#!/bin/bash

# Inventory Barcode System Deployment Script
# This script handles production deployment with Docker

set -e  # Exit on any error

# Configuration
APP_NAME="inventory-barcode-system"
DOCKER_IMAGE="$APP_NAME:latest"
CONTAINER_NAME="$APP_NAME-container"
BACKUP_DIR="./data/backups"
LOG_FILE="./logs/deployment.log"

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

# Logging function
log() {
    echo -e "${GREEN}[$(date +'%Y-%m-%d %H:%M:%S')] $1${NC}"
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] $1" >> "$LOG_FILE"
}

error() {
    echo -e "${RED}[ERROR] $1${NC}"
    echo "[ERROR] $1" >> "$LOG_FILE"
    exit 1
}

warn() {
    echo -e "${YELLOW}[WARNING] $1${NC}"
    echo "[WARNING] $1" >> "$LOG_FILE"
}

# Check prerequisites
check_prerequisites() {
    log "Checking prerequisites..."
    
    # Check if Docker is installed
    if ! command -v docker &> /dev/null; then
        error "Docker is not installed. Please install Docker first."
    fi
    
    # Check if Docker Compose is installed
    if ! command -v docker-compose &> /dev/null; then
        error "Docker Compose is not installed. Please install Docker Compose first."
    fi
    
    # Check if .env file exists
    if [ ! -f .env ]; then
        warn ".env file not found. Creating from .env.example..."
        if [ -f .env.example ]; then
            cp .env.example .env
            log "Please edit .env file with your configuration before continuing."
            exit 0
        else
            error ".env.example file not found. Cannot create .env file."
        fi
    fi
    
    log "Prerequisites check completed successfully."
}

# Create necessary directories
create_directories() {
    log "Creating necessary directories..."
    
    mkdir -p data/exports
    mkdir -p data/backups
    mkdir -p data/temp
    mkdir -p logs
    
    log "Directories created successfully."
}

# Backup existing database
backup_database() {
    if [ -f "./inventory.db" ]; then
        log "Backing up existing database..."
        
        BACKUP_FILE="$BACKUP_DIR/pre-deployment-backup-$(date +%Y%m%d-%H%M%S).db"
        mkdir -p "$BACKUP_DIR"
        cp "./inventory.db" "$BACKUP_FILE"
        
        log "Database backed up to: $BACKUP_FILE"
    else
        log "No existing database found. Skipping backup."
    fi
}

# Build Docker image
build_image() {
    log "Building Docker image..."
    
    docker build -t "$DOCKER_IMAGE" .
    
    if [ $? -eq 0 ]; then
        log "Docker image built successfully."
    else
        error "Failed to build Docker image."
    fi
}

# Stop existing container
stop_existing() {
    log "Stopping existing container..."
    
    if docker ps -q -f name="$CONTAINER_NAME" | grep -q .; then
        docker stop "$CONTAINER_NAME"
        docker rm "$CONTAINER_NAME"
        log "Existing container stopped and removed."
    else
        log "No existing container found."
    fi
}

# Deploy with Docker Compose
deploy() {
    log "Deploying application with Docker Compose..."
    
    # Pull latest images and start services
    docker-compose down
    docker-compose up -d
    
    if [ $? -eq 0 ]; then
        log "Application deployed successfully."
    else
        error "Failed to deploy application."
    fi
}

# Health check
health_check() {
    log "Performing health check..."
    
    # Wait for application to start
    sleep 10
    
    # Check if container is running
    if ! docker ps -q -f name="$APP_NAME" | grep -q .; then
        error "Container is not running."
    fi
    
    # Check application health endpoint
    local max_attempts=30
    local attempt=1
    
    while [ $attempt -le $max_attempts ]; do
        if curl -f -s http://localhost:3000/health > /dev/null; then
            log "Health check passed. Application is running."
            return 0
        fi
        
        log "Health check attempt $attempt/$max_attempts failed. Retrying in 5 seconds..."
        sleep 5
        ((attempt++))
    done
    
    error "Health check failed after $max_attempts attempts."
}

# Show deployment status
show_status() {
    log "Deployment Status:"
    echo ""
    echo "Container Status:"
    docker ps -f name="$APP_NAME"
    echo ""
    echo "Application Logs (last 20 lines):"
    docker-compose logs --tail=20
    echo ""
    echo "Access the application at: http://localhost:3000"
    echo "Health check endpoint: http://localhost:3000/health"
}

# Rollback function
rollback() {
    warn "Rolling back deployment..."
    
    # Stop current deployment
    docker-compose down
    
    # Restore database backup if exists
    local latest_backup=$(ls -t "$BACKUP_DIR"/pre-deployment-backup-*.db 2>/dev/null | head -n1)
    if [ -n "$latest_backup" ]; then
        log "Restoring database from: $latest_backup"
        cp "$latest_backup" "./inventory.db"
    fi
    
    warn "Rollback completed. Please check your previous deployment."
}

# Main deployment function
main() {
    log "Starting deployment of $APP_NAME..."
    
    # Trap errors and rollback
    trap rollback ERR
    
    check_prerequisites
    create_directories
    backup_database
    build_image
    stop_existing
    deploy
    health_check
    show_status
    
    log "Deployment completed successfully!"
}

# Handle command line arguments
case "${1:-deploy}" in
    "deploy")
        main
        ;;
    "rollback")
        rollback
        ;;
    "status")
        show_status
        ;;
    "logs")
        docker-compose logs -f
        ;;
    "stop")
        log "Stopping application..."
        docker-compose down
        log "Application stopped."
        ;;
    "restart")
        log "Restarting application..."
        docker-compose restart
        log "Application restarted."
        ;;
    *)
        echo "Usage: $0 {deploy|rollback|status|logs|stop|restart}"
        echo ""
        echo "Commands:"
        echo "  deploy   - Deploy the application (default)"
        echo "  rollback - Rollback to previous version"
        echo "  status   - Show deployment status"
        echo "  logs     - Show application logs"
        echo "  stop     - Stop the application"
        echo "  restart  - Restart the application"
        exit 1
        ;;
esac