# =============================================================================
# Multi-stage Dockerfile for Next.js 15 - Production Optimized
# =============================================================================
# Stage 1: Dependencies - Install all dependencies
# Stage 2: Builder - Build the application
# Stage 3: Runner - Production runtime
# =============================================================================

# -----------------------------------------------------------------------------
# Stage 1: Dependencies
# -----------------------------------------------------------------------------
FROM node:22-alpine AS deps

# Install system dependencies for node-gyp
RUN apk add --no-cache libc6-compat

WORKDIR /app

# Copy dependency files
COPY package.json package-lock.json* ./

# Install dependencies
# Use npm ci for reproducible builds
RUN npm ci --legacy-peer-deps || npm install --legacy-peer-deps

# -----------------------------------------------------------------------------
# Stage 2: Builder
# -----------------------------------------------------------------------------
FROM node:22-alpine AS builder

WORKDIR /app

# Copy dependencies from deps stage
COPY --from=deps /app/node_modules ./node_modules

# Copy source code
COPY . .

# Set build-time environment variables
ENV NEXT_TELEMETRY_DISABLED=1
ENV NODE_ENV=production

# Build application
RUN npm run build

# -----------------------------------------------------------------------------
# Stage 3: Runner (Production)
# -----------------------------------------------------------------------------
FROM node:22-alpine AS runner

# Install runtime dependencies
RUN apk add --no-cache \
    libc6-compat \
    dumb-init

WORKDIR /app

# Set production environment
ENV NODE_ENV=production
ENV NEXT_TELEMETRY_DISABLED=1
ENV PORT=3000
ENV HOSTNAME="0.0.0.0"

# Create non-root user for security
RUN addgroup --system --gid 1001 nodejs && \
    adduser --system --uid 1001 nextjs

# Copy necessary files from builder
COPY --from=builder --chown=nextjs:nodejs /app/next.config.js ./
COPY --from=builder --chown=nextjs:nodejs /app/public ./public
COPY --from=builder --chown=nextjs:nodejs /app/.next ./.next
COPY --from=builder --chown=nextjs:nodejs /app/package.json ./
COPY --from=builder --chown=nextjs:nodejs /app/node_modules ./node_modules

# Switch to non-root user
USER nextjs

# Expose port
EXPOSE 3000

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

# Use dumb-init to handle signals properly
ENTRYPOINT ["dumb-init", "--"]

# Start Next.js in production mode
CMD ["node_modules/.bin/next", "start"]