# Dockerfile.optimized
#
# Multi-stage Docker build for optimal image size and build performance
# Expected: 50% image size reduction compared to single-stage builds
#
# Build with BuildKit for layer caching:
#   DOCKER_BUILDKIT=1 docker build -f docker/Dockerfile.optimized -t cfn-app:optimized .
#
# Features:
# - Separate build and runtime stages
# - Minimal runtime dependencies
# - Layer caching optimization
# - Security hardening (non-root user)

# ================================
# Stage 1: Build Stage
# ================================
FROM node:18-alpine AS builder

# Install build dependencies
RUN apk add --no-cache \
    python3 \
    make \
    g++ \
    git \
    && rm -rf /var/cache/apk/*

# Set working directory
WORKDIR /build

# Copy package files
COPY package*.json ./
COPY tsconfig.json ./

# Install ALL dependencies (including devDependencies)
RUN npm ci --include=dev

# Copy source code
COPY src/ ./src/
COPY .claude/ ./.claude/
COPY scripts/ ./scripts/

# Build TypeScript
RUN npm run build

# Prune dev dependencies
RUN npm prune --production

# ================================
# Stage 2: Runtime Stage
# ================================
FROM node:18-alpine AS runtime

# Install runtime dependencies only
RUN apk add --no-cache \
    bash \
    curl \
    redis \
    postgresql-client \
    && rm -rf /var/cache/apk/*

# Create non-root user
RUN addgroup -g 1001 -S cfn && \
    adduser -u 1001 -S cfn -G cfn

# Set working directory
WORKDIR /app

# Copy production node_modules from builder
COPY --from=builder --chown=cfn:cfn /build/node_modules ./node_modules

# Copy built application from builder
COPY --from=builder --chown=cfn:cfn /build/dist ./dist

# Copy runtime scripts and configs
COPY --chown=cfn:cfn scripts/ ./scripts/
COPY --chown=cfn:cfn .claude/ ./.claude/
COPY --chown=cfn:cfn package*.json ./

# Set environment variables
ENV NODE_ENV=production
ENV CFN_MODE=production

# Switch to non-root user
USER cfn

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
    CMD node -e "require('http').get('http://localhost:3000/health', (r) => process.exit(r.statusCode === 200 ? 0 : 1))"

# Expose port
EXPOSE 3000

# Default command
CMD ["node", "dist/index.js"]

# ================================
# Stage 3: Development Stage
# ================================
FROM builder AS development

# Install development tools
RUN npm install -g nodemon ts-node

# Set environment
ENV NODE_ENV=development
ENV CFN_MODE=development

# Expose ports
EXPOSE 3000 9229

# Development command with hot reload
CMD ["npm", "run", "dev"]

# ================================
# Build Instructions
# ================================
# Production build (optimized):
#   DOCKER_BUILDKIT=1 docker build --target=runtime -f docker/Dockerfile.optimized -t cfn-app:prod .
#
# Development build:
#   DOCKER_BUILDKIT=1 docker build --target=development -f docker/Dockerfile.optimized -t cfn-app:dev .
#
# Size comparison:
#   docker images | grep cfn-app
#
# Expected results:
#   - Production image: ~150-200 MB (50% reduction from ~300-400 MB)
#   - Development image: ~300-400 MB (includes dev dependencies)
#   - Build time: 50-70% faster with BuildKit caching