#!/bin/bash

# Health Check Script for DevSecOps Todo Application
# This script verifies that both frontend and backend services are running correctly

set -e  # Exit on any error

echo "🏥 Starting health checks for DevSecOps Todo Application..."

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

# Configuration
BACKEND_URL="${BACKEND_URL:-http://localhost:3001}"
FRONTEND_URL="${FRONTEND_URL:-http://localhost:3000}"
MAX_RETRIES=5
RETRY_DELAY=2

# Function to check service health
check_service() {
    local url=$1
    local service_name=$2
    local retries=0
    
    echo "🔍 Checking $service_name at $url..."
    
    while [ $retries -lt $MAX_RETRIES ]; do
        if curl -f -s "$url/health" > /dev/null 2>&1; then
            echo -e "${GREEN}✅ $service_name is healthy${NC}"
            return 0
        else
            retries=$((retries + 1))
            echo -e "${YELLOW}⏳ $service_name not ready, attempt $retries/$MAX_RETRIES${NC}"
            if [ $retries -lt $MAX_RETRIES ]; then
                sleep $RETRY_DELAY
            fi
        fi
    done
    
    echo -e "${RED}❌ $service_name health check failed after $MAX_RETRIES attempts${NC}"
    return 1
}

# Function to check API endpoints
check_api_endpoints() {
    echo "🔍 Testing API endpoints..."
    
    # Test todos endpoint
    if curl -f -s "$BACKEND_URL/api/todos" > /dev/null 2>&1; then
        echo -e "${GREEN}✅ Todos API endpoint is working${NC}"
    else
        echo -e "${RED}❌ Todos API endpoint failed${NC}"
        return 1
    fi
    
    # Test stats endpoint  
    if curl -f -s "$BACKEND_URL/api/stats" > /dev/null 2>&1; then
        echo -e "${GREEN}✅ Stats API endpoint is working${NC}"
    else
        echo -e "${RED}❌ Stats API endpoint failed${NC}"
        return 1
    fi
    
    return 0
}

# Function to test basic functionality
test_basic_functionality() {
    echo "🧪 Testing basic functionality..."
    
    # Test creating a todo
    local response=$(curl -s -X POST \
        -H "Content-Type: application/json" \
        -d '{"title":"Health Check Todo","priority":"low"}' \
        "$BACKEND_URL/api/todos")
    
    if echo "$response" | grep -q "Health Check Todo"; then
        echo -e "${GREEN}✅ Todo creation test passed${NC}"
    else
        echo -e "${RED}❌ Todo creation test failed${NC}"
        return 1
    fi
    
    return 0
}

# Main health check execution
main() {
    echo "=================================================="
    echo "🚀 DevSecOps Todo Application Health Check"
    echo "=================================================="
    
    local failed=0
    
    # Check backend health
    if ! check_service "$BACKEND_URL" "Backend"; then
        failed=1
    fi
    
    # Check frontend health (if running on different port)
    if [ "$FRONTEND_URL" != "$BACKEND_URL" ]; then
        if ! check_service "$FRONTEND_URL" "Frontend"; then
            failed=1
        fi
    fi
    
    # Test API endpoints
    if ! check_api_endpoints; then
        failed=1
    fi
    
    # Test basic functionality
    if ! test_basic_functionality; then
        failed=1
    fi
    
    echo "=================================================="
    if [ $failed -eq 0 ]; then
        echo -e "${GREEN}🎉 All health checks passed!${NC}"
        echo -e "${GREEN}📊 Application is ready for use${NC}"
        exit 0
    else
        echo -e "${RED}💥 Some health checks failed!${NC}"
        echo -e "${RED}🔧 Please check the application logs${NC}"
        exit 1
    fi
}

# Show usage if help requested
if [[ "$1" == "--help" || "$1" == "-h" ]]; then
    echo "DevSecOps Todo Application Health Check Script"
    echo ""
    echo "Usage: $0 [OPTIONS]"
    echo ""
    echo "Environment Variables:"
    echo "  BACKEND_URL   Backend service URL (default: http://localhost:3001)"
    echo "  FRONTEND_URL  Frontend service URL (default: http://localhost:3000)"
    echo ""
    echo "Options:"
    echo "  -h, --help    Show this help message"
    echo ""
    echo "Examples:"
    echo "  $0                                    # Check local services"
    echo "  BACKEND_URL=http://api.example.com $0  # Check remote backend"
    exit 0
fi

# Run main function
main "$@"