import { spawn } from 'node:child_process';
import { join } from 'node:path';

/**
 * Result from running a CLI command.
 */
export interface RunResult {
  /** Stdout output with ANSI codes stripped */
  stdout: string;
  /** Stderr output */
  stderr: string;
  /** Process exit code */
  exitCode: number;
}

/**
 * Build a clean env for spawned CLI processes.
 * Strips INIT_CWD which npm/npx sets to the runner's directory — without this,
 * the CLI resolves the working directory from INIT_CWD instead of the spawn's cwd.
 * @see https://docs.npmjs.com/cli/v10/commands/npm-run-script
 */
export function cleanSpawnEnv(extraEnv: Record<string, string> = {}): NodeJS.ProcessEnv {
  return { ...process.env, INIT_CWD: undefined, ...extraEnv };
}

/**
 * Spawn a command, collect output, and strip ANSI codes.
 */
export function spawnAndCollect(
  command: string,
  args: string[],
  cwd: string,
  extraEnv: Record<string, string> = {}
): Promise<RunResult> {
  return new Promise(resolve => {
    const proc = spawn(command, args, {
      cwd,
      env: cleanSpawnEnv(extraEnv),
    });

    let stdout = '';
    let stderr = '';

    proc.stdout.on('data', (data: Buffer) => {
      stdout += data.toString();
    });

    proc.stderr.on('data', (data: Buffer) => {
      stderr += data.toString();
    });

    proc.on('close', code => {
      // Strip ANSI escape codes from stdout
      // eslint-disable-next-line no-control-regex
      stdout = stdout.replace(/\x1B\[\??\d*[a-zA-Z]/g, '').trim();
      resolve({ stdout, stderr, exitCode: code ?? 1 });
    });
  });
}

/**
 * Get the path to the CLI entry point.
 * Uses the built bundle - run `npm run build` before tests.
 */
function getCLIPath(): string {
  // Navigate from src/test-utils to dist/cli/index.mjs
  return join(__dirname, '..', '..', 'dist', 'cli', 'index.mjs');
}

/**
 * Run the AgentCore CLI via the local build (unit/integ tests).
 * Skips dependency installation by default for speed.
 */
export async function runCLI(args: string[], cwd: string, skipInstall = true): Promise<RunResult> {
  return spawnAndCollect('node', [getCLIPath(), ...args], cwd, skipInstall ? { AGENTCORE_SKIP_INSTALL: '1' } : {});
}