// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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 main

import (
  "os"
  "flag"
  "fmt"
  "sort"
  "strconv"
  "path/filepath"
)

// Variable setted by option
var (
  LIMIT   = flag.Int("limit", 20, "limit the number of processes to print")
  REVERSE = flag.Bool("reverse", false, "reverse the list of processes to print")
  HELP    = flag.Bool("help", false, "print this help message")
)

func init() {
  flag.Parse()

  if *HELP {
    flag.PrintDefaults()
    os.Exit(1)
  }
}

func main() {
  var procs []*Proc

  folders, _ := filepath.Glob("/proc/[0-9]*")
  for _, f := range folders {
    pid, err := strconv.Atoi(filepath.Base(f))
    if err == nil {
      procs = append(procs, NewProc(pid))
    }
  }

  sort.Slice(procs, func(i, j int) bool {
    return procs[i].Swap > procs[j].Swap
  })

  procs = procs[:*LIMIT]
  if *REVERSE {
    sort.Slice(procs, func(i, j int) bool {
      return procs[i].Swap < procs[j].Swap
    })
  }

  for _, proc := range procs {
    if proc.Swap == 0 || proc.CmdLine == "" {
      continue
    }
    fmt.Printf("%d kB [%d] %v\n", proc.Swap, proc.Pid, proc.CmdLine)
  }
}