#!/usr/bin/env bash

# 🚀 RxMinder Template-based Kubernetes Deployment Script
# This script processes template files and applies them to Kubernetes

set -euo pipefail

# Script configuration
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
K8S_DIR="$(dirname "$SCRIPT_DIR")/k8s"
ENV_FILE="$(dirname "$SCRIPT_DIR")/.env"

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

print_status() {
    echo -e "${BLUE}$1${NC}"
}

print_success() {
    echo -e "${GREEN}✅ $1${NC}"
}

print_warning() {
    echo -e "${YELLOW}⚠️ $1${NC}"
}

print_error() {
    echo -e "${RED}❌ $1${NC}"
}

# Function to load environment variables
load_env() {
    if [[ -f "$ENV_FILE" ]]; then
        print_status "Loading environment variables from .env..."
        # Export variables from .env file
        set -a
        source "$ENV_FILE"
        set +a
        print_success "Environment variables loaded"
    else
        print_warning ".env file not found at $ENV_FILE"
        print_warning "Using default values. Copy .env.example to .env and customize."
    fi
}

# Function to substitute environment variables in templates
substitute_template() {
    local template_file="$1"
    local output_file="$2"

    print_status "Processing template: $template_file"

    # Use envsubst to substitute environment variables
    if command -v envsubst >/dev/null 2>&1; then
        envsubst < "$template_file" > "$output_file"
    else
        print_error "envsubst not found. Please install gettext package."
        exit 1
    fi

    print_success "Generated: $output_file"
}

# Function to apply Kubernetes resources
apply_k8s_resource() {
    local resource_file="$1"

    if [[ -f "$resource_file" ]]; then
        print_status "Applying Kubernetes resource: $resource_file"
        if kubectl apply -f "$resource_file"; then
            print_success "Applied: $resource_file"
        else
            print_error "Failed to apply: $resource_file"
            return 1
        fi
    else
        print_warning "Resource file not found: $resource_file"
    fi
}

# Function to validate required environment variables
validate_env() {
    local required_vars=(
        "APP_NAME"
        "DOCKER_IMAGE"
        "COUCHDB_USER"
        "COUCHDB_PASSWORD"
        "INGRESS_HOST"
        "STORAGE_CLASS"
        "STORAGE_SIZE"
    )

    local missing_vars=()

    for var in "${required_vars[@]}"; do
        if [[ -z "${!var:-}" ]]; then
            missing_vars+=("$var")
        fi
    done

    if [[ ${#missing_vars[@]} -gt 0 ]]; then
        print_error "Missing required environment variables:"
        for var in "${missing_vars[@]}"; do
            echo -e "  ${RED}- $var${NC}"
        done
        print_warning "Please update your .env file with these variables."
        exit 1
    fi

    print_success "All required environment variables are set"
}

# Function to process all templates
process_templates() {
    local temp_dir="/tmp/rxminder-k8s-$$"
    mkdir -p "$temp_dir"

    print_status "Processing Kubernetes templates..."

    # Find all template files
    local template_files=(
        "$K8S_DIR/couchdb-secret.yaml.template"
        "$K8S_DIR/ingress.yaml.template"
    )

    # Add any additional template files
    for template_file in "$K8S_DIR"/*.template; do
        if [[ -f "$template_file" ]]; then
            template_files+=("$template_file")
        fi
    done

    # Process each template
    for template_file in "${template_files[@]}"; do
        if [[ -f "$template_file" ]]; then
            local base_name
            base_name="$(basename "$template_file" .template)"
            local output_file="$temp_dir/$base_name"
            substitute_template "$template_file" "$output_file"
        fi
    done

    echo "$temp_dir"
}

# Function to deploy resources in correct order
deploy_resources() {
    local resource_dir="$1"

    print_status "Deploying Kubernetes resources..."

    # Deploy in specific order for dependencies
    local deployment_order=(
        "couchdb-secret.yaml"
        "couchdb-pvc.yaml"
        "couchdb-service.yaml"
        "couchdb-statefulset.yaml"
        "configmap.yaml"
        "frontend-deployment.yaml"
        "frontend-service.yaml"
        "ingress.yaml"
        "$K8S_DIR/network-policy.yaml"
        "$K8S_DIR/hpa.yaml"
    )

    for resource in "${deployment_order[@]}"; do
        if [[ "$resource" == *.yaml ]]; then
            # Check if it's a template-generated file
            if [[ -f "$resource_dir/$(basename "$resource")" ]]; then
                apply_k8s_resource "$resource_dir/$(basename "$resource")"
            else
                # Apply directly from k8s directory
                apply_k8s_resource "$resource"
            fi
        fi
    done
}

# Function to run database seeding job
run_db_seed() {
    print_status "Running database seed job..."

    # Apply the db-seed-job (which uses environment variables from secret)
    if kubectl apply -f "$K8S_DIR/db-seed-job.yaml"; then
        print_success "Database seed job submitted"

        # Wait for job completion
        print_status "Waiting for database seed job to complete..."
        if kubectl wait --for=condition=complete --timeout=300s job/db-seed-job; then
            print_success "Database seeding completed successfully"
        else
            print_warning "Database seed job may have failed. Check logs:"
            echo "kubectl logs job/db-seed-job"
        fi
    else
        print_error "Failed to apply database seed job"
        return 1
    fi
}

# Function to display deployment status
show_status() {
    print_status "Deployment Status:"
    echo

    print_status "Pods:"
    kubectl get pods -l app="${APP_NAME:-rxminder}"
    echo

    print_status "Services:"
    kubectl get services -l app="${APP_NAME:-rxminder}"
    echo

    print_status "Ingress:"
    kubectl get ingress
    echo

    if [[ -n "${INGRESS_HOST:-}" ]]; then
        print_success "Application should be available at: http://${INGRESS_HOST}"
    fi
}

# Function to cleanup temporary files
cleanup() {
    if [[ -n "${temp_dir:-}" && -d "$temp_dir" ]]; then
        rm -rf "$temp_dir"
    fi
}

# Main deployment function
main() {
    local command="${1:-deploy}"

    case "$command" in
        "deploy"|"apply")
            print_status "🚀 Starting RxMinder Kubernetes deployment..."
            echo

            # Set default values for required variables
            export APP_NAME="${APP_NAME:-rxminder}"
            export DOCKER_IMAGE="${DOCKER_IMAGE:-gitea-http.taildb3494.ts.net/will/meds:latest}"
            export COUCHDB_USER="${COUCHDB_USER:-admin}"
            export COUCHDB_PASSWORD="${COUCHDB_PASSWORD:-change-this-secure-password}"
            export INGRESS_HOST="${INGRESS_HOST:-rxminder.local}"
            export STORAGE_CLASS="${STORAGE_CLASS:-longhorn}"
            export STORAGE_SIZE="${STORAGE_SIZE:-5Gi}"

            load_env
            validate_env

            # Process templates
            temp_dir=$(process_templates)
            trap cleanup EXIT

            # Deploy resources
            deploy_resources "$temp_dir"

            # Run database seeding
            run_db_seed

            # Show status
            echo
            show_status

            print_success "🎉 RxMinder deployment completed!"
        ;;

        "status")
            load_env
            show_status
        ;;

        "delete"|"cleanup")
            print_status "🗑️ Cleaning up RxMinder deployment..."
            kubectl delete all,pvc,secret,configmap,ingress -l app="${APP_NAME:-rxminder}" || true
            kubectl delete job db-seed-job || true
            print_success "Cleanup completed"
        ;;

        "help"|"-h"|"--help")
            echo "RxMinder Kubernetes Deployment Script"
            echo
            echo "Usage: $0 [command]"
            echo
            echo "Commands:"
            echo "  deploy   Deploy RxMinder to Kubernetes (default)"
            echo "  status   Show deployment status"
            echo "  delete   Delete all RxMinder resources"
            echo "  help     Show this help message"
            echo
            echo "Environment variables (set in .env):"
            echo "  APP_NAME         Application name (default: rxminder)"
            echo "  DOCKER_IMAGE     Container image to deploy"
            echo "  COUCHDB_USER     Database username (default: admin)"
            echo "  COUCHDB_PASSWORD Database password (required)"
            echo "  INGRESS_HOST     Ingress hostname (required)"
            echo "  STORAGE_CLASS    Storage class for PVCs (default: longhorn)"
            echo "  STORAGE_SIZE     Storage size for database (default: 5Gi)"
        ;;

        *)
            print_error "Unknown command: $command"
            echo "Use '$0 help' for usage information"
            exit 1
        ;;
    esac
}

# Check if kubectl is available
if ! command -v kubectl >/dev/null 2>&1; then
    print_error "kubectl not found. Please install kubectl and configure it to connect to your cluster."
    exit 1
fi

# Check if envsubst is available
if ! command -v envsubst >/dev/null 2>&1; then
    print_error "envsubst not found. Please install the gettext package:"
    echo "  Ubuntu/Debian: sudo apt-get install gettext"
    echo "  macOS:         brew install gettext"
    echo "  RHEL/CentOS:   sudo yum install gettext"
    exit 1
fi

# Run main function
main "$@"