import { spawn, type ChildProcess } from 'node:child_process';
import { createServer } from 'node:net';
import type { TestProject } from 'vitest/node';

// Fixed test-only secret, >= 32 chars as required by nuxt-auth-utils.
const SESSION_PASSWORD = 'integration-tests-only-not-for-prod-use!';

async function freePort(): Promise<number> {
  return new Promise((resolve, reject) => {
    const server = createServer();
    server.listen(0, '127.0.0.1', () => {
      const address = server.address();
      if (address === null || typeof address === 'string') {
        reject(new Error('Could not determine a free port'));
        return;
      }
      server.close(() => resolve(address.port));
    });
  });
}

function waitForLine(child: ChildProcess, pattern: RegExp): Promise<string[]> {
  return new Promise((resolve, reject) => {
    let buffer = '';
    const onData = (chunk: Buffer) => {
      buffer += chunk.toString();
      for (const line of buffer.split('\n')) {
        const match = line.match(pattern);
        if (match) {
          child.stdout?.off('data', onData);
          resolve(match.slice(1));
          return;
        }
      }
    };
    child.stdout?.on('data', onData);
    child.on('exit', (code) =>
      reject(new Error(`Child exited with code ${code} before being ready`))
    );
    child.on('error', reject);
  });
}

function run(command: string, args: string[], env: NodeJS.ProcessEnv = {}) {
  return new Promise<void>((resolve, reject) => {
    const child = spawn(command, args, {
      stdio: 'inherit',
      env: { ...process.env, ...env }
    });
    child.on('exit', (code) =>
      code === 0
        ? resolve()
        : reject(new Error(`${command} ${args.join(' ')} exited with ${code}`))
    );
    child.on('error', reject);
  });
}

async function waitForHealth(baseUrl: string, timeoutMs = 60_000) {
  const deadline = Date.now() + timeoutMs;
  let lastError: unknown = new Error('server never became healthy');
  while (Date.now() < deadline) {
    try {
      const res = await fetch(`${baseUrl}/api/health`);
      if (res.ok) return;
      lastError = new Error(`health responded with ${res.status}`);
    } catch (e) {
      lastError = e;
    }
    await new Promise((r) => setTimeout(r, 250));
  }
  throw lastError;
}

function kill(child: ChildProcess) {
  return new Promise<void>((resolve) => {
    if (child.exitCode !== null) return resolve();
    const timer = setTimeout(() => {
      child.kill('SIGKILL');
    }, 3_000);
    child.on('exit', () => {
      clearTimeout(timer);
      resolve();
    });
    child.kill('SIGTERM');
  });
}

export default async function globalSetup(project: TestProject) {
  // 1. Boot in-memory PGlite behind a Postgres wire protocol socket.
  // It runs in a child process: teardown under Bun exits with code 99
  // (Emscripten), and isolating it keeps the vitest process clean.
  const dbHost = spawn('node', ['tests/integration/pglite-host.mjs'], {
    stdio: ['ignore', 'pipe', 'inherit']
  });
  const [databaseUrl] = await waitForLine(dbHost, /^PGLITE_READY (.+)$/);

  // 2. Apply all migrations against the socket (proven path from Phase 0).
  await run('bunx', ['prisma', 'migrate', 'deploy'], {
    DATABASE_URL: databaseUrl
  });

  // 3. Build the Nuxt server once for all test files.
  if (process.env.SKIP_BUILD !== '1') {
    await run('bun', ['run', 'build']);
  }

  // 4. Spawn the built server against the WASM database.
  const port = await freePort();
  const baseUrl = `http://127.0.0.1:${port}`;
  const server = spawn('node', ['.output/server/index.mjs'], {
    stdio: 'inherit',
    env: {
      ...process.env,
      NODE_ENV: 'production',
      PORT: String(port),
      DATABASE_URL: databaseUrl,
      NUXT_SESSION_PASSWORD: SESSION_PASSWORD
    }
  });
  server.on('error', (e) => {
    throw e;
  });

  try {
    await waitForHealth(baseUrl);
  } catch (e) {
    await kill(server);
    await kill(dbHost);
    throw e;
  }

  project.provide('baseUrl', baseUrl);
  project.provide('databaseUrl', databaseUrl);

  return async () => {
    await kill(server);
    await kill(dbHost);
  };
}