import type { SuperagentMediaAttachment } from '../../types';

export const MAX_ATTACHMENTS = 10;
export const SUPERAGENT_SUPPORTED_ATTACHMENT_EXTENSIONS = [
  '.jpg',
  '.jpeg',
  '.png',
  '.webp',
  '.pdf',
  '.txt',
  '.html',
  '.csv',
  '.xlsx',
  '.docx',
  '.json',
  '.md',
] as const;

export const SUPERAGENT_ATTACHMENT_SIZE_LIMIT_MB: Record<string, number> = {
  '.jpg': 40,
  '.jpeg': 40,
  '.png': 40,
  '.webp': 40,
  '.pdf': 10,
  '.txt': 5,
  '.html': 5,
  '.csv': 10,
  '.xlsx': 15,
  '.docx': 5,
  '.json': 10,
  '.md': 5,
};

export function normalizeMediaAttachments(input: unknown) {
  const attachments = Array.isArray(input) ? input : input ? [input] : [];

  return attachments.filter(isAttachment).filter((attachment) => isSafeAttachmentUrl(attachment.url));
}

export function buildAttachmentPrompt(attachments: SuperagentMediaAttachment[]) {
  const images = attachments.filter(isImageAttachment);
  const allImages = images.length === attachments.length;

  if (allImages && attachments.length === 1) return "What's in this image?";
  if (allImages && attachments.length > 1) return `What's in these ${attachments.length} images?`;
  if (attachments.length === 1) return `Here's a file: ${getAttachmentName(attachments[0])}`;
  return `Here are ${attachments.length} files.`;
}

export function getAttachmentName(attachment: SuperagentMediaAttachment) {
  if (attachment.name) return attachment.name;
  const cleanUrl = attachment.url.split('?')[0];
  const filename = cleanUrl.split('/').pop();
  if (!filename) return 'file';

  try {
    return decodeURIComponent(filename);
  } catch {
    return filename;
  }
}

export function isImageAttachment(attachment: SuperagentMediaAttachment) {
  if (attachment.kind === 'image') return true;
  if (attachment.mimeType?.startsWith('image/')) return true;
  return isImageUrl(attachment.url);
}

export function isImageUrl(url: string) {
  return /\.(jpg|jpeg|png|gif|webp|bmp)(?:\?|$)/i.test(url);
}

/**
 * Recognized file types — each maps to a distinct icon in `FileAttachment`.
 * Mirrors the web DS `FileAttachment` (`file-attachment.tsx`) `FileType` union
 * and the builder's `fileTypeFromUrl` classifier.
 */
export type FileType = 'pdf' | 'image' | 'slides' | 'spreadsheet' | 'docs' | 'video' | 'upload';

export function fileTypeFromUrl(url: string): FileType {
  if (isImageUrl(url)) return 'image';
  const ext = url.split('?')[0].split('.').pop()?.toLowerCase() ?? '';
  if (ext === 'pdf') return 'pdf';
  if (['ppt', 'pptx', 'key'].includes(ext)) return 'slides';
  if (['xls', 'xlsx', 'csv'].includes(ext)) return 'spreadsheet';
  if (['doc', 'docx', 'txt', 'md'].includes(ext)) return 'docs';
  if (['mp4', 'mov', 'webm'].includes(ext)) return 'video';
  return 'upload';
}

function isAttachment(value: unknown): value is SuperagentMediaAttachment {
  return Boolean(value && typeof value === 'object' && typeof (value as { url?: unknown }).url === 'string');
}

function isSafeAttachmentUrl(url: string) {
  return /^https?:\/\//i.test(url.trim()) && !url.includes('\0');
}