import json
import os
from pathlib import Path

import pytest

from datasets.download.download_config import DownloadConfig
from datasets.download.download_manager import DownloadManager
from datasets.download.streaming_download_manager import StreamingDownloadManager
from datasets.utils.file_utils import hash_url_to_filename, xopen
from datasets.utils.py_utils import NestedDataStructure


URL = "tmp://file1.txt"
CONTENT = '"text": ["foo", "foo"]'
HASH = "ce0516943c3a4f9af269cf40fa658d615fa0f00d2dd9ef3f0ac5a3b35be0b719"


class MockResponse:
    status_code = 200
    headers = {"Content-Length": "100"}
    cookies = {}

    def iter_content(self, **kwargs):
        return [bytes(CONTENT, "utf-8")]


def mock_request(*args, **kwargs):
    return MockResponse()


@pytest.mark.parametrize("urls_type", ["str", "list", "dict", "dict_of_dict"])
def test_download_manager_download(urls_type, tmp_path, tmpfs):
    url = URL
    with tmpfs.open(url, "w") as f:
        f.write(CONTENT)
    urls_types = {"str": url, "list": [url], "dict": {"train": url}, "dict_of_dict": {"train": {"en": url}}}
    urls = urls_types[urls_type]
    dataset_name = "dummy"
    cache_subdir = "downloads"
    cache_dir_root = tmp_path
    download_config = DownloadConfig(
        cache_dir=os.path.join(cache_dir_root, cache_subdir),
        use_etag=False,
    )
    dl_manager = DownloadManager(dataset_name=dataset_name, download_config=download_config)
    downloaded_paths = dl_manager.download(urls)
    assert isinstance(downloaded_paths, type(urls))
    if "urls_type".startswith("list"):
        assert len(downloaded_paths) == len(urls)
    elif "urls_type".startswith("dict"):
        assert downloaded_paths.keys() == urls.keys()
        if "urls_type" == "dict_of_dict":
            key = list(urls.keys())[0]
            assert isinstance(downloaded_paths[key], dict)
            assert downloaded_paths[key].keys() == urls[key].keys()
    for downloaded_path, url in zip(
        NestedDataStructure(downloaded_paths).flatten(), NestedDataStructure(urls).flatten()
    ):
        downloaded_path = Path(downloaded_path)
        parts = downloaded_path.parts
        assert parts[-1] == HASH
        assert parts[-2] == cache_subdir
        assert downloaded_path.exists()
        content = downloaded_path.read_text()
        assert content == CONTENT
        metadata_downloaded_path = downloaded_path.with_suffix(".json")
        assert metadata_downloaded_path.exists()
        metadata_content = json.loads(metadata_downloaded_path.read_text())
        assert metadata_content == {"url": URL, "etag": None}


@pytest.mark.parametrize("paths_type", [str, list, dict])
@pytest.mark.parametrize("extract_on_the_fly", [False, True])
def test_download_manager_extract(paths_type, xz_file, text_file, extract_on_the_fly):
    filename = str(xz_file)
    if issubclass(paths_type, str):
        paths = filename
    elif issubclass(paths_type, list):
        paths = [filename]
    elif issubclass(paths_type, dict):
        paths = {"train": filename}
    dataset_name = "dummy"
    cache_dir = xz_file.parent
    extracted_subdir = "extracted"
    download_config = DownloadConfig(
        cache_dir=cache_dir,
        use_etag=False,
        extract_on_the_fly=extract_on_the_fly,
    )
    dl_manager = DownloadManager(dataset_name=dataset_name, download_config=download_config)
    extracted_paths = dl_manager.extract(paths)
    input_paths = paths
    for extracted_paths in [extracted_paths]:
        if isinstance(paths, str):
            extracted_paths = [extracted_paths]
            input_paths = [paths]
        elif isinstance(paths, dict):
            assert "train" in extracted_paths.keys()
            extracted_paths = extracted_paths.values()
            input_paths = paths.values()
        assert extracted_paths
        for extracted_path, input_path in zip(extracted_paths, input_paths):
            assert extracted_path == dl_manager.extracted_paths[input_path]
            if not extract_on_the_fly:
                extracted_path = Path(extracted_path)
                parts = extracted_path.parts
                assert parts[-1] == hash_url_to_filename(input_path, etag=None)
                assert parts[-2] == extracted_subdir
                assert extracted_path.exists()
                extracted_file_content = extracted_path.read_text()
                expected_file_content = text_file.read_text()
                assert extracted_file_content == expected_file_content
            else:
                assert extracted_path == StreamingDownloadManager(
                    dataset_name=dataset_name, download_config=download_config
                ).extract(xz_file)
                assert xopen(extracted_path).read() == text_file.read_text()


def test_download_manager_delete_extracted_files(xz_file):
    dataset_name = "dummy"
    cache_dir = xz_file.parent
    extracted_subdir = "extracted"
    download_config = DownloadConfig(
        cache_dir=cache_dir,
        use_etag=False,
    )
    dl_manager = DownloadManager(dataset_name=dataset_name, download_config=download_config)
    extracted_path = dl_manager.extract(xz_file)
    assert extracted_path == dl_manager.extracted_paths[xz_file]
    extracted_path = Path(extracted_path)
    parts = extracted_path.parts

    assert parts[-1] == hash_url_to_filename(str(xz_file), etag=None)
    assert parts[-2] == extracted_subdir
    assert extracted_path.exists()
    dl_manager.delete_extracted_files()
    assert not extracted_path.exists()


def _test_jsonl(path, file):
    assert path.endswith(".jsonl")
    for num_items, line in enumerate(file, start=1):
        item = json.loads(line.decode("utf-8"))
        assert item.keys() == {"col_1", "col_2", "col_3"}
    assert num_items == 4


@pytest.mark.parametrize("archive_jsonl", ["tar_jsonl_path", "zip_jsonl_path"])
def test_iter_archive_path(archive_jsonl, request):
    archive_jsonl_path = request.getfixturevalue(archive_jsonl)
    dl_manager = DownloadManager()
    for num_jsonl, (path, file) in enumerate(dl_manager.iter_archive(archive_jsonl_path), start=1):
        _test_jsonl(path, file)
    assert num_jsonl == 2


@pytest.mark.parametrize("archive_nested_jsonl", ["tar_nested_jsonl_path", "zip_nested_jsonl_path"])
def test_iter_archive_file(archive_nested_jsonl, request):
    archive_nested_jsonl_path = request.getfixturevalue(archive_nested_jsonl)
    dl_manager = DownloadManager()
    for num_tar, (path, file) in enumerate(dl_manager.iter_archive(archive_nested_jsonl_path), start=1):
        for num_jsonl, (subpath, subfile) in enumerate(dl_manager.iter_archive(file), start=1):
            _test_jsonl(subpath, subfile)
    assert num_tar == 1
    assert num_jsonl == 2


def test_iter_files(data_dir_with_hidden_files):
    dl_manager = DownloadManager()
    for num_file, file in enumerate(dl_manager.iter_files(data_dir_with_hidden_files), start=1):
        assert os.path.basename(file) == ("test.txt" if num_file == 1 else "train.txt")
    assert num_file == 2
