package types

// TokenType represents the type of a token
type TokenType int

// Token represents a lexical token
type Token struct {
	Type    TokenType
	Lexeme  string
	Literal any
	Line    int
	Column  int
}

// All token types in the language
const (
	// Special tokens
	EOF TokenType = iota
	ERROR

	// Literals
	IDENTIFIER
	STRING
	NUMBER

	// Operators
	PLUS          // +
	MINUS         // -
	STAR          // *
	SLASH         // /
	EQUAL         // =
	EQUAL_EQUAL   // ==
	BANG_EQUAL    // !=
	LESS          //
	LESS_EQUAL    // <=
	GREATER       // >
	GREATER_EQUAL // >=

	// Keywords
	AND
	OR
	IF
	ELSEIF
	ELSE
	THEN
	END
	FN
	RETURN
	ECHO
	TRUE
	FALSE
	NIL

	// Punctuation
	LEFT_PAREN  // (
	RIGHT_PAREN // )
	COMMA       // ,
	ELLIPSIS    // ...
)

// String returns the string representation of the token type
func (t TokenType) String() string {
	return tokenNames[t]
}

// Token type string representations
var tokenNames = [...]string{
	EOF:           "EOF",
	ERROR:         "ERROR",
	IDENTIFIER:    "IDENTIFIER",
	STRING:        "STRING",
	NUMBER:        "NUMBER",
	PLUS:          "PLUS",
	MINUS:         "MINUS",
	STAR:          "STAR",
	SLASH:         "SLASH",
	EQUAL:         "EQUAL",
	EQUAL_EQUAL:   "EQUAL_EQUAL",
	BANG_EQUAL:    "BANG_EQUAL",
	LESS:          "LESS",
	LESS_EQUAL:    "LESS_EQUAL",
	GREATER:       "GREATER",
	GREATER_EQUAL: "GREATER_EQUAL",
	AND:           "AND",
	OR:            "OR",
	IF:            "IF",
	ELSEIF:        "ELSEIF",
	ELSE:          "ELSE",
	THEN:          "THEN",
	END:           "END",
	FN:            "FN",
	RETURN:        "RETURN",
	ECHO:          "ECHO",
	TRUE:          "TRUE",
	FALSE:         "FALSE",
	NIL:           "NIL",
	LEFT_PAREN:    "LEFT_PAREN",
	RIGHT_PAREN:   "RIGHT_PAREN",
	COMMA:         "COMMA",
	ELLIPSIS:      "ELLIPSIS",
}