"""Rootfs builder — creates the root filesystem."""

from __future__ import annotations

import shutil
import tempfile
from pathlib import Path

from .distros import get as get_distro
from .distros.base import set_mode


def build(config: dict, output: Path) -> Path:
    """Build a rootfs and return its path."""
    set_mode(config.get("_mode", "root"))
    distro_name = config["distro"]

    # map distro name to backend (horizon = void)
    backend_name = "void" if distro_name == "horizon" else distro_name
    distro_cls = get_distro(backend_name)

    # artix vs arch
    if backend_name in ("artix",):
        distro = distro_cls(family="artix")
    elif backend_name in ("debian", "ubuntu"):
        distro = distro_cls(family=backend_name)
    elif backend_name in ("fedora", "rocky", "almalinux"):
        distro = distro_cls(family=backend_name)
    else:
        distro = distro_cls()

    rootfs = Path(tempfile.mkdtemp(prefix="mklive-"))
    print(f"\n\033[1;36m==>\033[0m \033[1mBuilding rootfs in {rootfs}\033[0m")

    # 1. bootstrap
    print(f"\033[1;36m==>\033[0m \033[1m[1/4] Bootstrapping {distro_name}...\033[0m")
    distro.bootstrap(rootfs, config)

    # 2. install packages
    pkgs = config.get("packages", [])
    if pkgs:
        print(f"\033[1;36m==>\033[0m \033[1m[2/4] Installing {len(pkgs)} packages...\033[0m")
        distro.install_packages(rootfs, pkgs)
    else:
        print(f"\033[1;36m==>\033[0m \033[1m[2/4] No extra packages to install\033[0m")

    # 3. configure
    print(f"\033[1;36m==>\033[0m \033[1m[3/4] Configuring base system...\033[0m")
    distro.configure_base(rootfs, config)

    # 3b. overlay files (if any) — artools-style root-overlay merge
    overlay = config.get("overlay")
    if overlay:
        overlay_path = Path(overlay)
        if overlay_path.is_dir():
            import subprocess
            subprocess.run(["cp", "-a", f"{overlay_path}/.", str(rootfs)],
                           check=False, capture_output=True)
            print(f"  \033[90m merged:\033[0m overlay -> rootfs")

    # 3c. write /etc/os-release only if user provided a name
    iso_cfg = config.get("iso", {})
    iso_name = iso_cfg.get("name", "")
    if iso_name:
        iso_version = iso_cfg.get("version", "1.0")
        os_id = iso_name.lower().replace(" ", "-").replace("/", "-")
        osrelease = rootfs / "etc" / "os-release"
        osrelease.parent.mkdir(parents=True, exist_ok=True)
        osrelease.write_text(
            f'NAME="{iso_name}"\n'
            f'VERSION="{iso_version}"\n'
            f'ID={os_id}\n'
            f'VERSION_ID="{iso_version}"\n'
            f'ID_LIKE="{config["distro"]}"\n'
            f'PRETTY_NAME="{iso_name} {iso_version}"\n'
        )
        print(f"  \033[90m wrote:\033[0m /etc/os-release")

    # 4. bootloader
    print(f"\033[1;36m==>\033[0m \033[1m[4/4] Installing bootloader...\033[0m")
    distro.install_bootloader(rootfs, config)

    return rootfs


def cleanup(rootfs: Path) -> None:
    """Remove the temporary rootfs."""
    shutil.rmtree(rootfs, ignore_errors=True)