draw-things-chat

import { ImageGenerationParams } from "../core-bundle.mjs";

/**
 * Progress callback for image generation.
 * @param step - Current sampling step (1-based)
 * @param totalSteps - Total number of sampling steps (if known)
 * @param message - Optional human-readable status message
 */
export type ProgressCallback = (
  step: number,
  totalSteps?: number,
  message?: string
) => void;

export type BackendGenerateResult = {
  isError: boolean;
  // Preferred binary image payload for downstream processing
  imageBuffer?: Buffer;
  // Optional base64-encoded image (data URL or raw base64)
  imageData?: string;
  // Optional filesystem path where the image was saved by the backend
  imagePath?: string;
  // Optional list for compatibility with some APIs
  images?: string[];
  status?: number;
  metadata?: Record<string, any>;
  error?: string;
  errorMessage?: string;
  audioBuffers?: Buffer[];
};

export interface ImageBackend {
  readonly name: string;
  setBaseUrl(url: string): void;
  checkApiConnection(): Promise<boolean>;
  generateImage(
    input: Partial<ImageGenerationParams>,
    onProgress?: ProgressCallback
  ): Promise<BackendGenerateResult>;
  // Optional but recommended: many backends support image-to-image.
  generateImageImg2Img(
    input: Partial<ImageGenerationParams>,
    sourceBuffer: Buffer,
    onProgress?: ProgressCallback
  ): Promise<BackendGenerateResult>;
  // Edit mode with multiple reference images (canvas + moodboard)
  generateImageEdit?(
    input: Partial<ImageGenerationParams>,
    referenceBuffers: Buffer[],
    onProgress?: ProgressCallback
  ): Promise<BackendGenerateResult>;
}