backend/api/image.ts

import { api, APIError } from "encore.dev/api";
import { auth, validateApiKey } from "../utils/auth";
import { checkRateLimit } from "../utils/rate_limit";
import { metrics } from "../utils/metrics";
import { imageService } from "../services/image_service";
import type { ImageGenerationRequest, ImageGenerationResponse } from "../types/models";

export const generate = api<ImageGenerationRequest, ImageGenerationResponse>(
  { expose: true, method: "POST", path: "/image/generate", auth: false },
  async (req) => {
    const startTime = Date.now();

    try {
      const authHeader = auth();
      const authData = validateApiKey(authHeader);
      checkRateLimit(authData.apiKey, authData.tier);

      metrics.incrementRequests("/image/generate");

      if (!req.prompt) {
        throw APIError.invalidArgument("prompt is required");
      }

      const response = await imageService.generate(req);

      metrics.recordResponseTime(Date.now() - startTime);

      return response;
    } catch (error) {
      metrics.incrementErrors();
      
      if (error && typeof error === 'object' && 'statusCode' in error && error.statusCode === 429) {
        const err = error as any;
        throw APIError.resourceExhausted(err.message).withDetails({
          limit: err.limit,
          remaining: err.remaining,
          reset_at: err.resetAt,
        });
      }

      throw error instanceof Error ? error : APIError.internal(String(error));
    }
  }
);