// Copyright 2020-2026 Buf Technologies, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package flagx

import (
	"errors"
	"flag"
	"fmt"
	"os"
	"os/exec"
)

// Main should be called from a main function. It is a wrapper for making it
// easy to have a main that returns an error.
//
// This function terminates the program when main returns.
func Main(main func() error) {
	flag.Parse()

	err := main()
	if err == nil {
		os.Exit(0)
	}

	exit := 1
	if exec := (*exec.ExitError)(nil); errors.As(err, &exec) {
		exit = exec.ExitCode()
	}

	fmt.Fprintf(os.Stderr, "%v\n", err)
	os.Exit(exit)
}