import unittest
from typing import Iterator

from . import test_data

from sia import util

class UtilTest(unittest.TestCase):
    def test_stop_before_value(self):
        # Helper function to create iterator from list
        def create_iterator(items: list) -> Iterator[str]:
            for item in items:
                yield item

        # Test case 1: Stop value in middle of sequence
        input_sequence = ['hello', 'world', 'STOP', 'ignored']
        result = list(util.stop_before_value(create_iterator(input_sequence), 'STOP'))
        self.assertEqual(result, ['hello', 'world'])

        # Test case 2: Stop value not in sequence
        input_sequence = ['hello', 'world']
        result = list(util.stop_before_value(create_iterator(input_sequence), 'STOP'))
        self.assertEqual(result, ['hello', 'world'])

        # Test case 3: Stop value at start of sequence
        input_sequence = ['STOP', 'ignored']
        result = list(util.stop_before_value(create_iterator(input_sequence), 'STOP'))
        self.assertEqual(result, [])

        # Test case 4: Stop value as part of an item
        input_sequence = ['hello', 'woSTOPrld', 'ignored']
        result = list(util.stop_before_value(create_iterator(input_sequence), 'STOP'))
        self.assertEqual(result, ['hello', 'wo'])

        # Test case 5: Empty sequence
        input_sequence = []
        result = list(util.stop_before_value(create_iterator(input_sequence), 'STOP'))
        self.assertEqual(result, [])

    def test_none_value(self):
        """Test that None values are converted to empty strings"""
        self.assertEqual(util.escape_text_for_xml(None), '')

    def test_number_values(self):
        """Test that numbers are properly converted to strings and wrapped in CDATA"""
        self.assertEqual(util.escape_text_for_xml(42), '<![CDATA[42]]>')
        self.assertEqual(util.escape_text_for_xml(3.14), '<![CDATA[3.14]]>')
        self.assertEqual(util.escape_text_for_xml(-100), '<![CDATA[-100]]>')
        self.assertEqual(util.escape_text_for_xml(0), '<![CDATA[0]]>')

    def test_simple_strings(self):
        """Test that simple strings are wrapped in CDATA"""
        self.assertEqual(util.escape_text_for_xml('hello'), '<![CDATA[hello]]>')
        self.assertEqual(util.escape_text_for_xml(''), '<![CDATA[]]>')
        self.assertEqual(util.escape_text_for_xml('  '), '<![CDATA[  ]]>')

    def test_strings_with_special_characters(self):
        """Test strings containing XML special characters but no CDATA end sequence"""
        self.assertEqual(util.escape_text_for_xml('<hello>'), '<![CDATA[<hello>]]>')
        self.assertEqual(util.escape_text_for_xml('a & b'), '<![CDATA[a & b]]>')
        self.assertEqual(util.escape_text_for_xml('"quoted"'), '<![CDATA["quoted"]]>')
        self.assertEqual(util.escape_text_for_xml("'single'"), "<![CDATA['single']]>")
        self.assertEqual(util.escape_text_for_xml('<![CDATA['), '<![CDATA[<![CDATA[]]>')

    def test_strings_with_cdata_end_sequence(self):
        """Test strings containing CDATA end sequence are properly escaped"""
        # Simple case with just the CDATA end sequence
        self.assertEqual(util.escape_text_for_xml(']]>'), ']]&gt;')
        
        # CDATA end sequence with other special characters
        self.assertEqual(
            util.escape_text_for_xml('Text with ]]> and <tags> & ampersands'),
            'Text with ]]&gt; and &lt;tags&gt; &amp; ampersands'
        )
        
        # Multiple CDATA end sequences
        self.assertEqual(
            util.escape_text_for_xml('Multiple ]]> end ]]> sequences'),
            'Multiple ]]&gt; end ]]&gt; sequences'
        )

    def test_multiline_strings(self):
        """Test multiline strings are properly handled"""
        multiline = """Line 1
        Line 2
        Line 3"""
        self.assertEqual(util.escape_text_for_xml(multiline), '<![CDATA[Line 1\n        Line 2\n        Line 3]]>')
        
        multiline_with_cdata = """Line 1
        Line ]]> 2
        Line 3"""
        self.assertEqual(
            util.escape_text_for_xml(multiline_with_cdata),
            'Line 1\n        Line ]]&gt; 2\n        Line 3'
        )

    def test_edge_cases(self):
        """Test edge cases and unusual inputs"""
        # Empty string
        self.assertEqual(util.escape_text_for_xml(''), '<![CDATA[]]>')
        
        # String with only whitespace
        self.assertEqual(util.escape_text_for_xml('\n\t '), '<![CDATA[\n\t ]]>')
        
        # String with Unicode characters
        self.assertEqual(util.escape_text_for_xml('Hello 世界'), '<![CDATA[Hello 世界]]>')
        
        # String with control characters
        self.assertEqual(util.escape_text_for_xml('Hello\0World'), '<![CDATA[Hello\0World]]>')
        
        # Very long string
        long_string = 'x' * 1000
        self.assertEqual(util.escape_text_for_xml(long_string), f'<![CDATA[{long_string}]]>')

    def test_boolean_values(self):
        """Test boolean values are properly converted"""
        self.assertEqual(util.escape_text_for_xml(True), '<![CDATA[True]]>')
        self.assertEqual(util.escape_text_for_xml(False), '<![CDATA[False]]>')