"""Tests for diff_utils."""

from __future__ import absolute_import
import difflib
import os
import sys
import unittest

# Allow imports from cq/scripts folder
sys.path.insert(
    0,
    os.path.realpath(
        os.path.join(os.path.dirname(__file__), os.pardir)))
from helpers import diff_utils

FROM_FILE = 'FROM_FILE'
TO_FILE = 'TO_FILE'


class DiffUtilsTest(unittest.TestCase):

  # pylint: disable=invalid-name
  def diff_strings(self, from_string, to_string, from_name, to_name):
    return difflib.unified_diff(from_string.splitlines(True),
                                to_string.splitlines(True),
                                fromfile=from_name,
                                tofile=to_name,
                                n=0)

  def testEmptyDiff(self):
    """Tests creating comments from an empty diff."""
    empty = ''

    diff = self.diff_strings(empty, empty, FROM_FILE, TO_FILE)
    comments = diff_utils.diff_to_comments(diff)

    self.assertEquals(comments, {})

  def testSingleLineSingleDiff(self):
    """Tests creating a comment from a diff made form a single line."""
    from_lines = 'This line is foo.'
    to_lines = 'This line is bar.'

    diff = self.diff_strings(from_lines, to_lines, FROM_FILE, TO_FILE)
    comments = diff_utils.diff_to_comments(diff)

    self.assertEqual(len(comments), 1)
    self.assertIn(TO_FILE, comments)
    self.assertEqual(len(comments[TO_FILE]), 1)

    expected_range = {'start_line': '1',
                      'start_character': '0',
                      'end_line': '1',
                      'end_character': '16'}
    comment_range = comments[TO_FILE][0]['range']
    self.assertEqual(expected_range, comment_range)

    message = comments[TO_FILE][0]['message']
    self.assertIn('-' + from_lines, message)
    self.assertIn('+' + to_lines, message)
    self.assertEqual(len(message.splitlines()), 2)

  def testMultipleLineSingleDiff(self):
    """Tests creating comments from a diff made of multiple lines."""
    from_lines = ('This line is the same.\n'
                  'This line is foo.\n'
                  'This line is foo also.\n'
                  'This line is the same.')
    to_lines = ('This line is the same.\n'
                'This line is bar.\n'
                'This line is bar also.\n'
                'This line is the same.')

    diff = self.diff_strings(from_lines, to_lines, FROM_FILE, TO_FILE)
    comments = diff_utils.diff_to_comments(diff)

    self.assertEqual(len(comments), 1)
    self.assertIn(TO_FILE, comments)
    self.assertEqual(len(comments[TO_FILE]), 1)

    expected_range = {'start_line': '2',
                      'start_character': '0',
                      'end_line': '3',
                      'end_character': '21'}
    comment_range = comments[TO_FILE][0]['range']
    self.assertEqual(expected_range, comment_range)

    message = comments[TO_FILE][0]['message']
    self.assertEqual(message.count('-'), 2)
    self.assertEqual(message.count('+'), 2)
    self.assertEqual(len(message.splitlines()), 4)

  def testMultipleLineMultipleDiff(self):
    """Tests creating multiple comments from a multi-part diff."""
    from_lines = ('This line is the same.\n'
                  'This line is foo.\n'
                  'This line is the same.\n'
                  'This line is foo.\n'
                  'This line is foo.')
    to_lines = ('This line is the same.\n'
                'This line is bar.\n'
                'This line is the same.\n'
                'This line is bar.\n'
                'This line is bar.')

    diff = self.diff_strings(from_lines, to_lines, FROM_FILE, TO_FILE)
    comments = diff_utils.diff_to_comments(diff)

    self.assertEqual(len(comments), 1)
    self.assertIn(TO_FILE, comments)
    self.assertEqual(len(comments[TO_FILE]), 2)

    # First diff
    expected_range = {'start_line': '2',
                      'start_character': '0',
                      'end_line': '2',
                      'end_character': '16'}
    comment_range = comments[TO_FILE][0]['range']
    self.assertEqual(expected_range, comment_range)

    message = comments[TO_FILE][0]['message']
    self.assertEqual(message.count('-'), 1)
    self.assertEqual(message.count('+'), 1)
    self.assertEqual(len(message.splitlines()), 2)

    # Second diff
    expected_range = {'start_line': '4',
                      'start_character': '0',
                      'end_line': '5',
                      'end_character': '16'}
    comment_range = comments[TO_FILE][1]['range']
    self.assertEqual(expected_range, comment_range)

    message = comments[TO_FILE][1]['message']
    self.assertEqual(message.count('-'), 2)
    self.assertEqual(message.count('+'), 2)
    self.assertEqual(len(message.splitlines()), 4)

  def testNoFileName(self):
    """Tests creating a comment when tofile is not passed to unified_diff()."""
    from_lines = 'This line is foo.'
    to_lines = 'This line is bar.'

    diff = difflib.unified_diff(from_lines, to_lines)
    comments = diff_utils.diff_to_comments(diff)

    self.assertEqual(len(comments), 1)
    self.assertIn('', comments)
    self.assertEqual(len(comments['']), 1)

  def testSpacesForGerritFormatting(self):
    """Tests that each line of a file level comment starts with a space."""
    from_lines = ('This line is the same.\n'
                  'This line is foo.\n'
                  'This line is foo also.\n'
                  'This line is the same.')
    to_lines = ('This line is the same.\n'
                'This line is bar.\n'
                'This line is bar also.\n'
                'This line is the same.')

    diff = self.diff_strings(from_lines, to_lines, FROM_FILE, TO_FILE)
    comments = diff_utils.diff_to_comments(diff)

    message = comments[TO_FILE][0]['message']
    for line in message.splitlines():
      self.assertTrue(line.startswith(' '))

  def testDiffWithMultipleFiles(self):
    """Tests that a multifile diff puts comments with the proper file."""
    diff = ['--- foo1.cc\n',
            '+++ foo1.cc\n',
            '@@ -123,1 +123,1 @@\n',
            'message1.0\n',
            '--- foo2.cc\n',
            '+++ foo2.cc\n',
            '@@ -456,1 +456,1 @@\n',
            'message2.0\n',
            '@@ -456,1 +456,1 @@\n',
            'message2.1\n',
            '--- foo3.cc\n',
            '+++ foo3.cc\n',
            '@@ -789,1 +789,1 @@\n',
            'message3.0\n',]
    comments = diff_utils.diff_to_comments(diff)

    self.assertEqual(len(comments), 3)
    self.assertIn('foo1.cc', comments)
    self.assertIn('foo2.cc', comments)
    self.assertIn('foo3.cc', comments)

    self.assertEqual(len(comments['foo1.cc']), 1)
    self.assertEqual(len(comments['foo2.cc']), 2)
    self.assertEqual(len(comments['foo3.cc']), 1)

    self.assertIn('message1.0', comments['foo1.cc'][0]['message'])
    self.assertIn('message2.0', comments['foo2.cc'][0]['message'])
    self.assertIn('message2.1', comments['foo2.cc'][1]['message'])
    self.assertIn('message3.0', comments['foo3.cc'][0]['message'])


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