const fs = require('fs');
const os = require('os');
const path = require('path');
const spawn = require('cross-spawn');

const manifestPath = path.resolve(__dirname, '../../../wecom-cli-runtime.json');
const runtimeManifest = JSON.parse(fs.readFileSync(manifestPath, 'utf8'));
const INSTALL_LOCK_STALE_MS = 10 * 60 * 1000;
const DEFAULT_INSTALL_TIMEOUT_MS = 5 * 60 * 1000;
const DEFAULT_CALL_TIMEOUT_MS = 120000;
const MAX_CAPTURE_BYTES = 10 * 1024 * 1024;

function expandHome(value) {
  const text = String(value || '');
  if (text === '~') return os.homedir();
  if (text.startsWith(`~${path.sep}`) || text.startsWith('~/') || text.startsWith('~\\')) {
    return path.join(os.homedir(), text.slice(2));
  }
  return text;
}

function getPlatformKey() {
  return `${process.platform}-${process.arch}`;
}

function isSupportedPlatform() {
  return runtimeManifest.supportedPlatforms.includes(getPlatformKey());
}

function getRuntimeRoot() {
  if (process.env.QIWE_OFFICIAL_CLI_RUNTIME_DIR) {
    return path.resolve(expandHome(process.env.QIWE_OFFICIAL_CLI_RUNTIME_DIR));
  }

  if (process.platform === 'win32') {
    const base = process.env.LOCALAPPDATA || path.join(os.homedir(), 'AppData', 'Local');
    return path.join(base, 'Fmode', 'qiwe-assistant', 'wecom-cli');
  }

  if (process.platform === 'darwin') {
    return path.join(os.homedir(), 'Library', 'Caches', 'fmode', 'qiwe-assistant', 'wecom-cli');
  }

  const base = process.env.XDG_CACHE_HOME || path.join(os.homedir(), '.cache');
  return path.join(base, 'fmode', 'qiwe-assistant', 'wecom-cli');
}

function getRuntimeDir() {
  return path.join(getRuntimeRoot(), runtimeManifest.version);
}

function getOfficialConfigDir() {
  const configured = process.env.WECOM_CLI_CONFIG_DIR;
  return configured
    ? path.resolve(expandHome(configured))
    : path.join(os.homedir(), '.config', 'wecom');
}

function getCliPackagePath(runtimeDir = getRuntimeDir()) {
  return path.join(runtimeDir, 'node_modules', '@wecom', 'cli', 'package.json');
}

function getCliEntrypoint(runtimeDir = getRuntimeDir()) {
  return path.join(runtimeDir, 'node_modules', '@wecom', 'cli', 'bin', 'wecom.js');
}

function inspectInstalledRuntime(runtimeDir = getRuntimeDir()) {
  const packagePath = getCliPackagePath(runtimeDir);
  const entrypoint = getCliEntrypoint(runtimeDir);
  if (!fs.existsSync(packagePath) || !fs.existsSync(entrypoint)) {
    return {
      installed: false,
      valid: false,
      expectedVersion: runtimeManifest.version
    };
  }

  try {
    const packageJson = JSON.parse(fs.readFileSync(packagePath, 'utf8'));
    return {
      installed: true,
      valid: packageJson.name === runtimeManifest.package && packageJson.version === runtimeManifest.version,
      packageName: packageJson.name,
      version: packageJson.version,
      expectedVersion: runtimeManifest.version
    };
  } catch {
    return {
      installed: true,
      valid: false,
      expectedVersion: runtimeManifest.version
    };
  }
}

function sanitizeCliText(value) {
  return String(value || '')
    .replace(/Bearer\s+[^"'\s,}]+/gi, 'Bearer [REDACTED]')
    .replace(
      /("(?:[^"]*secret|access[_-]?token|authorization|credentials?|provider(?:name|host)?|vendor(?:name|host)?|upstream(?:name|host)?)"\s*:\s*")([^"]+)(")/gi,
      '$1[REDACTED]$3'
    )
    .replace(/(Bot\s+Secret\s*[:=]\s*)\S+/gi, '$1[REDACTED]')
    .replace(/((?:provider|vendor|upstream)(?:Name|Host)?\s*[:=]\s*)[^\s,}]+/gi, '$1[REDACTED]');
}

function sanitizeOfficialPayload(value) {
  if (Array.isArray(value)) return value.map(sanitizeOfficialPayload);
  if (value && typeof value === 'object') {
    const output = {};
    for (const [key, item] of Object.entries(value)) {
      if (
        /^(?:secret|bot_?secret|client_?secret|access_?token|authorization|credentials?|provider(?:Name|Host)?|vendor(?:Name|Host)?|upstream(?:Name|Host)?)$/i.test(
          key
        )
      ) {
        continue;
      }
      output[key] = sanitizeOfficialPayload(item);
    }
    return output;
  }
  return typeof value === 'string' ? sanitizeCliText(value) : value;
}

function runProcess(command, args, options = {}) {
  const timeoutMs = options.timeoutMs || DEFAULT_CALL_TIMEOUT_MS;
  const inherited = options.inherited === true;
  const maxCaptureBytes = options.maxCaptureBytes || MAX_CAPTURE_BYTES;

  return new Promise((resolve, reject) => {
    let stdout = '';
    let stderr = '';
    let capturedBytes = 0;
    let settled = false;
    let timedOut = false;
    const child = spawn(command, args, {
      cwd: options.cwd || os.homedir(),
      env: options.env || process.env,
      shell: false,
      windowsHide: !inherited,
      stdio: inherited ? 'inherit' : ['ignore', 'pipe', 'pipe']
    });

    const timer = setTimeout(() => {
      timedOut = true;
      child.kill();
    }, timeoutMs);

    function capture(kind, chunk) {
      capturedBytes += chunk.length;
      if (capturedBytes > maxCaptureBytes) {
        child.kill();
        return;
      }
      if (kind === 'stdout') stdout += chunk.toString('utf8');
      else stderr += chunk.toString('utf8');
    }

    if (!inherited) {
      child.stdout.on('data', chunk => capture('stdout', chunk));
      child.stderr.on('data', chunk => capture('stderr', chunk));
    }

    child.on('error', error => {
      if (settled) return;
      settled = true;
      clearTimeout(timer);
      reject(error);
    });

    child.on('close', (code, signal) => {
      if (settled) return;
      settled = true;
      clearTimeout(timer);
      if (timedOut) {
        const error = new Error(`process timed out after ${timeoutMs}ms`);
        error.kind = 'timeout';
        reject(error);
        return;
      }
      if (capturedBytes > maxCaptureBytes) {
        const error = new Error(`process output exceeded ${maxCaptureBytes} bytes`);
        error.kind = 'output_limit';
        reject(error);
        return;
      }
      resolve({
        exitCode: Number.isInteger(code) ? code : 1,
        signal,
        stdout,
        stderr
      });
    });
  });
}

async function acquireInstallLock(lockPath, waitTimeoutMs = DEFAULT_INSTALL_TIMEOUT_MS) {
  const startedAt = Date.now();
  while (Date.now() - startedAt < waitTimeoutMs) {
    try {
      const handle = await fs.promises.open(lockPath, 'wx');
      await handle.writeFile(`${process.pid}\n${new Date().toISOString()}\n`);
      return async () => {
        await handle.close().catch(() => {});
        await fs.promises.rm(lockPath, { force: true }).catch(() => {});
      };
    } catch (error) {
      if (error.code !== 'EEXIST') throw error;
      try {
        const stat = await fs.promises.stat(lockPath);
        if (Date.now() - stat.mtimeMs > INSTALL_LOCK_STALE_MS) {
          await fs.promises.rm(lockPath, { force: true });
          continue;
        }
      } catch (statError) {
        if (statError.code !== 'ENOENT') throw statError;
        continue;
      }
      await new Promise(resolve => setTimeout(resolve, 250));
    }
  }
  throw new Error('等待企业微信官方 CLI 安装锁超时');
}

function assertRuntimeRequirements() {
  const nodeMajor = Number(process.versions.node.split('.')[0]);
  if (!Number.isFinite(nodeMajor) || nodeMajor < 18) {
    throw new Error(`企业微信官方 CLI 需要 Node.js >= 18，当前版本为 ${process.versions.node}`);
  }
  if (!isSupportedPlatform()) {
    throw new Error(
      `企业微信官方 CLI 不支持当前平台 ${getPlatformKey()}；支持 ${runtimeManifest.supportedPlatforms.join(', ')}`
    );
  }
}

async function prepareOfficialCli(options = {}) {
  assertRuntimeRequirements();
  const runtimeRoot = getRuntimeRoot();
  const runtimeDir = getRuntimeDir();
  const force = options.force === true;
  const installTimeoutMs = options.timeoutMs || DEFAULT_INSTALL_TIMEOUT_MS;
  const current = inspectInstalledRuntime(runtimeDir);
  if (current.valid && !force) return { ...current, runtimeDir, cached: true };

  await fs.promises.mkdir(runtimeRoot, { recursive: true });
  const lockPath = path.join(runtimeRoot, `.${runtimeManifest.version}.install.lock`);
  const releaseLock = await acquireInstallLock(lockPath, installTimeoutMs);
  let tempDir;
  try {
    const afterLock = inspectInstalledRuntime(runtimeDir);
    if (afterLock.valid && !force) return { ...afterLock, runtimeDir, cached: true };

    tempDir = path.join(runtimeRoot, `.${runtimeManifest.version}.tmp-${process.pid}-${Date.now()}`);
    await fs.promises.rm(tempDir, { recursive: true, force: true });
    await fs.promises.mkdir(tempDir, { recursive: true });

    const npmCommand = process.platform === 'win32' ? 'npm.cmd' : 'npm';
    const installResult = await runProcess(
      npmCommand,
      [
        'install',
        '--prefix',
        tempDir,
        `${runtimeManifest.package}@${runtimeManifest.version}`,
        '--omit=dev',
        '--no-audit',
        '--no-fund',
        '--save-exact'
      ],
      { timeoutMs: installTimeoutMs, cwd: runtimeRoot }
    );

    if (installResult.exitCode !== 0) {
      throw new Error(
        `下载企业微信官方 CLI 失败（exit ${installResult.exitCode}）：${sanitizeCliText(
          installResult.stderr || installResult.stdout
        ).trim()}`
      );
    }

    const installed = inspectInstalledRuntime(tempDir);
    if (!installed.valid) {
      throw new Error(
        `企业微信官方 CLI 安装校验失败：期望 ${runtimeManifest.package}@${runtimeManifest.version}`
      );
    }

    await fs.promises.rm(runtimeDir, { recursive: true, force: true });
    await fs.promises.rename(tempDir, runtimeDir);
    tempDir = undefined;
    return { ...installed, runtimeDir, cached: false };
  } finally {
    if (tempDir) await fs.promises.rm(tempDir, { recursive: true, force: true }).catch(() => {});
    await releaseLock();
  }
}

function parseCliOutput(stdout) {
  const text = String(stdout || '').trim();
  if (!text) return undefined;
  try {
    return sanitizeOfficialPayload(JSON.parse(text));
  } catch {
    return undefined;
  }
}

async function runOfficialCli(args, options = {}) {
  if (!Array.isArray(args) || args.some(item => typeof item !== 'string')) {
    throw new Error('CLI arguments must be an array of strings');
  }
  if (options.ensure !== false) await prepareOfficialCli();

  const runtime = inspectInstalledRuntime();
  if (!runtime.valid) throw new Error('企业微信官方 CLI 尚未安装或版本校验失败');

  const result = await runProcess(
    process.execPath,
    [getCliEntrypoint(), ...args],
    {
      timeoutMs: options.timeoutMs || DEFAULT_CALL_TIMEOUT_MS,
      inherited: options.inherited === true,
      cwd: options.cwd || os.homedir(),
      env: { ...process.env, ...(options.env || {}) }
    }
  );

  return {
    ...result,
    stdout: sanitizeCliText(result.stdout),
    stderr: sanitizeCliText(result.stderr),
    parsed: parseCliOutput(result.stdout)
  };
}

async function getOfficialCliStatus() {
  const runtime = inspectInstalledRuntime();
  const configDir = getOfficialConfigDir();
  const botConfigExists = fs.existsSync(path.join(configDir, 'bot.enc'));
  const mcpConfigExists = fs.existsSync(path.join(configDir, 'mcp_config.enc'));
  let authorized = false;

  if (runtime.valid) {
    try {
      const authResult = await runOfficialCli(['auth', 'show', '--auth-status'], {
        ensure: false,
        timeoutMs: 10000
      });
      authorized = authResult.exitCode === 0 && authResult.stdout.trim() === 'authorized';
    } catch {
      authorized = false;
    }
  }

  return {
    supported: isSupportedPlatform(),
    platform: getPlatformKey(),
    packageName: runtimeManifest.package,
    expectedVersion: runtimeManifest.version,
    installed: runtime.installed === true,
    valid: runtime.valid === true,
    installedVersion: runtime.version,
    authorized,
    mcpConfigExists,
    ready: runtime.valid === true && authorized && botConfigExists && mcpConfigExists
  };
}

function getInitCommand() {
  const wrapperPath = path.resolve(__dirname, '../../../bin/qiwe-official-cli.js');
  return `"${process.execPath}" "${wrapperPath}" init`;
}

module.exports = {
  runtimeManifest,
  getPlatformKey,
  getRuntimeRoot,
  getRuntimeDir,
  getOfficialConfigDir,
  getCliEntrypoint,
  inspectInstalledRuntime,
  sanitizeCliText,
  sanitizeOfficialPayload,
  prepareOfficialCli,
  runOfficialCli,
  getOfficialCliStatus,
  getInitCommand
};