package decanter

import "strings"

type Decanter map[rune]byte

const abcs = "abcdefghijklmnopqrstuvwxyz"

func New() Decanter {
	out := Decanter(map[rune]byte{})
	return out
}

func (D Decanter) AddAlphabets(as []string) Decanter {
	for _, a := range as {
		D.AddAlphabet(a)
	}
	return D
}
func (D Decanter) AddAlphabet(a string) {
	idx := 0
	for _, r := range a {
		if r != '_' && r != rune(abcs[idx]) {
			D[r] = abcs[idx]
		}
		idx = idx + 1
		if idx > 25 {
			break
		}
	}
}
func (D Decanter) AddLetter(b byte, r rune) {
	D[r] = b
}

func (D Decanter) AddLetters(b byte, rs []rune) {
	for _, r := range rs {
		D[r] = b
	}
}

func (D Decanter) DecantTransform(s string) []string {
	forms := []string{
		D.DecantString(s),
		D.DecantStringStrip(s, ' '),
		D.DecantStringNoRepeat(s),
	}
	return forms
}

func (D Decanter) Decant(r rune) rune {
	if _, ok := D[r]; ok {
		return rune(D[r])
	}
	return r
}

func (D Decanter) DecantString(s string) string {
	b := new(strings.Builder)
	for _, v := range s {
		b.WriteRune(D.Decant(v))
	}
	return b.String()
}

func (D Decanter) DecantStringStrip(s string, strip rune) string {
	b := new(strings.Builder)
	for _, v := range s {
		if v != strip {
			b.WriteRune(D.Decant(v))
		}
	}
	return b.String()
}

func (D Decanter) DecantStringNoRepeat(s string) string {
	b := new(strings.Builder)
	last := ' '
	for _, v := range s {
		if v != last {
			b.WriteRune(D.Decant(v))
		}
		v = last
	}
	return b.String()
}