/**
 * The request Atelier accepts, which is OpenAI's `POST /v1/images/generations` body verbatim.
 *
 * Kept as their vocabulary rather than a translated one of our own: a caller that already knows the
 * OpenAI API knows this, and a provider added later is the one that has to do the translating —
 * which is where the knowledge of that provider already lives.
 */
export type ImageRequest = {
  prompt: string;
  model?: string;
  n?: number;
  quality?: 'auto' | 'high' | 'medium' | 'low' | 'hd' | 'standard';
  size?: string;
  response_format?: 'url' | 'b64_json';
  output_format?: 'png' | 'jpeg' | 'webp';
  output_compression?: number;
  background?: 'transparent' | 'opaque' | 'auto';
  moderation?: 'low' | 'auto';
  style?: 'vivid' | 'natural';
  stream?: boolean;
  partial_images?: number;
  user?: string;
};

/**
 * OpenAI's `POST /v1/images/edits` body, minus the files themselves.
 *
 * A separate type rather than flags on ImageRequest, because the parameter sets genuinely differ:
 * edits take `input_fidelity` and no `style` or `moderation`, its `quality` has no `hd`, and its
 * model default is gpt-image-1.5 where generations default to dall-e-2.
 */
export type ImageEditRequest = {
  prompt: string;
  model?: string;
  n?: number;
  quality?: 'auto' | 'high' | 'medium' | 'low' | 'standard';
  size?: string;
  response_format?: 'url' | 'b64_json';
  output_format?: 'png' | 'jpeg' | 'webp';
  output_compression?: number;
  background?: 'transparent' | 'opaque' | 'auto';
  input_fidelity?: 'high' | 'low';
  stream?: boolean;
  partial_images?: number;
  user?: string;
};

/** An uploaded file on its way to a provider. */
export type UploadedImage = { filename: string; bytes: Uint8Array; type: string };

/** OpenAI's usage object. Stored raw so a cost computed with the wrong price can be recomputed. */
export type ImageUsage = {
  total_tokens?: number;
  input_tokens?: number;
  output_tokens?: number;
  input_tokens_details?: { text_tokens?: number; image_tokens?: number };
};

/** One generated image, as the provider returned it. */
export type ProviderImage = {
  /** Raw bytes. Providers hand back base64; decoding is theirs to do, so the queue only writes files. */
  bytes: Uint8Array;
  /** png / jpeg / webp — decides the extension on disk and the served content type. */
  format: string;
  revisedPrompt?: string;
};

export type ProviderResult = {
  images: ProviderImage[];
  usage?: ImageUsage;
  /** Echoed back by the provider: the size, quality and background actually used. */
  echoed: Record<string, unknown>;
};

/**
 * An adapter: how to talk to one vendor's image API.
 *
 * Deliberately holds no key, no chosen model and no enabled flag. Those live in a `providers` row,
 * because they are decisions rather than knowledge, and several rows share one adapter.
 */
export type ImageAdapter = {
  readonly name: string;
  /** For display — "OpenAI" rather than "openai", used to name providers built from it. */
  readonly label: string;
  /** Models this adapter is known to serve. Advisory — an unknown model is passed through. */
  readonly models: readonly string[];
  readonly defaultModel: string;
  /**
   * This adapter authenticates with nothing, because it talks to a service of OURS rather than a
   * vendor's. Availability is then a fact about the code, not about what is in the secret store.
   *
   * The alternative was storing a dummy secret so the existing "has a key?" test would pass. That would
   * make the store lie about what is configured, and the store is the one place that is supposed to be
   * the truth about credentials. A flag that says "this question does not apply" is smaller and honest.
   *
   * A category rather than an exception: whisper, OCR and TTS already run on this machine too.
   */
  readonly keyless?: boolean;
  /**
   * The key is passed in rather than read here: it can come from the database or the environment, and
   * which one is a question about configuration, not about how to talk to this provider.
   */
  generate(request: ImageRequest, apiKey: string, signal?: AbortSignal): Promise<ProviderResult>;
  /**
   * Edit. Optional: a provider that cannot do it says so by not having it, and the route answers 400
   * rather than the queue discovering it after the row is written.
   */
  edit?(
    request: ImageEditRequest,
    images: UploadedImage[],
    mask: UploadedImage | undefined,
    apiKey: string,
    signal?: AbortSignal,
  ): Promise<ProviderResult>;
  /** USD for the reported usage, or null when this model's price is not known. */
  costUsd(model: string, usage: ImageUsage | undefined): string | null;
};