pipeline {
    // 1. Run on your specific agent
    agent { label 'jenkins-agent' }

    environment {
        REGISTRY_URL = 'registry.digitalocean.com/kongseng'
        
        // 2. Dynamic Naming: Image tag includes Branch Name to prevent conflicts
        // Example: registry.../backend:Dev-42 or registry.../backend:main-42
        BACKEND_IMAGE = "${REGISTRY_URL}/devsecops-backend:${env.BRANCH_NAME}-${env.BUILD_NUMBER}"
        FRONTEND_IMAGE = "${REGISTRY_URL}/devsecops-frontend:${env.BRANCH_NAME}-${env.BUILD_NUMBER}"
    }
    
    stages {
        stage('Checkout') {
            steps {
                checkout scm
            }
        }
        
        stage('Install Dependencies') {
            steps {
                echo "Installing dependencies for ${env.BRANCH_NAME} branch..."
                dir('backend') { sh 'npm install' }
                dir('frontend') { sh 'npm install' }
            }
        }
        
        stage('Build Docker Images') {
            steps {
                script {
                    echo "Building Images for branch: ${env.BRANCH_NAME}..."
                    sh "docker build -t ${BACKEND_IMAGE} ./backend"
                    sh "docker build -t ${FRONTEND_IMAGE} ./frontend"
                }
            }
        }

        stage('Push to Registry') {
            steps {
                script {
                    echo "Pushing images to DigitalOcean..."
                    sh "docker push ${BACKEND_IMAGE}"
                    sh "docker push ${FRONTEND_IMAGE}"
                }
            }
        }
        
        // --- DYNAMIC DEPLOYMENT ---
        stage('Deploy') {
            steps {
                script {
                    // Define ports and names based on the branch
                    def appPort = "3000" // Fallback
                    def containerName = "backend-app"
                    
                    if (env.BRANCH_NAME == 'Dev') {
                        appPort = "3001"
                        containerName = "backend-dev"
                        echo "Deploying to DEV Environment (Port 3001)"
                    } 
                    else if (env.BRANCH_NAME == 'Release') {
                        appPort = "3002"
                        containerName = "backend-release"
                        echo "Deploying to STAGING Environment (Port 3002)"
                    } 
                    else if (env.BRANCH_NAME == 'main') {
                        appPort = "3003"
                        containerName = "backend-prod"
                        echo "Deploying to PRODUCTION Environment (Port 3003)"
                    }
                    else {
                         // Logic for any future feature branches
                        appPort = "3004"
                        containerName = "backend-feature-${env.BRANCH_NAME}"
                        echo "Deploying Feature Branch"
                    }

                    // 1. Clean up old container
                    try {
                        sh "docker stop ${containerName} || true"
                        sh "docker rm ${containerName} || true"
                    } catch (Exception e) {
                        echo "No container to stop"
                    }

                    // 2. Run new container on the assigned port
                    sh """
                        docker run -d \
                        --name ${containerName} \
                        --restart always \
                        -p ${appPort}:3000 \
                        ${BACKEND_IMAGE}
                    """
                }
            }
        }
    }
}