import { SilkeImageValue } from './utils';

/**
 * Reads a File and converts it to a SilkeImageValue with base64 data.
 * Returns a promise that resolves with the image value or null if reading fails.
 */
export function fileToImageValue(file: File): Promise<SilkeImageValue | null> {
  return new Promise((resolve) => {
    if (!file.type.startsWith('image/')) {
      resolve(null);
      return;
    }

    const reader = new FileReader();
    reader.onload = (event) => {
      const result = event.target?.result;
      if (typeof result === 'string') {
        const [, base64Data] = result.split(',');
        resolve({
          type: 'image',
          data: base64Data,
          mimeType: file.type,
          name: file.name || undefined,
        });
      } else {
        resolve(null);
      }
    };
    reader.onerror = () => resolve(null);
    reader.readAsDataURL(file);
  });
}

/**
 * Extracts the first image file from a ClipboardEvent.
 * Returns the File or null if no image is found.
 */
export function getImageFromClipboard(e: React.ClipboardEvent): File | null {
  const items = e.clipboardData?.items;
  if (!items) return null;

  for (const item of items) {
    if (item.type.startsWith('image/')) {
      return item.getAsFile();
    }
  }
  return null;
}

/**
 * Extracts the first image file from a DragEvent.
 * Returns the File or null if no image is found.
 */
export function getImageFromDragEvent(e: DragEvent): File | null {
  const files = e.dataTransfer?.files;
  if (!files || files.length === 0) return null;

  for (const file of files) {
    if (file.type.startsWith('image/')) {
      return file;
    }
  }
  return null;
}

/**
 * Generates a data URL from a SilkeImageValue for use in img src.
 */
export function imageValueToDataUrl(img: SilkeImageValue): string {
  return `data:${img.mimeType};base64,${img.data}`;
}