import unittest
from calc.lexer import tokenize, Token, LexError


def kinds(src):
    return [t.kind for t in tokenize(src)]


def kv(src):
    return [(t.kind, t.value) for t in tokenize(src)]


class TestNumbers(unittest.TestCase):
    def test_integer(self):
        toks = tokenize("42")
        self.assertEqual(toks, [Token('NUMBER', 42), Token('EOF', None)])
        self.assertIsInstance(toks[0].value, int)

    def test_float_standard(self):
        toks = tokenize("3.14")
        self.assertEqual(toks, [Token('NUMBER', 3.14), Token('EOF', None)])
        self.assertIsInstance(toks[0].value, float)

    def test_float_leading_dot(self):
        toks = tokenize(".5")
        self.assertAlmostEqual(toks[0].value, 0.5)
        self.assertIsInstance(toks[0].value, float)

    def test_float_trailing_dot(self):
        toks = tokenize("10.")
        self.assertAlmostEqual(toks[0].value, 10.0)
        self.assertIsInstance(toks[0].value, float)

    def test_zero(self):
        toks = tokenize("0")
        self.assertEqual(toks[0], Token('NUMBER', 0))
        self.assertIsInstance(toks[0].value, int)


class TestOperatorsAndParens(unittest.TestCase):
    def test_all_ops(self):
        self.assertEqual(kinds("+-*/()"), ['PLUS','MINUS','STAR','SLASH','LPAREN','RPAREN','EOF'])

    def test_expression(self):
        self.assertEqual(kinds("1+2*3"), ['NUMBER','PLUS','NUMBER','STAR','NUMBER','EOF'])

    def test_values_preserved(self):
        self.assertEqual([t.value for t in tokenize("1+2*3")], [1, '+', 2, '*', 3, None])

    def test_parens(self):
        self.assertEqual(kinds("(1+2)"), ['LPAREN','NUMBER','PLUS','NUMBER','RPAREN','EOF'])


class TestWhitespaceAndErrors(unittest.TestCase):
    def test_spaces_between(self):
        self.assertEqual(kinds("  12  +  3 "), ['NUMBER','PLUS','NUMBER','EOF'])
        vals = [t.value for t in tokenize("  12  +  3 ")]
        self.assertEqual(vals, [12, '+', 3, None])

    def test_complex_expr(self):
        toks = tokenize("3.5*(1-2)")
        expected_kinds = ['NUMBER','STAR','LPAREN','NUMBER','MINUS','NUMBER','RPAREN','EOF']
        self.assertEqual([t.kind for t in toks], expected_kinds)
        self.assertAlmostEqual(toks[0].value, 3.5)

    def test_tabs(self):
        self.assertEqual(kinds("1\t+\t2"), ['NUMBER','PLUS','NUMBER','EOF'])

    def test_at_raises(self):
        with self.assertRaises(LexError) as ctx:
            tokenize("1 @ 2")
        self.assertIn('@', str(ctx.exception))

    def test_dollar_raises(self):
        with self.assertRaises(LexError):
            tokenize("$5")

    def test_letter_raises(self):
        with self.assertRaises(LexError) as ctx:
            tokenize("1 x 2")
        self.assertIn('x', str(ctx.exception))

    def test_error_position_in_message(self):
        try:
            tokenize("1 @ 2")
        except LexError as e:
            self.assertIn('2', str(e))  # position 2

    def test_malformed_float_raises_lex_error(self):
        with self.assertRaises(LexError):
            tokenize("..")

    def test_malformed_float_multiple_dots_raises_lex_error(self):
        with self.assertRaises(LexError):
            tokenize("1.2.3")

    def test_bare_dot_raises_lex_error(self):
        with self.assertRaises(LexError):
            tokenize(".")


if __name__ == '__main__':
    unittest.main()