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

// ── Types ──────────────────────────────────────────────────────────────

export interface OpenSearchStatus {
  reachable: boolean;
  clusterHealth: string;
  version: string | null;
  nodeCount: number;
  host: string;
}

export interface PipelineStats {
  queueDepth: number;
  maxQueueSize: number;
  failedCount: number;
  indexedCount: number;
  debounceMs: number;
  indexingRate: number;
  lastIndexedAt: string | null;
}

export interface IndexInfo {
  name: string;
  docCount: number;
  size: string;
  sizeBytes: number;
  health: string;
  primaryShards: number;
  replicas: number;
}

export interface IndicesPage {
  indices: IndexInfo[];
  totalIndices: number;
  totalDocs: number;
  totalSize: string;
  page: number;
  pageSize: number;
  totalPages: number;
}

export interface PerformanceStats {
  queryCacheHitRate: number;
  requestCacheHitRate: number;
  searchLatencyMs: number;
  indexingLatencyMs: number;
  heapUsedBytes: number;
  heapMaxBytes: number;
}

// ── Query Hooks ────────────────────────────────────────────────────────

export function useOpenSearchStatus() {
  const refetchInterval = useRefreshInterval(30_000);
  return useQuery({
    queryKey: ['admin', 'opensearch', 'status'],
    queryFn: () => adminFetch<OpenSearchStatus>('/opensearch/status'),
    refetchInterval,
  });
}

export function usePipelineStats() {
  const refetchInterval = useRefreshInterval(10_000);
  return useQuery({
    queryKey: ['admin', 'opensearch', 'pipeline'],
    queryFn: () => adminFetch<PipelineStats>('/opensearch/pipeline'),
    refetchInterval,
  });
}

export function useOpenSearchIndices(page = 0, size = 20, search = '', prefix = 'executions') {
  return useQuery({
    queryKey: ['admin', 'opensearch', 'indices', prefix, page, size, search],
    queryFn: () => {
      const params = new URLSearchParams();
      params.set('page', String(page));
      params.set('size', String(size));
      params.set('prefix', prefix);
      if (search) params.set('search', search);
      return adminFetch<IndicesPage>(`/opensearch/indices?${params}`);
    },
    placeholderData: (prev) => prev,
  });
}

export function useOpenSearchPerformance() {
  const refetchInterval = useRefreshInterval(30_000);
  return useQuery({
    queryKey: ['admin', 'opensearch', 'performance'],
    queryFn: () => adminFetch<PerformanceStats>('/opensearch/performance'),
    refetchInterval,
  });
}

// ── Mutation Hooks ─────────────────────────────────────────────────────

export function useDeleteIndex() {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: (indexName: string) =>
      adminFetch<void>(`/opensearch/indices/${indexName}`, { method: 'DELETE' }),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: ['admin', 'opensearch', 'indices'] });
    },
  });
}