#!/bin/bash

# ============================================================================
# WebDAV Server Installation and Setup Script
# ============================================================================

set -e  # Exit on error

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

# Functions
print_info() {
    echo -e "${BLUE}ℹ ${1}${NC}"
}

print_success() {
    echo -e "${GREEN}✓ ${1}${NC}"
}

print_warning() {
    echo -e "${YELLOW}⚠ ${1}${NC}"
}

print_error() {
    echo -e "${RED}✗ ${1}${NC}"
}

print_header() {
    echo ""
    echo -e "${BLUE}╔══════════════════════════════════════════════════════════════╗${NC}"
    echo -e "${BLUE}║          WebDAV Server Installation Script                  ║${NC}"
    echo -e "${BLUE}╚══════════════════════════════════════════════════════════════╝${NC}"
    echo ""
}

# Check if running as root
check_root() {
    if [ "$EUID" -eq 0 ]; then 
        print_warning "Running as root. It's recommended to run as a regular user."
        read -p "Continue? (y/n) " -n 1 -r
        echo
        if [[ ! $REPLY =~ ^[Yy]$ ]]; then
            exit 1
        fi
    fi
}

# Check system requirements
check_requirements() {
    print_info "Checking system requirements..."
    
    # Check Python version
    if command -v python3 &> /dev/null; then
        PYTHON_VERSION=$(python3 --version | awk '{print $2}')
        print_success "Python $PYTHON_VERSION found"
    else
        print_error "Python 3 not found. Please install Python 3.8 or higher."
        exit 1
    fi
    
    # Check pip
    if command -v pip3 &> /dev/null; then
        print_success "pip3 found"
    else
        print_warning "pip3 not found. Installing..."
        python3 -m ensurepip --upgrade
    fi
    
    # Check git (optional)
    if command -v git &> /dev/null; then
        print_success "git found"
    else
        print_warning "git not found. Some features may be limited."
    fi
}

# Install system dependencies
install_dependencies() {
    print_info "Installing system dependencies..."
    
    if [ -f /etc/debian_version ]; then
        # Debian/Ubuntu
        sudo apt-get update
        sudo apt-get install -y python3-dev python3-venv build-essential libxml2-dev libxslt-dev
        print_success "Dependencies installed (Debian/Ubuntu)"
    elif [ -f /etc/redhat-release ]; then
        # RHEL/CentOS/Fedora
        sudo yum install -y python3-devel gcc gcc-c++ libxml2-devel libxslt-devel
        print_success "Dependencies installed (RHEL/CentOS/Fedora)"
    else
        print_warning "Unknown distribution. Please install python3-dev, build-essential manually."
    fi
}

# Setup installation directory
setup_directory() {
    print_info "Setting up installation directory..."
    
    read -p "Installation directory [./webdav-server]: " INSTALL_DIR
    INSTALL_DIR=${INSTALL_DIR:-./webdav-server}
    
    if [ -d "$INSTALL_DIR" ]; then
        print_warning "Directory $INSTALL_DIR already exists."
        read -p "Continue and potentially overwrite files? (y/n) " -n 1 -r
        echo
        if [[ ! $REPLY =~ ^[Yy]$ ]]; then
            exit 1
        fi
    else
        mkdir -p "$INSTALL_DIR"
    fi
    
    cd "$INSTALL_DIR"
    print_success "Using directory: $(pwd)"
}

# Create virtual environment
setup_venv() {
    print_info "Creating Python virtual environment..."
    
    python3 -m venv venv
    . venv/bin/activate
    
    pip install --upgrade pip setuptools wheel
    print_success "Virtual environment created"
}

# Install Python packages
install_packages() {
    print_info "Installing Python packages..."
    
    source venv/bin/activate
    
    if [ -f requirements.txt ]; then
        pip install -r requirements.txt
        print_success "Packages installed from requirements.txt"
    else
        print_warning "requirements.txt not found. Installing core packages..."
        pip install aiohttp aiofiles aiohttp-session cryptography python-dotenv lxml gunicorn
        print_success "Core packages installed"
    fi
}

# Setup configuration
setup_config() {
    print_info "Setting up configuration..."
    
    if [ ! -f .env ]; then
        if [ -f .env.example ]; then
            cp .env.example .env
            print_success "Created .env from .env.example"
        else
            print_warning ".env.example not found. Creating basic .env..."
            cat > .env << EOF
HOST=0.0.0.0
PORT=8080
DB_PATH=./webdav.db
WEBDAV_ROOT=./webdav
AUTH_METHODS=basic,digest
JWT_SECRET_KEY=$(python3 -c "import secrets; print(secrets.token_hex(32))")
SESSION_TIMEOUT=3600
MAX_FILE_SIZE=104857600
LOG_LEVEL=INFO
EOF
            print_success "Created basic .env file"
        fi
    else
        print_warning ".env already exists. Skipping..."
    fi
    
    # Generate secret key if needed
    if grep -q "your-secret-key-here" .env 2>/dev/null; then
        SECRET_KEY=$(python3 -c "import secrets; print(secrets.token_hex(32))")
        if [[ "$OSTYPE" == "darwin"* ]]; then
            # macOS
            sed -i '' "s/your-secret-key-here-change-this-in-production/$SECRET_KEY/" .env
        else
            # Linux
            sed -i "s/your-secret-key-here-change-this-in-production/$SECRET_KEY/" .env
        fi
        print_success "Generated new JWT secret key"
    fi
}

# Create directory structure
create_directories() {
    print_info "Creating directory structure..."
    
    mkdir -p webdav/users
    mkdir -p webdav/shared
    mkdir -p logs
    mkdir -p backups
    
    print_success "Directory structure created"
}

# Initialize database
init_database() {
    print_info "Initializing database..."
    
    source venv/bin/activate
    python3 << EOF
import asyncio
from main import Database, create_default_user

async def init():
    db = Database('./webdav.db')
    await create_default_user(db)

asyncio.run(init())
EOF
    
    print_success "Database initialized"
}

# Setup systemd service (optional)
setup_systemd() {
    print_info "Would you like to set up systemd service? (requires sudo)"
    read -p "Setup systemd service? (y/n) " -n 1 -r
    echo
    
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        # Create webdav user if doesn't exist
        if ! id -u webdav &>/dev/null; then
            sudo useradd -r -s /bin/false webdav
            print_success "Created webdav user"
        fi
        
        # Copy service file
        if [ -f webdav.service ]; then
            sudo cp webdav.service /etc/systemd/system/
            sudo systemctl daemon-reload
            print_success "Systemd service installed"
            
            print_info "To enable and start the service:"
            echo "  sudo systemctl enable webdav"
            echo "  sudo systemctl start webdav"
            echo "  sudo systemctl status webdav"
        else
            print_warning "webdav.service not found. Skipping..."
        fi
    fi
}

# Setup nginx (optional)
setup_nginx() {
    print_info "Would you like to set up Nginx reverse proxy?"
    read -p "Setup Nginx? (y/n) " -n 1 -r
    echo
    
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        if command -v nginx &> /dev/null; then
            read -p "Enter your domain name: " DOMAIN_NAME
            
            if [ -f nginx.conf ]; then
                mkdir -p nginx/conf.d nginx/ssl
                sed "s/webdav.example.com/$DOMAIN_NAME/g" nginx.conf > nginx/conf.d/webdav.conf
                
                print_success "Nginx configuration created"
                print_info "Configuration saved to: nginx/conf.d/webdav.conf"
                print_warning "Don't forget to configure SSL certificates!"
            else
                print_warning "nginx.conf template not found"
            fi
        else
            print_warning "Nginx not installed. Skipping..."
        fi
    fi
}

# Setup Docker (optional)
setup_docker() {
    print_info "Would you like to set up Docker deployment?"
    read -p "Setup Docker? (y/n) " -n 1 -r
    echo
    
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        if command -v docker &> /dev/null; then
            if [ -f Dockerfile ] && [ -f docker-compose.yml ]; then
                print_info "Building Docker image..."
                docker-compose build
                print_success "Docker image built"
                
                print_info "To start the service:"
                echo "  docker-compose up -d"
                echo "  docker-compose logs -f"
            else
                print_warning "Dockerfile or docker-compose.yml not found"
            fi
        else
            print_warning "Docker not installed. Skipping..."
        fi
    fi
}

# Final instructions
print_instructions() {
    echo ""
    echo -e "${GREEN}╔══════════════════════════════════════════════════════════════╗${NC}"
    echo -e "${GREEN}║                 Installation Complete!                      ║${NC}"
    echo -e "${GREEN}╚══════════════════════════════════════════════════════════════╝${NC}"
    echo ""
    
    print_info "Getting Started:"
    echo ""
    echo "1. Activate virtual environment:"
    echo "   source venv/bin/activate"
    echo ""
    echo "2. Start the server:"
    echo "   python main.py"
    echo "   OR with Gunicorn (production):"
    echo "   gunicorn main:init_app --config gunicorn_config.py"
    echo ""
    echo "3. Access WebDAV server:"
    echo "   http://localhost:8080/"
    echo ""
    echo "4. Default credentials:"
    echo "   Username: admin"
    echo "   Password: admin123"
    echo "   ⚠️  CHANGE THIS PASSWORD IMMEDIATELY!"
    echo ""
    echo "5. Manage users with CLI:"
    echo "   python webdav_cli.py user create newuser"
    echo "   python webdav_cli.py user list"
    echo "   python webdav_cli.py stats"
    echo ""
    print_warning "Remember to:"
    echo "  • Change the default admin password"
    echo "  • Configure SSL/TLS for production"
    echo "  • Set up firewall rules"
    echo "  • Configure backups"
    echo ""
}

# Main installation process
main() {
    print_header
    
    check_root
    check_requirements
    install_dependencies
    setup_directory
    setup_venv
    install_packages
    setup_config
    create_directories
    init_database
    setup_systemd
    setup_nginx
    setup_docker
    print_instructions
    
    print_success "Installation complete!"
}

# Run main function
main