import bz2
import gzip
import os
import re
import tarfile
import zipfile
from io import (
    BytesIO,
    StringIO,
)
from typing import (
    Dict,
    IO,
    Tuple,
)

from typing_extensions import Protocol

from galaxy import util
from galaxy.util.image_util import image_type

HTML_CHECK_LINES = 100
CHUNK_SIZE = 2**15  # 32Kb
HTML_REGEXPS = (
    re.compile(r"<A\s+[^>]*HREF[^>]+>", re.I),
    re.compile(r"<IFRAME[^>]*>", re.I),
    re.compile(r"<FRAMESET[^>]*>", re.I),
    re.compile(r"<META[\W][^>]*>", re.I),
    re.compile(r"<SCRIPT[^>]*>", re.I),
)


class CompressionChecker(Protocol):
    def __call__(self, file_path: str, check_content: bool = True) -> Tuple[bool, bool]:
        ...


def check_html(name, file_path: bool = True) -> bool:
    """
    Returns True if the file/string contains HTML code.
    """
    # Handles files if file_path is True or text if file_path is False
    temp: IO[str]
    if file_path:
        temp = open(name, encoding="utf-8")
    else:
        temp = StringIO(util.unicodify(name))
    try:
        for _ in range(HTML_CHECK_LINES):
            line = temp.readline(CHUNK_SIZE)
            if not line:
                break
            if any(regexp.search(line) for regexp in HTML_REGEXPS):
                return True
    except UnicodeDecodeError:
        return False
    finally:
        temp.close()
    return False


def check_binary(name, file_path: bool = True) -> bool:
    # Handles files if file_path is True or text if file_path is False
    temp: IO[bytes]
    if file_path:
        temp = open(name, "rb")
        size = os.stat(name).st_size
    else:
        temp = BytesIO(name)
        size = len(name)
    read_start = int(size / 2)
    read_length = 1024
    try:
        if util.is_binary(temp.read(read_length)):
            return True
        # Some binary files have text only within the first 1024
        # Read 1024 from the middle of the file if this is not
        # a gzip or zip compressed file (bzip are indexed),
        # to avoid issues with long txt headers on binary files.
        if file_path and not is_gzip(name) and not is_zip(name) and not is_bz2(name):
            # file_path=False doesn't seem to be used in the codebase
            temp.seek(read_start)
            return util.is_binary(temp.read(read_length))
        return False
    finally:
        temp.close()


def check_gzip(file_path: str, check_content: bool = True) -> Tuple[bool, bool]:
    # This method returns a tuple of booleans representing ( is_gzipped, is_valid )
    # Make sure we have a gzipped file
    try:
        with open(file_path, "rb") as temp:
            magic_check = temp.read(2)
        if magic_check != util.gzip_magic:
            return (False, False)
    except Exception:
        return (False, False)
    # We support some binary data types, so check if the compressed binary file is valid
    # If the file is Bam, it should already have been detected as such, so we'll just check
    # for sff format.
    try:
        with gzip.open(file_path, "rb") as fh:
            header = fh.read(4)
        if header == b".sff":
            return (True, True)
    except Exception:
        return (False, False)

    if not check_content:
        return (True, True)

    with gzip.open(file_path, mode="rb") as gzipped_file:
        chunk = gzipped_file.read(CHUNK_SIZE)
    # See if we have a compressed HTML file
    if check_html(chunk, file_path=False):
        return (True, False)
    return (True, True)


def check_bz2(file_path: str, check_content: bool = True) -> Tuple[bool, bool]:
    try:
        with open(file_path, "rb") as temp:
            magic_check = temp.read(3)
        if magic_check != util.bz2_magic:
            return (False, False)
    except Exception:
        return (False, False)

    if not check_content:
        return (True, True)

    with bz2.BZ2File(file_path, mode="rb") as bzipped_file:
        chunk = bzipped_file.read(CHUNK_SIZE)
    # See if we have a compressed HTML file
    if check_html(chunk, file_path=False):
        return (True, False)
    return (True, True)


def check_zip(file_path: str, check_content: bool = True, files=1) -> Tuple[bool, bool]:
    if not zipfile.is_zipfile(file_path):
        return (False, False)

    if not check_content:
        return (True, True)

    chunk = None
    for filect, member in enumerate(iter_zip(file_path)):
        handle, name = member
        chunk = handle.read(CHUNK_SIZE)
        if chunk and check_html(chunk, file_path=False):
            return (True, False)
        if filect >= files:
            break
    return (True, True)


def is_bz2(file_path: str) -> bool:
    is_bz2, is_valid = check_bz2(file_path, check_content=False)
    return is_bz2


def is_gzip(file_path: str) -> bool:
    is_gzipped, is_valid = check_gzip(file_path, check_content=False)
    return is_gzipped


def is_zip(file_path: str) -> bool:
    is_zipped, is_valid = check_zip(file_path, check_content=False)
    return is_zipped


def is_single_file_zip(file_path: str) -> bool:
    for i, _ in enumerate(iter_zip(file_path)):
        if i > 1:
            return False
    return True


def is_tar(file_path: str) -> bool:
    return tarfile.is_tarfile(file_path)


def iter_zip(file_path: str):
    with zipfile.ZipFile(file_path) as z:
        for f in filter(lambda x: not x.endswith("/"), z.namelist()):
            yield (z.open(f), f)


def check_image(file_path: str):
    """Simple wrapper around image_type to yield a True/False verdict"""
    if image_type(file_path):
        return True
    return False


COMPRESSION_CHECK_FUNCTIONS: Dict[str, CompressionChecker] = {
    "gzip": check_gzip,
    "bz2": check_bz2,
    "zip": check_zip,
}


__all__ = (
    "check_binary",
    "check_bz2",
    "check_gzip",
    "check_html",
    "check_image",
    "check_zip",
    "COMPRESSION_CHECK_FUNCTIONS",
    "is_gzip",
    "is_bz2",
    "is_zip",
)