#!/bin/bash
# ==============================================================================
# FaceTime HD Camera Driver Installer for Linux
#
# Installs the FaceTime HD camera driver on Linux for MacBook Air, MacBook Pro,
# and iMac models that have the Broadcom 1570 FaceTime HD camera (connected
# via PCIe, not USB like newer models).
#
# Compatible with MacBook Air A1466 EMC 3178 and similar models.
#
# What this script does:
#   1. Detects your distro (Ubuntu/Mint/Debian/Fedora) and kernel version
#   2. Checks for Secure Boot (the unsigned module won't load with SB enabled)
#   3. Installs build dependencies (gcc, kernel headers, DKMS, etc.)
#   4. Cleans up any previous facetimehd installations
#   5. Downloads and installs the camera firmware from Apple's macOS driver
#   6. Downloads, patches, and installs the facetimehd kernel module via DKMS
#   7. Blacklists the conflicting bdc_pci module
#   8. Loads the module and verifies the camera appears as /dev/videoN
#
# DKMS ensures the module is automatically rebuilt when the kernel is updated.
#
# The firmware extraction step downloads Apple's Boot Camp driver package,
# extracts the camera firmware binary, and places it where the kernel module
# expects to find it (/lib/firmware/facetimehd/).
#
# Usage:
#   chmod +x facetimehd-installer.sh
#   ./facetimehd-installer.sh
#   (Do NOT run with sudo — the script uses sudo internally where needed)
# ==============================================================================

set -e

# Color codes for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Script name for logging
SCRIPT_NAME=$(basename "$0")
LOG_FILE="/tmp/facetimehd-install-$(date +%Y%m%d-%H%M%S).log"

# Function to print colored output
print_status() {
    echo -e "${BLUE}[${SCRIPT_NAME}]${NC} $1" | tee -a "$LOG_FILE"
}

print_success() {
    echo -e "${GREEN}[✓]${NC} $1" | tee -a "$LOG_FILE"
}

print_error() {
    echo -e "${RED}[✗]${NC} $1" | tee -a "$LOG_FILE"
}

print_warning() {
    echo -e "${YELLOW}[!]${NC} $1" | tee -a "$LOG_FILE"
}

# Function to check if running as root
check_root() {
    if [[ $EUID -eq 0 ]]; then
        print_error "This script should not be run as root!"
        print_status "Please run without sudo: ./$SCRIPT_NAME"
        exit 1
    fi
}

# Function to detect distribution
detect_distro() {
    if [ -f /etc/os-release ]; then
        . /etc/os-release
        OS=$NAME
        VER=$VERSION_ID
    else
        print_error "Cannot detect distribution"
        exit 1
    fi
}

# Function to check kernel version
check_kernel() {
    KERNEL_VERSION=$(uname -r)
    KERNEL_MAJOR=$(echo $KERNEL_VERSION | cut -d. -f1)
    KERNEL_MINOR=$(echo $KERNEL_VERSION | cut -d. -f2)
    
    print_status "Detected kernel version: $KERNEL_VERSION"
    
    if [[ $KERNEL_MAJOR -lt 5 ]] || ([[ $KERNEL_MAJOR -eq 5 ]] && [[ $KERNEL_MINOR -lt 7 ]]); then
        print_warning "Kernel version is older than 5.7, using legacy installation method"
        USE_LEGACY=true
    else
        USE_LEGACY=false
    fi
}

# Function to check if camera is already working
check_camera() {
    if [ -e /dev/video0 ] || [ -e /dev/video1 ]; then
        if lsmod | grep -q facetimehd; then
            print_warning "FaceTime HD camera driver appears to be already installed"
            read -p "Do you want to reinstall? (y/N): " -n 1 -r
            echo
            if [[ ! $REPLY =~ ^[Yy]$ ]]; then
                print_status "Exiting..."
                exit 0
            fi
        fi
    fi
}

# Function to check and disable Secure Boot if needed
check_secure_boot() {
    if command -v mokutil &> /dev/null; then
        if mokutil --sb-state 2>&1 | grep -q "SecureBoot enabled"; then
            print_warning "Secure Boot is enabled. The camera driver may not load."
            print_status "You have three options:"
            echo "  1. Disable Secure Boot in BIOS/UEFI (recommended)"
            echo "  2. Sign the kernel module (advanced)"
            echo "  3. Continue anyway (module may not load)"
            read -p "Choose option (1-3): " -n 1 -r
            echo
            case $REPLY in
                1)
                    print_status "Please reboot and disable Secure Boot in BIOS/UEFI settings"
                    print_status "Then run this script again"
                    exit 0
                    ;;
                2)
                    SIGN_MODULE=true
                    ;;
                3)
                    print_warning "Continuing with Secure Boot enabled..."
                    ;;
            esac
        fi
    fi
}

# Function to install dependencies
install_dependencies() {
    print_status "Installing required dependencies..."
    
    if [[ "$OS" == "Ubuntu" ]] || [[ "$OS" == "Linux Mint" ]] || [[ "$OS" == "Debian"* ]]; then
        sudo apt update
        sudo apt install -y \
            git \
            curl \
            xz-utils \
            cpio \
            make \
            gcc \
            linux-headers-$(uname -r) \
            libssl-dev \
            checkinstall \
            build-essential \
            dkms \
            v4l-utils || {
            print_error "Failed to install dependencies"
            exit 1
        }
    elif [[ "$OS" == "Fedora" ]]; then
        sudo dnf install -y \
            git \
            curl \
            xz \
            cpio \
            make \
            gcc \
            kernel-devel-$(uname -r) \
            openssl-devel \
            dkms \
            v4l-utils || {
            print_error "Failed to install dependencies"
            exit 1
        }
    else
        print_error "Unsupported distribution: $OS"
        exit 1
    fi
    
    print_success "Dependencies installed successfully"
}

# Function to remove old installations
cleanup_old_installation() {
    print_status "Cleaning up old installations..."
    
    # Unload module if loaded
    if lsmod | grep -q facetimehd; then
        sudo modprobe -r facetimehd 2>/dev/null || true
    fi
    
    # Remove old DKMS installations
    if dkms status | grep -q facetimehd; then
        sudo dkms remove facetimehd/0.6.13 --all 2>/dev/null || true
        sudo dkms remove facetimehd/0.1 --all 2>/dev/null || true
    fi
    
    # Remove old files
    sudo rm -rf /usr/src/facetimehd* 2>/dev/null || true
    sudo rm -f /lib/modules/*/extra/facetimehd.ko* 2>/dev/null || true
    
    print_success "Cleanup completed"
}

# Function to download and install firmware
install_firmware() {
    print_status "Downloading and installing camera firmware..."
    
    WORK_DIR=$(mktemp -d)
    cd "$WORK_DIR"
    
    # Clone firmware repository
    git clone https://github.com/patjak/facetimehd-firmware.git || {
        print_error "Failed to download firmware repository"
        exit 1
    }
    
    cd facetimehd-firmware
    
    # Build and install firmware
    make || {
        print_error "Failed to build firmware"
        exit 1
    }
    
    sudo make install || {
        print_error "Failed to install firmware"
        exit 1
    }
    
    # Verify firmware installation
    if [ ! -f /lib/firmware/facetimehd/firmware.bin ]; then
        print_warning "Firmware not found in expected location, creating symlink..."
        sudo mkdir -p /lib/firmware/facetimehd
        if [ -f /usr/lib/firmware/facetimehd/firmware.bin ]; then
            sudo ln -sf /usr/lib/firmware/facetimehd/firmware.bin /lib/firmware/facetimehd/firmware.bin
        else
            print_error "Firmware installation failed"
            exit 1
        fi
    fi
    
    print_success "Firmware installed successfully"
    cd ~
    rm -rf "$WORK_DIR"
}

# Function to install driver for kernel 6.8+
install_driver() {
    print_status "Downloading and installing FaceTime HD driver..."
    
    WORK_DIR=$(mktemp -d)
    cd "$WORK_DIR"
    
    # For kernel 6.8+, try the updated repository first
    if [[ $KERNEL_MAJOR -ge 6 ]] && [[ $KERNEL_MINOR -ge 8 ]]; then
        print_status "Using updated driver for kernel 6.8+"
        
        # Try multiple repositories in order of compatibility
        REPOS=(
            "https://github.com/patjak/facetimehd.git"
            "https://github.com/kekrby/facetimehd.git"
            "https://github.com/bartkessels/facetimehd.git"
        )
        
        CLONED=false
        for repo in "${REPOS[@]}"; do
            print_status "Trying repository: $repo"
            if git clone "$repo" facetimehd 2>/dev/null; then
                CLONED=true
                break
            fi
        done
        
        if [ "$CLONED" = false ]; then
            print_error "Failed to download any driver repository"
            exit 1
        fi
    else
        # For older kernels, use the standard repository
        git clone https://github.com/patjak/facetimehd.git || {
            print_error "Failed to download driver repository"
            exit 1
        }
    fi
    
    cd facetimehd
    
    # Apply patches for kernel 6.8+ if needed
    if [[ $KERNEL_MAJOR -ge 6 ]]; then
        print_status "Applying kernel 6.x compatibility patches..."
        
        # Fix for VFL_TYPE_GRABBER deprecation
        if grep -q "VFL_TYPE_GRABBER" fthd_v4l2.c 2>/dev/null; then
            sed -i 's/VFL_TYPE_GRABBER/VFL_TYPE_VIDEO/g' fthd_v4l2.c
        fi
        
        # Fix for other kernel 6.x API changes
        if grep -q "v4l2_device_release" fthd_v4l2.c 2>/dev/null; then
            sed -i 's/v4l2_device_release/video_device_release/g' fthd_v4l2.c
        fi
    fi
    
    # Install via DKMS
    print_status "Installing driver via DKMS..."
    
    DRIVER_VERSION="0.6.13"
    sudo cp -r . "/usr/src/facetimehd-$DRIVER_VERSION"
    
    # Create DKMS configuration if it doesn't exist
    if [ ! -f "/usr/src/facetimehd-$DRIVER_VERSION/dkms.conf" ]; then
        sudo tee "/usr/src/facetimehd-$DRIVER_VERSION/dkms.conf" > /dev/null <<EOF
PACKAGE_NAME="facetimehd"
PACKAGE_VERSION="$DRIVER_VERSION"
BUILT_MODULE_NAME[0]="facetimehd"
DEST_MODULE_LOCATION[0]="/extra"
AUTOINSTALL="yes"
MAKE="make -C \${kernel_source_dir} M=\${dkms_tree}/\${PACKAGE_NAME}/\${PACKAGE_VERSION}/build modules"
CLEAN="make -C \${kernel_source_dir} M=\${dkms_tree}/\${PACKAGE_NAME}/\${PACKAGE_VERSION}/build clean"
EOF
    fi
    
    sudo dkms add -m facetimehd -v "$DRIVER_VERSION" || {
        print_error "Failed to add driver to DKMS"
        exit 1
    }
    
    sudo dkms build -m facetimehd -v "$DRIVER_VERSION" || {
        print_error "Failed to build driver with DKMS"
        exit 1
    }
    
    sudo dkms install -m facetimehd -v "$DRIVER_VERSION" || {
        print_error "Failed to install driver with DKMS"
        exit 1
    }
    
    print_success "Driver installed successfully"
    cd ~
    rm -rf "$WORK_DIR"
}

# Function to configure module loading
configure_module() {
    print_status "Configuring module loading..."
    
    # Blacklist conflicting modules
    echo 'blacklist bdc_pci' | sudo tee /etc/modprobe.d/blacklist-facetimehd.conf > /dev/null
    
    # Add facetimehd to modules
    if ! grep -q "^facetimehd$" /etc/modules 2>/dev/null; then
        echo 'facetimehd' | sudo tee -a /etc/modules > /dev/null
    fi
    
    # Load the module
    print_status "Loading FaceTime HD module..."
    sudo modprobe -r bdc_pci 2>/dev/null || true
    sudo modprobe facetimehd || {
        print_error "Failed to load module"
        print_status "Check dmesg for errors: sudo dmesg | tail -20"
        exit 1
    }
    
    print_success "Module configured and loaded"
}

# Function to verify installation
verify_installation() {
    print_status "Verifying installation..."
    
    # Check if module is loaded
    if ! lsmod | grep -q facetimehd; then
        print_error "Module is not loaded"
        return 1
    fi
    
    # Check for video device
    if [ ! -e /dev/video0 ] && [ ! -e /dev/video1 ] && [ ! -e /dev/video2 ]; then
        print_error "No video device found"
        return 1
    fi
    
    # Get video device
    VIDEO_DEVICE=$(ls /dev/video* 2>/dev/null | head -1)
    
    if [ -n "$VIDEO_DEVICE" ]; then
        print_success "Camera device found at: $VIDEO_DEVICE"
        
        # Show camera information
        print_status "Camera information:"
        v4l2-ctl -d "$VIDEO_DEVICE" --info 2>/dev/null || true
    fi
    
    return 0
}

# Function to test camera
test_camera() {
    print_status "Would you like to test the camera now? (y/N): "
    read -n 1 -r
    echo
    
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        VIDEO_DEVICE=$(ls /dev/video* 2>/dev/null | head -1)
        
        if command -v cheese &> /dev/null; then
            print_status "Starting Cheese..."
            cheese &
        elif command -v guvcview &> /dev/null; then
            print_status "Starting guvcview..."
            guvcview &
        else
            print_warning "No camera application found. Install cheese or guvcview to test."
            print_status "You can install with: sudo apt install cheese"
        fi
    fi
}

# Main installation flow
main() {
    clear
    echo "======================================"
    echo "FaceTime HD Camera Installation Script"
    echo "======================================"
    echo
    print_status "Log file: $LOG_FILE"
    echo
    
    # Pre-installation checks
    check_root
    detect_distro
    check_kernel
    check_camera
    check_secure_boot
    
    # Installation
    install_dependencies
    cleanup_old_installation
    install_firmware
    install_driver
    configure_module
    
    # Post-installation
    if verify_installation; then
        print_success "Installation completed successfully!"
        echo
        print_status "Camera should now be working."
        print_status "You can test it with applications like:"
        echo "  - cheese"
        echo "  - guvcview"
        echo "  - Google Chrome/Chromium"
        echo "  - Firefox"
        echo
        test_camera
    else
        print_error "Installation completed but verification failed"
        print_status "Please check the log file: $LOG_FILE"
        print_status "And kernel messages: sudo dmesg | grep -i facetime"
    fi
    
    echo
    print_status "If you encounter issues, please check:"
    echo "  1. Secure Boot status (disable if enabled)"
    echo "  2. Kernel messages: sudo dmesg | grep -i facetime"
    echo "  3. Module status: lsmod | grep facetimehd"
    echo "  4. Log file: $LOG_FILE"
}

# Run main function
main "$@"