import type sharp from "sharp";
import { getFormat } from "./loader.ts";

export interface SaveOptions {
  quality?: number;
  compressionLevel?: number;
}

/**
 * Save a sharp instance to a file with format-specific options
 */
export async function saveImage(
  image: sharp.Sharp,
  outputPath: string,
  options: SaveOptions = {}
): Promise<string> {
  const { quality = 85, compressionLevel = 6 } = options;
  const format = getFormat(outputPath);

  let processed: sharp.Sharp;

  switch (format) {
    case "jpeg":
      processed = image.jpeg({ quality });
      break;
    case "png":
      processed = image.png({ compressionLevel });
      break;
    case "webp":
      processed = image.webp({ quality });
      break;
    case "gif":
      processed = image.gif();
      break;
    default:
      throw new Error(`Unsupported output format: ${format}`);
  }

  await processed.toFile(outputPath);
  return outputPath;
}

/**
 * Determine output path based on input and options
 */
export function determineOutputPath(
  inputPath: string,
  explicitOutput?: string
): string {
  if (explicitOutput) {
    return explicitOutput;
  }
  // Default: add -scaled suffix before extension
  return inputPath.replace(/\.[^.]+$/, `-scaled${inputPath.match(/\.[^.]+$/)?.[0] || ""}`);
}