import { spawn, ChildProcess } from 'child_process';
import { createServer } from 'net';
import {
  getClientScenario,
  listActiveClientScenarios,
  listDraftClientScenarios,
  listPendingClientScenarios
} from '../index';
import path from 'path';

function getFreePort(): Promise<number> {
  return new Promise((resolve, reject) => {
    const server = createServer();
    server.listen(0, () => {
      const port = (server.address() as { port: number }).port;
      server.close(() => resolve(port));
    });
    server.on('error', reject);
  });
}

describe('Server Scenarios', () => {
  let serverProcess: ChildProcess | null = null;
  let serverUrl: string;
  const SERVER_STARTUP_TIMEOUT = 30000; // 30 seconds for CI

  beforeAll(async () => {
    const testPort = await getFreePort();
    serverUrl = `http://localhost:${testPort}/mcp`;

    // Start the everything-server once for all scenarios in this file
    const serverPath = path.join(
      process.cwd(),
      'examples/servers/typescript/everything-server.ts'
    );

    // Use shell: true on Windows only (npx is npx.cmd on Windows)
    const isWindows = process.platform === 'win32';
    serverProcess = spawn('npx', ['tsx', serverPath], {
      env: { ...process.env, PORT: testPort.toString() },
      stdio: ['ignore', 'pipe', 'pipe'],
      detached: false,
      shell: isWindows
    });

    // Capture output for debugging
    let stdoutData = '';
    let stderrData = '';

    serverProcess.stdout?.on('data', (data) => {
      stdoutData += data.toString();
    });

    serverProcess.stderr?.on('data', (data) => {
      stderrData += data.toString();
    });

    // Wait for server to be ready
    await new Promise<void>((resolve, reject) => {
      const timeout = setTimeout(() => {
        if (serverProcess) {
          serverProcess.kill('SIGKILL');
        }
        reject(
          new Error(`Server failed to start within ${SERVER_STARTUP_TIMEOUT}ms`)
        );
      }, SERVER_STARTUP_TIMEOUT);

      let resolved = false;

      serverProcess!.stdout?.on('data', (data) => {
        const output = data.toString();
        if (output.includes('running on')) {
          clearTimeout(timeout);
          resolved = true;
          resolve();
        }
      });

      serverProcess!.on('error', (error) => {
        clearTimeout(timeout);
        reject(new Error(`Failed to start server: ${error.message}`));
      });

      serverProcess!.on('exit', (code) => {
        // Only reject if server exits unexpectedly during startup
        if (!resolved && code !== null && code !== 0) {
          clearTimeout(timeout);
          reject(
            new Error(
              `Server exited prematurely with code ${code}. STDOUT: ${stdoutData}, STDERR: ${stderrData}`
            )
          );
        }
      });
    });
  }, SERVER_STARTUP_TIMEOUT + 5000);

  afterAll(async () => {
    // Stop the server and clean up
    if (serverProcess && !serverProcess.killed) {
      // Try graceful shutdown first
      serverProcess.kill('SIGTERM');

      // Wait for graceful shutdown with timeout
      await new Promise<void>((resolve) => {
        const killTimeout = setTimeout(() => {
          if (serverProcess && !serverProcess.killed) {
            serverProcess.kill('SIGKILL');
          }
          resolve();
        }, 5000);

        serverProcess!.once('exit', () => {
          clearTimeout(killTimeout);
          resolve();
        });
      });

      serverProcess = null;
    }
  });

  // Generate individual test for each scenario: the active suite plus the
  // draft-spec scenarios that aren't parked in `pending` — the same set this
  // file covered before draft scenarios were split out of `active`.
  const pendingScenarios = new Set(listPendingClientScenarios());
  const scenarios = [
    ...listActiveClientScenarios(),
    ...listDraftClientScenarios().filter((name) => !pendingScenarios.has(name))
  ];

  for (const scenarioName of scenarios) {
    it(`${scenarioName}`, async () => {
      const scenario = getClientScenario(scenarioName);
      expect(scenario).toBeDefined();

      if (!scenario) {
        throw new Error(`Scenario ${scenarioName} not found`);
      }

      const checks = await scenario.run(serverUrl);

      // Verify checks were returned
      expect(checks.length).toBeGreaterThan(0);

      // Verify all checks passed
      const failures = checks.filter((c) => c.status === 'FAILURE');
      if (failures.length > 0) {
        const failureMessages = failures
          .map((c) => `${c.name}: ${c.errorMessage || c.description}`)
          .join('\n  ');
        throw new Error(`Scenario failed with checks:\n  ${failureMessages}`);
      }

      // All checks should be non-FAILURE (SUCCESS, WARNING, or INFO are acceptable)
      const nonFailures = checks.filter((c) => c.status !== 'FAILURE');
      expect(nonFailures.length).toBe(checks.length);
    }, 10000); // 10 second timeout per scenario
  }
});