#!/bin/bash
# Installation script for System Backup Tool

set -e

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

# Print colored output
print_status() {
    echo -e "${BLUE}[INFO]${NC} $1"
}

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

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

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

# Check if running as root
check_root() {
    if [[ $EUID -eq 0 ]]; then
        print_error "Do not run this installer as root. It will use sudo when needed."
        exit 1
    fi
}

# Check dependencies
check_dependencies() {
    print_status "Checking dependencies..."
    
    # Check Python 3
    if ! command -v python3 &> /dev/null; then
        print_error "Python 3 is required but not installed"
        exit 1
    fi
    
    # Check tkinter
    if ! python3 -c "import tkinter" &> /dev/null; then
        print_warning "tkinter not available. Installing python3-tk..."
        sudo apt update
        sudo apt install -y python3-tk
    fi
    
    # Check for pv (progress viewer)
    if ! command -v pv &> /dev/null; then
        print_warning "pv (progress viewer) not found. Installing..."
        sudo apt install -y pv
    fi
    
    print_success "All dependencies satisfied"
}

# Make scripts executable
setup_permissions() {
    print_status "Setting up permissions..."
    
    chmod +x backup_manager.py
    chmod +x backup_script.sh
    
    print_success "Permissions set"
}

# Create desktop entry
create_desktop_entry() {
    print_status "Creating desktop entry..."
    
    local desktop_dir="$HOME/Desktop"
    local applications_dir="$HOME/.local/share/applications"
    local script_path=$(realpath backup_manager.py)
    local icon_path=$(realpath ".")
    
    # Create applications directory if it doesn't exist
    mkdir -p "$applications_dir"
    
    # Create desktop entry content
    local desktop_content="[Desktop Entry]
Version=1.0
Type=Application
Name=System Backup Manager
Comment=Clone internal drive to external M.2 SSD
Exec=python3 '$script_path'
Icon=drive-harddisk
Terminal=false
Categories=System;Utility;
StartupNotify=true"

    # Create desktop file in applications
    echo "$desktop_content" > "$applications_dir/system-backup.desktop"
    chmod +x "$applications_dir/system-backup.desktop"
    
    # Create desktop shortcut if Desktop directory exists
    if [[ -d "$desktop_dir" ]]; then
        echo "$desktop_content" > "$desktop_dir/System Backup.desktop"
        chmod +x "$desktop_dir/System Backup.desktop"
        print_success "Desktop shortcut created"
    fi
    
    print_success "Application entry created"
}

# Create systemd service (optional)
create_systemd_service() {
    local service_dir="systemd"
    local script_path=$(realpath backup_script.sh)
    
    print_status "Creating systemd service template..."
    
    mkdir -p "$service_dir"
    
    cat > "$service_dir/backup-service.service" << EOF
[Unit]
Description=System Backup Service
After=multi-user.target

[Service]
Type=oneshot
ExecStart=$script_path --target /dev/sdb
User=root
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target
EOF

    cat > "$service_dir/README.md" << EOF
# Systemd Service for Backup

To install the systemd service:

1. Edit the service file to specify your target drive
2. Copy to systemd directory:
   \`\`\`bash
   sudo cp backup-service.service /etc/systemd/system/
   \`\`\`

3. Enable and start:
   \`\`\`bash
   sudo systemctl daemon-reload
   sudo systemctl enable backup-service
   sudo systemctl start backup-service
   \`\`\`

4. Check status:
   \`\`\`bash
   sudo systemctl status backup-service
   \`\`\`
EOF

    print_success "Systemd service template created in systemd/"
}

# Create log directory
setup_logging() {
    print_status "Setting up logging..."
    
    # Create log file with proper permissions
    sudo touch /var/log/system_backup.log
    sudo chmod 666 /var/log/system_backup.log
    
    print_success "Log file created: /var/log/system_backup.log"
}

# Main installation function
main() {
    echo ""
    echo "======================================"
    echo "  System Backup Tool Installer"
    echo "======================================"
    echo ""
    
    check_root
    check_dependencies
    setup_permissions
    setup_logging
    create_desktop_entry
    create_systemd_service
    
    echo ""
    print_success "Installation completed successfully!"
    echo ""
    echo "You can now:"
    echo "  • Launch GUI: python3 backup_manager.py"
    echo "  • Use CLI: ./backup_script.sh --help"
    echo "  • Click desktop icon: System Backup Manager"
    echo ""
    print_warning "Remember to run the backup tool with appropriate privileges"
    print_warning "Always verify your drive selections before starting backup"
    echo ""
}

# Run installer
main "$@"