feat(cli): implement comprehensive command-line interface

example.conf

@@ -0,0 +1,23 @@
+# pgbun configuration file example
+[server]
+listen_port = 6433
+listen_host = "127.0.0.1"
+server_host = "localhost"
+server_port = 5432
+
+[pool]
+pool_mode = "transaction"
+max_client_conn = 200
+pool_size = 50
+
+[logging]
+log_connections = true
+stats_period = 30000
+
+[timeouts]
+server_connect_timeout = 10000
+client_login_timeout = 30000
+
+[tls]
+client_tls_mode = "disable"
+server_tls_mode = "prefer"

package.json

@@ -19,6 +19,7 @@
   "author": "",
   "license": "MIT",
   "devDependencies": {
+    "@iarna/toml": "^2.2.5",
     "bun-types": "^1.2.22"
   },
   "peerDependencies": {

src/cli.ts

@@ -0,0 +1,276 @@
+export interface CLIOptions {
+  help?: boolean;
+  version?: boolean;
+  command?: 'start' | 'config' | 'version' | 'help';
+
+  // Connection options
+  listenPort?: number;
+  listenHost?: string;
+  serverHost?: string;
+  serverPort?: number;
+
+  // Pool options
+  poolMode?: 'session' | 'transaction' | 'statement';
+  maxClientConn?: number;
+  poolSize?: number;
+
+  // Config options
+  config?: string;
+  env?: string;
+  dryRun?: boolean;
+
+  // Logging options
+  verbose?: boolean;
+  quiet?: boolean;
+  logLevel?: 'debug' | 'info' | 'warn' | 'error';
+  logConnections?: boolean;
+  statsPeriod?: number;
+
+  // Operational options
+  daemon?: boolean;
+  pidFile?: string;
+}
+
+export class CLIParser {
+  static parse(args: string[] = Bun.argv.slice(2)): CLIOptions {
+    const options: CLIOptions = {};
+    let i = 0;
+
+    while (i < args.length) {
+      const arg = args[i];
+      const nextArg = args[i + 1];
+
+      switch (arg) {
+        case '-h':
+        case '--help':
+          options.help = true;
+          break;
+
+        case '-V':
+        case '--version':
+          options.version = true;
+          break;
+
+        case '-p':
+        case '--listen-port':
+          if (!nextArg || isNaN(Number(nextArg))) {
+            throw new Error(`Invalid port value: ${nextArg}`);
+          }
+          options.listenPort = Number(nextArg);
+          i++;
+          break;
+
+        case '--listen-host':
+          if (!nextArg) {
+            throw new Error('--listen-host requires a value');
+          }
+          options.listenHost = nextArg;
+          i++;
+          break;
+
+        case '--server-host':
+          if (!nextArg) {
+            throw new Error('--server-host requires a value');
+          }
+          options.serverHost = nextArg;
+          i++;
+          break;
+
+        case '--server-port':
+          if (!nextArg || isNaN(Number(nextArg))) {
+            throw new Error(`Invalid server port value: ${nextArg}`);
+          }
+          options.serverPort = Number(nextArg);
+          i++;
+          break;
+
+        case '--pool-mode':
+          if (!nextArg || !['session', 'transaction', 'statement'].includes(nextArg)) {
+            throw new Error(`Invalid pool mode '${nextArg}'. Must be one of: session, transaction, statement`);
+          }
+          options.poolMode = nextArg as 'session' | 'transaction' | 'statement';
+          i++;
+          break;
+
+        case '--max-client-conn':
+          if (!nextArg || isNaN(Number(nextArg))) {
+            throw new Error(`Invalid max client connections value: ${nextArg}`);
+          }
+          options.maxClientConn = Number(nextArg);
+          i++;
+          break;
+
+        case '--pool-size':
+          if (!nextArg || isNaN(Number(nextArg))) {
+            throw new Error(`Invalid pool size value: ${nextArg}`);
+          }
+          options.poolSize = Number(nextArg);
+          i++;
+          break;
+
+        case '-c':
+        case '--config':
+          if (!nextArg) {
+            throw new Error('--config requires a file path');
+          }
+          options.config = nextArg;
+          i++;
+          break;
+
+        case '--env':
+          if (!nextArg || !['dev', 'prod', 'test'].includes(nextArg)) {
+            throw new Error(`Invalid environment '${nextArg}'. Must be one of: dev, prod, test`);
+          }
+          options.env = nextArg;
+          i++;
+          break;
+
+        case '--dry-run':
+          options.dryRun = true;
+          break;
+
+        case '-v':
+        case '--verbose':
+          options.verbose = true;
+          break;
+
+        case '-q':
+        case '--quiet':
+          options.quiet = true;
+          break;
+
+        case '--log-level':
+          if (!nextArg || !['debug', 'info', 'warn', 'error'].includes(nextArg)) {
+            throw new Error(`Invalid log level '${nextArg}'. Must be one of: debug, info, warn, error`);
+          }
+          options.logLevel = nextArg as 'debug' | 'info' | 'warn' | 'error';
+          i++;
+          break;
+
+        case '--log-connections':
+          options.logConnections = true;
+          break;
+
+        case '--stats-period':
+          if (!nextArg || isNaN(Number(nextArg))) {
+            throw new Error(`Invalid stats period value: ${nextArg}`);
+          }
+          options.statsPeriod = Number(nextArg);
+          i++;
+          break;
+
+        case '-d':
+        case '--daemon':
+          options.daemon = true;
+          break;
+
+        case '--pid-file':
+          if (!nextArg) {
+            throw new Error('--pid-file requires a file path');
+          }
+          options.pidFile = nextArg;
+          i++;
+          break;
+
+        default:
+          // Handle commands
+          if (!arg.startsWith('-')) {
+            if (['start', 'config', 'version', 'help'].includes(arg)) {
+              options.command = arg as 'start' | 'config' | 'version' | 'help';
+            } else {
+              throw new Error(`Unknown command: ${arg}`);
+            }
+          } else {
+            throw new Error(`Unknown option: ${arg}`);
+          }
+          break;
+      }
+      i++;
+    }
+
+    // Set default command
+    if (!options.command && !options.help && !options.version) {
+      options.command = 'start';
+    }
+
+    // Validate port ranges
+    if (options.listenPort && (options.listenPort < 1 || options.listenPort > 65535)) {
+      throw new Error(`Invalid listen port '${options.listenPort}'. Must be between 1 and 65535`);
+    }
+    if (options.serverPort && (options.serverPort < 1 || options.serverPort > 65535)) {
+      throw new Error(`Invalid server port '${options.serverPort}'. Must be between 1 and 65535`);
+    }
+
+    return options;
+  }
+
+  static getVersion(): string {
+    try {
+      const packageJson = require('../package.json');
+      return packageJson.version || '0.1.0';
+    } catch {
+      return '0.1.0';
+    }
+  }
+
+  static showHelp(): void {
+    const version = this.getVersion();
+    console.log(`pgbun ${version} - PostgreSQL Connection Pool and Proxy
+
+USAGE:
+    pgbun [OPTIONS] [COMMAND]
+
+COMMANDS:
+    start      Start the connection pool server (default)
+    config     Show current configuration
+    version    Show version information
+    help       Show help information
+
+CONNECTION OPTIONS:
+    -p, --listen-port <PORT>     Listen port [default: 6432]
+        --listen-host <HOST>     Listen host [default: 0.0.0.0]
+        --server-host <HOST>     PostgreSQL server host [default: localhost]
+        --server-port <PORT>     PostgreSQL server port [default: 5432]
+
+POOL OPTIONS:
+    --pool-mode <MODE>           Pool mode: session|transaction|statement [default: session]
+    --max-client-conn <NUM>      Maximum client connections [default: 100]
+    --pool-size <NUM>            Default pool size [default: 25]
+
+CONFIG OPTIONS:
+    -c, --config <FILE>          Configuration file path
+        --env <ENV>              Environment: dev|prod|test
+        --dry-run                Validate configuration without starting
+
+LOGGING OPTIONS:
+    -v, --verbose                Verbose logging
+    -q, --quiet                  Suppress non-error output
+        --log-level <LEVEL>      Log level: debug|info|warn|error [default: info]
+        --log-connections        Log connection events
+        --stats-period <MS>      Statistics reporting interval [default: 60000]
+
+OTHER OPTIONS:
+    -d, --daemon                 Run as daemon
+        --pid-file <FILE>        Write PID to file
+    -h, --help                   Show this help message
+    -V, --version                Show version information
+
+EXAMPLES:
+    pgbun                                    # Start with defaults
+    pgbun -p 6433 --pool-mode transaction   # Custom port and pool mode
+    pgbun --config /etc/pgbun.conf          # Use config file
+    pgbun config                             # Show current configuration
+
+ENVIRONMENT VARIABLES:
+    PGBUN_LISTEN_PORT            Override listen port
+    PGBUN_LISTEN_HOST            Override listen host
+    PGBUN_SERVER_HOST            Override server host
+    PGBUN_SERVER_PORT            Override server port
+    PGBUN_POOL_MODE              Override pool mode
+    PGBUN_LOG_LEVEL              Override log level`);
+  }
+
+  static showVersion(): void {
+    console.log(`pgbun ${this.getVersion()}`);
+  }
+}