import { execFileSync, spawn } from 'node:child_process';
import {
  createWriteStream,
  existsSync,
  mkdirSync,
  readFileSync,
} from 'node:fs';
import { dirname, isAbsolute, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';

const repoRoot = process.cwd();
const apiServerExePath = resolve(
  repoRoot,
  'server-rs/target/debug/api-server.exe',
);
const LOCAL_ENV_FILES = ['.env', '.env.local', '.env.secrets.local'];

function buildProtectedEnvKeys(baseEnv) {
  return new Set(
    Object.entries(baseEnv)
      .filter(([, value]) => String(value ?? '').trim())
      .map(([key]) => key),
  );
}

const shellEnvKeys = buildProtectedEnvKeys(process.env);

function loadEnvFile(path, target, protectedKeys = shellEnvKeys) {
  if (!existsSync(path)) {
    return;
  }

  const rawText = readFileSync(path, 'utf8');
  for (const rawLine of rawText.split(/\r?\n/u)) {
    const line = rawLine.trim();
    if (!line || line.startsWith('#')) {
      continue;
    }

    const match = line.match(/^([A-Za-z_][A-Za-z0-9_]*)=(.*)$/u);
    if (!match) {
      continue;
    }

    const [, key, rawValue] = match;
    // 只保留启动命令行和外层 shell 已显式传入的环境变量优先级；
    // `.env.local` 与 `.env.secrets.local` 需要能覆盖 `.env`，
    // 否则本地短信登录或私密模型密钥会被默认空值压住。
    if (protectedKeys.has(key)) {
      continue;
    }

    target[key] = rawValue.replace(/^['"]|['"]$/gu, '');
  }
}

export function loadApiServerEnv(
  repoRootPath,
  target,
  protectedKeys = shellEnvKeys,
) {
  // 保持与 dev-web-rust.mjs / dev-rust-stack.sh 一致：
  // shell > .env > .env.local > .env.secrets.local。
  for (const fileName of LOCAL_ENV_FILES) {
    loadEnvFile(resolve(repoRootPath, fileName), target, protectedKeys);
  }
}

export function mergeApiServerEnv(repoRootPath, baseEnv = process.env) {
  const mergedEnv = { ...baseEnv };
  loadApiServerEnv(repoRootPath, mergedEnv, buildProtectedEnvKeys(baseEnv));
  return mergedEnv;
}

export function formatApiServerLogTimestamp(date = new Date()) {
  const pad = (value) => String(value).padStart(2, '0');

  return [
    date.getFullYear(),
    pad(date.getMonth() + 1),
    pad(date.getDate()),
    '-',
    pad(date.getHours()),
    pad(date.getMinutes()),
    pad(date.getSeconds()),
  ].join('');
}

export function resolveApiServerLogFile(
  repoRootPath,
  env = process.env,
  now = new Date(),
) {
  const explicitLogFile = String(
    env.GENARRATIVE_API_SERVER_LOG_FILE ?? '',
  ).trim();

  if (explicitLogFile) {
    return isAbsolute(explicitLogFile)
      ? explicitLogFile
      : resolve(repoRootPath, explicitLogFile);
  }

  const logDir =
    String(env.GENARRATIVE_API_SERVER_LOG_DIR ?? '').trim() ||
    'logs/api-server';
  const resolvedLogDir = isAbsolute(logDir)
    ? logDir
    : resolve(repoRootPath, logDir);

  return resolve(
    resolvedLogDir,
    `api-server-${formatApiServerLogTimestamp(now)}.log`,
  );
}

function createApiServerLogStream(logFilePath) {
  mkdirSync(dirname(logFilePath), { recursive: true });
  const logStream = createWriteStream(logFilePath, {
    flags: 'a',
    encoding: 'utf8',
  });
  logStream.on('error', (error) => {
    console.error(`[api-server] 写入日志失败: ${error.message}`);
  });
  return logStream;
}

function writeLauncherLog(logStream, message, stream = process.stdout) {
  const line = `${message}\n`;
  stream.write(line);
  if (!logStream.destroyed) {
    logStream.write(line);
  }
}

function stopExistingWindowsApiServer(logStream) {
  if (process.platform !== 'win32') {
    return;
  }

  // Windows 下 cargo 重新编译时无法覆盖仍在运行的 exe，只清理本仓库 target 内的旧进程。
  const command = [
    '$ErrorActionPreference = "Continue"',
    '$target = [System.IO.Path]::GetFullPath($env:GENARRATIVE_API_SERVER_EXE_TARGET)',
    '$processes = Get-Process -Name api-server -ErrorAction SilentlyContinue | Where-Object {',
    '  $_.Path -and ([System.IO.Path]::GetFullPath($_.Path) -ieq $target)',
    '}',
    'foreach ($process in $processes) {',
    '  try {',
    '    Stop-Process -Id $process.Id -Force -ErrorAction Stop',
    '    Wait-Process -Id $process.Id -Timeout 5 -ErrorAction SilentlyContinue',
    '    Write-Output $process.Id',
    '  } catch {',
    '    Write-Error "[api-server] 忽略旧进程清理瞬时失败 pid=$($process.Id): $($_.Exception.Message)"',
    '  }',
    '}',
    'exit 0',
  ].join('\n');

  const output = execFileSync(
    'powershell.exe',
    ['-NoProfile', '-ExecutionPolicy', 'Bypass', '-Command', command],
    {
      encoding: 'utf8',
      env: {
        ...process.env,
        GENARRATIVE_API_SERVER_EXE_TARGET: apiServerExePath,
      },
    },
  ).trim();

  if (output) {
    writeLauncherLog(logStream, `[api-server] 已停止旧 api-server 进程: ${output}`);
  }
}

function main() {
  const mergedEnv = mergeApiServerEnv(repoRoot);

  mergedEnv.GENARRATIVE_API_HOST =
    mergedEnv.GENARRATIVE_API_HOST || '127.0.0.1';
  mergedEnv.GENARRATIVE_API_PORT = mergedEnv.GENARRATIVE_API_PORT || '3100';
  mergedEnv.GENARRATIVE_SPACETIME_SERVER_URL =
    mergedEnv.GENARRATIVE_SPACETIME_SERVER_URL || 'http://127.0.0.1:3101';
  mergedEnv.GENARRATIVE_SPACETIME_DATABASE =
    mergedEnv.GENARRATIVE_SPACETIME_DATABASE || '';
  mergedEnv.GENARRATIVE_SPACETIME_TOKEN =
    mergedEnv.GENARRATIVE_SPACETIME_TOKEN || '';

  const logFilePath = resolveApiServerLogFile(repoRoot, mergedEnv);
  const logStream = createApiServerLogStream(logFilePath);
  mergedEnv.GENARRATIVE_API_SERVER_LOG_FILE = logFilePath;

  let didExit = false;
  const exitAfterLogFlush = (code) => {
    const finish = () => {
      if (didExit) {
        return;
      }
      didExit = true;
      process.exit(code);
    };

    if (logStream.destroyed) {
      finish();
      return;
    }

    logStream.end(finish);
    setTimeout(finish, 1000).unref();
  };

  writeLauncherLog(logStream, `[api-server] 日志: ${logFilePath}`);

  if (!mergedEnv.GENARRATIVE_SPACETIME_DATABASE) {
    writeLauncherLog(
      logStream,
      '[api-server] 缺少 GENARRATIVE_SPACETIME_DATABASE。',
      process.stderr,
    );
    exitAfterLogFlush(1);
    return;
  }

  try {
    stopExistingWindowsApiServer(logStream);
  } catch (error) {
    writeLauncherLog(
      logStream,
      `[api-server] 清理旧 api-server 进程失败: ${error.message}`,
      process.stderr,
    );
    exitAfterLogFlush(1);
    return;
  }

  writeLauncherLog(
    logStream,
    `[api-server] SpacetimeDB ${mergedEnv.GENARRATIVE_SPACETIME_DATABASE} @ ${mergedEnv.GENARRATIVE_SPACETIME_SERVER_URL}`,
  );

  const child = spawn(
    'cargo',
    ['run', '-p', 'api-server', '--manifest-path', 'server-rs/Cargo.toml'],
    {
      cwd: repoRoot,
      env: mergedEnv,
      stdio: ['inherit', 'pipe', 'pipe'],
    },
  );

  child.stdout?.on('data', (chunk) => {
    process.stdout.write(chunk);
    logStream.write(chunk);
  });

  child.stderr?.on('data', (chunk) => {
    process.stderr.write(chunk);
    logStream.write(chunk);
  });

  child.on('error', (error) => {
    writeLauncherLog(
      logStream,
      `[api-server] 启动 cargo 失败: ${error.message}`,
      process.stderr,
    );
    exitAfterLogFlush(1);
  });

  child.on('close', (code, signal) => {
    if (signal) {
      writeLauncherLog(
        logStream,
        `[api-server] api-server 被信号终止: ${signal}`,
        process.stderr,
      );
      exitAfterLogFlush(1);
      return;
    }

    exitAfterLogFlush(code ?? 0);
  });
}

if (
  process.argv[1] &&
  resolve(process.argv[1]) === fileURLToPath(import.meta.url)
) {
  main();
}