import os
import shutil
import subprocess

from . import packie

BASE_REQUIREMENTS = [
    # Basic packages for running shell scripts
    "mksh",
    "coreutils",
    "findutils",
    "diffutils",
    # Packages for running `semios-packages` scripts
    "python",
    "packie",
    "zstd",
    "libarchive-tools",
    # Packages for building packages that require patching
    "patch",
    # Packages for downloading various formats of tarballs
    "libz-ng",
    "liblzma",
    "libbzip2",
    # Basic libraries
    "sqlite",
    "libgcc-compat",
    "libcxx",
    "semi-libc",
    # Networking
    "ca-certificates",
    "certutil",
    "aws-lc-libssl",
    "aws-lc-tools",
]


def _prepare_build_env_base_files(root: str):
    # Create root directory
    os.makedirs(root, exist_ok=True)

    # Create var, run and tmp
    os.mkdir(f"{root}/var")
    os.mkdir(f"{root}/var/tmp")
    os.mkdir(f"{root}/var/run")
    os.mkdir(f"{root}/tmp")
    os.mkdir(f"{root}/run")

    # Copy repository config files
    os.makedirs(f"{root}/var/db/packie")
    shutil.copytree("/var/config/packie/repos.d", f"{root}/var/config/packie/repos.d")

    # Create directories for kernel pseudo filesystems
    os.mkdir(f"{root}/dev")
    os.mkdir(f"{root}/sys")
    os.mkdir(f"{root}/proc")

    # Create home directory of root (some scripts may require it)
    os.makedirs(f"{root}/home/root")

    # Copy DNS config
    os.makedirs(f"{root}/etc", exist_ok=True)
    shutil.copy2("/etc/resolv.conf", f"{root}/etc/resolv.conf")


def prepare_build_env(root: str, extreq: list[str] = []):
    # Skip if the environment is already initialized
    if os.path.exists(f"{root}/.INIT"):
        return
    try:
        shutil.rmtree(root)
    except:
        pass

    # Prepare basic filesystem hierarchy
    _prepare_build_env_base_files(root)

    # Install packages
    packie.chroot_update(root)
    packie.chroot_install(root, BASE_REQUIREMENTS + extreq)

    # Refresh certificates
    enter_build_env(root, ["certutil", "refresh"])

    # Create initialized tag
    with open(f"{root}/.INIT", "wt+") as file:
        file.write("OK")


def enter_build_env(root: str, cmd: list[str], chdir: str = "/"):
    reserve_env = ["https_proxy", "http_proxy", "all_proxy"]
    reserve_env_args = []
    for i in reserve_env:
        if os.environ.get(i):
            reserve_env_args += ["--setenv", i, os.environ[i]]
    subprocess.run(
        [
            "bwrap",
            "--bind", root, "/",
            "--unshare-pid",
            "--unshare-user",
            "--uid", "0",
            "--gid", "0",
            "--dev", "/dev",
            "--bind", "/sys", "/sys",
            "--proc", "/proc",
            "--clearenv",
            "--setenv", "HOME", "/home/root",
            "--setenv", "PATH", "/bin",
            "--setenv", "SEMIOS_PKGBUILD_IN_ATOMIC", "1",
            "--setenv", "USER", "root",
            "--setenv", "LOGNAME", "root",
            "--chdir",
            chdir,
        ]
        + reserve_env_args
        + cmd
    )


def copy_pkgbuild_tree(repo_root: str, pkgname: str, build_env_root: str):
    build_dir = f"{build_env_root}/Atom"
    if os.path.exists(build_dir):
        return
    os.mkdir(build_dir)
    shutil.copytree(f"{repo_root}/hooks", f"{build_dir}/hooks")
    shutil.copytree(f"{repo_root}/lib", f"{build_dir}/lib")
    shutil.copy2(f"{repo_root}/x", f"{build_dir}/x")
    shutil.copy2(f"{repo_root}/x.py", f"{build_dir}/x.py")
    os.makedirs(f"{build_dir}/packages/{pkgname}")
    for i in os.listdir(f"{repo_root}/packages/{pkgname}"):
        srcpath = f"{repo_root}/packages/{pkgname}/{i}"
        dstpath = f"{build_dir}/packages/{pkgname}/{i}"
        if i in ["target", "__pycache__"]:
            continue
        if os.path.isdir(srcpath):
            shutil.copytree(srcpath, dstpath)
        elif os.path.isfile(srcpath):
            shutil.copy2(srcpath, dstpath)