import sys
import decimal
from unittest import TestCase

import json
import json.decoder

class TestScanString(TestCase):
    def test_py_scanstring(self):
        self._test_scanstring(json.decoder.py_scanstring)

    def test_c_scanstring(self):
        self._test_scanstring(json.decoder.c_scanstring)

    def _test_scanstring(self, scanstring):
        self.assertEqual(
            scanstring('"z\\ud834\\udd20x"', 1, None, True),
            (u'z\U0001d120x', 16))

        if sys.maxunicode == 65535:
            self.assertEqual(
                scanstring(u'"z\U0001d120x"', 1, None, True),
                (u'z\U0001d120x', 6))
        else:
            self.assertEqual(
                scanstring(u'"z\U0001d120x"', 1, None, True),
                (u'z\U0001d120x', 5))

        self.assertEqual(
            scanstring('"\\u007b"', 1, None, True),
            (u'{', 8))

        self.assertEqual(
            scanstring('"A JSON payload should be an object or array, not a string."', 1, None, True),
            (u'A JSON payload should be an object or array, not a string.', 60))

        self.assertEqual(
            scanstring('["Unclosed array"', 2, None, True),
            (u'Unclosed array', 17))

        self.assertEqual(
            scanstring('["extra comma",]', 2, None, True),
            (u'extra comma', 14))

        self.assertEqual(
            scanstring('["double extra comma",,]', 2, None, True),
            (u'double extra comma', 21))

        self.assertEqual(
            scanstring('["Comma after the close"],', 2, None, True),
            (u'Comma after the close', 24))

        self.assertEqual(
            scanstring('["Extra close"]]', 2, None, True),
            (u'Extra close', 14))

        self.assertEqual(
            scanstring('{"Extra comma": true,}', 2, None, True),
            (u'Extra comma', 14))

        self.assertEqual(
            scanstring('{"Extra value after close": true} "misplaced quoted value"', 2, None, True),
            (u'Extra value after close', 26))

        self.assertEqual(
            scanstring('{"Illegal expression": 1 + 2}', 2, None, True),
            (u'Illegal expression', 21))

        self.assertEqual(
            scanstring('{"Illegal invocation": alert()}', 2, None, True),
            (u'Illegal invocation', 21))

        self.assertEqual(
            scanstring('{"Numbers cannot have leading zeroes": 013}', 2, None, True),
            (u'Numbers cannot have leading zeroes', 37))

        self.assertEqual(
            scanstring('{"Numbers cannot be hex": 0x14}', 2, None, True),
            (u'Numbers cannot be hex', 24))

        self.assertEqual(
            scanstring('[[[[[[[[[[[[[[[[[[[["Too deep"]]]]]]]]]]]]]]]]]]]]', 21, None, True),
            (u'Too deep', 30))

        self.assertEqual(
            scanstring('{"Missing colon" null}', 2, None, True),
            (u'Missing colon', 16))

        self.assertEqual(
            scanstring('{"Double colon":: null}', 2, None, True),
            (u'Double colon', 15))

        self.assertEqual(
            scanstring('{"Comma instead of colon", null}', 2, None, True),
            (u'Comma instead of colon', 25))

        self.assertEqual(
            scanstring('["Colon instead of comma": false]', 2, None, True),
            (u'Colon instead of comma', 25))

        self.assertEqual(
            scanstring('["Bad value", truth]', 2, None, True),
            (u'Bad value', 12))

    def test_issue3623(self):
        self.assertRaises(ValueError, json.decoder.scanstring, b"xxx", 1,
                          "xxx")
        self.assertRaises(UnicodeDecodeError,
                          json.encoder.encode_basestring_ascii, b"xx\xff")

    def test_overflow(self):
        self.assertRaises(OverflowError, json.decoder.scanstring, b"xxx", sys.maxsize+1)
