#!/bin/bash

# PDF Sort and Merge Application - Ubuntu Installation Script
# This script installs and configures the Flask web application for PDF processing

set -e  # Exit on any 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

# 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 if running as root
if [[ $EUID -eq 0 ]]; then
   log_error "This script should not be run as root. Please run as a regular user with sudo privileges."
   exit 1
fi

# Check Ubuntu version
UBUNTU_VERSION=$(lsb_release -rs)
log_info "Detected Ubuntu version: $UBUNTU_VERSION"

# Update system
log_info "Updating system packages..."
sudo apt update && sudo apt upgrade -y

# Install Python 3.9+ and pip
log_info "Installing Python and pip..."
sudo apt install -y python3 python3-pip python3-venv python3-dev

# Install system dependencies for PDF processing
log_info "Installing system dependencies..."
sudo apt install -y build-essential libpoppler-cpp-dev pkg-config

# Install Node.js and npm (for potential frontend assets)
log_info "Installing Node.js and npm..."
curl -fsSL https://deb.nodesource.com/setup_18.x | sudo -E bash -
sudo apt install -y nodejs

# Create application directory
APP_DIR="$HOME/pdf-sort-merge"
log_info "Creating application directory: $APP_DIR"
mkdir -p "$APP_DIR"
cd "$APP_DIR"

# Clone or download the application
# Note: Replace with your actual repository URL
REPO_URL="https://github.com/yourusername/pdf-sort-merge.git"
log_info "Cloning application repository..."
if command -v git &> /dev/null; then
    sudo apt install -y git
    git clone "$REPO_URL" .
else
    log_warning "Git not available. Please manually download and extract the application files to $APP_DIR"
    exit 1
fi

# Create Python virtual environment
log_info "Creating Python virtual environment..."
python3 -m venv venv
source venv/bin/activate

# Install Python dependencies
log_info "Installing Python dependencies..."
pip install --upgrade pip
pip install -r requirements.txt

# Create .env file template
log_info "Creating environment configuration..."
if [ ! -f .env ]; then
    cat > .env << 'EOF'
# Microsoft Entra (Azure AD) Configuration
# Get these values from your Azure AD app registration in the Azure portal

# Azure AD Tenant ID (Directory ID)
AZURE_TENANT_ID=your-tenant-id-here

# Azure AD Client ID (Application ID)
AZURE_CLIENT_ID=your-client-id-here

# Azure AD Client Secret
AZURE_CLIENT_SECRET=your-client-secret-here

# Azure AD Authority URL (usually https://login.microsoftonline.com/{tenant_id})
AZURE_AUTHORITY=https://login.microsoftonline.com/your-tenant-id-here

# Redirect URI (must match what's configured in Azure AD app registration)
AZURE_REDIRECT_URI=http://localhost:5000/auth/callback

# Scopes to request (openid, profile, email are common)
AZURE_SCOPES=openid profile email

# Flask Configuration
SECRET_KEY=your-secret-key-here-change-this-in-production
EOF
    log_warning "Created .env template. You MUST edit it with your Azure AD credentials before running the app."
else
    log_info ".env file already exists"
fi

# Create systemd service file
log_info "Creating systemd service..."
SERVICE_FILE="/etc/systemd/system/pdf-sort-merge.service"
sudo tee "$SERVICE_FILE" > /dev/null << EOF
[Unit]
Description=PDF Sort and Merge Flask Application
After=network.target

[Service]
Type=simple
User=$USER
WorkingDirectory=$APP_DIR
Environment=PATH=$APP_DIR/venv/bin
ExecStart=$APP_DIR/venv/bin/python $APP_DIR/app.py
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF

# Set proper permissions
sudo chmod 644 "$SERVICE_FILE"

# Create log directory
log_info "Creating log directory..."
sudo mkdir -p /var/log/pdf-sort-merge
sudo chown $USER:$USER /var/log/pdf-sort-merge

# Create application data directories
log_info "Creating application data directories..."
mkdir -p results static templates

# Set up firewall (optional)
log_info "Configuring firewall..."
sudo ufw allow 5000/tcp || log_warning "Failed to configure firewall - you may need to do this manually"

# Enable and start service
log_info "Enabling and starting service..."
sudo systemctl daemon-reload
sudo systemctl enable pdf-sort-merge
sudo systemctl start pdf-sort-merge

# Check service status
sleep 3
if sudo systemctl is-active --quiet pdf-sort-merge; then
    log_success "Service started successfully!"
else
    log_error "Service failed to start. Check logs with: sudo journalctl -u pdf-sort-merge -f"
fi

# Create management script
log_info "Creating management script..."
cat > manage.sh << 'EOF'
#!/bin/bash

case "$1" in
    start)
        sudo systemctl start pdf-sort-merge
        echo "Service started"
        ;;
    stop)
        sudo systemctl stop pdf-sort-merge
        echo "Service stopped"
        ;;
    restart)
        sudo systemctl restart pdf-sort-merge
        echo "Service restarted"
        ;;
    status)
        sudo systemctl status pdf-sort-merge
        ;;
    logs)
        sudo journalctl -u pdf-sort-merge -f
        ;;
    update)
        cd /home/$USER/pdf-sort-merge
        source venv/bin/activate
        git pull
        pip install -r requirements.txt
        sudo systemctl restart pdf-sort-merge
        echo "Application updated"
        ;;
    *)
        echo "Usage: $0 {start|stop|restart|status|logs|update}"
        exit 1
        ;;
esac
EOF

chmod +x manage.sh

# Final instructions
log_success "Installation completed!"
echo ""
echo "=================================================================="
echo "NEXT STEPS:"
echo "1. Edit the .env file with your Azure AD credentials:"
echo "   nano $APP_DIR/.env"
echo ""
echo "2. Configure your Azure AD app registration with redirect URI:"
echo "   http://your-server-ip:5000/auth/callback"
echo ""
echo "3. Access the application at:"
echo "   http://localhost:5000"
echo ""
echo "MANAGEMENT COMMANDS:"
echo "  Start service:   sudo systemctl start pdf-sort-merge"
echo "  Stop service:    sudo systemctl stop pdf-sort-merge"
echo "  Check status:    sudo systemctl status pdf-sort-merge"
echo "  View logs:       sudo journalctl -u pdf-sort-merge -f"
echo "  Update app:      ./manage.sh update"
echo "=================================================================="

# Check if .env needs configuration
if grep -q "your-tenant-id-here" .env; then
    log_warning "IMPORTANT: Configure your .env file before using the application!"
fi