#!/bin/bash

# CI/CD Script for Docker Build and Push
# This script builds a Docker image and pushes it to a private container registry

# =============================================================================
# Environment Variables (with default values)
# =============================================================================
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="${CONTAINER_IMAGE_NAME:-stats-api}"
CONTAINER_IMAGE_TAG="${CONTAINER_IMAGE_TAG:-latest}"

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

# Print help message
print_help() {
    echo "Usage: $0 [OPTIONS]"
    echo ""
    echo "Options:"
    echo "  build       Build Docker image"
    echo "  push        Push Docker image to registry"
    echo "  help        Show this help message (default)"
    echo ""
    echo "Environment Variables:"
    echo "  CONTAINER_REGISTRY_URL       Registry URL (default: 127.0.0.1)"
    echo "  CONTAINER_REGISTRY_USERNAME  Registry username (default: username)"
    echo "  CONTAINER_REGISTRY_NAMESPACE Registry namespace (default: username)"
    echo "  CONTAINER_REGISTRY_PASSWORD  Registry password (default: password)"
    echo "  CONTAINER_IMAGE_NAME         Image name (default: stats-api)"
    echo "  CONTAINER_IMAGE_TAG          Image tag (default: latest)"
}

# Build Docker image
build_image() {
    FULL_IMAGE_NAME="${CONTAINER_REGISTRY_URL}/${CONTAINER_REGISTRY_NAMESPACE}/${CONTAINER_IMAGE_NAME}:${CONTAINER_IMAGE_TAG}"
    
    echo "=========================================="
    echo "Building Docker Image"
    echo "=========================================="
    echo "Image: ${FULL_IMAGE_NAME}"
    echo ""
    
    docker build -t "${FULL_IMAGE_NAME}" .
    
    if [ $? -eq 0 ]; then
        echo ""
        echo "✓ Build successful: ${FULL_IMAGE_NAME}"
        return 0
    else
        echo ""
        echo "✗ Build failed"
        return 1
    fi
}

# Push Docker image to registry
push_image() {
    FULL_IMAGE_NAME="${CONTAINER_REGISTRY_URL}/${CONTAINER_REGISTRY_NAMESPACE}/${CONTAINER_IMAGE_NAME}:${CONTAINER_IMAGE_TAG}"
    
    echo "=========================================="
    echo "Pushing Docker Image"
    echo "=========================================="
    echo "Registry: ${CONTAINER_REGISTRY_URL}"
    echo "Image: ${FULL_IMAGE_NAME}"
    echo ""
    
    # Login to registry
    echo "${CONTAINER_REGISTRY_PASSWORD}" | docker login "${CONTAINER_REGISTRY_URL}" \
        --username "${CONTAINER_REGISTRY_USERNAME}" \
        --password-stdin
    
    if [ $? -ne 0 ]; then
        echo "✗ Registry login failed"
        return 1
    fi
    
    # Push image
    docker push "${FULL_IMAGE_NAME}"
    
    if [ $? -eq 0 ]; then
        echo ""
        echo "✓ Push successful: ${FULL_IMAGE_NAME}"
        docker logout "${CONTAINER_REGISTRY_URL}"
        return 0
    else
        echo ""
        echo "✗ Push failed"
        docker logout "${CONTAINER_REGISTRY_URL}"
        return 1
    fi
}

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

case "${1:-help}" in
    build)
        build_image
        ;;
    push)
        push_image
        ;;
    help|*)
        print_help
        ;;
esac