import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import { keepPreviousData, useMutation, useQuery, useQueryClient } from '@tanstack/react-query';

import { HttpUtil, Msg } from '@/utils';
import { parseMsg } from '@/utils/zodValidate';
import { keys } from '@/api/queryKeys';
import {
  ClientHydrateSchema,
  ClientPageResponseSchema,
  InboundOptionsSchema,
  OnlinesSchema,
  BulkAdjustResultSchema,
  BulkCreateResultSchema,
  BulkDeleteResultSchema,
  DelDepletedResultSchema,
  type ClientHydrate,
  type ClientRecord,
  type ClientTraffic,
  type ClientsSummary,
  type ClientPageResponse,
  type InboundOption,
  type BulkAdjustResult,
  type BulkCreateResult,
  type BulkDeleteResult,
} from '@/schemas/client';
import { DefaultsPayloadSchema } from '@/schemas/defaults';

export type { ClientRecord, ClientTraffic, ClientsSummary, InboundOption };

const JSON_HEADERS = { headers: { 'Content-Type': 'application/json' } } as const;

interface SubSettings {
  enable: boolean;
  subURI: string;
  subJsonURI: string;
  subJsonEnable: boolean;
  subClashURI: string;
  subClashEnable: boolean;
}

export interface ClientQueryParams {
  page: number;
  pageSize: number;
  search?: string;
  // CSV strings — frontend joins arrays on ',', backend splits the same way.
  filter?: string;
  protocol?: string;
  inbound?: string;
  sort?: string;
  order?: 'ascend' | 'descend';
  expiryFrom?: number;
  expiryTo?: number;
  usageFrom?: number;
  usageTo?: number;
  autoRenew?: 'on' | 'off' | '';
  hasTgId?: 'yes' | 'no' | '';
  hasComment?: 'yes' | 'no' | '';
  group?: string;
}

const DEFAULT_QUERY: ClientQueryParams = { page: 1, pageSize: 25 };
const DEFAULT_SUMMARY: ClientsSummary = {
  total: 0, active: 0, online: [], depleted: [], expiring: [], deactive: [],
};

function buildQS(p: ClientQueryParams): string {
  const sp = new URLSearchParams();
  sp.set('page', String(p.page || 1));
  sp.set('pageSize', String(p.pageSize || DEFAULT_QUERY.pageSize));
  if (p.search) sp.set('search', p.search);
  if (p.filter) sp.set('filter', p.filter);
  if (p.protocol) sp.set('protocol', p.protocol);
  if (p.inbound) sp.set('inbound', p.inbound);
  if (p.sort) sp.set('sort', p.sort);
  if (p.order) sp.set('order', p.order);
  if (p.expiryFrom && p.expiryFrom > 0) sp.set('expiryFrom', String(p.expiryFrom));
  if (p.expiryTo && p.expiryTo > 0) sp.set('expiryTo', String(p.expiryTo));
  if (p.usageFrom && p.usageFrom > 0) sp.set('usageFrom', String(p.usageFrom));
  if (p.usageTo && p.usageTo > 0) sp.set('usageTo', String(p.usageTo));
  if (p.autoRenew) sp.set('autoRenew', p.autoRenew);
  if (p.hasTgId) sp.set('hasTgId', p.hasTgId);
  if (p.hasComment) sp.set('hasComment', p.hasComment);
  if (p.group) sp.set('group', p.group);
  return sp.toString();
}

async function fetchClientPage(params: ClientQueryParams): Promise<ClientPageResponse> {
  const qs = buildQS(params);
  const msg = await HttpUtil.get(`/panel/api/clients/list/paged?${qs}`, undefined, { silent: true });
  if (!msg?.success || !msg.obj) throw new Error(msg?.msg || 'Failed to fetch clients');
  const validated = parseMsg(msg, ClientPageResponseSchema, 'clients/list/paged');
  if (!validated.obj) throw new Error('Empty clients response');
  return validated.obj;
}

async function fetchInboundOptions(): Promise<InboundOption[]> {
  const msg = await HttpUtil.get('/panel/api/inbounds/options', undefined, { silent: true });
  if (!msg?.success) throw new Error(msg?.msg || 'Failed to fetch inbound options');
  const validated = parseMsg(msg, InboundOptionsSchema, 'inbounds/options');
  return Array.isArray(validated.obj) ? validated.obj : [];
}

async function fetchDefaults(): Promise<Record<string, unknown>> {
  const msg = await HttpUtil.post('/panel/setting/defaultSettings', undefined, { silent: true });
  if (!msg?.success) throw new Error(msg?.msg || 'Failed to fetch defaults');
  const validated = parseMsg(msg, DefaultsPayloadSchema, 'setting/defaultSettings');
  return validated.obj || {};
}

export function useClients() {
  const queryClient = useQueryClient();

  const [query, setQueryState] = useState<ClientQueryParams>(DEFAULT_QUERY);
  // setQuery shallow-compares so callers can pass a fresh object every render
  // (the common React pattern) without triggering a re-fetch when nothing
  // actually changed.
  const setQuery = useCallback((next: ClientQueryParams) => {
    setQueryState((prev) => {
      if (
        prev.page === next.page
        && prev.pageSize === next.pageSize
        && (prev.search ?? '') === (next.search ?? '')
        && (prev.filter ?? '') === (next.filter ?? '')
        && (prev.protocol ?? '') === (next.protocol ?? '')
        && (prev.inbound ?? '') === (next.inbound ?? '')
        && (prev.sort ?? '') === (next.sort ?? '')
        && (prev.order ?? '') === (next.order ?? '')
        && (prev.expiryFrom ?? 0) === (next.expiryFrom ?? 0)
        && (prev.expiryTo ?? 0) === (next.expiryTo ?? 0)
        && (prev.usageFrom ?? 0) === (next.usageFrom ?? 0)
        && (prev.usageTo ?? 0) === (next.usageTo ?? 0)
        && (prev.autoRenew ?? '') === (next.autoRenew ?? '')
        && (prev.hasTgId ?? '') === (next.hasTgId ?? '')
        && (prev.hasComment ?? '') === (next.hasComment ?? '')
        && (prev.group ?? '') === (next.group ?? '')
      ) return prev;
      return next;
    });
  }, []);

  const listQuery = useQuery({
    queryKey: keys.clients.list(query),
    queryFn: () => fetchClientPage(query),
    staleTime: Infinity,
    placeholderData: keepPreviousData,
  });

  const inboundOptionsQuery = useQuery({
    queryKey: keys.inbounds.options(),
    queryFn: fetchInboundOptions,
    staleTime: Infinity,
  });

  const defaultsQuery = useQuery({
    queryKey: keys.settings.defaults(),
    queryFn: fetchDefaults,
    staleTime: Infinity,
  });

  const onlinesQuery = useQuery({
    queryKey: keys.clients.onlines(),
    queryFn: async () => {
      const msg = await HttpUtil.post('/panel/api/clients/onlines', undefined, { silent: true });
      if (!msg?.success) throw new Error(msg?.msg || 'Failed to fetch onlines');
      const validated = parseMsg(msg, OnlinesSchema, 'clients/onlines');
      return Array.isArray(validated.obj) ? validated.obj : [];
    },
    staleTime: Infinity,
  });

  const clients = listQuery.data?.items ?? [];
  const total = listQuery.data?.total ?? 0;
  const filtered = listQuery.data?.filtered ?? 0;
  const summary = listQuery.data?.summary ?? DEFAULT_SUMMARY;
  const allGroups = listQuery.data?.groups ?? [];
  const fetched = listQuery.data !== undefined;
  const loading = listQuery.isFetching;

  const inbounds = inboundOptionsQuery.data ?? [];
  const onlines = onlinesQuery.data ?? [];

  const defaults = defaultsQuery.data ?? {};
  const subSettings: SubSettings = useMemo(() => ({
    enable: !!defaults.subEnable,
    subURI: (defaults.subURI as string) || '',
    subJsonURI: (defaults.subJsonURI as string) || '',
    subJsonEnable: !!defaults.subJsonEnable,
    subClashURI: (defaults.subClashURI as string) || '',
    subClashEnable: !!defaults.subClashEnable,
  }), [
    defaults.subEnable,
    defaults.subURI,
    defaults.subJsonURI,
    defaults.subJsonEnable,
    defaults.subClashURI,
    defaults.subClashEnable,
  ]);

  const ipLimitEnable = !!defaults.ipLimitEnable;
  const tgBotEnable = !!defaults.tgBotEnable;
  const expireDiff = ((defaults.expireDiff as number) ?? 0) * 86400000;
  const trafficDiff = ((defaults.trafficDiff as number) ?? 0) * 1073741824;
  const pageSize = (defaults.pageSize as number) ?? 0;

  // Client mutations (add/update/remove/attach/detach/resetTraffic/…) all
  // mutate inbound rows server-side too — adding a client appends to
  // settings.clients on each attached inbound, the slim list's per-inbound
  // client count is derived from that. Invalidate both buckets so the
  // Inbounds page and any open edit modal pick up the new shape without
  // a manual reload.
  const invalidateAll = useCallback(
    () => Promise.all([
      queryClient.invalidateQueries({ queryKey: keys.clients.root() }),
      queryClient.invalidateQueries({ queryKey: keys.inbounds.root() }),
    ]),
    [queryClient],
  );

  const refresh = useCallback(async () => {
    await invalidateAll();
  }, [invalidateAll]);

  const hydrate = useCallback(async (email: string): Promise<ClientHydrate | null> => {
    if (!email) return null;
    const msg = await HttpUtil.get(`/panel/api/clients/get/${encodeURIComponent(email)}`);
    if (!msg?.success || !msg.obj) return null;
    const validated = parseMsg(msg, ClientHydrateSchema, 'clients/get');
    return validated.obj;
  }, []);

  const createMut = useMutation({
    mutationFn: (payload: unknown) =>
      HttpUtil.post('/panel/api/clients/add', payload, JSON_HEADERS),
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const bulkAssignGroupMut = useMutation({
    mutationFn: (body: { emails: string[]; group: string }) =>
      HttpUtil.post('/panel/api/clients/bulkAssignGroup', body, JSON_HEADERS),
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const updateMut = useMutation({
    mutationFn: ({ email, client }: { email: string; client: unknown }) =>
      HttpUtil.post(`/panel/api/clients/update/${encodeURIComponent(email)}`, client, JSON_HEADERS),
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const removeMut = useMutation({
    mutationFn: ({ email, keepTraffic }: { email: string; keepTraffic?: boolean }) => {
      const url = keepTraffic
        ? `/panel/api/clients/del/${encodeURIComponent(email)}?keepTraffic=1`
        : `/panel/api/clients/del/${encodeURIComponent(email)}`;
      return HttpUtil.post(url);
    },
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const bulkDeleteMut = useMutation({
    mutationFn: async (payload: { emails: string[]; keepTraffic?: boolean }): Promise<Msg<BulkDeleteResult>> => {
      const raw = await HttpUtil.post('/panel/api/clients/bulkDel', payload, JSON_HEADERS);
      return parseMsg(raw, BulkDeleteResultSchema, 'clients/bulkDel');
    },
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const bulkCreateMut = useMutation({
    mutationFn: async (payloads: unknown[]): Promise<Msg<BulkCreateResult>> => {
      const raw = await HttpUtil.post('/panel/api/clients/bulkCreate', payloads, JSON_HEADERS);
      return parseMsg(raw, BulkCreateResultSchema, 'clients/bulkCreate');
    },
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const bulkAdjustMut = useMutation({
    mutationFn: async (payload: { emails: string[]; addDays: number; addBytes: number }): Promise<Msg<BulkAdjustResult>> => {
      const raw = await HttpUtil.post('/panel/api/clients/bulkAdjust', payload, JSON_HEADERS);
      return parseMsg(raw, BulkAdjustResultSchema, 'clients/bulkAdjust');
    },
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const attachMut = useMutation({
    mutationFn: ({ email, inboundIds }: { email: string; inboundIds: number[] }) =>
      HttpUtil.post(`/panel/api/clients/${encodeURIComponent(email)}/attach`, { inboundIds }, JSON_HEADERS),
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const detachMut = useMutation({
    mutationFn: ({ email, inboundIds }: { email: string; inboundIds: number[] }) =>
      HttpUtil.post(`/panel/api/clients/${encodeURIComponent(email)}/detach`, { inboundIds }, JSON_HEADERS),
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const resetTrafficMut = useMutation({
    mutationFn: (email: string) =>
      HttpUtil.post(`/panel/api/clients/resetTraffic/${encodeURIComponent(email)}`),
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const resetAllTrafficsMut = useMutation({
    mutationFn: () => HttpUtil.post('/panel/api/clients/resetAllTraffics'),
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const delDepletedMut = useMutation({
    mutationFn: async () => {
      const raw = await HttpUtil.post('/panel/api/clients/delDepleted');
      return parseMsg(raw, DelDepletedResultSchema, 'clients/delDepleted');
    },
    onSuccess: (msg) => { if (msg?.success) invalidateAll(); },
  });

  const create = useCallback((payload: unknown) => createMut.mutateAsync(payload), [createMut]);
  const update = useCallback((email: string, client: unknown) => {
    if (!email) return Promise.resolve(null as unknown as Msg<unknown>);
    return updateMut.mutateAsync({ email, client });
  }, [updateMut]);
  const remove = useCallback((email: string, keepTraffic = false) => {
    if (!email) return Promise.resolve(null as unknown as Msg<unknown>);
    return removeMut.mutateAsync({ email, keepTraffic });
  }, [removeMut]);
  const bulkDelete = useCallback((emails: string[], keepTraffic = false) => {
    if (!Array.isArray(emails) || emails.length === 0) return Promise.resolve(null as unknown as Msg<BulkDeleteResult>);
    return bulkDeleteMut.mutateAsync({ emails, keepTraffic });
  }, [bulkDeleteMut]);
  const bulkCreate = useCallback((payloads: unknown[]) => {
    if (!Array.isArray(payloads) || payloads.length === 0) return Promise.resolve(null as unknown as Msg<BulkCreateResult>);
    return bulkCreateMut.mutateAsync(payloads);
  }, [bulkCreateMut]);
  const bulkAdjust = useCallback((emails: string[], addDays: number, addBytes: number) => {
    if (!Array.isArray(emails) || emails.length === 0) return Promise.resolve(null);
    return bulkAdjustMut.mutateAsync({ emails, addDays, addBytes });
  }, [bulkAdjustMut]);
  const bulkAssignGroup = useCallback((emails: string[], group: string) => {
    if (!Array.isArray(emails) || emails.length === 0) return Promise.resolve(null);
    return bulkAssignGroupMut.mutateAsync({ emails, group });
  }, [bulkAssignGroupMut]);
  const attach = useCallback((email: string, inboundIds: number[]) => {
    if (!email) return Promise.resolve(null as unknown as Msg<unknown>);
    return attachMut.mutateAsync({ email, inboundIds });
  }, [attachMut]);
  const detach = useCallback((email: string, inboundIds: number[]) => {
    if (!email) return Promise.resolve(null as unknown as Msg<unknown>);
    return detachMut.mutateAsync({ email, inboundIds });
  }, [detachMut]);
  const resetTraffic = useCallback((client: ClientRecord) => {
    if (!client?.email) return Promise.resolve(null as unknown as Msg<unknown>);
    return resetTrafficMut.mutateAsync(client.email);
  }, [resetTrafficMut]);
  const resetAllTraffics = useCallback(() => resetAllTrafficsMut.mutateAsync(), [resetAllTrafficsMut]);
  const delDepleted = useCallback(() => delDepletedMut.mutateAsync(), [delDepletedMut]);

  const setEnable = useCallback(async (client: ClientRecord, enable: boolean) => {
    if (!client?.email) return null;
    const payload = {
      email: client.email,
      subId: client.subId,
      id: client.uuid,
      password: client.password,
      auth: client.auth,
      totalGB: client.totalGB || 0,
      expiryTime: client.expiryTime || 0,
      limitIp: client.limitIp || 0,
      comment: client.comment || '',
      enable: !!enable,
    };
    return update(client.email, payload);
  }, [update]);

  // WS-driven in-place merges. Page wires these via useWebSocket; the bridge
  // covers coarse 'invalidate' and 'inbounds' events centrally.
  const queryRef = useRef(query);
  queryRef.current = query;

  const applyTrafficEvent = useCallback((payload: unknown) => {
    if (!payload || typeof payload !== 'object') return;
    const p = payload as { onlineClients?: string[] };
    if (Array.isArray(p.onlineClients)) {
      queryClient.setQueryData(keys.clients.onlines(), p.onlineClients);
    }
  }, [queryClient]);

  const applyClientStatsEvent = useCallback((payload: unknown) => {
    if (!payload || typeof payload !== 'object') return;
    const p = payload as { clients?: (ClientTraffic & { email?: string })[] };
    if (!Array.isArray(p.clients) || p.clients.length === 0) return;
    const byEmail = new Map<string, ClientTraffic>();
    for (const row of p.clients) {
      if (row && row.email) byEmail.set(row.email, row);
    }
    queryClient.setQueryData<ClientPageResponse>(keys.clients.list(queryRef.current), (prev) => {
      if (!prev) return prev;
      let touched = false;
      const next = prev.items.slice();
      for (let i = 0; i < next.length; i++) {
        const row = next[i];
        const upd = byEmail.get(row?.email);
        if (!upd) continue;
        const merged: ClientTraffic = { ...(row.traffic || {}) };
        if (typeof upd.up === 'number') merged.up = upd.up;
        if (typeof upd.down === 'number') merged.down = upd.down;
        if (typeof upd.total === 'number') merged.total = upd.total;
        if (typeof upd.expiryTime === 'number') merged.expiryTime = upd.expiryTime;
        if (typeof upd.enable === 'boolean') merged.enable = upd.enable;
        if (typeof upd.lastOnline === 'number') merged.lastOnline = upd.lastOnline;
        next[i] = { ...row, traffic: merged };
        touched = true;
      }
      if (!touched) return prev;
      return { ...prev, items: next };
    });
  }, [queryClient]);

  useEffect(() => {
    queryRef.current = query;
  }, [query]);

  return {
    clients,
    total,
    filtered,
    summary,
    allGroups,
    hydrate,
    query,
    setQuery,
    inbounds,
    onlines,
    loading,
    fetched,
    subSettings,
    ipLimitEnable,
    tgBotEnable,
    expireDiff,
    trafficDiff,
    pageSize,
    refresh,
    create,
    bulkCreate,
    update,
    remove,
    bulkDelete,
    bulkAdjust,
    bulkAssignGroup,
    attach,
    detach,
    resetTraffic,
    resetAllTraffics,
    delDepleted,
    setEnable,
    applyTrafficEvent,
    applyClientStatsEvent,
  };
}