import subprocess
import logging
import os

logger = logging.getLogger(__name__)

def run_command(cmd, check=True):
    logger.info(f"Running command: {' '.join(cmd)}")
    try:
        result = subprocess.run(cmd, check=check, capture_output=True, text=True)
        return result
    except subprocess.CalledProcessError as e:
        logger.error(f"Command failed: {e.stderr}")
        raise

def install_minimal_os(mount_root, releasever="41"):
    """
    Installs minimal Fedora packages to mount_root.
    """
    logger.info(f"Installing minimal Fedora {releasever} to {mount_root}...")
    
    packages = [
        "basesystem",
        "bash",
        "coreutils",
        "kernel",
        "systemd",
        "dnf",
        "grub2-efi-x64",
        "shim-x64",
        "efibootmgr",
        "passwd",
        "rootfiles",
        "vim-minimal"
    ]
    
    # Fedora 41 (or whatever is current)
    # We use --releasever to ensure dnf knows which version to fetch
    cmd = [
        "dnf", "install", "-y",
        f"--installroot={mount_root}",
        f"--releasever={releasever}",
        "--setopt=install_weak_deps=False",
        "--nodocs"
    ] + packages
    
    run_command(cmd)
    logger.info("Base system installation complete.")

def configure_system(mount_root, partition_info):
    """
    Basic configuration: fstab and grub.
    """
    logger.info("Configuring system...")
    
    # 1. Generate fstab
    # We can get UUIDs using blkid
    def get_uuid(dev):
        res = run_command(["blkid", "-s", "UUID", "-o", "value", dev])
        return res.stdout.strip()

    root_uuid = get_uuid(partition_info["root"])
    efi_uuid = get_uuid(partition_info["efi"])
    swap_uuid = get_uuid(partition_info["swap"])

    fstab_content = f"""
UUID={root_uuid} / ext4 defaults 1 1
UUID={efi_uuid} /boot/efi vfat defaults 0 2
UUID={swap_uuid} none swap defaults 0 0
"""
    with open(os.path.join(mount_root, "etc/fstab"), "w") as f:
        f.write(fstab_content)
    
    # 2. Configure GRUB
    # This is tricky because we need to chroot or use --boot-directory
    # Simplest for "barely bootable shell" is to try running grub2-mkconfig inside chroot
    
    # Need to bind mount dev, proc, sys for chroot
    for dev in ["dev", "proc", "sys"]:
        target = os.path.join(mount_root, dev)
        run_command(["mount", "--bind", f"/{dev}", target])
    
    try:
        # grub2-mkconfig -o /boot/grub2/grub.cfg (or wherever Fedora puts it)
        # On UEFI Fedora: /boot/efi/EFI/fedora/grub.cfg usually just redirects to /boot/grub2/grub.cfg
        # Let's just do both or standard one.
        chroot_cmd = ["chroot", mount_root, "grub2-mkconfig", "-o", "/boot/grub2/grub.cfg"]
        run_command(chroot_cmd)
        
        # Also need to make sure EFI boot entry is there, but shim/grub2 packages usually handle it in %post?
        # Maybe not in --installroot.
    finally:
        # Unmount binds
        for dev in ["sys", "proc", "dev"]:
            run_command(["umount", os.path.join(mount_root, dev)])

    logger.info("System configuration complete.")