#
# This file is distributed under the MIT License. See LICENSE.md for details.
#

import os
import shlex
import signal
import sys
from contextlib import contextmanager
from dataclasses import dataclass
from io import BytesIO
from subprocess import Popen
from tarfile import open as tar_open
from tempfile import NamedTemporaryFile
from typing import Any, Callable, Dict, Iterable, List, Literal, Mapping, NoReturn, Optional
from typing import Tuple, Union

import yaml

from revng.internal.support.collect import collect_libraries
from revng.internal.support.elf import is_executable
from revng.support import get_command

OptionalEnv = Optional[Mapping[str, str]]


@dataclass
class Options:
    parsed_args: Any
    remaining_args: List[str]
    command_prefix: List[str]
    verbose: bool
    dry_run: bool
    keep_temporaries: bool
    search_prefixes: List[str]


def shlex_join(split_command: Iterable[str]) -> str:
    return " ".join(shlex.quote(arg) for arg in split_command)


def wrap(args: List[str], command_prefix: List[str]):
    return command_prefix + args


def relative(path: str) -> str:
    relative_path = os.path.relpath(path, os.getcwd())
    if len(relative_path) < len(path):
        return relative_path
    else:
        return path


def _run_common(
    command, options: Options, environment: OptionalEnv = None
) -> Tuple[List[str], Dict[str, str]]:
    if not os.path.isfile(command[0]):
        command = [get_command(command[0], options.search_prefixes), *command[1:]]

    if len(options.command_prefix) > 0:
        if is_executable(command[0]):
            command = wrap(command, options.command_prefix)
        else:
            sh = get_command("sh", options.search_prefixes)
            command = wrap([sh, "-c", 'exec "$0" "$@"', *command], options.command_prefix)

    if options.verbose:
        program_path = relative(command[0])
        sys.stderr.write("{}\n\n".format(" \\\n  ".join([program_path] + command[1:])))

    environment = dict(os.environ if environment is None else environment)

    if "valgrind" in command:
        environment["PYTHONMALLOC"] = "malloc"

    return command, environment


def popen(command, options: Options, environment: OptionalEnv = None, **kwargs) -> int | Popen:
    command, environment = _run_common(command, options, environment)

    if options.dry_run:
        return 0

    return Popen(command, env=environment, **kwargs)


def try_run(command, options: Options, environment: OptionalEnv = None) -> int:
    try:
        signal.signal(signal.SIGINT, signal.SIG_IGN)
        process = popen(
            command,
            options,
            environment,
            preexec_fn=lambda: signal.signal(signal.SIGINT, signal.SIG_DFL),
            close_fds=False,
        )
        if isinstance(process, int):
            return process
        return process.wait()
    finally:
        signal.signal(signal.SIGINT, signal.SIG_DFL)


def run(command, options: Options, environment: OptionalEnv = None):
    result = try_run(command, options, environment)
    if result != 0:
        sys.exit(result)

    return result


def exec_run(command, options: Options, environment: OptionalEnv) -> Union[int, NoReturn]:
    command, environment = _run_common(command, options, environment)

    if options.dry_run:
        return 0

    return os.execvpe(command[0], command, environment)


def interleave(base: List[str], repeat: str):
    return list(sum(zip([repeat] * len(base), base), ()))


def handle_asan(dependencies: Iterable[str], search_prefixes: Iterable[str]) -> List[str]:
    libasan = [name for name in dependencies if ("libasan." in name or "libclang_rt.asan" in name)]

    if len(libasan) != 1:
        return []

    libasan_path = relative(libasan[0])
    original_asan_options = os.environ.get("ASAN_OPTIONS", "")
    if original_asan_options:
        asan_options = dict([option.split("=") for option in original_asan_options.split(":")])
    else:
        asan_options = {}
    asan_options["abort_on_error"] = "1"
    asan_options["detect_leaks"] = "0"
    new_asan_options = ":".join(["=".join(option) for option in asan_options.items()])

    # Use `sh` instead of `env` since `env` sometimes is not a real executable
    # but a shebang script spawning /usr/bin/coreutils, which makes gdb unhappy
    return [
        get_command("sh", search_prefixes),
        "-c",
        f'ASAN_OPTIONS={new_asan_options} ld.so --preload {libasan_path} "$0" "$@"',
    ]


def build_command_with_loads(command: str, args: Iterable[str], options: Options) -> List[str]:
    (to_load, dependencies) = collect_libraries(options.search_prefixes)
    prefix = handle_asan(dependencies, options.search_prefixes)

    return (
        prefix
        + [relative(get_command(command, options.search_prefixes))]
        + interleave(to_load, "-load")
        + args
    )


def executable_name() -> str:
    return os.path.basename(sys.argv[0])


def is_tar(raw: bytes) -> bool:
    return raw.startswith(b"\x1f\x8b")


def to_string(filename: str, raw: bytes) -> str:
    return raw.decode("utf8")


def extract_tar(raw: bytes, process: Callable[[str, bytes], Any] = to_string) -> Dict[str, Any]:
    if not is_tar(raw):
        raise ValueError("A tar archive was expected")

    result: Dict[str, Any] = {}

    with tar_open(fileobj=BytesIO(raw), mode="r:gz") as file:
        for element in file.getmembers():
            extracted_element = file.extractfile(element)
            if extracted_element is not None:
                result[element.name] = process(element.name, extracted_element.read())

    return result


def to_yaml(filename: str, raw: bytes) -> str:
    return yaml.safe_load(raw)


def is_file_executable(filename: str) -> bool:
    stat = os.stat(filename)
    return stat.st_mode & 0o111 == 0o111


def temporary_file_gen(prefix: str, options: Options):
    def temporary_file(suffix="", mode="w+"):
        return NamedTemporaryFile(
            prefix=prefix,
            suffix=suffix,
            mode=mode,
            delete=not options.keep_temporaries,
        )

    return temporary_file


@contextmanager
def file_wrapper(path: str | None, mode: Literal["r", "rb", "w", "wb"]):
    """Automatic wrapper for `open` for command-line arguments, to be used in
    a `with` statement. Will automatically return stdin/stdout based on `mode`
    in case the provided path is None or "-".
    """
    assert mode in ("r", "rb", "w", "wb")
    if path is None or path == "-":
        if "r" in mode:
            yield sys.stdin.buffer if "b" in mode else sys.stdin
        else:
            yield sys.stdout.buffer if "b" in mode else sys.stdout
    else:
        with open(path, mode) as f:
            yield f