#!/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:-blog-api.example.com}"
KUBERNETES_DEPLOYMENT_REPLICAS="${KUBERNETES_DEPLOYMENT_REPLICAS:-2}"

# Container Registry
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="${CONTAINER_IMAGE_NAME:-blog}"
CONTAINER_IMAGE_TAG="${CONTAINER_IMAGE_TAG:-latest}"

# Application Configuration
DATABASE_DSN="${DATABASE_DSN:-postgres://postgres:password@localhost:5432/steam_union?sslmode=disable}"
JWT_SECRET="${JWT_SECRET:-your-secret-key-change-in-production}"
JWT_ISSUER="${JWT_ISSUER:-cialloo-authenticator}"
JWT_EXPIRES_IN="${JWT_EXPIRES_IN:-604800}"
S3_REGION="${S3_REGION:-us-east-1}"
S3_BUCKET="${S3_BUCKET:-your-bucket-name}"
S3_ACCESS_KEY_ID="${S3_ACCESS_KEY_ID:-your-access-key-id}"
S3_SECRET_ACCESS_KEY="${S3_SECRET_ACCESS_KEY:-your-secret-access-key}"
S3_ENDPOINT="${S3_ENDPOINT:-}"
S3_PRESIGNED_URL_EXPIRATION="${S3_PRESIGNED_URL_EXPIRATION:-3600}"
FORCE_RESTART="${FORCE_RESTART:-true}"

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

# Print help message
print_help() {
    echo "Usage: $0 [OPTIONS]"
    echo ""
    echo "Environment Variables:"
    echo "  KUBECONFIG_DATA              Kubernetes config data (base64 encoded)"
    echo "  KUBERNETES_URL               Kubernetes API URL (default: https://kubernetes.default.svc)"
    echo "  KUBERNETES_NAMESPACE         Kubernetes namespace (default: default)"
    echo "  KUBERNETES_INGRESS_HOST      Ingress host (default: blog-api.example.com)"
    echo "  KUBERNETES_DEPLOYMENT_REPLICAS  Number of pod replicas (default: 2)"
    echo "  CONTAINER_REGISTRY_URL       Container registry URL (default: 127.0.0.1)"
    echo "  CONTAINER_REGISTRY_USERNAME  Registry username"
    echo "  CONTAINER_REGISTRY_PASSWORD  Registry password"
    echo "  CONTAINER_IMAGE_NAME         Image name (default: blog)"
    echo "  CONTAINER_IMAGE_TAG          Image tag (default: latest)"
    echo "  DATABASE_DSN                 Database connection string"
    echo "  JWT_SECRET                   JWT secret key"
    echo "  JWT_ISSUER                   JWT issuer"
    echo "  JWT_EXPIRES_IN               JWT expiration time in seconds"
    echo "  S3_REGION                    S3 region"
    echo "  S3_BUCKET                    S3 bucket name"
    echo "  S3_ACCESS_KEY_ID             S3 access key ID"
    echo "  S3_SECRET_ACCESS_KEY         S3 secret access key"
    echo "  S3_ENDPOINT                  S3 endpoint (optional)"
    echo "  S3_PRESIGNED_URL_EXPIRATION  Presigned URL expiration in seconds"
    echo "  FORCE_RESTART                Force rollout restart (default: true)"
    echo ""
    echo "Commands:"
    echo "  deploy      Deploy application to Kubernetes"
    echo "  help        Show this help message (default)"
}

# Setup kubectl configuration
setup_kubectl() {
    echo "Setting up kubectl configuration..."
    
    if [ -z "${KUBECONFIG_DATA}" ]; then
        echo "✗ KUBECONFIG_DATA is not set"
        return 1
    fi
    
    mkdir -p ~/.kube
    echo "${KUBECONFIG_DATA}" | base64 -d > ~/.kube/config
    chmod 600 ~/.kube/config
    
    echo "✓ kubectl configured"
    return 0
}

# Create namespace if it doesn't exist
create_namespace() {
    echo "Checking namespace: ${KUBERNETES_NAMESPACE}"
    
    kubectl get namespace "${KUBERNETES_NAMESPACE}" &> /dev/null
    
    if [ $? -ne 0 ]; then
        echo "Creating namespace: ${KUBERNETES_NAMESPACE}"
        kubectl create namespace "${KUBERNETES_NAMESPACE}"
    else
        echo "✓ Namespace exists: ${KUBERNETES_NAMESPACE}"
    fi
}

# Create image pull secret
create_image_pull_secret() {
    echo "Creating image pull secret..."
    
    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 -
    
    echo "✓ Image pull secret created/updated"
}

# Create or update application secrets
create_app_secrets() {
    echo "Creating application secrets..."
    
    kubectl create secret generic blog-secrets \
        --from-literal=database-dsn="${DATABASE_DSN}" \
        --from-literal=jwt-secret="${JWT_SECRET}" \
        --from-literal=s3-access-key-id="${S3_ACCESS_KEY_ID}" \
        --from-literal=s3-secret-access-key="${S3_SECRET_ACCESS_KEY}" \
        --namespace="${KUBERNETES_NAMESPACE}" \
        --dry-run=client -o yaml | kubectl apply -f -
    
    echo "✓ Application secrets created/updated"
}

# Apply Kubernetes manifests
apply_manifests() {
    echo "Applying Kubernetes manifests..."
    
    # Substitute environment variables in manifests
    export KUBERNETES_NAMESPACE
    export KUBERNETES_INGRESS_HOST
    export KUBERNETES_DEPLOYMENT_REPLICAS
    export CONTAINER_REGISTRY_URL
    export CONTAINER_REGISTRY_NAMESPACE
    export CONTAINER_IMAGE_NAME
    export CONTAINER_IMAGE_TAG
    export JWT_ISSUER
    export JWT_EXPIRES_IN
    export S3_REGION
    export S3_BUCKET
    export S3_ENDPOINT
    export S3_PRESIGNED_URL_EXPIRATION
    
    # Apply namespace
    envsubst < script/k8s/namespace.yaml | kubectl apply -f -
    
    # Apply deployment
    envsubst < script/k8s/deployment.yaml | kubectl apply -f -
    
    # Apply service
    envsubst < script/k8s/service.yaml | kubectl apply -f -
    
    # Apply ingress
    envsubst < script/k8s/ingress.yaml | kubectl apply -f -
    
    echo "✓ Manifests applied"
}

# Wait for deployment to be ready
wait_for_deployment() {
    echo "Waiting for deployment to be ready..."
    
    kubectl rollout status deployment/blog \
        --namespace="${KUBERNETES_NAMESPACE}" \
        --timeout=300s
    
    if [ $? -eq 0 ]; then
        echo "✓ Deployment ready"
        return 0
    else
        echo "✗ Deployment failed"
        return 1
    fi
}

# Force restart deployment
force_restart_deployment() {
    if [ "${FORCE_RESTART}" = "true" ]; then
        echo "Forcing deployment restart..."
        kubectl rollout restart deployment/blog \
            --namespace="${KUBERNETES_NAMESPACE}"
        echo "✓ Deployment restarted"
    fi
}

# Deploy application
deploy() {
    echo "=========================================="
    echo "Deploying Blog Application"
    echo "=========================================="
    echo "Namespace: ${KUBERNETES_NAMESPACE}"
    echo "Image: ${CONTAINER_REGISTRY_URL}/${CONTAINER_REGISTRY_NAMESPACE}/${CONTAINER_IMAGE_NAME}:${CONTAINER_IMAGE_TAG}"
    echo "Host: ${KUBERNETES_INGRESS_HOST}"
    echo ""
    
    setup_kubectl || return 1
    create_namespace || return 1
    create_image_pull_secret || return 1
    create_app_secrets || return 1
    apply_manifests || return 1
    force_restart_deployment
    wait_for_deployment || return 1
    
    echo ""
    echo "=========================================="
    echo "✓ Deployment Successful"
    echo "=========================================="
    echo "Application URL: http://${KUBERNETES_INGRESS_HOST}"
    echo ""
    
    return 0
}

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

case "$1" in
    deploy)
        deploy
        exit $?
        ;;
    help|--help|-h|"")
        print_help
        exit 0
        ;;
    *)
        echo "Unknown option: $1"
        echo ""
        print_help
        exit 1
        ;;
esac