#!/usr/bin/env python3
from gitutils import PeekableIterator, patterns_to_regex, GitRepo, are_ghstack_branches_in_sync, _shasum
from unittest import TestCase, main, SkipTest
from pathlib import Path


BASE_DIR = Path(__file__).parent


class TestPeekableIterator(TestCase):
    def test_iterator(self, input_: str = "abcdef") -> None:
        iter_ = PeekableIterator(input_)
        for idx, c in enumerate(iter_):
            self.assertEqual(c, input_[idx])

    def test_is_iterable(self) -> None:
        from collections.abc import Iterator
        iter_ = PeekableIterator("")
        self.assertTrue(isinstance(iter_, Iterator))

    def test_peek(self, input_: str = "abcdef") -> None:
        iter_ = PeekableIterator(input_)
        for idx, c in enumerate(iter_):
            if idx + 1 < len(input_):
                self.assertEqual(iter_.peek(), input_[idx + 1])
            else:
                self.assertTrue(iter_.peek() is None)


class TestPattern(TestCase):
    def test_double_asterisks(self) -> None:
        allowed_patterns = [
            "aten/src/ATen/native/**LinearAlgebra*",
        ]
        patterns_re = patterns_to_regex(allowed_patterns)
        fnames = [
            "aten/src/ATen/native/LinearAlgebra.cpp",
            "aten/src/ATen/native/cpu/LinearAlgebraKernel.cpp"]
        for filename in fnames:
            self.assertTrue(patterns_re.match(filename))


class TestGitRepo(TestCase):
    def setUp(self) -> None:
        repo_dir = BASE_DIR.parent.parent.absolute()
        if not (repo_dir / ".git").is_dir():
            raise SkipTest("Can't find git directory, make sure to run this test on real repo checkout")
        self.repo = GitRepo(str(repo_dir))

    def _skip_if_ref_does_not_exist(self, ref: str) -> None:
        """ Skip test if ref is missing as stale branches are deleted with time """
        try:
            self.repo.show_ref(ref)
        except RuntimeError as e:
            raise SkipTest(f"Can't find head ref {ref} due to {str(e)}") from e

    def test_compute_diff(self) -> None:
        diff = self.repo.diff("HEAD")
        sha = _shasum(diff)
        self.assertEqual(len(sha), 64)

    def test_ghstack_branches_in_sync(self) -> None:
        head_ref = "gh/SS-JIA/206/head"
        self._skip_if_ref_does_not_exist(head_ref)
        self.assertTrue(are_ghstack_branches_in_sync(self.repo, head_ref))

    def test_ghstack_branches_not_in_sync(self) -> None:
        head_ref = "gh/clee2000/1/head"
        self._skip_if_ref_does_not_exist(head_ref)
        self.assertFalse(are_ghstack_branches_in_sync(self.repo, head_ref))

if __name__ == '__main__':
    main()