backend/src/generation/generation.ts

import { z } from 'zod';

export type UploadedImage = {
  originalName: string;
  mimeType: string;
  size: number;
  buffer?: Buffer;
};

export type GenerationVariant = {
  id: string;
  label: string;
  status: 'queued' | 'completed';
  prompt: string;
  providerPromptId?: string;
  imageUrl?: string;
  imageBase64?: string;
};

export type GenerationImage = {
  id: string;
  originalName: string;
  variants: GenerationVariant[];
};

export type GenerationProvider = 'mock' | 'kaggle';

export type GenerationResponse = {
  jobId: string;
  provider: GenerationProvider;
  preset: string;
  ratio: string;
  images: GenerationImage[];
  metrics?: GenerationMetrics;
};

export type GenerationMetrics = {
  durationSeconds?: number;
  inferenceSeconds?: number;
  modelLoadSeconds?: number;
  setupSeconds?: number;
  height?: number;
  width?: number;
  steps?: number;
  smallDecoder?: boolean;
  cudaAvailable?: boolean;
  gpuName?: string;
  hfHome?: string;
  mode?: GenerationMode;
  modelId?: string;
};

export type GenerationMode = 'product' | 'menu';

export const generationRequestSchema = z.object({
  prompt: z.string().trim().min(1),
  preset: z.enum(['studio', 'food', 'retail', 'premium']),
  ratio: z.enum(['16:9', '9:16', '1:1']),
  mode: z.enum(['product', 'menu']).default('product'),
});

export function buildGenerationResponse(input: z.infer<typeof generationRequestSchema>, images: UploadedImage[], provider: GenerationProvider = 'mock'): GenerationResponse {
  const responseImages = input.mode === 'menu' ? images.slice(0, 1) : images;

  return {
    jobId: crypto.randomUUID(),
    provider,
    preset: input.preset,
    ratio: input.ratio,
    images: responseImages.map((image) => ({
      id: crypto.randomUUID(),
      originalName: image.originalName,
      variants: buildVariants(input.prompt),
    })),
  };
}

function buildVariants(prompt: string): GenerationVariant[] {
  return [
    {
      id: crypto.randomUUID(),
      label: 'Clean studio',
      status: 'queued',
      prompt: `${prompt}. Clean studio background, realistic product shadow.`,
    },
    {
      id: crypto.randomUUID(),
      label: 'Warme food sfeer',
      status: 'queued',
      prompt: `${prompt}. Warm hospitality setting, photorealistic lighting.`,
    },
    {
      id: crypto.randomUUID(),
      label: 'Premium donker',
      status: 'queued',
      prompt: `${prompt}. Dark premium campaign scene, controlled highlights.`,
    },
  ];
}