package tokenizer

type TokenType = string

const (
	Underline TokenType = "_"
	Star      TokenType = "*"
	Hash      TokenType = "#"
	Backtick  TokenType = "`"
	Newline   TokenType = "\n"
	Space     TokenType = " "
)

const (
	Text TokenType = ""
)

type Token struct {
	Type  TokenType
	Value string
}

func NewToken(tp, text string) *Token {
	return &Token{
		Type:  tp,
		Value: text,
	}
}

func Tokenize(text string) []*Token {
	tokens := []*Token{}
	for _, c := range text {
		switch c {
		case '_':
			tokens = append(tokens, NewToken(Underline, "_"))
		case '*':
			tokens = append(tokens, NewToken(Star, "*"))
		case '#':
			tokens = append(tokens, NewToken(Hash, "#"))
		case '\n':
			tokens = append(tokens, NewToken(Newline, "\n"))
		case '`':
			tokens = append(tokens, NewToken(Backtick, "`"))
		case ' ':
			tokens = append(tokens, NewToken(Space, " "))
		default:
			var lastToken *Token
			if len(tokens) > 0 {
				lastToken = tokens[len(tokens)-1]
			}
			if lastToken == nil || lastToken.Type != Text {
				tokens = append(tokens, NewToken(Text, string(c)))
			} else {
				lastToken.Value += string(c)
			}
		}
	}
	return tokens
}