package lexer

import (
	"mana/tokens"
	"testing"
)

func TestNextToken(t *testing.T) {
	const input string = `
		let five = 5;
		let ten = 10;

		let add = fn(x, y) {
			x + y;
		};

		let result = add(five, ten);

		!-/*5;
		5 < 10 > 5;

		if (5 < 10) {
			return true;
		} else {
			return false;
		}

		10 == 10;
		10 != 9;
		"foobar"
		"foo bar"
		[1, 2];
		{"foo": "bar"}
	`

	var tests = []struct {
		expectedType    tokens.TokenType
		expectedLiteral string
	}{
		{tokens.LET, "let"},
		{tokens.IDENT, "five"},
		{tokens.ASSIGN, "="},
		{tokens.INT, "5"},
		{tokens.SEMICOLON, ";"},
		{tokens.LET, "let"},
		{tokens.IDENT, "ten"},
		{tokens.ASSIGN, "="},
		{tokens.INT, "10"},
		{tokens.SEMICOLON, ";"},
		{tokens.LET, "let"},
		{tokens.IDENT, "add"},
		{tokens.ASSIGN, "="},
		{tokens.FUNCTION, "fn"},
		{tokens.LPAREN, "("},
		{tokens.IDENT, "x"},
		{tokens.COMMA, ","},
		{tokens.IDENT, "y"},
		{tokens.RPAREN, ")"},
		{tokens.LBRACE, "{"},
		{tokens.IDENT, "x"},
		{tokens.PLUS, "+"},
		{tokens.IDENT, "y"},
		{tokens.SEMICOLON, ";"},
		{tokens.RBRACE, "}"},
		{tokens.SEMICOLON, ";"},
		{tokens.LET, "let"},
		{tokens.IDENT, "result"},
		{tokens.ASSIGN, "="},
		{tokens.IDENT, "add"},
		{tokens.LPAREN, "("},
		{tokens.IDENT, "five"},
		{tokens.COMMA, ","},
		{tokens.IDENT, "ten"},
		{tokens.RPAREN, ")"},
		{tokens.SEMICOLON, ";"},
		{tokens.BANG, "!"},
		{tokens.MINUS, "-"},
		{tokens.SLASH, "/"},
		{tokens.ASTERISK, "*"},
		{tokens.INT, "5"},
		{tokens.SEMICOLON, ";"},
		{tokens.INT, "5"},
		{tokens.LT, "<"},
		{tokens.INT, "10"},
		{tokens.GT, ">"},
		{tokens.INT, "5"},
		{tokens.SEMICOLON, ";"},
		{tokens.IF, "if"},
		{tokens.LPAREN, "("},
		{tokens.INT, "5"},
		{tokens.LT, "<"},
		{tokens.INT, "10"},
		{tokens.RPAREN, ")"},
		{tokens.LBRACE, "{"},
		{tokens.RETURN, "return"},
		{tokens.TRUE, "true"},
		{tokens.SEMICOLON, ";"},
		{tokens.RBRACE, "}"},
		{tokens.ELSE, "else"},
		{tokens.LBRACE, "{"},
		{tokens.RETURN, "return"},
		{tokens.FALSE, "false"},
		{tokens.SEMICOLON, ";"},
		{tokens.RBRACE, "}"},
		{tokens.INT, "10"},
		{tokens.EQ, "=="},
		{tokens.INT, "10"},
		{tokens.SEMICOLON, ";"},
		{tokens.INT, "10"},
		{tokens.NOT_EQ, "!="},
		{tokens.INT, "9"},
		{tokens.SEMICOLON, ";"},
		{tokens.STRING, "foobar"},
		{tokens.STRING, "foo bar"},
		{tokens.LBRACKET, "["},
		{tokens.INT, "1"},
		{tokens.COMMA, ","},
		{tokens.INT, "2"},
		{tokens.RBRACKET, "]"},
		{tokens.SEMICOLON, ";"},
		{tokens.LBRACE, "{"},
		{tokens.STRING, "foo"},
		{tokens.COLON, ":"},
		{tokens.STRING, "bar"},
		{tokens.RBRACE, "}"},
		{tokens.EOF, ""},
	}

	var l *Lexer = New(input)

	for i, tt := range tests {
		var tok tokens.Token = l.NextToken()

		if tok.Type != tt.expectedType {
			t.Fatalf("tests[%d] - tokentype wrong. expected=%q, got=%q",
				i, tt.expectedType, tok.Type)
		}

		if tok.Literal != tt.expectedLiteral {
			t.Fatalf("tests[%d] - literal wrong. expected=%q, got=%q",
				i, tt.expectedLiteral, tok.Literal)
		}
	}
}