processor.go

package main

import (
	"strconv"
	"strings"
)

func normalizeText(s string) string {
	replacer := strings.NewReplacer(
		",", " , ",
		".", " . ",
		"!", " ! ",
		"?", " ? ",
		":", " : ",
		";", " ; ",
		"'", " ' ",
	)

	// temporarily protect commands
	s = strings.ReplaceAll(s, "(up,", "UPCOMMAND")
	s = strings.ReplaceAll(s, "(low,", "LOWCOMMAND")
	s = strings.ReplaceAll(s, "(cap,", "CAPCOMMAND")

	s = replacer.Replace(s)

	// restore commands
	s = strings.ReplaceAll(s, "UPCOMMAND", "(up,")
	s = strings.ReplaceAll(s, "LOWCOMMAND", "(low,")
	s = strings.ReplaceAll(s, "CAPCOMMAND", "(cap,")

	return s
}
func handleAll(input string) string {
	input = normalizeText(input)

	word := strings.Fields(input)
	quoteOpen := false
	for i := 0; i < len(word); i++ {
		// HEX / BIN
		if i > 0 && (word[i] == "(hex)" || word[i] == "(bin)") {

			var base int
			if word[i] == "(hex)" {
				base = 16
			} else {
				base = 2
			}

			prev, err := strconv.ParseInt(word[i-1], base, 64)
			if err == nil {
				word[i-1] = strconv.FormatInt(prev, 10)
			}
			word = append(word[:i], word[i+1:]...)
			i--
			continue
		}

		// UP
		if i > 0 && word[i] == "(up)" {
			word[i-1] = strings.ToUpper(word[i-1])
			word = append(word[:i], word[i+1:]...)
			i--
			continue
		}

		// LOW
		if i > 0 && word[i] == "(low)" {
			word[i-1] = strings.ToLower(word[i-1])
			word = append(word[:i], word[i+1:]...)
			i--
			continue
		}

		// CAP
		if i > 0 && word[i] == "(cap)" {
			if len(word[i-1]) > 0 {
				word[i-1] = strings.ToUpper(word[i-1][:1]) + strings.ToLower(word[i-1][1:])
			}
			word = append(word[:i], word[i+1:]...)
			i--
			continue
		}

		// CASE WITH NUMBER (up, 2) (low, 3) (cap, 4)
		if i > 0 && (strings.HasPrefix(word[i], "(up,") || strings.HasPrefix(word[i], "(low,") || strings.HasPrefix(word[i], "(cap,")) {

			if i+1 >= len(word) {
				continue
			}

			command := strings.TrimPrefix(word[i], "(")
			command = strings.TrimSuffix(command, ",")
			numberPart := strings.TrimSuffix(word[i+1], ")")

			count, err := strconv.Atoi(numberPart)
			if err != nil {
				continue
			}

			for j := 1; j <= count && i-j >= 0; j++ {
				switch command {
				case "up":
					word[i-j] = strings.ToUpper(word[i-j])
				case "low":
					word[i-j] = strings.ToLower(word[i-j])
				case "cap":
					if len(word[i-j]) > 0 {
						word[i-j] = strings.ToUpper(word[i-j][:1]) + strings.ToLower(word[i-j][1:])
					}
				}
			}
			word = append(word[:i], word[i+2:]...)
			i--
			continue
		}

		// PUNCTUATION FIX
		puncts := ".,!?;:"
		if i > 0 && allPunct(word[i], puncts) {
			word[i-1] += word[i]
			word = append(word[:i], word[i+1:]...)
			i--
			continue
		}

		// QUOTES

		if word[i] == "'" {

			if !quoteOpen && i+1 < len(word) {
				word[i+1] = "'" + word[i+1]
			} else if quoteOpen && i > 0 {
				word[i-1] = word[i-1] + "'"
			}

			quoteOpen = !quoteOpen
			word = append(word[:i], word[i+1:]...)
			i--
			continue
		}
		// A -> AN RULE
		if i < len(word)-1 && (word[i] == "a" || word[i] == "A") && len(word[i+1]) > 0 {
			vowel := strings.ToLower(word[i+1][:1])

			if strings.Contains("aeiouh", vowel) {
				if word[i] == "A" {
					word[i] = "An"
				} else {
					word[i] = "an"
				}
			}
		}
	}
	return strings.Join(word, " ")
}

func allPunct(s, puncts string) bool {
	for _, r := range s {
		if !strings.ContainsRune(puncts, r) {
			return false
		}
	}
	return true
}