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

from __future__ import annotations

import os
import shlex
import signal
import sys
from contextlib import contextmanager
from dataclasses import dataclass
from subprocess import Popen
from tempfile import NamedTemporaryFile
from typing import TYPE_CHECKING, Any, Callable, Dict, Iterable, List, Literal, Mapping, NoReturn
from typing import Optional, Tuple, Union

import yaml

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

if TYPE_CHECKING:
    from _typeshed import FileDescriptorLike

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 popen(
    command,
    options: Options,
    environment: OptionalEnv = None,
    stdin: FileDescriptorLike | None = None,
    stdout: FileDescriptorLike | None = None,
    stderr: FileDescriptorLike | None = None,
) -> int | Popen:
    return _popen(command, options, environment, stdin=stdin, stdout=stdout, stderr=stderr)


def try_run(
    command,
    options: Options,
    environment: OptionalEnv = None,
    stdin: FileDescriptorLike | None = None,
    stdout: FileDescriptorLike | None = None,
    stderr: FileDescriptorLike | None = 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,
            stdin=stdin,
            stdout=stdout,
            stderr=stderr,
        )
        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,
    stdin: FileDescriptorLike | None = None,
    stdout: FileDescriptorLike | None = None,
    stderr: FileDescriptorLike | None = None,
):
    result = try_run(command, options, environment, stdin, stdout, stderr)
    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 to_string(filename: str, raw: bytes) -> str:
    return raw.decode("utf8")


def extract_tar[T](raw: bytes, process: Callable[[str, bytes], Any] = to_string) -> Dict[str, Any]:
    return {key: process(key, value) for key, value in TarDictionary(raw).items()}


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