package profanity

import (
	"bufio"
	"os"
	"profanity/common"
	"profanity/common/decanter"
	"strings"
)

type Filter struct {
	words    map[string]string
	Decanter decanter.Decanter

	transforms []common.TransformFunc
}

func New() *Filter {
	dec := decanter.NewDefaultDecanter()
	return &Filter{
		words:      make(map[string]string, 3000),
		Decanter:   dec,
		transforms: []common.TransformFunc{dec.DecantTransform},
	}
}

//FilterWord
//curse is "" if bad == false, else curse is populated with the match
func (F *Filter) FilterWord(s string) (bad bool, curse string, form string) {
	forms := common.FlattenTransformFunc(F.transforms)(s)
	for _, form := range forms {
		if curse, ok := F.words[form]; ok {
			return true, curse, form
		}
		for _, v := range F.words {
			if strings.Contains(form, v) {
				return true, curse, form
			}
		}
	}
	return false, "", ""
}

func (F *Filter) CensorSentence(s string, replacer string) (censored string) {
	return F.CensorSentenceN(s, replacer, 0)
}

func (F *Filter) CensorSentenceMany(s string, replacer string, widths ...uint8) (censored string) {
	sentence := s
	for _, width := range widths {
		sentence = F.CensorSentenceN(sentence, replacer, width)
	}
	return sentence
}

func (F *Filter) CensorSentenceToN(s string, replacer string, maxwidth uint8) (censored string) {
	sentence := s
	for width := uint8(0); width < maxwidth; width++ {
		sentence = F.CensorSentenceN(sentence, replacer, width)
	}
	return sentence
}

func (F *Filter) CensorSentenceN(s string, replacer string, width uint8) (censored string) {
	sep := " "
	sb := new(strings.Builder)
	words := strings.Split(s, sep)
	for idx := 0; idx < len(words); idx++ {
		original := words[idx]
		word := words[idx]
		for i := 1; i <= int(width); i++ {
			if len(words) > (idx + i) {
				word = word + " " + words[idx+i]
			}
		}
		if bad, _, form := F.FilterWord(word); bad {
			idx = idx + int(width)
			sb.WriteString(strings.Repeat(replacer, len(form)))
		} else {
			sb.WriteString(original)
		}
		sb.WriteString(sep)
	}
	return strings.TrimSpace(sb.String())
}

func (F *Filter) MustAddFile(file *os.File, err error) {
	if err != nil {
		panic(err)
	}
	F.AddFile(file)
}

func (F *Filter) AddFile(file *os.File) {
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		txt := scanner.Text()
		F.AddWord(txt)
	}
}

func (F *Filter) AddWords(wx []string) {
	for _, w := range wx {
		F.AddWord(w)
	}
}

func (F *Filter) AddWord(w string) {
	F.words[w] = w
}