# ============================================================================
# HR Portal Frontend Dockerfile
# Next.js 14 + React 18 + TypeScript
# ============================================================================

FROM node:18-alpine AS base

# 設定環境變數
ENV NODE_ENV=production \
    NEXT_TELEMETRY_DISABLED=1

# ============================================================================
# Dependencies Stage - 安裝依賴
# ============================================================================
FROM base AS deps

WORKDIR /app

# 安裝依賴 (使用 package-lock.json 確保一致性)
COPY package.json package-lock.json ./
RUN npm ci --only=production && npm cache clean --force

# ============================================================================
# Builder Stage - 建置應用
# ============================================================================
FROM base AS builder

WORKDIR /app

# 複製依賴
COPY --from=deps /app/node_modules ./node_modules
COPY . .

# 建置 Next.js 應用
# 注意: 環境變數在建置時需要提供
RUN npm run build

# ============================================================================
# Runner Stage - 執行應用
# ============================================================================
FROM base AS runner

WORKDIR /app

# 創建非 root 用戶
RUN addgroup --system --gid 1001 nodejs && \
    adduser --system --uid 1001 nextjs

# 複製必要檔案
COPY --from=builder /app/public ./public
COPY --from=builder /app/.next/standalone ./
COPY --from=builder /app/.next/static ./.next/static

# 設定權限
RUN chown -R nextjs:nodejs /app

# 切換到非 root 用戶
USER nextjs

# 暴露端口
EXPOSE 3000

# 設定環境變數
ENV PORT=3000 \
    HOSTNAME="0.0.0.0"

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

# 啟動命令
CMD ["node", "server.js"]