package token

type TokenType string

type Token struct {
	Type    TokenType
	Literal string
}

const (
	ILLEGAL = "ILLEGAL"
	EOF     = "EOF"

	// COMMENT a line comment, e.g: # this is a comment
	COMMENT = "COMMENT"

	// Identifiers + literals
	IDENT  = "IDENT" // add, foobar, x, y
	INT    = "INT"   // 123456
	STRING = "STRING"

	// Operators
	BIND     = ":="
	ASSIGN   = "="
	PLUS     = "+"
	MINUS    = "-"
	MULTIPLY = "*"
	DIVIDE   = "/"
	MODULO   = "%"

	// Bitwise / Logical operators

	// BITWISE_AND AND
	BITWISE_AND = "&"
	// BITWISE_OR OR
	BITWISE_OR = "|"
	// BITWISE_XOR XOR
	BITWISE_XOR = "^"
	// BITWISE_NOT NOT
	BITWISE_NOT = "~"
	// LeftShift
	LEFT_SHIFT = "<<"
	// RightShift
	RIGHT_SHIFT = ">>"

	//
	// Comparision operators
	//

	// NOT the not operator
	NOT = "!"
	// AND the and operator
	AND = "&&"
	// OR the or operator
	OR = "||"

	LT  = "<"
	LTE = "<="
	GT  = ">"
	GTE = ">="

	EQ     = "=="
	NOT_EQ = "!="

	// Delimiters
	COMMA     = ","
	SEMICOLON = ";"
	COLON     = ":"
	DOT       = "."

	LPAREN   = "("
	RPAREN   = ")"
	LBRACE   = "{"
	RBRACE   = "}"
	LBRACKET = "["
	RBRACKET = "]"

	// Keywords
	FUNCTION = "FUNCTION"
	TRUE     = "TRUE"
	FALSE    = "FALSE"
	NULL     = "NULL"
	IF       = "IF"
	ELSE     = "ELSE"
	RETURN   = "RETURN"
	WHILE    = "WHILE"
)

var keywords = map[string]TokenType{
	"fn":     FUNCTION,
	"true":   TRUE,
	"false":  FALSE,
	"if":     IF,
	"null":   NULL,
	"else":   ELSE,
	"return": RETURN,
	"while":  WHILE,
}

func LookupIdent(ident string) TokenType {
	if tok, ok := keywords[ident]; ok {
		return tok
	}
	return IDENT
}