'use client';

import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';

import { apiFetch } from '@/lib/api/client';
import type { DocumentFolder } from '@/lib/db/schema/documents';

export interface FolderNode extends DocumentFolder {
  children: FolderNode[];
}

const FOLDERS_KEY = ['document-folders'] as const;

export function useDocumentFolders() {
  return useQuery<FolderNode[]>({
    queryKey: FOLDERS_KEY,
    queryFn: () => apiFetch<{ data: FolderNode[] }>('/api/v1/document-folders').then((r) => r.data),
    staleTime: 30_000,
  });
}

export function useCreateFolder() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: (input: { name: string; parentId: string | null }) =>
      apiFetch('/api/v1/document-folders', { method: 'POST', body: input }),
    onSuccess: () => qc.invalidateQueries({ queryKey: FOLDERS_KEY }),
  });
}

export function useRenameFolder() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: ({ id, name }: { id: string; name: string }) =>
      apiFetch(`/api/v1/document-folders/${id}`, { method: 'PATCH', body: { name } }),
    onSuccess: () => qc.invalidateQueries({ queryKey: FOLDERS_KEY }),
  });
}

export function useMoveFolder() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: ({ id, parentId }: { id: string; parentId: string | null }) =>
      apiFetch(`/api/v1/document-folders/${id}`, { method: 'PATCH', body: { parentId } }),
    onSuccess: () => qc.invalidateQueries({ queryKey: FOLDERS_KEY }),
  });
}

export function useDeleteFolder() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: (id: string) => apiFetch(`/api/v1/document-folders/${id}`, { method: 'DELETE' }),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: FOLDERS_KEY });
      qc.invalidateQueries({ queryKey: ['documents'] });
    },
  });
}

export function useMoveDocument() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: ({ docId, folderId }: { docId: string; folderId: string | null }) =>
      apiFetch(`/api/v1/documents/${docId}/folder`, {
        method: 'PATCH',
        body: { folderId },
      }),
    onSuccess: () => qc.invalidateQueries({ queryKey: ['documents'] }),
  });
}

/** Walk the tree → produce flat path strings like "Deals 2026 / Q1". */
export function buildFolderPaths(tree: FolderNode[]): Array<{ id: string; path: string }> {
  const out: Array<{ id: string; path: string }> = [];
  function walk(nodes: FolderNode[], prefix: string) {
    for (const n of nodes) {
      const path = prefix ? `${prefix} / ${n.name}` : n.name;
      out.push({ id: n.id, path });
      walk(n.children, path);
    }
  }
  walk(tree, '');
  return out;
}