# Build stage
FROM node:20-alpine AS builder

WORKDIR /app

# Copy package files
COPY package*.json ./

# Install dependencies
RUN npm ci

# Copy source code
COPY . .

# Build the application
# Raise Node heap limit: nest build (tsc) OOMs at the default ~1GB old-space cap.
ENV NODE_OPTIONS=--max-old-space-size=1536
RUN npm run build && \
    echo "Build completed, checking dist folder..." && \
    ls -laR dist/ && \
    test -f dist/src/main.js || (echo "ERROR: dist/src/main.js not found!" && exit 1)

# Production stage
FROM node:20-alpine AS production

WORKDIR /app

# Create non-root user
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nestjs -u 1001

# Copy package files
COPY package*.json ./

# Install only production dependencies
RUN npm ci --only=production && \
    npm cache clean --force

# Copy built application from builder stage
COPY --from=builder /app/dist ./dist

# Copy any other necessary files (e.g., if you have static files)
# COPY --from=builder /app/public ./public

# Change ownership to non-root user
RUN chown -R nestjs:nodejs /app

# Switch to non-root user
USER nestjs

# Expose port
EXPOSE 3000

# Set environment to production
ENV NODE_ENV=production

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

# Start the application
CMD ["node", "dist/src/main.js"]