// Copyright 2018 Google 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 cmd holds implementations of the runsc commands.
package cmd

import (
	"fmt"
	"os"
	"strconv"

	"flag"
	"gvisor.googlesource.com/gvisor/pkg/log"
)

// Fatalf logs to stderr and exits with a failure status code.
func Fatalf(s string, args ...interface{}) {
	// If runsc is being invoked by docker or cri-o, then we might not have
	// access to stderr, so we log a serious-looking warning in addition to
	// writing to stderr.
	log.Warningf("FATAL ERROR: "+s, args...)
	fmt.Fprintf(os.Stderr, s+"\n", args...)
	// Return an error that is unlikely to be used by the application.
	os.Exit(128)
}

// commandLineFlags returns a slice of all top-level command line flags that
// have been set.
func commandLineFlags() []string {
	var args []string
	flag.CommandLine.Visit(func(f *flag.Flag) {
		args = append(args, fmt.Sprintf("--%s=%s", f.Name, f.Value.String()))
	})
	return args
}

// intFlags can be used with int flags that appear multiple times.
type intFlags []int

// String implements flag.Value.
func (i *intFlags) String() string {
	return fmt.Sprintf("%v", *i)
}

// Get implements flag.Value.
func (i *intFlags) Get() interface{} {
	return i
}

// GetArray returns array of FDs.
func (i *intFlags) GetArray() []int {
	return *i
}

// Set implements flag.Value.
func (i *intFlags) Set(s string) error {
	fd, err := strconv.Atoi(s)
	if err != nil {
		return fmt.Errorf("invalid flag value: %v", err)
	}
	if fd < 0 {
		return fmt.Errorf("flag value must be greater than 0: %d", fd)
	}
	*i = append(*i, fd)
	return nil
}