#!/bin/bash

# ==============================================================================
# SCRIPT: setup_host_build_env.sh
# PURPOSE: Prepares a Void Linux host environment for cross-architecture ISO builds.
#
# This script automates several setup steps required on the host machine
# when building ISO images for architectures different from the host (e.g.,
# building aarch64 or i686 ISOs on an x86_64 host).
#
# What this script does:
# 1. Updates the host's package list.
# 2. **Enables the multilib repository on the host.**
# 3. Installs necessary 32-bit libraries (like lzo, libgcc, readline) on the
#    x86_64 host if needed for host-executed tools.
# 4. Installs QEMU user mode emulators, including the one for aarch64, and the
#    binfmt-support package.
# 5. Ensures the 'binfmt_misc' kernel module is loaded and its filesystem is
#    mounted.
# 6. Registers the installed QEMU user emulators with the kernel's binfmt_misc
#    interface using the correct update-binfmts command and ensures the
#    binfmt-support service is enabled and running for persistence.
#
# PREREQUISITES:
# - A Void Linux host system.
# - An active internet connection to download packages.
# - sudo privileges to install packages and configure system settings.
#
# USAGE:
# 1. Save this code to a file (e.g., setup_host_build_env.sh).
# 2. Make the file executable: chmod +x setup_host_build_env.sh
# 3. Run the script with sudo: sudo ./setup_host_build_env.sh
#
# IMPORTANT NOTE:
# This script ONLY sets up the HOST environment dependencies required for
# cross-building. It DOES NOT modify your iso_builder.py script logic.
# Your iso_builder.py script still needs to be correctly configured to:
# - Use the right package names for the target architecture in its YAML configs.
# - Execute package management and system configuration commands, directing them
#   to the target rootfs (e.g., using -r, XBPS_ARCH, or chroot helpers).
# ==============================================================================

# Exit immediately if a command exits with a non-zero status.
set -e

# Check if running as root
if [ "$EUID" -ne 0 ]; then
    echo "Error: Please run this script with sudo."
    exit 1
fi

echo "=> Updating host package list..."
xbps-install -S -y

# --- START: Enable Multilib Repository on Host ---
echo "=> Enabling multilib repository on host..."
# Install the void-repo-multilib package to add the multilib repository configuration
if xbps-install -y void-repo-multilib; then
    echo "Multilib repository package installed."
    # Synchronize repositories again to include the newly added multilib repo
    echo "Synchronizing repositories to include multilib..."
    xbps-install -S -y
    echo "Repositories synchronized with multilib enabled."
else
    echo "Warning: Failed to install void-repo-multilib package. Multilib dependencies may not be available."
    # Do not exit, continue with the rest of the setup
fi
# --- END: Enable Multilib Repository on Host ---


# Install 32-bit libraries needed for i686 tools executed on the host
# These might be needed if you don't run mksquashfs/xorriso etc. in a chroot/uchroot
# Ensure these packages are available *after* enabling multilib
echo "=> Installing 32-bit libraries for i686 execution on the host (if needed)..."
xbps-install -y lzo-32bit libgcc-32bit readline-32bit || {
    echo "Warning: Failed to install one or more 32-bit packages. This might affect i686 builds if host tools require them."
    # Don't exit here, as QEMU packages are still required for aarch64 etc.
}

# Install QEMU user mode emulators and binfmt-support
echo "=> Installing QEMU user mode emulators (including aarch64) and binfmt-support..."
# Install the qemu-user dummy package (depends on architecture-specific ones)
# Explicitly installing qemu-user-aarch64 for clarity and binfmt-support
xbps-install -y qemu-user qemu-user-aarch64 binfmt-support

echo "=> Ensuring binfmt_misc kernel module is loaded and filesystem is mounted..."
# Load module if not loaded
if ! lsmod | grep -q binfmt_misc; then
    echo "Loading binfmt_misc kernel module..."
    modprobe binfmt_misc
    sleep 1
fi

# Mount filesystem if not mounted
if ! mountpoint -q /proc/sys/fs/binfmt_misc; then
    echo "Mounting binfmt_misc filesystem..."
    mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
    sleep 1
fi

# Verificar se o diretório está acessível após tentar carregar/montar
if [ ! -d "/proc/sys/fs/binfmt_misc" ]; then
    echo "ERRO FATAL: O diretório /proc/sys/fs/binfmt_misc não existe ou não está acessível."
    echo "A configuração do binfmt_misc falhou. Não é possível continuar com a emulação."
    exit 1
fi

# --- START CORRECTED BINFMT REGISTRATION ---
echo "=> Registering QEMU user binfmts from /usr/share/binfmts/ using update-binfmts --import..."

# Use the correct command to import and register all binfmt configurations from /usr/share/binfmts/
# This command reads the config files and writes to /proc/sys/fs/binfmt_misc/register correctly.
if /usr/bin/update-binfmts --import; then
    echo "All binfmt entries from /usr/share/binfmts/ registered successfully."
else
    echo "Warning: Failed to register one or more binfmt entries using update-binfmts --import."
    echo "Check /proc/sys/fs/binfmt_misc/ for registered entries (e.g., qemu-aarch64)."
    # The build might still work if the required ones are registered, but this indicates a potential issue.
    # Don't exit here to allow checking registered entries afterwards.
fi

# We also need to ensure the runit service is enabled and running so registration
# happens automatically on boot.
echo "=> Ensuring binfmt-support runit service is enabled and running..."
if [ -d "/etc/sv/binfmt-support" ]; then
    # Check if the symlink in /var/service exists and is correct
    if [ ! -L "/var/service/binfmt-support" ] || [ "$(readlink /var/service/binfmt-support)" != "/etc/sv/binfmt-support" ]; then
        echo "Enabling binfmt-support service..."
        # Create/force symlink in /var/service to enable the service
        ln -sf /etc/sv/binfmt-support /var/service/ || echo "Warning: Failed to enable binfmt-support service."
    fi
    # Restart the service to ensure it runs the (now hopefully corrected run script)
    # This is important if the script was modified while the service was running.
    echo "Restarting binfmt-support service to ensure configuration is applied..."
    sv restart binfmt-support || echo "Warning: Failed to restart binfmt-support service."
else
    echo "Warning: binfmt-support runit service directory /etc/sv/binfmt-support not found."
    echo "Automatic binfmt registration on boot may not be configured."
fi

echo "=> Verifying registration for qemu-aarch64 in /proc/sys/fs/binfmt_misc/..."
# Check if the specific qemu-aarch64 entry exists after attempting registration
if [ -f "/proc/sys/fs/binfmt_misc/qemu-aarch64" ]; then
    echo "SUCCESS: Emulação qemu-aarch64 está ativa e registada."
else
    echo "ERRO: O registo da emulação qemu-aarch64 falhou!"
    echo "A build para aarch64 provavelmente falhará com 'Erro de formato do executável'."
    # Do not exit here. Allow the user to see the check result and potentially debug manually.
fi


echo "=> Host environment setup complete."
echo "You can now try running your iso_builder.py script for aarch64 (or another architecture)."