pipeline {
    // 1. Run heavy lifting (Build/Push) on the Agent
    agent { label 'jenkins-agent' }

    environment {
        // CRITICAL FIX: Use the Registry Name we verified via 'doctl'
        REGISTRY_URL = 'registry.digitalocean.com/devsecops-lab'
        
        // CRITICAL FIX: Use 'core' to stay within 1-repo limit
        REPO_NAME = 'core'
        
        // Dynamic Tags
        BACKEND_TAG = "backend-${env.BRANCH_NAME}-${env.BUILD_NUMBER}"
        FRONTEND_TAG = "frontend-${env.BRANCH_NAME}-${env.BUILD_NUMBER}"

        // Deployment Target (The Gitea Server)
        DEPLOY_HOST = 'gitea.kongseng.in' 
        DEPLOY_USER = 'root'
    }
    
    stages {
        stage('Checkout') {
            steps { checkout scm }
        }
        
        stage('Install Dependencies') {
            steps {
                echo "Installing dependencies for ${env.BRANCH_NAME}..."
                // Ensure folders exist to avoid errors
                sh 'ls -la'
                dir('backend') { sh 'npm install' }
                dir('frontend') { sh 'npm install' }
            }
        }
        
        stage('Build Docker Images') {
            steps {
                script {
                    echo "Building Images..."
                    sh "docker build -t ${REGISTRY_URL}/${REPO_NAME}:${BACKEND_TAG} ./backend"
                    sh "docker build -t ${REGISTRY_URL}/${REPO_NAME}:${FRONTEND_TAG} ./frontend"
                }
            }
        }

        stage('Push to Registry') {
            steps {
                // We MUST inject the token here, or the push will fail with "Unauthorized"
                withCredentials([string(credentialsId: 'do-registry-token', variable: 'DO_TOKEN')]) {
                    script {
                        echo "Logging into Registry..."
                        // 1. Clean previous state
                        sh 'rm -f ~/.docker/config.json'
                        
                        // 2. Login using Token as Password
                        sh 'echo $DO_TOKEN | docker login registry.digitalocean.com -u token --password-stdin'
                        
                        echo "Pushing images..."
                        sh "docker push ${REGISTRY_URL}/${REPO_NAME}:${BACKEND_TAG}"
                        sh "docker push ${REGISTRY_URL}/${REPO_NAME}:${FRONTEND_TAG}"
                        
                        // 3. Logout
                        sh 'docker logout registry.digitalocean.com'
                    }
                }
            }
        }
        
        // --- REMOTE DEPLOYMENT (AGENT -> GITEA SERVER) ---
        stage('Deploy') {
            steps {
                script {
                    // Define Ports based on Branch
                    def appPort = "3000"
                    if (env.BRANCH_NAME == 'Dev') { appPort = "3001" } 
                    else if (env.BRANCH_NAME == 'Release') { appPort = "3002" } 
                    else if (env.BRANCH_NAME == 'main') { appPort = "3003" }

                    def containerName = "backend-${env.BRANCH_NAME}"

                    // Define SSH Command using the specific deploy key we created
                    def remote = "ssh -o StrictHostKeyChecking=no -i ~/.ssh/id_rsa_deploy ${DEPLOY_USER}@${DEPLOY_HOST}"

                    echo "Deploying to ${DEPLOY_HOST} on Port ${appPort}..."

                    // We need the token again to PULL the image on the remote server
                    withCredentials([string(credentialsId: 'do-registry-token', variable: 'DO_TOKEN')]) {
                        
                        // 1. Remote Login
                        sh "${remote} 'echo ${DO_TOKEN} | docker login registry.digitalocean.com -u token --password-stdin'"
                        
                        // 2. Remote Pull
                        sh "${remote} 'docker pull ${REGISTRY_URL}/${REPO_NAME}:${BACKEND_TAG}'"
                        
                        // 3. Remote Restart (Stop -> Remove -> Run)
                        sh "${remote} 'docker stop ${containerName} || true'"
                        sh "${remote} 'docker rm ${containerName} || true'"

                        sh """
                            ${remote} 'docker run -d \
                            --name ${containerName} \
                            --restart always \
                            -p ${appPort}:3000 \
                            ${REGISTRY_URL}/${REPO_NAME}:${BACKEND_TAG}'
                        """
                        
                        echo "SUCCESS: App is live at http://${DEPLOY_HOST}:${appPort}"
                    }
                }
            }
        }
    }
    
    post {
        always {
            // Save disk space on the Agent
            sh 'docker system prune -f'
        }
    }
}