import type {SuperagentNativeMediaItem} from './useSuperagentAttachmentPicker';
import {
  SUPERAGENT_ATTACHMENT_SIZE_LIMIT_MB,
  SUPERAGENT_SUPPORTED_ATTACHMENT_EXTENSIONS,
} from './mediaUtils';

export function validateNativeAttachment(item: SuperagentNativeMediaItem, name: string, extension: string) {
  if (!SUPERAGENT_SUPPORTED_ATTACHMENT_EXTENSIONS.includes(extension as typeof SUPERAGENT_SUPPORTED_ATTACHMENT_EXTENSIONS[number])) {
    throw new Error(`File type "${extension || 'unknown'}" is not supported.`);
  }

  const limitMb = SUPERAGENT_ATTACHMENT_SIZE_LIMIT_MB[extension] ?? 5;
  if (typeof item.size === 'number' && item.size > limitMb * 1024 * 1024) {
    throw new Error(`File "${name}" exceeds the maximum size of ${limitMb}MB.`);
  }
}

export function getUploadName(item: SuperagentNativeMediaItem, index: number) {
  const baseName = item.name || getNameFromUri(item.uri) || `attachment-${index + 1}`;
  if (getExtension(baseName)) {
    return baseName;
  }

  const extension = getExtension(item.uri) || getExtensionForMimeType(item.mimeType) || '.jpg';
  return `${baseName}${extension}`;
}

export function getExtension(value?: string) {
  const cleanValue = String(value || '').split('?')[0].toLowerCase();
  const index = cleanValue.lastIndexOf('.');
  return index >= 0 ? cleanValue.slice(index) : '';
}

export function getMimeType(item: SuperagentNativeMediaItem, extension: string) {
  if (item.mimeType) {
    return item.mimeType;
  }

  switch (extension) {
    case '.jpg':
    case '.jpeg':
      return 'image/jpeg';
    case '.png':
      return 'image/png';
    case '.webp':
      return 'image/webp';
    case '.pdf':
      return 'application/pdf';
    case '.csv':
      return 'text/csv';
    case '.html':
      return 'text/html';
    case '.txt':
      return 'text/plain';
    case '.xlsx':
      return 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet';
    case '.docx':
      return 'application/vnd.openxmlformats-officedocument.wordprocessingml.document';
    case '.json':
      return 'application/json';
    case '.md':
      return 'text/markdown';
    default:
      return 'application/octet-stream';
  }
}

function getNameFromUri(uri?: string) {
  if (!uri) {
    return null;
  }

  const cleanUri = uri.split('?')[0];
  const name = cleanUri.split('/').filter(Boolean).pop();
  if (!name || name.startsWith('ph:')) {
    return null;
  }

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

function getExtensionForMimeType(mimeType?: string) {
  switch (mimeType) {
    case 'image/jpeg':
      return '.jpg';
    case 'image/png':
      return '.png';
    case 'image/webp':
      return '.webp';
    case 'application/pdf':
      return '.pdf';
    case 'text/plain':
      return '.txt';
    case 'text/html':
      return '.html';
    case 'text/csv':
      return '.csv';
    case 'application/json':
      return '.json';
    case 'text/markdown':
      return '.md';
    default:
      return null;
  }
}