#!/bin/bash

# Continuous Deployment Script for Kubernetes
# This script deploys your application to a Kubernetes cluster

# =============================================================================
# Environment Variables (with default values)
# =============================================================================

# Kubernetes Configuration
KUBECONFIG_DATA="${KUBECONFIG_DATA:-}"
KUBERNETES_URL="${KUBERNETES_URL:-https://kubernetes.default.svc}"
KUBERNETES_NAMESPACE="${KUBERNETES_NAMESPACE:-default}"
KUBERNETES_INGRESS_HOST="${KUBERNETES_INGRESS_HOST:-example.com}"

# Container Registry (inherited from ci.sh)
CONTAINER_REGISTRY_URL="${CONTAINER_REGISTRY_URL:-127.0.0.1}"
CONTAINER_REGISTRY_USERNAME="${CONTAINER_REGISTRY_USERNAME:-username}"
CONTAINER_REGISTRY_NAMESPACE="${CONTAINER_REGISTRY_NAMESPACE:-username}"
CONTAINER_REGISTRY_PASSWORD="${CONTAINER_REGISTRY_PASSWORD:-password}"
CONTAINER_IMAGE_NAME="${CONTAINER_IMAGE_NAME:-image-name}"
CONTAINER_IMAGE_TAG="${CONTAINER_IMAGE_TAG:-latest}"
FORCE_RESTART="${FORCE_RESTART:-true}"

# =============================================================================
# Functions
# =============================================================================

# Print help message
print_help() {
    echo "Usage: $0 [OPTIONS]"
    echo ""
    echo "Options:"
    echo "  deploy      Deploy application to Kubernetes"
    echo "  help        Show this help message (default)"
    echo ""
    echo "Environment Variables:"
    echo "  KUBECONFIG_DATA           Base64 encoded kubeconfig file"
    echo "  KUBERNETES_URL            Kubernetes API server URL"
    echo "  KUBERNETES_NAMESPACE      Deploy namespace (default: default)"
    echo "  KUBERNETES_INGRESS_HOST   Ingress host (default: example.com)"
    echo ""
    echo "  Container Registry Variables (from ci.sh):"
    echo "  CONTAINER_REGISTRY_URL"
    echo "  CONTAINER_REGISTRY_USERNAME"
    echo "  CONTAINER_REGISTRY_NAMESPACE"
    echo "  CONTAINER_REGISTRY_PASSWORD"
    echo "  CONTAINER_IMAGE_NAME"
    echo "  CONTAINER_IMAGE_TAG"
    echo "  FORCE_RESTART                 Force rollout restart (default: true)"
    echo ""
    echo "Examples:"
    echo "  $0 deploy"
    echo "  KUBERNETES_NAMESPACE=production $0 deploy"
}

# Setup Kubernetes configuration
setup_kubeconfig() {
    echo "=========================================="
    echo "Setting up Kubernetes Configuration"
    echo "=========================================="
    
    # Check if KUBECONFIG_DATA is provided
    if [ -z "$KUBECONFIG_DATA" ]; then
        echo "Warning: KUBECONFIG_DATA not provided, using existing kubectl config"
        return 0
    fi
    
    # Create temporary kubeconfig file from base64 encoded data
    echo "Decoding kubeconfig..."
    echo "$KUBECONFIG_DATA" | base64 -d > /tmp/kubeconfig
    
    # Set KUBECONFIG environment variable to use the temporary file
    export KUBECONFIG=/tmp/kubeconfig
    
    echo "✓ Kubeconfig configured"
    echo ""
}

# Create Docker registry secret for pulling private images
create_registry_secret() {
    echo "=========================================="
    echo "Creating Docker Registry Secret"
    echo "=========================================="
    
    # Create or update the docker registry secret in the namespace
    kubectl create secret docker-registry regcred \
        --docker-server="${CONTAINER_REGISTRY_URL}" \
        --docker-username="${CONTAINER_REGISTRY_USERNAME}" \
        --docker-password="${CONTAINER_REGISTRY_PASSWORD}" \
        --namespace="${KUBERNETES_NAMESPACE}" \
        --dry-run=client -o yaml | kubectl apply -f -
    
    if [ $? -eq 0 ]; then
        echo "✓ Registry secret created/updated"
        echo ""
    else
        echo "✗ Failed to create registry secret"
        exit 1
    fi
}

# Deploy application to Kubernetes
deploy_application() {
    # Construct the full image name
    FULL_IMAGE_NAME="${CONTAINER_REGISTRY_URL}/${CONTAINER_REGISTRY_NAMESPACE}/${CONTAINER_IMAGE_NAME}:${CONTAINER_IMAGE_TAG}"
    
    echo "=========================================="
    echo "Deploying Application to Kubernetes"
    echo "=========================================="
    echo "Namespace: ${KUBERNETES_NAMESPACE}"
    echo "Image: ${FULL_IMAGE_NAME}"
    echo "Ingress Host: ${KUBERNETES_INGRESS_HOST}"
    echo ""
    
    # Setup kubeconfig
    setup_kubeconfig
    
    # Test kubectl connection
    echo "Testing Kubernetes connection..."
    kubectl cluster-info > /dev/null 2>&1
    if [ $? -ne 0 ]; then
        echo "✗ Failed to connect to Kubernetes cluster"
        exit 1
    fi
    echo "✓ Connected to Kubernetes cluster"
    echo ""
    
    # Create namespace if it doesn't exist
    echo "Creating namespace..."
    envsubst < script/k8s/namespace.yaml | kubectl apply -f -
    echo ""
    
    # Create registry secret for pulling images
    create_registry_secret
    
    # Export environment variables for envsubst (template substitution)
    export KUBERNETES_NAMESPACE
    export KUBERNETES_INGRESS_HOST
    export FULL_IMAGE_NAME
    
    # Apply Kubernetes manifests with environment variable substitution
    echo "Applying Kubernetes manifests..."
    
    # Apply deployment
    echo "- Applying deployment..."
    envsubst < script/k8s/deployment.yaml | kubectl apply -f -
    
    # Apply service
    echo "- Applying service..."
    envsubst < script/k8s/service.yaml | kubectl apply -f -
    
    # Apply ingress
    echo "- Applying ingress..."
    envsubst < script/k8s/ingress.yaml | kubectl apply -f -
    
    echo ""
    
    # Wait for deployment to be ready
    echo "Waiting for deployment to be ready..."
    
    # Force restart if enabled
    if [ "${FORCE_RESTART}" = "true" ]; then
        echo "Forcing rollout restart..."
        kubectl rollout restart deployment/${CONTAINER_IMAGE_NAME} -n ${KUBERNETES_NAMESPACE}
    fi
    
    kubectl rollout status deployment/${CONTAINER_IMAGE_NAME} \
        -n ${KUBERNETES_NAMESPACE} \
        --timeout=300s
    
    if [ $? -eq 0 ]; then
        echo ""
        echo "=========================================="
        echo "✓ Deployment Successful!"
        echo "=========================================="
        echo "Application: ${CONTAINER_IMAGE_NAME}"
        echo "Namespace: ${KUBERNETES_NAMESPACE}"
        echo "URL: http://${KUBERNETES_INGRESS_HOST}"
        echo ""
        
        # Show pod status
        echo "Pod Status:"
        kubectl get pods -n ${KUBERNETES_NAMESPACE} -l app=${CONTAINER_IMAGE_NAME}
        echo ""
        
        # Show service status
        echo "Service Status:"
        kubectl get svc -n ${KUBERNETES_NAMESPACE} -l app=${CONTAINER_IMAGE_NAME}
        echo ""
        
        # Show ingress status
        echo "Ingress Status:"
        kubectl get ingress -n ${KUBERNETES_NAMESPACE}
    else
        echo ""
        echo "✗ Deployment failed or timed out"
        exit 1
    fi
    
    # Cleanup temporary kubeconfig if it was created
    if [ -f /tmp/kubeconfig ]; then
        rm -f /tmp/kubeconfig
    fi
}

# =============================================================================
# Main Script Logic
# =============================================================================

# If no arguments provided, show help
if [ $# -eq 0 ]; then
    print_help
    exit 0
fi

# Process command line arguments
case "$1" in
    deploy)
        deploy_application
        ;;
    help|--help|-h)
        print_help
        ;;
    *)
        echo "Error: Unknown option '$1'"
        echo ""
        print_help
        exit 1
        ;;
esac