import { config } from "./config";

let genaiModule: typeof import("@google/generative-ai") | null = null;

async function getClient() {
  if (!config.geminiApiKey) {
    throw new Error("GEMINI_API_KEY not configured");
  }
  if (!genaiModule) {
    genaiModule = await import("@google/generative-ai");
  }
  return new genaiModule.GoogleGenerativeAI(config.geminiApiKey);
}

/**
 * Send an image + prompt to Gemini vision.
 */
export async function geminiVision(prompt: string, imageBase64: string): Promise<string> {
  const ai = await getClient();
  const model = ai.getGenerativeModel({ model: config.geminiModel });

  const result = await model.generateContent([
    prompt,
    {
      inlineData: {
        mimeType: "image/jpeg",
        data: imageBase64,
      },
    },
  ]);

  return result.response.text();
}

/**
 * Identify ALL food/grocery products visible in a photo.
 */
export async function geminiIdentifyProducts(
  imageBase64: string
): Promise<Record<string, unknown>[]> {
  const prompt = `Identify ALL food and grocery products visible in this photo. \
There may be one product or many (e.g. a grocery haul, a shelf, a receipt).

Return ONLY a JSON array of objects. Each object must have:
- "name": product name (string)
- "brand": brand name if visible, otherwise "" (string). Produce typically has no brand.
- "category": one of "produce", "dairy", "meat", "seafood", "bakery", "snacks", "beverages", "frozen", "pantry", "condiments", "other" (string)
- "is_organic": "yes" or "no" based on visible labels (string)

Return ONLY the JSON array, no other text.`;

  const raw = await geminiVision(prompt, imageBase64);

  try {
    const start = raw.indexOf("[");
    const end = raw.lastIndexOf("]");
    if (start !== -1 && end > start) {
      const items = JSON.parse(raw.slice(start, end + 1));
      return (items as Record<string, unknown>[]).filter(
        (i) => typeof i === "object" && i !== null && i.name
      );
    }
  } catch {
    // try single object
  }

  try {
    const start = raw.indexOf("{");
    const end = raw.lastIndexOf("}");
    if (start !== -1 && end > start) {
      const item = JSON.parse(raw.slice(start, end + 1)) as Record<string, unknown>;
      if (item.name) return [item];
    }
  } catch {
    // unparseable
  }

  console.warn(`Failed to parse Gemini product identification: ${raw.slice(0, 200)}`);
  return [];
}