// Jenkinsfile for Manual Rollback
// This allows rolling back to any previous version

pipeline {
    agent any
    
    parameters {
        choice(
            name: 'ROLLBACK_METHOD',
            choices: ['IMAGE_TAG', 'REVISION_NUMBER', 'GIT_COMMIT'],
            description: 'Select rollback method'
        )
        string(
            name: 'TARGET_VERSION',
            defaultValue: '',
            description: '''
            Enter target version based on method:
            - IMAGE_TAG: main-21, main-20, etc.
            - REVISION_NUMBER: 1, 2, 3 (from rollout history)
            - GIT_COMMIT: abc123def (git commit SHA)
            '''
        )
        booleanParam(
            name: 'SKIP_HEALTH_CHECK',
            defaultValue: false,
            description: 'Skip health checks (use with caution!)'
        )
        booleanParam(
            name: 'DRY_RUN',
            defaultValue: false,
            description: 'Dry run - show what would happen without applying'
        )
    }
    
    environment {
        APP_NAME = 'demo-nginx'
        NAMESPACE = 'demo-app'
        DOCKER_REGISTRY = 'docker.io'
        DOCKER_REPO = 'vladcrypto'
        GITEA_URL = 'http://gitea-http.gitea.svc.cluster.local:3000'
        HEALTH_CHECK_TIMEOUT = '300s'
    }
    
    stages {
        stage('Validate Input') {
            steps {
                script {
                    echo "🔍 Validating rollback request..."
                    
                    if (params.TARGET_VERSION == '') {
                        error("❌ TARGET_VERSION cannot be empty!")
                    }
                    
                    echo """
                    📋 Rollback Configuration:
                    Method: ${params.ROLLBACK_METHOD}
                    Target: ${params.TARGET_VERSION}
                    Skip Health Check: ${params.SKIP_HEALTH_CHECK}
                    Dry Run: ${params.DRY_RUN}
                    """
                }
            }
        }
        
        stage('Show Current State') {
            steps {
                script {
                    echo "📸 Current Deployment State:"
                    
                    sh """
                        echo "=== Current Deployment ==="
                        kubectl get deployment ${APP_NAME} -n ${NAMESPACE}
                        
                        echo ""
                        echo "=== Current Image ==="
                        kubectl get deployment ${APP_NAME} -n ${NAMESPACE} \
                            -o jsonpath='{.spec.template.spec.containers[0].image}'
                        echo ""
                        
                        echo ""
                        echo "=== Current Pods ==="
                        kubectl get pods -n ${NAMESPACE} -l app=${APP_NAME}
                        
                        echo ""
                        echo "=== Rollout History ==="
                        kubectl rollout history deployment/${APP_NAME} -n ${NAMESPACE}
                    """
                }
            }
        }
        
        stage('Prepare Rollback') {
            steps {
                script {
                    echo "🔄 Preparing rollback to: ${params.TARGET_VERSION}"
                    
                    if (params.ROLLBACK_METHOD == 'IMAGE_TAG') {
                        env.TARGET_IMAGE = "${DOCKER_REGISTRY}/${DOCKER_REPO}/${APP_NAME}:${params.TARGET_VERSION}"
                        
                        sh """
                            echo "Target image: ${env.TARGET_IMAGE}"
                        """
                        
                    } else if (params.ROLLBACK_METHOD == 'REVISION_NUMBER') {
                        env.REVISION = params.TARGET_VERSION
                        
                        sh """
                            echo "Rolling back to revision: ${env.REVISION}"
                            
                            # Verify revision exists
                            kubectl rollout history deployment/${APP_NAME} -n ${NAMESPACE} \
                                --revision=${env.REVISION}
                        """
                        
                    } else if (params.ROLLBACK_METHOD == 'GIT_COMMIT') {
                        env.GIT_SHA = params.TARGET_VERSION
                        
                        echo "Rolling back to git commit: ${env.GIT_SHA}"
                    }
                }
            }
        }
        
        stage('Execute Rollback') {
            when {
                expression { !params.DRY_RUN }
            }
            steps {
                script {
                    echo "🚀 Executing rollback..."
                    
                    if (params.ROLLBACK_METHOD == 'IMAGE_TAG') {
                        // Method 1: Update image directly
                        sh """
                            echo "Setting image to: ${env.TARGET_IMAGE}"
                            kubectl set image deployment/${APP_NAME} \
                                ${APP_NAME}=${env.TARGET_IMAGE} \
                                -n ${NAMESPACE} \
                                --record
                        """
                        
                        // Update Git manifests
                        withCredentials([usernamePassword(
                            credentialsId: 'gitea-credentials',
                            usernameVariable: 'GIT_USER',
                            passwordVariable: 'GIT_PASS'
                        )]) {
                            sh """
                                rm -rf k3s-gitops || true
                                git clone http://\${GIT_USER}:\${GIT_PASS}@gitea-http.gitea.svc.cluster.local:3000/admin/k3s-gitops.git
                                cd k3s-gitops
                                git config user.name "Jenkins"
                                git config user.email "jenkins@thedevops.dev"
                                
                                sed -i 's|image: .*|image: ${env.TARGET_IMAGE}|' apps/demo-nginx/deployment.yaml
                                git add apps/demo-nginx/deployment.yaml
                                git commit -m "rollback(demo-nginx): Manual rollback to ${params.TARGET_VERSION}" || echo "No changes"
                                git push origin main
                            """
                        }
                        
                    } else if (params.ROLLBACK_METHOD == 'REVISION_NUMBER') {
                        // Method 2: Rollback to specific revision
                        sh """
                            kubectl rollout undo deployment/${APP_NAME} \
                                -n ${NAMESPACE} \
                                --to-revision=${env.REVISION}
                        """
                        
                    } else if (params.ROLLBACK_METHOD == 'GIT_COMMIT') {
                        // Method 3: Checkout specific git commit
                        withCredentials([usernamePassword(
                            credentialsId: 'gitea-credentials',
                            usernameVariable: 'GIT_USER',
                            passwordVariable: 'GIT_PASS'
                        )]) {
                            sh """
                                rm -rf k3s-gitops || true
                                git clone http://\${GIT_USER}:\${GIT_PASS}@gitea-http.gitea.svc.cluster.local:3000/admin/k3s-gitops.git
                                cd k3s-gitops
                                git config user.name "Jenkins"
                                git config user.email "jenkins@thedevops.dev"
                                
                                # Get image from specific commit
                                git checkout ${env.GIT_SHA} -- apps/demo-nginx/deployment.yaml
                                TARGET_IMAGE=\$(grep 'image:' apps/demo-nginx/deployment.yaml | awk '{print \$2}')
                                
                                git checkout main
                                git checkout ${env.GIT_SHA} -- apps/demo-nginx/deployment.yaml
                                git add apps/demo-nginx/deployment.yaml
                                git commit -m "rollback(demo-nginx): Rollback to commit ${env.GIT_SHA}" || echo "No changes"
                                git push origin main
                                
                                echo "Rolled back to image: \${TARGET_IMAGE}"
                            """
                        }
                    }
                    
                    echo "✅ Rollback command executed"
                }
            }
        }
        
        stage('Wait for Rollout') {
            when {
                expression { !params.DRY_RUN }
            }
            steps {
                script {
                    echo "⏳ Waiting for rollout to complete..."
                    
                    sh """
                        kubectl rollout status deployment/${APP_NAME} \
                            -n ${NAMESPACE} \
                            --timeout=${HEALTH_CHECK_TIMEOUT}
                    """
                    
                    echo "✅ Rollout completed"
                }
            }
        }
        
        stage('Health Check') {
            when {
                expression { !params.DRY_RUN && !params.SKIP_HEALTH_CHECK }
            }
            steps {
                script {
                    echo "🏥 Running health checks..."
                    
                    sh """
                        # Check all pods are ready
                        READY_PODS=\$(kubectl get deployment ${APP_NAME} -n ${NAMESPACE} -o jsonpath='{.status.readyReplicas}')
                        DESIRED_PODS=\$(kubectl get deployment ${APP_NAME} -n ${NAMESPACE} -o jsonpath='{.spec.replicas}')
                        
                        echo "Ready pods: \${READY_PODS}/\${DESIRED_PODS}"
                        
                        if [ "\${READY_PODS}" != "\${DESIRED_PODS}" ]; then
                            echo "❌ Not all pods are ready!"
                            exit 1
                        fi
                        
                        # Test health endpoint
                        POD_NAME=\$(kubectl get pods -n ${NAMESPACE} -l app=${APP_NAME} -o jsonpath='{.items[0].metadata.name}')
                        kubectl exec \${POD_NAME} -n ${NAMESPACE} -- wget -q -O- http://localhost/health
                    """
                    
                    echo "✅ Health checks passed"
                }
            }
        }
        
        stage('Show New State') {
            when {
                expression { !params.DRY_RUN }
            }
            steps {
                script {
                    echo "📊 New Deployment State:"
                    
                    sh """
                        echo "=== New Deployment ==="
                        kubectl get deployment ${APP_NAME} -n ${NAMESPACE}
                        
                        echo ""
                        echo "=== New Image ==="
                        kubectl get deployment ${APP_NAME} -n ${NAMESPACE} \
                            -o jsonpath='{.spec.template.spec.containers[0].image}'
                        echo ""
                        
                        echo ""
                        echo "=== New Pods ==="
                        kubectl get pods -n ${NAMESPACE} -l app=${APP_NAME}
                    """
                }
            }
        }
        
        stage('Dry Run Summary') {
            when {
                expression { params.DRY_RUN }
            }
            steps {
                script {
                    echo """
                    🔍 DRY RUN SUMMARY
                    
                    This is what would happen:
                    
                    Method: ${params.ROLLBACK_METHOD}
                    Target: ${params.TARGET_VERSION}
                    
                    Steps that would be executed:
                    1. Update deployment to target version
                    2. Update Git manifests
                    3. Wait for rollout (timeout: ${HEALTH_CHECK_TIMEOUT})
                    ${params.SKIP_HEALTH_CHECK ? '4. (Health check skipped)' : '4. Run health checks'}
                    
                    No actual changes were made.
                    """
                }
            }
        }
    }
    
    post {
        success {
            script {
                if (params.DRY_RUN) {
                    echo "✅ DRY RUN COMPLETED - No changes made"
                } else {
                    echo """
                    ✅ ROLLBACK SUCCESSFUL!
                    
                    Application: ${APP_NAME}
                    Method: ${params.ROLLBACK_METHOD}
                    Target: ${params.TARGET_VERSION}
                    Namespace: ${NAMESPACE}
                    
                    The application has been rolled back successfully! ✨
                    """
                }
            }
        }
        
        failure {
            echo """
            ❌ ROLLBACK FAILED!
            
            Please check the logs and try again.
            
            Manual rollback command:
            kubectl rollout undo deployment/${APP_NAME} -n ${NAMESPACE}
            """
        }
    }
}