#!/bin/bash

################################################################################
# VidRip Production Startup Script
################################################################################
# This script builds and runs the VidRip service in production mode.
# It handles dependency checks, builds both frontend and backend, and starts
# the backend server with proper process management.
################################################################################

set -e  # Exit on error
set -u  # Exit on undefined variable

# 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 directory
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"

# Configuration
BACKEND_DIR="$SCRIPT_DIR/backend"
FRONTEND_DIR="$SCRIPT_DIR/frontend"
LOG_DIR="$SCRIPT_DIR/logs"
PID_FILE="$SCRIPT_DIR/vidrip.pid"
LOG_FILE="$LOG_DIR/vidrip.log"
ERROR_LOG_FILE="$LOG_DIR/vidrip-error.log"

################################################################################
# Helper 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_command() {
    if ! command -v "$1" &> /dev/null; then
        log_error "$1 is not installed or not in PATH"
        return 1
    fi
    log_success "$1 is installed"
    return 0
}

cleanup_on_exit() {
    log_info "Cleaning up..."
    if [ -f "$PID_FILE" ]; then
        rm -f "$PID_FILE"
    fi
}

################################################################################
# Pre-flight Checks
################################################################################

log_info "Starting VidRip production deployment..."
echo ""

log_info "Checking system requirements..."

# Check for Node.js
if ! check_command node; then
    log_error "Node.js is required but not installed"
    exit 1
fi

NODE_VERSION=$(node --version | cut -d'v' -f2 | cut -d'.' -f1)
if [ "$NODE_VERSION" -lt 18 ]; then
    log_error "Node.js version 18 or higher is required (found v$NODE_VERSION)"
    exit 1
fi
log_success "Node.js version: $(node --version)"

# Check for npm
if ! check_command npm; then
    log_error "npm is required but not installed"
    exit 1
fi

# Check for yt-dlp
if ! check_command yt-dlp; then
    log_warning "yt-dlp is not installed or not in PATH"
    log_warning "Install with: pip install yt-dlp OR brew install yt-dlp"
    log_warning "The application will not be able to download videos without yt-dlp"
else
    log_success "yt-dlp version: $(yt-dlp --version)"
fi

echo ""

################################################################################
# Check for existing process
################################################################################

if [ -f "$PID_FILE" ]; then
    OLD_PID=$(cat "$PID_FILE")
    if ps -p "$OLD_PID" > /dev/null 2>&1; then
        log_error "VidRip is already running (PID: $OLD_PID)"
        log_info "Stop it first with: kill $OLD_PID"
        exit 1
    else
        log_warning "Stale PID file found, removing..."
        rm -f "$PID_FILE"
    fi
fi

################################################################################
# Create necessary directories
################################################################################

log_info "Creating necessary directories..."
mkdir -p "$LOG_DIR"
mkdir -p "$BACKEND_DIR/downloads"
mkdir -p "$BACKEND_DIR/dist"
log_success "Directories created"

echo ""

################################################################################
# Install Dependencies
################################################################################

log_info "Installing dependencies..."

# Backend dependencies
log_info "Installing backend dependencies..."
cd "$BACKEND_DIR"
if [ ! -d "node_modules" ]; then
    npm install --production=false
else
    log_info "Backend node_modules already exists, skipping install"
fi
log_success "Backend dependencies installed"

# Frontend dependencies
log_info "Installing frontend dependencies..."
cd "$FRONTEND_DIR"
if [ ! -d "node_modules" ]; then
    npm install --production=false
else
    log_info "Frontend node_modules already exists, skipping install"
fi
log_success "Frontend dependencies installed"

cd "$SCRIPT_DIR"
echo ""

################################################################################
# Build Applications
################################################################################

log_info "Building applications..."

# Build backend
log_info "Building backend (TypeScript compilation)..."
cd "$BACKEND_DIR"
npm run build
if [ ! -f "dist/server.js" ]; then
    log_error "Backend build failed - dist/server.js not found"
    exit 1
fi
log_success "Backend built successfully"

# Build frontend
log_info "Building frontend (Vite production build)..."
cd "$FRONTEND_DIR"
npm run build
if [ ! -d "dist" ]; then
    log_error "Frontend build failed - dist directory not found"
    exit 1
fi
log_success "Frontend built successfully"

cd "$SCRIPT_DIR"
echo ""

################################################################################
# Start Backend Server
################################################################################

log_info "Starting VidRip backend server..."

# Setup environment
export NODE_ENV=production

# Start the backend server
cd "$BACKEND_DIR"

# Run in background with output redirected to log files
nohup node dist/server.js > "$LOG_FILE" 2> "$ERROR_LOG_FILE" &
SERVER_PID=$!

# Save PID
echo "$SERVER_PID" > "$PID_FILE"

# Wait a moment and check if process is still running
sleep 2
if ! ps -p "$SERVER_PID" > /dev/null 2>&1; then
    log_error "Server failed to start"
    log_error "Check logs at:"
    log_error "  - $LOG_FILE"
    log_error "  - $ERROR_LOG_FILE"
    rm -f "$PID_FILE"
    exit 1
fi

log_success "VidRip backend started successfully!"
echo ""
log_info "Process ID: $SERVER_PID"
log_info "PID file: $PID_FILE"
log_info "Log file: $LOG_FILE"
log_info "Error log: $ERROR_LOG_FILE"
echo ""

# Check for port in logs (default 3001)
sleep 1
if grep -q "Server running" "$LOG_FILE" 2>/dev/null; then
    PORT_INFO=$(grep "Server running" "$LOG_FILE" | tail -1)
    log_success "$PORT_INFO"
else
    log_info "Server should be running on port 3001 (or PORT from .env)"
fi

echo ""
log_info "==================================================================="
log_info "VidRip is now running in production mode"
log_info "==================================================================="
echo ""
log_info "To stop the service:"
log_info "  ./stop-production.sh"
echo ""
log_info "To view logs:"
log_info "  tail -f $LOG_FILE"
echo ""
log_info "To view errors:"
log_info "  tail -f $ERROR_LOG_FILE"
echo ""
log_warning "IMPORTANT: In production, you'll need to:"
log_warning "  1. Serve the frontend build (frontend/dist) via nginx/Apache"
log_warning "  2. Setup reverse proxy from frontend to backend API"
log_warning "  3. Configure proper firewall rules"
echo ""

# Register cleanup on script exit
trap cleanup_on_exit EXIT

exit 0