1; continue; }
  await captureShot(name, shot);
}