import type { HostApiContext } from '../context';
import type { NormalizedHostApiRequest } from '../route-utils';
import { fail, ok, parseJsonBody } from '../route-utils';
import {
  deleteKnowledgeDoc,
  listKnowledgeDocs,
  uploadKnowledgeDoc,
  isSafeKnowledgeDocName,
} from '../../utils/knowledge-docs';

function getDeleteTarget(request: NormalizedHostApiRequest): string | null {
  const fromQuery = request.url.searchParams.get('name')?.trim() || '';
  if (fromQuery) return fromQuery;

  const body = request.body && typeof request.body === 'string'
    ? parseJsonBody<{ fileName?: string; name?: string }>(request.body)
    : (request.body as { fileName?: string; name?: string } | null);

  const candidate = String(body?.fileName || body?.name || '').trim();
  return candidate || null;
}

export async function handleKnowledgeRoutes(
  request: NormalizedHostApiRequest,
  _ctx: HostApiContext,
) {
  const { pathname, method } = request;

  if (pathname === '/api/knowledge/docs' && method === 'GET') {
    try {
      return ok({
        success: true,
        files: await listKnowledgeDocs(),
      });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  if (pathname === '/api/knowledge/docs' && method === 'POST') {
    try {
      const body = parseJsonBody<{ base64?: string; fileName?: string }>(request.body);
      const fileName = String(body?.fileName || '').trim();
      const base64 = String(body?.base64 || '').trim();

      if (!fileName) {
        return fail(400, 'fileName is required');
      }
      if (!base64) {
        return fail(400, 'base64 is required');
      }
      if (!isSafeKnowledgeDocName(fileName)) {
        return fail(400, 'Invalid file name');
      }

      return ok({
        success: true,
        file: await uploadKnowledgeDoc({ fileName, base64 }),
      });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  if (method === 'DELETE' && (pathname === '/api/knowledge/docs' || pathname.startsWith('/api/knowledge/docs/'))) {
    try {
      const fileName = pathname.startsWith('/api/knowledge/docs/')
        ? decodeURIComponent(pathname.slice('/api/knowledge/docs/'.length))
        : getDeleteTarget(request);

      if (!fileName) {
        return fail(400, 'fileName is required');
      }
      if (!isSafeKnowledgeDocName(fileName)) {
        return fail(400, 'Invalid file name');
      }

      await deleteKnowledgeDoc(fileName);
      return ok({ success: true });
    } catch (error) {
      return fail(500, error instanceof Error ? error.message : String(error));
    }
  }

  return null;
}