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

export interface DatabaseStatus {
  connected: boolean;
  version: string;
  host: string;
  schema: string;
}

export interface PoolStats {
  activeConnections: number;
  idleConnections: number;
  pendingConnections: number;
  maxConnections: number;
  maxWaitMillis: number;
}

export interface TableInfo {
  tableName: string;
  rowEstimate: number;
  dataSize: string;
  indexSize: string;
}

export interface ActiveQuery {
  pid: number;
  durationMs: number;
  state: string;
  query: string;
}

export function useDatabaseStatus() {
  return useQuery({
    queryKey: ['admin', 'database', 'status'],
    queryFn: () => adminFetch<DatabaseStatus>('/database/status'),
  });
}

export function useDatabasePool() {
  return useQuery({
    queryKey: ['admin', 'database', 'pool'],
    queryFn: () => adminFetch<PoolStats>('/database/pool'),
    refetchInterval: 15000,
  });
}

export function useDatabaseTables() {
  return useQuery({
    queryKey: ['admin', 'database', 'tables'],
    queryFn: () => adminFetch<TableInfo[]>('/database/tables'),
  });
}

export function useDatabaseQueries() {
  return useQuery({
    queryKey: ['admin', 'database', 'queries'],
    queryFn: () => adminFetch<ActiveQuery[]>('/database/queries'),
    refetchInterval: 15000,
  });
}

export function useKillQuery() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: async (pid: number) => {
      await adminFetch<void>(`/database/queries/${pid}`, { method: 'DELETE' });
    },
    onSuccess: () => qc.invalidateQueries({ queryKey: ['admin', 'database', 'queries'] }),
  });
}