import { generateObject } from "ai";
import { z } from "zod";
import { resolveModel, type AiConfig } from "../factory";

const PantryScanSchema = z.object({
  items: z.array(
    z.object({
      rawName: z.string(),
      estimatedQuantity: z.string().optional(),
      unit: z.string().optional(),
    })
  ).max(30),
});

export type PantryScanResult = z.infer<typeof PantryScanSchema>;

export async function scanPantryPhoto(
  imageBase64: string,
  mimeType: "image/jpeg" | "image/png" | "image/webp",
  config?: AiConfig,
): Promise<PantryScanResult> {
  const model = resolveModel(config);

  const { object } = await generateObject({
    model,
    schema: PantryScanSchema,
    system:
      "You identify food items visible in a photo of a pantry, fridge, or shelf, or a single unbarcoded item (e.g. fresh produce). " +
      "List each distinct item once with a short, common ingredient name. Only include an estimated quantity or unit when it can be " +
      "reasonably judged from the image (e.g. '3' apples, '1' bunch). Do not guess brand names or nutrition facts.",
    messages: [
      {
        role: "user",
        content: [
          { type: "image", image: imageBase64, mediaType: mimeType },
          { type: "text", text: "Identify the food items in this photo." },
        ],
      },
    ],
  });

  return object;
}