#!/bin/bash

# BBeOS Emulation Script
# Emulates BBeOS on Linux using QEMU

set -e

# Configuration
BBEOS_VERSION="1.0.0"
QEMU_ARCH="arm"
QEMU_MACHINE="vexpress-a9"
QEMU_CPU="cortex-a9"
QEMU_RAM="2G"
QEMU_DISPLAY="720x720"
QEMU_KERNEL="kernel-source/arch/arm/boot/zImage"
QEMU_DTB="kernel-source/arch/arm/boot/dts/vexpress-v2p-ca9.dtb"
QEMU_INITRAMFS="initramfs.img"
QEMU_DISK="bbeos-emulation.img"

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

# Logging functions
log_info() {
    echo -e "${BLUE}[INFO]${NC} $1"
}

log_success() {
    echo -e "${GREEN}[SUCCESS]${NC} $1"
}

log_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

log_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

# Check dependencies
check_dependencies() {
    log_info "Checking dependencies..."
    
    local missing_deps=()
    
    # Check QEMU
    if ! command -v qemu-system-arm &> /dev/null; then
        missing_deps+=("qemu-system-arm")
    fi
    
    # Check ARM toolchain
    if ! command -v arm-linux-gnueabihf-gcc &> /dev/null; then
        missing_deps+=("gcc-arm-linux-gnueabihf")
    fi
    
    # Check additional tools
    for tool in make git wget; do
        if ! command -v $tool &> /dev/null; then
            missing_deps+=("$tool")
        fi
    done
    
    if [ ${#missing_deps[@]} -ne 0 ]; then
        log_error "Missing dependencies: ${missing_deps[*]}"
        log_info "Install them with:"
        log_info "  sudo apt-get install ${missing_deps[*]}"
        exit 1
    fi
    
    log_success "All dependencies found"
}

# Create virtual disk
create_virtual_disk() {
    log_info "Creating virtual disk..."
    
    if [ ! -f "$QEMU_DISK" ]; then
        qemu-img create -f raw "$QEMU_DISK" 8G
        log_success "Created virtual disk: $QEMU_DISK"
    else
        log_info "Virtual disk already exists: $QEMU_DISK"
    fi
}

# Build kernel and initramfs
build_system() {
    log_info "Building BBeOS system components..."
    
    # Build kernel if not exists
    if [ ! -f "$QEMU_KERNEL" ]; then
        log_info "Building kernel..."
        cd kernel-source
        make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- vexpress_defconfig
        make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j$(nproc)
        cd ..
    fi
    
    # Build initramfs if not exists
    if [ ! -f "$QEMU_INITRAMFS" ]; then
        log_info "Building initramfs..."
        ./scripts/build-rootfs.sh
    fi
    
    log_success "System components built"
}

# Create QEMU configuration
create_qemu_config() {
    log_info "Creating QEMU configuration..."
    
    cat > qemu-bbeos.conf << EOF
# BBeOS QEMU Configuration
# Generated by BBeOS emulation script

# Machine configuration
-machine $QEMU_MACHINE
-cpu $QEMU_CPU
-m $QEMU_RAM

# Display configuration
-display gtk
-vga none
-fbdev /dev/fb0

# Input devices
-kernel $QEMU_KERNEL
-dtb $QEMU_DTB
-initrd $QEMU_INITRAMFS

# Storage
-drive file=$QEMU_DISK,if=sd,format=raw

# Network (optional)
-net nic,model=lan9118
-net user

# Serial console
-serial stdio

# Additional options
-no-reboot
-no-shutdown
EOF

    log_success "QEMU configuration created: qemu-bbeos.conf"
}

# Start emulation
start_emulation() {
    log_info "Starting BBeOS emulation..."
    
    # Check if components exist
    if [ ! -f "$QEMU_KERNEL" ]; then
        log_error "Kernel not found: $QEMU_KERNEL"
        log_info "Run: ./scripts/build-kernel.sh"
        exit 1
    fi
    
    if [ ! -f "$QEMU_INITRAMFS" ]; then
        log_error "Initramfs not found: $QEMU_INITRAMFS"
        log_info "Run: ./scripts/build-rootfs.sh"
        exit 1
    fi
    
    # Start QEMU
    log_info "Launching QEMU with BBeOS..."
    log_info "Press Ctrl+A, then X to exit"
    
    qemu-system-arm \
        -machine $QEMU_MACHINE \
        -cpu $QEMU_CPU \
        -m $QEMU_RAM \
        -display gtk \
        -vga none \
        -kernel $QEMU_KERNEL \
        -dtb $QEMU_DTB \
        -initrd $QEMU_INITRAMFS \
        -drive file=$QEMU_DISK,if=sd,format=raw \
        -net nic,model=lan9118 \
        -net user \
        -serial stdio \
        -no-reboot \
        -no-shutdown \
        -append "console=ttyAMA0,115200 root=/dev/ram0 rw init=/init"
}

# Create development environment
create_dev_environment() {
    log_info "Creating development environment..."
    
    # Create development directory
    mkdir -p bbeos-dev
    
    # Copy system components
    cp $QEMU_KERNEL bbeos-dev/
    cp $QEMU_INITRAMFS bbeos-dev/
    cp $QEMU_DISK bbeos-dev/
    
    # Create development script
    cat > bbeos-dev/run-dev.sh << 'EOF'
#!/bin/bash
# BBeOS Development Environment

echo "BBeOS Development Environment"
echo "============================="
echo ""
echo "Available commands:"
echo "  ./run-emulation.sh    - Start BBeOS emulation"
echo "  ./build-apps.sh       - Build applications"
echo "  ./test-apps.sh        - Test applications"
echo "  ./debug.sh           - Start with debugging"
echo ""
EOF

    chmod +x bbeos-dev/run-dev.sh
    
    # Create emulation script
    cat > bbeos-dev/run-emulation.sh << 'EOF'
#!/bin/bash
# Run BBeOS emulation

qemu-system-arm \
    -machine vexpress-a9 \
    -cpu cortex-a9 \
    -m 2G \
    -display gtk \
    -vga none \
    -kernel zImage \
    -dtb vexpress-v2p-ca9.dtb \
    -initrd initramfs.img \
    -drive file=bbeos-emulation.img,if=sd,format=raw \
    -net nic,model=lan9118 \
    -net user \
    -serial stdio \
    -no-reboot \
    -no-shutdown \
    -append "console=ttyAMA0,115200 root=/dev/ram0 rw init=/init"
EOF

    chmod +x bbeos-dev/run-emulation.sh
    
    log_success "Development environment created in bbeos-dev/"
}

# Create debugging configuration
create_debug_config() {
    log_info "Creating debugging configuration..."
    
    cat > qemu-debug.conf << EOF
# BBeOS QEMU Debug Configuration

# Machine configuration
-machine $QEMU_MACHINE
-cpu $QEMU_CPU
-m $QEMU_RAM

# Display configuration
-display gtk
-vga none

# Kernel and initramfs
-kernel $QEMU_KERNEL
-dtb $QEMU_DTB
-initrd $QEMU_INITRAMFS

# Storage
-drive file=$QEMU_DISK,if=sd,format=raw

# Network
-net nic,model=lan9118
-net user

# Debugging
-serial stdio
-gdb tcp::1234
-S

# Additional options
-no-reboot
-no-shutdown
EOF

    log_success "Debug configuration created: qemu-debug.conf"
}

# Show help
show_help() {
    echo "BBeOS Emulation Script"
    echo "====================="
    echo ""
    echo "Usage: $0 [OPTION]"
    echo ""
    echo "Options:"
    echo "  start           - Start BBeOS emulation"
    echo "  build           - Build system components"
    echo "  setup           - Setup emulation environment"
    echo "  dev             - Create development environment"
    echo "  debug           - Start with debugging enabled"
    echo "  clean           - Clean build artifacts"
    echo "  help            - Show this help"
    echo ""
    echo "Examples:"
    echo "  $0 setup        - Setup emulation environment"
    echo "  $0 start        - Start BBeOS emulation"
    echo "  $0 dev          - Create development environment"
    echo ""
}

# Clean build artifacts
clean_build() {
    log_info "Cleaning build artifacts..."
    
    rm -f $QEMU_DISK
    rm -f qemu-bbeos.conf
    rm -f qemu-debug.conf
    rm -rf bbeos-dev
    
    log_success "Build artifacts cleaned"
}

# Main function
main() {
    case "${1:-start}" in
        "start")
            check_dependencies
            build_system
            create_virtual_disk
            start_emulation
            ;;
        "build")
            check_dependencies
            build_system
            ;;
        "setup")
            check_dependencies
            build_system
            create_virtual_disk
            create_qemu_config
            create_debug_config
            log_success "BBeOS emulation environment setup complete"
            ;;
        "dev")
            check_dependencies
            build_system
            create_dev_environment
            log_success "Development environment created"
            ;;
        "debug")
            check_dependencies
            build_system
            create_debug_config
            log_info "Starting BBeOS with debugging enabled..."
            log_info "Connect GDB to localhost:1234"
            qemu-system-arm -readconfig qemu-debug.conf
            ;;
        "clean")
            clean_build
            ;;
        "help"|"-h"|"--help")
            show_help
            ;;
        *)
            log_error "Unknown option: $1"
            show_help
            exit 1
            ;;
    esac
}

# Run main function
main "$@"