#!/usr/bin/env node

import { spawn } from "node:child_process";
import { existsSync, readdirSync, statSync } from "node:fs";
import { mkdir, mkdtemp, rm } from "node:fs/promises";
import { arch, platform, tmpdir } from "node:os";
import { dirname, join, resolve, sep } from "node:path";
import { fileURLToPath, pathToFileURL } from "node:url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const ROOT = join(__dirname, "..", "..");

const DEFAULT_TIMEOUT_MS = 45_000;
const DEFAULT_SETTLE_MS = 2_000;
const DEFAULT_URL = "http://127.0.0.1:20128/login";
export const LINUX_EXECUTABLE_NAMES = ["omniroute-desktop", "omniroute", "OmniRoute"];
export const FATAL_LOG_PATTERNS = [
  /Cannot find module/i,
  /MODULE_NOT_FOUND/,
  /ERR_DLOPEN_FAILED/,
  /Server exited with code:\s*[1-9]/,
  /Failed to start server/i,
  /Unhandled Rejection/i,
  /Uncaught Exception/i,
];

function parsePositiveInteger(value, fallback) {
  const parsed = Number.parseInt(value || "", 10);
  return Number.isFinite(parsed) && parsed > 0 ? parsed : fallback;
}

function sleep(ms) {
  return new Promise((resolveSleep) => setTimeout(resolveSleep, ms));
}

function discoverMacExecutable() {
  const distDir = join(ROOT, "electron", "dist-electron");
  if (process.env.ELECTRON_SMOKE_APP_EXECUTABLE) {
    return process.env.ELECTRON_SMOKE_APP_EXECUTABLE;
  }

  const candidates = [
    join(
      distDir,
      arch() === "arm64" ? "mac-arm64" : "mac",
      "OmniRoute.app",
      "Contents",
      "MacOS",
      "OmniRoute"
    ),
    join(distDir, "mac", "OmniRoute.app", "Contents", "MacOS", "OmniRoute"),
    join(distDir, "mac-arm64", "OmniRoute.app", "Contents", "MacOS", "OmniRoute"),
  ];

  return candidates.find((candidate) => existsSync(candidate)) || candidates[0];
}

function findExecutableByName(rootDir, names) {
  const pending = [rootDir];
  const wanted = new Set(names.map((name) => name.toLowerCase()));

  while (pending.length > 0) {
    const dir = pending.shift();
    if (!existsSync(dir)) continue;

    for (const entry of readdirSync(dir)) {
      const fullPath = join(dir, entry);
      const stat = statSync(fullPath);

      if (stat.isDirectory()) {
        pending.push(fullPath);
        continue;
      }

      if (!wanted.has(entry.toLowerCase())) continue;
      if (platform() === "linux" && (stat.mode & 0o111) === 0) continue;
      return fullPath;
    }
  }

  return null;
}

function discoverWindowsExecutable() {
  const distDir = join(ROOT, "electron", "dist-electron");
  const candidates = [
    join(distDir, "win-unpacked", "OmniRoute.exe"),
    join(distDir, "win-x64-unpacked", "OmniRoute.exe"),
    join(distDir, "win-arm64-unpacked", "OmniRoute.exe"),
  ];

  return (
    candidates.find((candidate) => existsSync(candidate)) ||
    findExecutableByName(distDir, ["OmniRoute.exe"]) ||
    candidates[0]
  );
}

function discoverLinuxExecutable() {
  const distDir = join(ROOT, "electron", "dist-electron");
  const unpackedDirs = ["linux-unpacked", "linux-arm64-unpacked"];
  const candidates = unpackedDirs.flatMap((dir) =>
    LINUX_EXECUTABLE_NAMES.map((name) => join(distDir, dir, name))
  );

  return (
    candidates.find((candidate) => existsSync(candidate)) ||
    findExecutableByName(distDir, LINUX_EXECUTABLE_NAMES) ||
    candidates[0]
  );
}

function discoverPackagedExecutable() {
  if (process.env.ELECTRON_SMOKE_APP_EXECUTABLE) {
    return process.env.ELECTRON_SMOKE_APP_EXECUTABLE;
  }

  if (platform() === "darwin") return discoverMacExecutable();
  if (platform() === "win32") return discoverWindowsExecutable();
  if (platform() === "linux") return discoverLinuxExecutable();

  throw new Error(`Packaged Electron smoke check does not support ${platform()}.`);
}

async function fetchWithTimeout(url, timeoutMs) {
  const controller = new AbortController();
  const timeout = setTimeout(() => controller.abort(), timeoutMs);

  try {
    return await fetch(url, {
      cache: "no-store",
      redirect: "manual",
      signal: controller.signal,
    });
  } finally {
    clearTimeout(timeout);
  }
}

async function assertPortIsFree(url) {
  try {
    const response = await fetchWithTimeout(url, 1_000);
    throw new Error(
      `Smoke URL already responded with HTTP ${response.status}: ${url}. Stop the existing OmniRoute process before running this check.`
    );
  } catch (error) {
    if (error instanceof Error && error.message.startsWith("Smoke URL already responded")) {
      throw error;
    }
  }
}

async function waitForPortClosed(url, timeoutMs = 5_000) {
  const deadline = Date.now() + timeoutMs;
  let lastStatus = null;

  while (Date.now() < deadline) {
    try {
      const response = await fetchWithTimeout(url, 1_000);
      lastStatus = response.status;
    } catch {
      return;
    }

    await sleep(250);
  }

  throw new Error(
    `Smoke URL still responded after app shutdown${
      lastStatus === null ? "" : ` with HTTP ${lastStatus}`
    }: ${url}`
  );
}

function appendLog(buffer, chunk, prefix, streamLogs) {
  const text = chunk.toString();
  if (streamLogs) {
    process.stdout.write(`${prefix}${text}`);
  }
  const next = buffer.value + text;
  buffer.value = next.length > 40_000 ? next.slice(-40_000) : next;
}

function printLogTail(logs) {
  if (!logs.trim()) return;

  console.error("[electron-smoke] captured app log tail:");
  console.error(logs.trimEnd());
}

function assertNoFatalLogs(logs) {
  const fatalPattern = FATAL_LOG_PATTERNS.find((pattern) => pattern.test(logs));
  if (fatalPattern) {
    throw new Error(`Packaged Electron app emitted fatal startup logs matching ${fatalPattern}.`);
  }
}

async function waitForExit(child, timeoutMs) {
  if (child.exitCode !== null || child.signalCode !== null) return;

  await Promise.race([new Promise((resolve) => child.once("exit", resolve)), sleep(timeoutMs)]);
}

function isProcessGroupAlive(pid) {
  if (!pid || platform() === "win32") return false;

  try {
    process.kill(-pid, 0);
    return true;
  } catch (error) {
    if (error?.code === "ESRCH") return false;
    if (error?.code === "EPERM") return true;
    throw error;
  }
}

async function waitForProcessTreeExit(child, timeoutMs) {
  if (!child.pid || platform() === "win32") {
    await waitForExit(child, timeoutMs);
    return;
  }

  const deadline = Date.now() + timeoutMs;
  while (Date.now() < deadline) {
    if (!isProcessGroupAlive(child.pid)) return;
    await sleep(100);
  }
}

async function runQuietly(command, args) {
  await new Promise((resolveRun) => {
    const proc = spawn(command, args, { stdio: "ignore" });
    proc.once("error", resolveRun);
    proc.once("exit", resolveRun);
  });
}

async function signalProcessTree(child, signal) {
  if (!child.pid) return;

  if (platform() === "win32") {
    if (signal === "SIGKILL") {
      await runQuietly("taskkill", ["/pid", String(child.pid), "/t", "/f"]);
    } else {
      child.kill(signal);
    }
    return;
  }

  try {
    process.kill(-child.pid, signal);
  } catch (error) {
    if (error?.code !== "ESRCH") throw error;
  }
}

async function stopApp(child) {
  if (!child.pid) return;

  await signalProcessTree(child, "SIGTERM");
  await waitForProcessTreeExit(child, 5_000);

  const isStillRunning =
    platform() === "win32"
      ? child.exitCode === null && child.signalCode === null
      : isProcessGroupAlive(child.pid);

  if (isStillRunning) {
    await signalProcessTree(child, "SIGKILL");
    await waitForProcessTreeExit(child, 2_000);
  }
}

export function buildSmokeEnv({
  dataDir,
  parentEnv = process.env,
  currentPlatform = platform(),
} = {}) {
  if (!dataDir) {
    throw new Error("buildSmokeEnv requires dataDir.");
  }

  const inheritedNames = [
    "PATH",
    "Path",
    "SystemRoot",
    "WINDIR",
    "COMSPEC",
    "PATHEXT",
    "TMPDIR",
    "TMP",
    "TEMP",
    "LANG",
    "LC_ALL",
    "LC_CTYPE",
    "DISPLAY",
    "WAYLAND_DISPLAY",
    "XAUTHORITY",
    "XDG_RUNTIME_DIR",
    "DBUS_SESSION_BUS_ADDRESS",
    "ELECTRON_OZONE_PLATFORM_HINT",
  ];
  const smokeEnv = {};

  for (const name of inheritedNames) {
    if (parentEnv[name]) {
      smokeEnv[name] = parentEnv[name];
    }
  }

  if (currentPlatform === "win32") {
    smokeEnv.USERPROFILE = join(dataDir, "userprofile");
    smokeEnv.APPDATA = join(dataDir, "AppData", "Roaming");
    smokeEnv.LOCALAPPDATA = join(dataDir, "AppData", "Local");
    smokeEnv.TEMP ||= join(dataDir, "tmp");
    smokeEnv.TMP ||= smokeEnv.TEMP;
  } else {
    smokeEnv.HOME = join(dataDir, "home");
    smokeEnv.XDG_CONFIG_HOME = join(dataDir, "config");
    smokeEnv.XDG_CACHE_HOME = join(dataDir, "cache");
    smokeEnv.XDG_DATA_HOME = join(dataDir, "data");
    smokeEnv.TMPDIR ||= join(dataDir, "tmp");
  }

  const baseEnv = {
    ...smokeEnv,
    DATA_DIR: dataDir,
    ELECTRON_ENABLE_LOGGING: "1",
    ELECTRON_ENABLE_STACK_DUMPING: "1",
  };

  // CI environments need sandbox disabled (GitHub Actions runners
  // cannot configure SUID chrome-sandbox on Linux, and Windows
  // runners may exit silently without it).
  if (parentEnv.CI) {
    baseEnv.CI = parentEnv.CI;
    baseEnv.ELECTRON_DISABLE_SANDBOX = "1";
  }

  return baseEnv;
}

function isInsideDir(parentDir, candidateDir) {
  const parent = resolve(parentDir);
  const candidate = resolve(candidateDir);
  return candidate === parent || candidate.startsWith(parent + sep);
}

async function ensureSmokeEnvDirs(smokeEnv, dataDir) {
  const dirNames = [
    "DATA_DIR",
    "HOME",
    "USERPROFILE",
    "APPDATA",
    "LOCALAPPDATA",
    "XDG_CONFIG_HOME",
    "XDG_CACHE_HOME",
    "XDG_DATA_HOME",
    "TMPDIR",
    "TMP",
    "TEMP",
  ];
  const dirs = [
    ...new Set(
      dirNames.map((name) => smokeEnv[name]).filter((dir) => dir && isInsideDir(dataDir, dir))
    ),
  ];

  // On Windows, Electron derives its userData from APPDATA/<productName>.
  // requestSingleInstanceLock() runs synchronously at module load and
  // fails silently if the directory doesn't exist yet — causing exit(0).
  if (platform() === "win32" && smokeEnv.APPDATA) {
    for (const subdir of ["omniroute-desktop", "OmniRoute", "omniroute"]) {
      dirs.push(join(smokeEnv.APPDATA, subdir));
    }
  }

  await Promise.all(dirs.map((dir) => mkdir(dir, { recursive: true })));
}

async function settleAfterReady({ getExitState, logs, settleMs }) {
  const deadline = Date.now() + settleMs;

  while (Date.now() < deadline) {
    assertNoFatalLogs(logs.value);

    const { exitCode, signalCode } = getExitState();
    if (exitCode !== null || signalCode !== null) {
      throw new Error(
        `Packaged Electron app exited during readiness settle: code=${exitCode} signal=${signalCode}`
      );
    }

    await sleep(Math.min(250, Math.max(0, deadline - Date.now())));
  }
}

async function main() {
  const appExecutable = discoverPackagedExecutable();
  if (!existsSync(appExecutable)) {
    throw new Error(
      `Packaged OmniRoute executable not found at ${appExecutable}. Build it first with \`npm run build:<target> --prefix electron\` or set ELECTRON_SMOKE_APP_EXECUTABLE.`
    );
  }

  const smokeUrl = process.env.ELECTRON_SMOKE_URL || DEFAULT_URL;
  const timeoutMs = parsePositiveInteger(process.env.ELECTRON_SMOKE_TIMEOUT_MS, DEFAULT_TIMEOUT_MS);
  const settleMs = parsePositiveInteger(process.env.ELECTRON_SMOKE_SETTLE_MS, DEFAULT_SETTLE_MS);
  const dataDir =
    process.env.ELECTRON_SMOKE_DATA_DIR ||
    (await mkdtemp(join(tmpdir(), "omniroute-electron-smoke-")));
  const removeDataDir =
    !process.env.ELECTRON_SMOKE_DATA_DIR && process.env.ELECTRON_SMOKE_KEEP_DATA !== "1";
  const smokeEnv = buildSmokeEnv({ dataDir });

  await assertPortIsFree(smokeUrl);
  await ensureSmokeEnvDirs(smokeEnv, dataDir);

  // ── CI sandbox workaround ──────────────────────────────────
  // GitHub Actions runners cannot set SUID on chrome-sandbox (Linux)
  // and Windows runners may fail silently without --no-sandbox.
  const spawnArgs = [];
  if (process.env.CI) {
    spawnArgs.push("--no-sandbox", "--disable-gpu");
    if (platform() === "linux") {
      spawnArgs.push("--disable-dev-shm-usage");
    }
  }

  console.log(`[electron-smoke] launching ${appExecutable}`);
  if (spawnArgs.length) console.log(`[electron-smoke] CI args: ${spawnArgs.join(" ")}`);
  console.log(`[electron-smoke] DATA_DIR=${dataDir}`);
  console.log(`[electron-smoke] waiting for ${smokeUrl}`);

  const logs = { value: "" };
  const streamLogs = process.env.ELECTRON_SMOKE_STREAM_LOGS === "1";
  const child = spawn(appExecutable, spawnArgs, {
    detached: platform() !== "win32",
    env: smokeEnv,
    stdio: ["ignore", "pipe", "pipe"],
  });

  child.stdout?.on("data", (chunk) => appendLog(logs, chunk, "[electron] ", streamLogs));
  child.stderr?.on("data", (chunk) => appendLog(logs, chunk, "[electron:err] ", streamLogs));

  let exitCode = null;
  let signalCode = null;
  let spawnError = null;
  child.once("exit", (code, signal) => {
    exitCode = code;
    signalCode = signal;
  });
  child.once("error", (error) => {
    spawnError = error;
  });

  try {
    const startedAt = Date.now();
    let lastError = null;

    while (Date.now() - startedAt < timeoutMs) {
      assertNoFatalLogs(logs.value);

      if (spawnError !== null) {
        throw new Error(`Packaged Electron app failed to launch: ${spawnError.message}`);
      }

      if (exitCode !== null || signalCode !== null) {
        throw new Error(
          `Packaged Electron app exited before readiness: code=${exitCode} signal=${signalCode}`
        );
      }

      try {
        const response = await fetchWithTimeout(smokeUrl, 1_000);
        if (response.status === 200) {
          assertNoFatalLogs(logs.value);
          console.log(`[electron-smoke] ready: ${smokeUrl} returned HTTP 200`);
          await settleAfterReady({
            getExitState: () => ({ exitCode, signalCode }),
            logs,
            settleMs,
          });
          console.log(`[electron-smoke] stable for ${settleMs}ms after readiness`);
          return;
        }
        lastError = new Error(`HTTP ${response.status}`);
      } catch (error) {
        lastError = error;
      }

      await new Promise((resolve) => setTimeout(resolve, 500));
    }

    throw new Error(
      `Packaged Electron app did not serve ${smokeUrl} within ${timeoutMs}ms. Last error: ${
        lastError instanceof Error ? lastError.message : String(lastError)
      }`
    );
  } catch (error) {
    if (!streamLogs) {
      printLogTail(logs.value);
    }
    throw error;
  } finally {
    await stopApp(child);
    await waitForPortClosed(smokeUrl);
    if (removeDataDir) {
      await rm(dataDir, { recursive: true, force: true });
    }
  }
}

if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
  main().catch((error) => {
    console.error(
      `[electron-smoke] failed: ${error instanceof Error ? error.message : String(error)}`
    );
    process.exit(1);
  });
}