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


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


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


class TestNumbers(unittest.TestCase):
    def test_integer(self):
        result = tokenize("42")
        self.assertEqual(result[0], Token('NUMBER', 42))
        self.assertEqual(result[1], Token('EOF', None))

    def test_float(self):
        t = tokenize("3.14")[0]
        self.assertEqual(t.kind, 'NUMBER')
        self.assertAlmostEqual(t.value, 3.14)

    def test_leading_dot(self):
        t = tokenize(".5")[0]
        self.assertEqual(t.kind, 'NUMBER')
        self.assertAlmostEqual(t.value, 0.5)

    def test_trailing_dot(self):
        t = tokenize("10.")[0]
        self.assertEqual(t.kind, 'NUMBER')
        self.assertAlmostEqual(t.value, 10.0)

    def test_integer_value_type(self):
        t = tokenize("42")[0]
        self.assertIsInstance(t.value, int)

    def test_float_value_type(self):
        t = tokenize("3.14")[0]
        self.assertIsInstance(t.value, float)


class TestOperatorsAndParens(unittest.TestCase):
    def test_all_operators(self):
        result = kinds("1+2*3")
        self.assertEqual(result, ['NUMBER', 'PLUS', 'NUMBER', 'STAR', 'NUMBER', 'EOF'])

    def test_minus(self):
        self.assertIn('MINUS', kinds("1-2"))

    def test_slash(self):
        self.assertIn('SLASH', kinds("1/2"))

    def test_parens(self):
        ks = kinds("(1)")
        self.assertEqual(ks[0], 'LPAREN')
        self.assertEqual(ks[2], 'RPAREN')

    def test_complex_expr(self):
        result = values("3.5*(1-2)")
        expected_kinds = ['NUMBER', 'STAR', 'LPAREN', 'NUMBER', 'MINUS', 'NUMBER', 'RPAREN', 'EOF']
        self.assertEqual([k for k, _ in result], expected_kinds)
        self.assertAlmostEqual(result[0][1], 3.5)


class TestWhitespaceAndErrors(unittest.TestCase):
    def test_whitespace_skipped(self):
        result = kinds("  12  +  3 ")
        self.assertEqual(result, ['NUMBER', 'PLUS', 'NUMBER', 'EOF'])

    def test_whitespace_values(self):
        result = values("  12  +  3 ")
        self.assertEqual(result[0], ('NUMBER', 12))
        self.assertEqual(result[1], ('PLUS', '+'))
        self.assertEqual(result[2], ('NUMBER', 3))

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

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

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

    def test_lex_error_letter(self):
        with self.assertRaises(LexError):
            tokenize("1 + x")

    def test_lex_error_dollar(self):
        with self.assertRaises(LexError):
            tokenize("$10")


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