package lexer

import "fmt"

//go:generate stringer -type TokenType -linecomment -trimprefix TokenType
type TokenType int

const (
	// single char tokens

	TokenTypeLeftParen TokenType = iota
	TokenTypeRightParen
	TokenTypeLeftBrace
	TokenTypeRightBrace
	TokenTypeComma
	TokenTypeDot
	TokenTypeMinus
	TokenTypePlus
	TokenTypeSemicolon
	TokenTypeSlash
	TokenTypeStar

	// 1-2 char token

	TokenTypeBang
	TokenTypeBangEq
	TokenTypeEqual
	TokenTypeEqualEqual
	TokenTypeGreater
	TokenTypeGreaterEq
	TokenTypeLess
	TokenTypeLessEq

	// literals

	TokenTypeIdentifier
	TokenTypeString
	TokenTypeNumber

	// keywords

	TokenTypeAnd
	TokenTypeClass
	TokenTypeElse
	TokenTypeFalse
	TokenTypeFun
	TokenTypeFor
	TokenTypeIf
	TokenTypeNil
	TokenTypeOr
	TokenTypePrint
	TokenTypeReturn
	TokenTypeSuper
	TokenTypeThis
	TokenTypeTrue
	TokenTypeVar
	TokenTypeWhile

	TokenTypeEOF
)

var KeywordTokenTypes = []TokenType{
	TokenTypeClass,
	TokenTypeFun,
	TokenTypeVar,
	TokenTypeFor,
	TokenTypeIf,
	TokenTypeReturn,
	TokenTypeWhile,
	TokenTypePrint,
}

type Token struct {
	Type    TokenType
	Lexeme  string
	Literal any
	Line    int
}

func (t Token) String() string {
	return fmt.Sprintf("%s %s %+v", t.Type, t.Lexeme, t.Literal)
}

func IsKeyword(token *Token) bool {
	for _, kt := range KeywordTokenTypes {
		if token.Type == kt {
			return true
		}
	}
	return false
}