import { $ } from 'command-stream';

// All these work without any system dependencies!
await $`mkdir -p project/src`;
await $`touch project/src/index.js`;
await $`echo "console.log('Hello!');" > project/src/index.js`;
await $`ls -la project/src`;
await $`cat project/src/index.js`;
await $`cp -r project project-backup`;
await $`rm -r project-backup`;

// Mix built-ins with pipelines and virtual commands
await $`seq 1 5 | cat > numbers.txt`;
await $`basename /path/to/file.txt .txt`; // → "file"

import { $ } from 'command-stream';

const result = await $`ls -la`;
console.log(result.stdout);
console.log(result.code); // exit code

import { $ } from 'command-stream';

// Create a $ with custom options
const $silent = $({ mirror: false, capture: true });
const result = await $silent`echo "quiet operation"`;

// Options for stdin handling
const $withInput = $({ stdin: 'input data\n' });
await $withInput`cat`; // Pipes the input to cat

// Custom environment variables
const $withEnv = $({ env: { ...process.env, MY_VAR: 'value' } });
await $withEnv`printenv MY_VAR`; // Prints: value

// Custom working directory
const $inTmp = $({ cwd: '/tmp' });
await $inTmp`pwd`; // Prints: /tmp

// Combine multiple options
const $custom = $({
  stdin: 'test data',
  mirror: false,
  capture: true,
  cwd: '/tmp'
});
await $custom`cat > output.txt`; // Writes to /tmp/output.txt silently

// Reusable configurations
const $prod = $({ env: { NODE_ENV: 'production' }, capture: true });
await $prod`npm start`;
await $prod`npm test`;

import { $ } from 'command-stream';

// Commands don't auto-start when created
const cmd = $`echo "hello"`;

// Three ways to start execution:

// 1. Explicit start with options
cmd.start();                    // Default async mode
cmd.start({ mode: 'async' });   // Explicitly async
cmd.start({ mode: 'sync' });    // Synchronous execution

// 2. Convenience methods
cmd.async();  // Same as start({ mode: 'async' })
cmd.sync();   // Same as start({ mode: 'sync' })

// 3. Auto-start by awaiting (always async)
await cmd;    // Auto-starts in async mode

// Event handlers can be attached before starting
const process = $`long-command`
  .on('data', chunk => console.log('Received:', chunk))
  .on('end', result => console.log('Done!'));

// Start whenever you're ready
process.start();

import { $ } from 'command-stream';

// Use .sync() for blocking execution
const result = $`echo "hello"`.sync();
console.log(result.stdout); // "hello\n"

// Events still work but are batched after completion
$`echo "world"`
  .on('end', result => console.log('Done:', result))
  .sync();

import { $ } from 'command-stream';

for await (const chunk of $`long-running-command`.stream()) {
  if (chunk.type === 'stdout') {
    console.log('Real-time output:', chunk.data.toString());
  }
}

import { $ } from 'command-stream';

// Attach event handlers then start execution
$`command`
  .on('data', chunk => {
    if (chunk.type === 'stdout') {
      console.log('Stdout:', chunk.data.toString());
    }
  })
  .on('stderr', chunk => console.log('Stderr:', chunk))
  .on('end', result => console.log('Done:', result))
  .on('exit', code => console.log('Exit code:', code))
  .start(); // Explicitly start the command

// Or auto-start by awaiting
const cmd = $`another-command`
  .on('data', chunk => console.log(chunk));
await cmd; // Auto-starts in async mode

import { $ } from 'command-stream';

// Async mode - events fire in real-time
const process = $`streaming-command`;
process.on('data', chunk => {
  processRealTimeData(chunk);
});
const result = await process;
console.log('Final output:', result.stdout);

// Sync mode - events fire after completion (batched)
const syncCmd = $`another-command`;
syncCmd.on('end', result => {
  console.log('Completed with:', result.stdout);
});
const syncResult = syncCmd.sync();

import { $, shell, set, unset } from 'command-stream';

// set -e equivalent: exit on any error
shell.errexit(true);

await $`mkdir -p build`;
await $`npm run build`;

// set +e equivalent: allow errors (like bash)
shell.errexit(false);
const cleanup = await $`rm -rf temp`; // Won't throw if fails

// set -e again for critical operations  
shell.errexit(true);
await $`cp -r build/* deploy/`;

// Other bash-like settings
shell.verbose(true);  // set -v: print commands
shell.xtrace(true);   // set -x: trace execution

// Or use the bash-style API
set('e');    // set -e
unset('e');  // set +e
set('x');    // set -x
set('verbose'); // Long form also supported

import { $ } from 'command-stream';

// File system operations work on Windows, macOS, and Linux identically
await $`mkdir -p project/src project/tests`;
await $`touch project/src/index.js project/tests/test.js`;

// List files with details
const files = await $`ls -la project/src`;
console.log(files.stdout);

// Copy and move operations
await $`cp project/src/index.js project/src/backup.js`;
await $`mv project/src/backup.js project/backup.js`;

// File content operations
await $`echo "export default 'Hello World';" > project/src/index.js`;
const content = await $`cat project/src/index.js`;
console.log(content.stdout);

// Path operations
const filename = await $`basename project/src/index.js .js`; // → "index"
const directory = await $`dirname project/src/index.js`;     // → "project/src"

// Generate sequences and process them
await $`seq 1 10 | cat > numbers.txt`;
const numbers = await $`cat numbers.txt`;

// Cleanup
await $`rm -r project numbers.txt`;

import { $, register, unregister, listCommands } from 'command-stream';

// Register a custom command
register('greet', async (args, stdin) => {
  const name = args[0] || 'World';
  return { stdout: `Hello, ${name}!\n`, code: 0 };
});

// Use it like any other command
await $`greet Alice`;                    // → "Hello, Alice!"
await $`echo "Bob" | greet`;             // → "Hello, Bob!"

// Streaming virtual commands with async generators
register('countdown', async function* (args) {
  const start = parseInt(args[0] || 5);
  for (let i = start; i >= 0; i--) {
    yield `${i}\n`;
    await new Promise(r => setTimeout(r, 1000));
  }
});

// Use in pipelines with built-ins
await $`countdown 3 | cat > countdown.txt`;

// Virtual commands work in all patterns
for await (const chunk of $`countdown 3`.stream()) {
  console.log('Countdown:', chunk.data.toString().trim());
}

// Management functions
console.log(listCommands());  // List all registered commands
unregister('greet');          // Remove custom commands

// ❌ Other libraries: Choose JavaScript OR shell
await execa('node', ['script.js']);  // execa: separate processes
await $`node script.js`;             // zx: shell commands only

// ✅ command-stream: JavaScript functions AS shell commands  
register('deploy', async (args) => {
  const env = args[0] || 'staging';
  await deployToEnvironment(env);
  return { stdout: `Deployed to ${env}!\n`, code: 0 };
});

await $`deploy production`;           // JavaScript function as shell command!
await $`deploy staging | tee log.txt`; // Works in pipelines!

import { $, register } from 'command-stream';

// ✅ Standard shell piping (like all libraries)
await $`echo "hello world" | wc -w`;  // → "2"

// ✅ Built-in to built-in piping  
await $`seq 1 5 | cat > numbers.txt`;

// ✅ System to built-in piping
await $`git log --oneline | head -n 5`;

// 🚀 UNIQUE: Virtual command piping
register('uppercase', async (args, stdin) => {
  return { stdout: stdin.toUpperCase(), code: 0 };
});

register('reverse', async (args, stdin) => {
  return { stdout: stdin.split('').reverse().join(''), code: 0 };
});

// ✅ Built-in to virtual piping
await $`echo "hello" | uppercase`;  // → "HELLO"

// ✅ Virtual to virtual piping  
await $`echo "hello" | uppercase | reverse`;  // → "OLLEH"

// ✅ Mixed pipelines (system + built-in + virtual)
await $`git log --oneline | head -n 3 | uppercase | cat > LOG.txt`;

// ✅ Complex multi-stage pipelines
await $`find . -name "*.js" | head -n 10 | basename | sort | uniq`;

import { $, register } from 'command-stream';

// ✅ Basic programmatic piping
const result = await $`echo "hello"`.pipe($`echo "World: $(cat)"`);

// 🌟 Virtual command chaining
register('add-prefix', async (args, stdin) => {
  const prefix = args[0] || 'PREFIX:';
  return { stdout: `${prefix} ${stdin.trim()}\n`, code: 0 };
});

register('add-suffix', async (args, stdin) => {
  const suffix = args[0] || 'SUFFIX';
  return { stdout: `${stdin.trim()} ${suffix}\n`, code: 0 };
});

// ✅ Chain virtual commands with .pipe()
const result = await $`echo "Hello"`
  .pipe($`add-prefix "[PROCESSED]"`)
  .pipe($`add-suffix "!!!"`);
// → "[PROCESSED] Hello !!!"

// ✅ Mix with built-in commands
const fileData = await $`cat large-file.txt`
  .pipe($`head -n 100`)
  .pipe($`add-prefix "Line:"`);

// ✅ Error handling in pipelines
try {
  const result = await $`cat nonexistent.txt`.pipe($`add-prefix "Data:"`);
} catch (error) {
  // Source error propagates - destination never executes
  console.log('File not found, pipeline stopped');
}

// ✅ Complex data processing
register('json-parse', async (args, stdin) => {
  try {
    const data = JSON.parse(stdin);
    return { stdout: JSON.stringify(data, null, 2), code: 0 };
  } catch (error) {
    return { stdout: '', stderr: `JSON Error: ${error.message}`, code: 1 };
  }
});

register('extract-field', async (args, stdin) => {
  const field = args[0];
  try {
    const data = JSON.parse(stdin);
    const value = data[field] || 'null';
    return { stdout: `${value}\n`, code: 0 };
  } catch (error) {
    return { stdout: '', stderr: `Extract Error: ${error.message}`, code: 1 };
  }
});

// Real-world API processing pipeline
const userName = await $`curl -s https://api.github.com/users/octocat`
  .pipe($`json-parse`)
  .pipe($`extract-field name`);
// → "The Octocat"

// Cleanup
unregister('add-prefix');
unregister('add-suffix');
unregister('json-parse');
unregister('extract-field');

import { $ } from 'command-stream';

// This command will:
// 1. Print "Hello" to your terminal (stdout→stdout)
// 2. Print "Error!" to your terminal (stderr→stderr) 
// 3. Capture both outputs for programmatic access
const result = await $`sh -c "echo 'Hello'; echo 'Error!' >&2"`;

console.log('Captured stdout:', result.stdout); // "Hello\n"
console.log('Captured stderr:', result.stderr); // "Error!\n"
console.log('Exit code:', result.code);         // 0

import { $, create, sh } from 'command-stream';

// Disable terminal output but still capture
const result = await sh('echo "silent"', { mirror: false });

// Custom stdin input  
const custom = await sh('cat', { stdin: "custom input" });

// Create custom $ with different defaults
const quiet$ = create({ mirror: false });
await quiet$`echo "silent"`; // Won't print to terminal

// Disable both mirroring and capturing for performance
await sh('make build', { mirror: false, capture: false });

import { $ } from 'command-stream';
import { appendFileSync, writeFileSync } from 'fs';

let sessionId = null;
let logFile = null;

for await (const chunk of $`your-streaming-command`.stream()) {
  if (chunk.type === 'stdout') {
    const data = chunk.data.toString();
    
    // Extract session ID from output
    if (!sessionId && data.includes('session_id')) {
      try {
        const parsed = JSON.parse(data);
        sessionId = parsed.session_id;
        logFile = `${sessionId}.log`;
        console.log(`Session ID: ${sessionId}`);
      } catch (e) {
        // Handle JSON parse errors
      }
    }
    
    // Write to log file in real-time
    if (logFile) {
      appendFileSync(logFile, data);
    }
  }
}

import { $ } from 'command-stream';

let progress = 0;

$`download-large-file`
  .on('stdout', (chunk) => {
    const output = chunk.toString();
    if (output.includes('Progress:')) {
      progress = parseProgress(output);
      updateProgressBar(progress);
    }
  })
  .on('end', (result) => {
    console.log('Download completed!');
  });

{
  mirror: true,    // Live output to terminal (stdout→stdout, stderr→stderr)
  capture: true,   // Capture output for programmatic access
  stdin: 'inherit' // Inherit stdin from parent process
}

import { $, shell } from 'command-stream';

// ✅ Default behavior: Commands don't throw on non-zero exit
const result = await $`ls nonexistent-file`; // Won't throw
console.log(result.code); // → 2 (non-zero, but no exception)

// ✅ Enable errexit: Commands throw on non-zero exit
shell.errexit(true);
try {
  await $`ls nonexistent-file`; // Throws error
} catch (error) {
  console.log('Command failed:', error.code); // → 2
}

// ✅ Disable errexit: Back to non-throwing behavior
shell.errexit(false);
await $`ls nonexistent-file`; // Won't throw, returns result with code 2

// ✅ One-time override without changing global settings
try {
  const result = await $`ls nonexistent-file`;
  if (result.code !== 0) {
    throw new Error(`Command failed with code ${result.code}`);
  }
} catch (error) {
  console.log('Manual error handling');
}

import { $, register } from 'command-stream';

// ✅ Cancellation support with AbortController
register('cancellable', async function* (args, stdin, options) {
  for (let i = 0; i < 10; i++) {
    if (options.signal?.aborted) {
      break; // Proper cancellation handling
    }
    yield `Count: ${i}\n`;
    await new Promise(resolve => setTimeout(resolve, 1000));
  }
});

// ✅ Access to all process options
register('debug-info', async (args, stdin, options) => {
  return {
    stdout: JSON.stringify({
      args,
      cwd: options.cwd,
      env: Object.keys(options.env || {}),
      stdinLength: stdin.length,
      mirror: options.mirror,
      capture: options.capture
    }, null, 2),
    code: 0
  };
});

// ✅ Error handling and non-zero exit codes
register('maybe-fail', async (args) => {
  if (Math.random() > 0.5) {
    return {
      stdout: 'Success!\n',
      code: 0
    };
  } else {
    return {
      stdout: '',
      stderr: 'Random failure occurred\n',
      code: 1
    };
  }
});

// Regular async function
async function handler(args, stdin, options) {
  return {
    code: 0,           // Exit code (number)
    stdout: "output",  // Standard output (string)
    stderr: "",        // Standard error (string)
  };
}

// Async generator for streaming
async function* streamingHandler(args, stdin, options) {
  yield "chunk1\n";
  yield "chunk2\n";
  // Each yield sends a chunk in real-time
}

{
  code: number,        // Exit code
  stdout: string,      // Complete stdout output
  stderr: string,      // Complete stderr output
  stdin: string,       // Input sent to process
  child: ChildProcess, // Original child process object
  async text()         // Bun.$ compatibility method - returns stdout as string
}

import { $ } from 'command-stream';

// Both sync and async execution support .text()
const result1 = await $`echo "hello world"`;
const text1 = await result1.text(); // "hello world\n"

const result2 = $`echo "sync example"`.sync();  
const text2 = await result2.text(); // "sync example\n"

// .text() is equivalent to accessing .stdout
expect(await result.text()).toBe(result.stdout);

// Works with built-in commands
const result3 = await $`seq 1 3`;
const text3 = await result3.text(); // "1\n2\n3\n"

// Works with .pipe() method
const result4 = await $`echo "pipe test"`.pipe($`cat`);
const text4 = await result4.text(); // "pipe test\n"

// ✅ Smart signal handling - only interferes when necessary
import { $ } from 'command-stream';

// Case 1: No children active - your handlers work normally  
process.on('SIGINT', () => {
  console.log('My custom handler runs!');
  process.exit(42); // Custom exit code
});
// Press CTRL+C → Your handler runs, exits with code 42

// Case 2: Children active - automatic forwarding
await $`ping 8.8.8.8`; // Press CTRL+C → Forwards to ping, exits with code 130

// Case 3: Multiple processes - all interrupted
await Promise.all([
  $`sleep 100`,
  $`ping google.com`  
]); // Press CTRL+C → All processes terminated, exits with code 130

// Long-running command that can be interrupted with CTRL+C
try {
  await $`ping 8.8.8.8`;  // Press CTRL+C to stop
} catch (error) {
  console.log('Command interrupted:', error.code); // Exit code 130 (SIGINT)
}

// Multiple concurrent processes - CTRL+C stops all
try {
  await Promise.all([
    $`sleep 100`,
    $`ping google.com`,
    $`tail -f /var/log/system.log`
  ]);
} catch (error) {
  // All processes are terminated when you press CTRL+C
}

// Works with streaming patterns too
try {
  for await (const chunk of $`ping 8.8.8.8`.stream()) {
    console.log(chunk);
    // Press CTRL+C to break the loop and stop the process
  }
} catch (error) {
  console.log('Streaming interrupted');
}

// Understanding how commands are resolved:

// 1. Virtual Commands (highest priority)
register('echo', () => ({ stdout: 'virtual!\n', code: 0 }));
await $`echo test`; // → "virtual!"

// 2. Built-in Commands (if no virtual match)  
unregister('echo');
await $`echo test`; // → Uses built-in echo

// 3. System Commands (if no built-in/virtual match)
await $`unknown-command`; // → Uses system PATH lookup

// 4. Virtual Bypass (special case)
await $({ stdin: 'data' })`sleep 1`; // Bypasses virtual sleep, uses system sleep

import { $ } from 'command-stream';

// ✅ Use await for simple command execution
const result = await $`ls -la`;

// ✅ Use .sync() when you need blocking execution with events
const syncCmd = $`build-script`
  .on('stdout', chunk => updateProgress(chunk))
  .sync(); // Events fire after completion

// ✅ Use .start() for non-blocking execution with real-time events  
const asyncCmd = $`long-running-server`
  .on('stdout', chunk => logOutput(chunk))
  .start(); // Events fire in real-time

// ✅ Use .stream() for processing large outputs efficiently
for await (const chunk of $`generate-big-file`.stream()) {
  processChunkInRealTime(chunk);
} // Memory efficient - processes chunks as they arrive

// ✅ Use EventEmitter pattern for complex workflows
$`deployment-script`
  .on('stdout', chunk => {
    if (chunk.toString().includes('ERROR')) {
      handleError(chunk);
    }
  })
  .on('stderr', chunk => logError(chunk))
  .on('end', result => {
    if (result.code === 0) {
      notifySuccess();
    }
  })
  .start();

// 🚀 Memory Efficient: For large outputs, use streaming
for await (const chunk of $`cat huge-file.log`.stream()) {
  processChunk(chunk); // Processes incrementally
}

// 🐌 Memory Inefficient: Buffers entire output in memory
const result = await $`cat huge-file.log`;
processFile(result.stdout); // Loads everything into memory

// ⚡ Fastest: Sync execution for small, quick commands
const quickResult = $`pwd`.sync();

// 🔄 Best for UX: Async with events for long-running commands
$`npm install`
  .on('stdout', showProgress)
  .start();