# Stage 1: Build Frontend
FROM node:20-alpine AS frontend-builder

WORKDIR /app/frontend

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

# Generate lockfile if it doesn't exist, then install dependencies
RUN if [ ! -f package-lock.json ]; then \
        echo "Generating package-lock.json..."; \
        npm install --package-lock-only; \
    fi && \
    npm ci

# Copy frontend source and build
COPY frontend/ ./
RUN npm run build

# Stage 2: Build Backend
FROM node:20-alpine AS backend-builder

WORKDIR /app/backend

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

# Generate lockfile if it doesn't exist, then install dependencies
RUN if [ ! -f package-lock.json ]; then \
        echo "Generating package-lock.json..."; \
        npm install --package-lock-only; \
    fi && \
    npm ci

# Copy backend source and compile TypeScript
COPY backend/ ./
RUN npm run build

# Stage 3: Production Runtime
FROM node:20-alpine

WORKDIR /app

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

# Generate lockfile if it doesn't exist, then install production dependencies only
RUN if [ ! -f package-lock.json ]; then \
        echo "Generating package-lock.json..."; \
        npm install --package-lock-only; \
    fi && \
    npm ci --omit=dev && \
    npm cache clean --force

# Copy compiled backend from builder
COPY --from=backend-builder /app/backend/dist ./dist

# Copy built frontend into public directory for Express to serve
COPY --from=frontend-builder /app/frontend/dist ./dist/public

# Create temp upload directory
RUN mkdir -p /app/temp && \
    chown -R node:node /app

# Switch to non-root user
USER node

# Environment variables (can be overridden via Unraid UI)
ENV NODE_ENV=production
ENV PORT=3000
ENV MAX_FILE_SIZE=10485760
ENV TEMP_DIR=/app/temp

# Expose port
EXPOSE 3000

# Health check
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
    CMD node -e "require('http').get('http://localhost:3000/', (r) => {process.exit(r.statusCode === 200 ? 0 : 1)})"

# Start server
CMD ["node", "dist/index.js"]