from unittest.mock import patch

from src.utils import s3_backoff_utils as s3u


def test_s3_key_exists_true():
    with patch.object(s3u, 'head_object_backoff', return_value=None):
        assert s3u.s3_key_exists('key', 'bucket') is True


def test_s3_key_exists_false():
    from botocore.exceptions import ClientError  # type: ignore
    err = ClientError({'Error': {'Code': '404'}}, 'HeadObject')
    with patch.object(s3u, 'head_object_backoff', side_effect=err):
        assert s3u.s3_key_exists('key', 'bucket') is False


def test_filter_file_keys_keeps_txt_and_leaf_objects(monkeypatch):
    class Obj:
        def __init__(self, key):
            self.key = key

    fake = [
        Obj('dir/'),
        Obj('dir/file.txt'),
        Obj('dir/file.csv'),
        Obj('file.txt'),
    ]

    class BucketObjects:
        def filter(self, Prefix=None):
            return fake

    class Bucket:
        def __init__(self, name):
            self.name = name
            self.objects = BucketObjects()

    monkeypatch.setattr(
        s3u,
        's3_resource',
        type('SR', (), {'Bucket': lambda name: Bucket(name)}),
    )
    out = s3u.filter_file_keys('dir', 'bucket', file_ext='.txt')
    # Both 'dir/file.txt' and 'file.txt' collapse to 'file.txt' leaf
    assert out == ['file.txt', 'file.txt']