const fs = require("fs");
const path = require("path");

const root = path.resolve(__dirname, "..");

function fail(message, error) {
  console.error(`[verify] ${message}`);
  if (error) {
    console.error(`[verify] ${error instanceof Error ? error.message : String(error)}`);
  }
  if (process.platform === "win32") {
    console.error("[verify] Retry with windows\\install.bat.");
    console.error("[verify] Native fallback: run C:\\Program Files\\nodejs\\install_tools.bat as Administrator.");
  }
  process.exit(1);
}

function warn(message) {
  console.warn(`[verify] WARNING: ${message}`);
}

function compareVersions(left, right) {
  const leftParts = String(left || "").split(".").map((part) => Number(part) || 0);
  const rightParts = String(right || "").split(".").map((part) => Number(part) || 0);
  const length = Math.max(leftParts.length, rightParts.length);
  for (let index = 0; index < length; index += 1) {
    const difference = (leftParts[index] || 0) - (rightParts[index] || 0);
    if (difference !== 0) return difference;
  }
  return 0;
}

try {
  require("express");
} catch (error) {
  fail("Express could not be loaded.", error);
}

try {
  const Database = require("better-sqlite3");
  const db = new Database(":memory:");
  const row = db.prepare("SELECT 1 AS ok").get();
  db.close();
  if (row?.ok !== 1) {
    fail("SQLite verification query returned an unexpected result.");
  }
} catch (error) {
  fail("better-sqlite3 could not be loaded or initialized.", error);
}

for (const directory of ["data", "logs"]) {
  fs.mkdirSync(path.join(root, directory), { recursive: true });
}

if (process.platform === "win32") {
  const ammcDir = path.join(root, "AMMC", "windows64");
  const requiredFiles = ["ammc-amb.exe", "ammc.dll", "MyLapsSDK.dll"];
  const missingFiles = requiredFiles.filter((file) => !fs.existsSync(path.join(ammcDir, file)));
  if (missingFiles.length > 0) {
    fail(`Bundled AMMC runtime is incomplete: ${missingFiles.join(", ")}`);
  }
  console.log(`[verify] AMMC Windows runtime: ${ammcDir}`);
}

function verifyUnixAmmcExecutables(directory, executableNames, runtimeLabel) {
  const missingFiles = [];
  const nonExecutableFiles = [];

  for (const executableName of executableNames) {
    const executablePath = path.join(directory, executableName);
    if (!fs.existsSync(executablePath)) {
      missingFiles.push(executableName);
      continue;
    }
    try {
      fs.accessSync(executablePath, fs.constants.X_OK);
    } catch {
      nonExecutableFiles.push(executableName);
    }
  }

  if (missingFiles.length > 0) {
    warn(`Bundled ${runtimeLabel} tools are missing: ${missingFiles.join(", ")}`);
  }
  if (nonExecutableFiles.length > 0) {
    warn(`Bundled ${runtimeLabel} tools are not executable: ${nonExecutableFiles.join(", ")}. Run: chmod +x ${path.relative(root, directory)}/ammc-*`);
  }
  return missingFiles.length === 0 && nonExecutableFiles.length === 0;
}

if (process.platform === "linux" && process.arch === "x64") {
  const ammcDir = path.join(root, "AMMC", "linux_x86-64");
  const executableNames = ["ammc-amb", "ammc-prochip", "ammc-sim", "ammc-vostok", "ammc-x2"];
  const requiredGlibc = "2.39";
  const runtimeReady = verifyUnixAmmcExecutables(ammcDir, executableNames, "Linux AMMC");
  const glibcVersion = process.report?.getReport?.().header?.glibcVersionRuntime || "";
  if (!glibcVersion) {
    warn(`Could not detect the host GLIBC version. The bundled Linux AMMC tools require GLIBC ${requiredGlibc} or newer.`);
  } else if (compareVersions(glibcVersion, requiredGlibc) < 0) {
    warn(`Host GLIBC ${glibcVersion} is too old for the bundled Linux AMMC tools (requires >= ${requiredGlibc}). RC RaceCore can still run, but use a compatible AMMC build or a newer Linux distribution. Do not replace the system GLIBC manually.`);
  } else if (runtimeReady) {
    console.log(`[verify] AMMC Linux runtime: ${ammcDir} (all tools executable; GLIBC ${glibcVersion}, requires >= ${requiredGlibc})`);
  }
}

if (process.platform === "darwin" && process.arch === "arm64") {
  const ammcDir = path.join(root, "AMMC", "apple_m");
  const executableNames = ["ammc-amb", "ammc-prochip", "ammc-sim", "ammc-vostok"];
  if (verifyUnixAmmcExecutables(ammcDir, executableNames, "Apple Silicon AMMC")) {
    console.log(`[verify] AMMC Apple Silicon runtime: ${ammcDir} (all tools executable)`);
  }
}

console.log(`[verify] Express and SQLite: OK (${process.platform}/${process.arch}, Node ${process.version})`);
console.log(`[verify] Installation is ready. Start with: ${process.platform === "win32" ? "npm.cmd start" : "npm start"}`);