# Copyright 2010-2025 The pygit2 contributors
#
# This file is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License, version 2,
# as published by the Free Software Foundation.
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
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# along with this program; see the file COPYING.  If not, write to
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import pygit2
from pygit2.enums import ApplyLocation, CheckoutStrategy, FileStatus
import pytest

import os
from pathlib import Path


def read_content(testrepo):
    with (Path(testrepo.workdir) / 'hello.txt').open('rb') as f:
        return f.read().decode('utf-8')


@pytest.fixture
def new_content():
    content = ['bye world', 'adiós', 'au revoir monde']
    content = ''.join(x + os.linesep for x in content)
    return content


@pytest.fixture
def old_content(testrepo):
    with (Path(testrepo.workdir) / 'hello.txt').open('rb') as f:
        return f.read().decode('utf-8')


@pytest.fixture
def patch_diff(testrepo, new_content):
    # Create the patch
    with (Path(testrepo.workdir) / 'hello.txt').open('wb') as f:
        f.write(new_content.encode('utf-8'))

    patch = testrepo.diff().patch

    # Rollback all changes
    testrepo.checkout('HEAD', strategy=CheckoutStrategy.FORCE)

    # Return the diff
    return pygit2.Diff.parse_diff(patch)


@pytest.fixture
def foreign_patch_diff():
    patch_contents = """diff --git a/this_file_does_not_exist b/this_file_does_not_exist
index 7f129fd..af431f2 100644
--- a/this_file_does_not_exist
+++ b/this_file_does_not_exist
@@ -1 +1 @@
-a contents 2
+a contents
"""
    return pygit2.Diff.parse_diff(patch_contents)


def test_apply_type_error(testrepo):
    # Check apply type error
    with pytest.raises(TypeError):
        testrepo.apply('HEAD')


def test_apply_diff_to_workdir(testrepo, new_content, patch_diff):
    # Apply the patch and compare
    testrepo.apply(patch_diff, ApplyLocation.WORKDIR)

    assert read_content(testrepo) == new_content
    assert testrepo.status_file('hello.txt') == FileStatus.WT_MODIFIED


def test_apply_diff_to_index(testrepo, old_content, patch_diff):
    # Apply the patch and compare
    testrepo.apply(patch_diff, ApplyLocation.INDEX)

    assert read_content(testrepo) == old_content
    assert testrepo.status_file('hello.txt') & FileStatus.INDEX_MODIFIED


def test_apply_diff_to_both(testrepo, new_content, patch_diff):
    # Apply the patch and compare
    testrepo.apply(patch_diff, ApplyLocation.BOTH)

    assert read_content(testrepo) == new_content
    assert testrepo.status_file('hello.txt') & FileStatus.INDEX_MODIFIED


def test_diff_applies_to_workdir(testrepo, old_content, patch_diff):
    # See if patch applies
    assert testrepo.applies(patch_diff, ApplyLocation.WORKDIR)

    # Ensure it was a dry run
    assert read_content(testrepo) == old_content

    # Apply patch for real, then ensure it can't be applied again
    testrepo.apply(patch_diff, ApplyLocation.WORKDIR)
    assert not testrepo.applies(patch_diff, ApplyLocation.WORKDIR)

    # It can still be applied to the index, though
    assert testrepo.applies(patch_diff, ApplyLocation.INDEX)


def test_diff_applies_to_index(testrepo, old_content, patch_diff):
    # See if patch applies
    assert testrepo.applies(patch_diff, ApplyLocation.INDEX)

    # Ensure it was a dry run
    assert read_content(testrepo) == old_content

    # Apply patch for real, then ensure it can't be applied again
    testrepo.apply(patch_diff, ApplyLocation.INDEX)
    assert not testrepo.applies(patch_diff, ApplyLocation.INDEX)

    # It can still be applied to the workdir, though
    assert testrepo.applies(patch_diff, ApplyLocation.WORKDIR)


def test_diff_applies_to_both(testrepo, old_content, patch_diff):
    # See if patch applies
    assert testrepo.applies(patch_diff, ApplyLocation.BOTH)

    # Ensure it was a dry run
    assert read_content(testrepo) == old_content

    # Apply patch for real, then ensure it can't be applied again
    testrepo.apply(patch_diff, ApplyLocation.BOTH)
    assert not testrepo.applies(patch_diff, ApplyLocation.BOTH)
    assert not testrepo.applies(patch_diff, ApplyLocation.WORKDIR)
    assert not testrepo.applies(patch_diff, ApplyLocation.INDEX)


def test_applies_error(testrepo, old_content, patch_diff, foreign_patch_diff):
    # Try to apply a "foreign" patch that affects files that aren't in the repo;
    # ensure we get OSError about the missing file (due to raise_error)
    with pytest.raises(OSError):
        testrepo.applies(foreign_patch_diff, ApplyLocation.BOTH, raise_error=True)

    # Apply a valid patch
    testrepo.apply(patch_diff, ApplyLocation.BOTH)

    # Ensure it can't be applied again and we get an exception about it (due to raise_error)
    with pytest.raises(pygit2.GitError):
        testrepo.applies(patch_diff, ApplyLocation.BOTH, raise_error=True)