import os
from clang.cindex import Config
if 'CLANG_LIBRARY_PATH' in os.environ:
    Config.set_library_path(os.environ['CLANG_LIBRARY_PATH'])

from clang.cindex import Cursor
from clang.cindex import File
from clang.cindex import SourceLocation
from clang.cindex import SourceRange
from .util import get_cursor
from .util import get_tu

import unittest


baseInput="int one;\nint two;\n"


class TestLocation(unittest.TestCase):
    def assert_location(self, loc, line, column, offset):
        self.assertEqual(loc.line, line)
        self.assertEqual(loc.column, column)
        self.assertEqual(loc.offset, offset)

    def test_location(self):
        tu = get_tu(baseInput)
        one = get_cursor(tu, 'one')
        two = get_cursor(tu, 'two')

        self.assertIsNotNone(one)
        self.assertIsNotNone(two)

        self.assert_location(one.location,line=1,column=5,offset=4)
        self.assert_location(two.location,line=2,column=5,offset=13)

        # adding a linebreak at top should keep columns same
        tu = get_tu('\n' + baseInput)
        one = get_cursor(tu, 'one')
        two = get_cursor(tu, 'two')

        self.assertIsNotNone(one)
        self.assertIsNotNone(two)

        self.assert_location(one.location,line=2,column=5,offset=5)
        self.assert_location(two.location,line=3,column=5,offset=14)

        # adding a space should affect column on first line only
        tu = get_tu(' ' + baseInput)
        one = get_cursor(tu, 'one')
        two = get_cursor(tu, 'two')

        self.assert_location(one.location,line=1,column=6,offset=5)
        self.assert_location(two.location,line=2,column=5,offset=14)

        # define the expected location ourselves and see if it matches
        # the returned location
        tu = get_tu(baseInput)

        file = File.from_name(tu, 't.c')
        location = SourceLocation.from_position(tu, file, 1, 5)
        cursor = Cursor.from_location(tu, location)

        one = get_cursor(tu, 'one')
        self.assertIsNotNone(one)
        self.assertEqual(one, cursor)

        # Ensure locations referring to the same entity are equivalent.
        location2 = SourceLocation.from_position(tu, file, 1, 5)
        self.assertEqual(location, location2)
        location3 = SourceLocation.from_position(tu, file, 1, 4)
        self.assertNotEqual(location2, location3)

        offset_location = SourceLocation.from_offset(tu, file, 5)
        cursor = Cursor.from_location(tu, offset_location)
        verified = False
        for n in [n for n in tu.cursor.get_children() if n.spelling == 'one']:
            self.assertEqual(n, cursor)
            verified = True

        self.assertTrue(verified)

    def test_extent(self):
        tu = get_tu(baseInput)
        one = get_cursor(tu, 'one')
        two = get_cursor(tu, 'two')

        self.assert_location(one.extent.start,line=1,column=1,offset=0)
        self.assert_location(one.extent.end,line=1,column=8,offset=7)
        self.assertEqual(baseInput[one.extent.start.offset:one.extent.end.offset], "int one")

        self.assert_location(two.extent.start,line=2,column=1,offset=9)
        self.assert_location(two.extent.end,line=2,column=8,offset=16)
        self.assertEqual(baseInput[two.extent.start.offset:two.extent.end.offset], "int two")

        file = File.from_name(tu, 't.c')
        location1 = SourceLocation.from_position(tu, file, 1, 1)
        location2 = SourceLocation.from_position(tu, file, 1, 8)

        range1 = SourceRange.from_locations(location1, location2)
        range2 = SourceRange.from_locations(location1, location2)
        self.assertEqual(range1, range2)

        location3 = SourceLocation.from_position(tu, file, 1, 6)
        range3 = SourceRange.from_locations(location1, location3)
        self.assertNotEqual(range1, range3)