combo/pin/pin.go

package pin

import (
	"fmt"
	//"strconv"
	//"log"
	"io"
	"os"

	"surdeus.su/core/cli/mtool"
)

var (
	delim rune = '\n'
	Tool = mtool.T("pin").Func(Run).Desc(
		"print all the possible PIN combinations made of custom characters",
	).Usage(
		"",
	)
)

func Pow(x, p int) int {
	ret := 1
	for i:=0 ; i<p ; i++ {
		ret *= x
	}
	return ret
}

func GetPin(chars []rune, length int, i int) string {
	ret := ""
	slen := len(chars)
	for j:=0 ; j<length ; j++ {
		ret = string(chars[ ( i/Pow(slen, j) ) % slen] ) + ret
	}
	return ret
}

func FprintPins(
	output io.Writer,
	chars []rune,
	length int,
) {
	n := Pow(len(chars), length)
	for i:=0 ; i<n ; i++ {
		pin := GetPin(chars, length, i)
		if Fits([]rune(pin), chars, length) {
			fmt.Fprintln(
				output,
				GetPin(chars, length, i),
			)
		}
	}
}

func Fits(s []rune, chrs []rune, maxReps int) bool {
	a := make([]int, len(chrs))
	for i, v1 := range chrs {
		for _, v2 := range s {
			if v1 == v2 {
				a[i]++
				if a[i] > maxReps {
					return false
				}
			}
		}
	}
	return true
}

func Run(
	flags *mtool.Flags,
) {
	CustomRun(
		os.Stdin,
		os.Stdout,
		flags,
	)
}

func CustomRun(
	input io.Reader,
	output io.Writer,
	flags *mtool.Flags,
) {
	var (
		length int
		rFlag bool
		mFlag bool
		minLength int
		maxReps int
	)
	var (
		charsString string
		chrs []rune
	)

	flags.StringVar(
		&charsString,
		"c",
		"0123456789",
		"character set for substitution",
		"COMBO_CHARS",
	)
	flags.IntVar(
		&minLength, "min-len", 1,
		"min length of the output pins",
	)
	flags.BoolVar(
		&mFlag, "m", false,
		"set the '-min-len' flag value to 1 (overrides the '-min' it)",
	)
	flags.IntVar(
		&length, "max", 0,
		"max length of the output pins",
	)

	flags.IntVar(&maxReps, "max-reps", 1, "max repeats of the rune." )
	flags.BoolVar(&rFlag, "r", false, "make the -max-reps value equal to the length of input chars" )

	_ = flags.Parse()

	/*if len(args) == 0 {
		flags.Usage()
		os.Exit(1)
	}*/

	chrs = []rune(charsString)

	if length == 0 {
		length = 4
	}

	if mFlag {
		minLength = 1
	}

	if rFlag {
		maxReps = len(chrs)
	}

	if minLength != 0 {
		if minLength > length {
			flags.Usage()
			os.Exit(1)
		}
		for i := minLength ; i<=length ; i++ {
			FprintPins(output, chrs, i)
		}
	} else {
		FprintPins(output, chrs, length)
	}

}