export interface ResizeImageOptions {
  maxWidth?: number;
  maxHeight?: number;
  quality?: number;
  mimeType?: string;
}

const DEFAULT_OPTIONS: Required<ResizeImageOptions> = {
  maxWidth: 1280,
  maxHeight: 1280,
  quality: 0.9,
  mimeType: "image/jpeg",
};

/**
 * Redimensiona uma imagem no client preservando boa qualidade.
 * Retorna uma dataURL compactada para envio à IA.
 */
export async function resizeImageToDataURL(
  file: File,
  options: ResizeImageOptions = {},
): Promise<{ dataUrl: string; width: number; height: number }> {
  const opts = { ...DEFAULT_OPTIONS, ...options };
  const bitmap = await createImageBitmap(file);

  let { width, height } = bitmap;
  const ratio = Math.min(opts.maxWidth / width, opts.maxHeight / height, 1);

  if (ratio < 1) {
    width = Math.round(width * ratio);
    height = Math.round(height * ratio);
  }

  const canvas = document.createElement("canvas");
  canvas.width = width;
  canvas.height = height;

  const ctx = canvas.getContext("2d");
  if (!ctx) {
    throw new Error("Contexto 2D não disponível para redimensionamento.");
  }

  ctx.drawImage(bitmap, 0, 0, width, height);

  return {
    dataUrl: canvas.toDataURL(opts.mimeType, opts.quality),
    width,
    height,
  };
}