SnapOtter/packages/ai/src/upscaling.ts

import { readFile, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { type ProgressCallback, runPythonWithProgress } from "./bridge.js";

export interface UpscaleOptions {
  scale?: number;
  model?: string;
  faceEnhance?: boolean;
  denoise?: number;
  format?: string;
  quality?: number;
}

export interface UpscaleResult {
  buffer: Buffer;
  width: number;
  height: number;
  method: string;
  format: string;
}

export async function upscale(
  inputBuffer: Buffer,
  outputDir: string,
  options: UpscaleOptions = {},
  onProgress?: ProgressCallback,
): Promise<UpscaleResult> {
  const inputPath = join(outputDir, "input_upscale.png");
  const outputPath = join(outputDir, "output_upscale.png");

  await writeFile(inputPath, inputBuffer);
  const { stdout } = await runPythonWithProgress(
    "upscale.py",
    [inputPath, outputPath, JSON.stringify(options)],
    { onProgress },
  );

  const result = JSON.parse(stdout);
  if (!result.success) {
    throw new Error(result.error || "Upscaling failed");
  }

  // Python may write to a different path when the output format changes
  const actualOutputPath = result.output_path || outputPath;
  const buffer = await readFile(actualOutputPath);
  return {
    buffer,
    width: result.width,
    height: result.height,
    method: result.method ?? "unknown",
    format: result.format ?? "png",
  };
}