import hashlib
import logging
import os
import uuid
from typing import Any, Optional

from frostfs_testlib import reporter
from frostfs_testlib.resources.common import ASSETS_DIR
from frostfs_testlib.utils import string_utils

logger = logging.getLogger("NeoLogger")


class TestFile(os.PathLike):
    def __init__(self, path: str):
        self.path = path

    def __del__(self):
        logger.debug(f"Removing file {self.path}")
        if os.path.exists(self.path):
            os.remove(self.path)

    def __str__(self):
        return self.path

    def __repr__(self):
        return self.path

    def __fspath__(self):
        return self.path


def ensure_directory(path):
    directory = os.path.dirname(path)

    if not os.path.exists(directory):
        os.makedirs(directory)


def ensure_directory_opener(path, flags):
    ensure_directory(path)
    return os.open(path, flags)


# TODO: Do not add {size} to title yet, since it produces dynamic info in top level steps
# Use object_size dt in future as argument
@reporter.step("Generate file")
def generate_file(size: int, file_name: Optional[str] = None) -> TestFile:
    """Generates a binary file with the specified size in bytes.

    Args:
        size: Size in bytes, can be declared as 6e+6 for example.

    Returns:
        The path to the generated file.
    """

    if file_name is None:
        file_name = string_utils.unique_name("object-")

    test_file = TestFile(os.path.join(ASSETS_DIR, file_name))
    with open(test_file, "wb", opener=ensure_directory_opener) as file:
        file.write(os.urandom(size))
    logger.info(f"File with size {size} bytes has been generated: {test_file}")

    return test_file


# TODO: Do not add {size} to title yet, since it produces dynamic info in top level steps
# Use object_size dt in future as argument
@reporter.step("Generate file with content")
def generate_file_with_content(
    size: int,
    file_path: Optional[str | TestFile] = None,
    content: Optional[str] = None,
) -> TestFile:
    """Creates a new file with specified content.

    Args:
        file_path: Path to the file that should be created. If not specified, then random file
            path will be generated.
        content: Content that should be stored in the file. If not specified, then random binary
            content will be generated.

    Returns:
        Path to the generated file.
    """
    mode = "w+"
    if content is None:
        content = os.urandom(size)
        mode = "wb"

    test_file = None
    if not file_path:
        test_file = TestFile(os.path.join(os.getcwd(), ASSETS_DIR, str(uuid.uuid4())))
    elif isinstance(file_path, TestFile):
        test_file = file_path
    else:
        test_file = TestFile(file_path)

    with open(test_file, mode, opener=ensure_directory_opener) as file:
        file.write(content)

    return test_file


@reporter.step("Get File Hash")
def get_file_hash(file_path: str | TestFile, len: Optional[int] = None, offset: Optional[int] = None) -> str:
    """Generates hash for the specified file.

    Args:
        file_path: Path to the file to generate hash for.
        len: How many bytes to read.
        offset: Position to start reading from.

    Returns:
        Hash of the file as hex-encoded string.
    """
    file_hash = hashlib.sha256()
    with open(file_path, "rb") as out:
        if len and not offset:
            file_hash.update(out.read(len))
        elif len and offset:
            out.seek(offset, 0)
            file_hash.update(out.read(len))
        elif offset and not len:
            out.seek(offset, 0)
            file_hash.update(out.read())
        else:
            file_hash.update(out.read())
    return file_hash.hexdigest()


@reporter.step("Concatenation set of files to one file")
def concat_files(file_paths: list[str | TestFile], resulting_file_path: Optional[str | TestFile] = None) -> TestFile:
    """Concatenates several files into a single file.

    Args:
        file_paths: Paths to the files to concatenate.
        resulting_file_path: Path to the file where concatenated content should be stored.

    Returns:
        Path to the resulting file.
    """

    test_file = None
    if not resulting_file_path:
        test_file = TestFile(os.path.join(os.getcwd(), ASSETS_DIR, str(uuid.uuid4())))
    elif isinstance(resulting_file_path, TestFile):
        test_file = resulting_file_path
    else:
        test_file = TestFile(resulting_file_path)

    with open(test_file, "wb", opener=ensure_directory_opener) as f:
        for file in file_paths:
            with open(file, "rb") as part_file:
                f.write(part_file.read())
    return test_file


@reporter.step("Split file to {parts} parts")
def split_file(file_path: str | TestFile, parts: int) -> list[TestFile]:
    """Splits specified file into several specified number of parts.

    Each part is saved under name `{original_file}_part_{i}`.

    Args:
        file_path: Path to the file that should be split.
        parts: Number of parts the file should be split into.

    Returns:
        Paths to the part files.
    """
    with open(file_path, "rb") as file:
        content = file.read()

    content_size = len(content)
    chunk_size = int((content_size + parts) / parts)

    part_id = 1
    part_file_paths = []
    for content_offset in range(0, content_size + 1, chunk_size):
        part_file_name = f"{file_path}_part_{part_id}"
        part_file_paths.append(TestFile(part_file_name))
        with open(part_file_name, "wb") as out_file:
            out_file.write(content[content_offset : content_offset + chunk_size])
        part_id += 1

    return part_file_paths


@reporter.step("Get file content")
def get_file_content(file_path: str | TestFile, content_len: Optional[int] = None, mode: str = "r", offset: Optional[int] = None) -> Any:
    """Returns content of specified file.

    Args:
        file_path: Path to the file.
        content_len: Limit of content length. If None, then entire file content is returned;
            otherwise only the first content_len bytes of the content are returned.
        mode: Mode of opening the file.
        offset: Position to start reading from.

    Returns:
        Content of the specified file.
    """
    with open(file_path, mode) as file:
        if content_len and not offset:
            content = file.read(content_len)
        elif content_len and offset:
            file.seek(offset, 0)
            content = file.read(content_len)
        elif offset and not content_len:
            file.seek(offset, 0)
            content = file.read()
        else:
            content = file.read()

    return content