'use client';

import {Suspense, useCallback, useEffect, useMemo, useState} from 'react';
import {useMutation, useQuery, useQueryClient} from '@tanstack/react-query';
import axios from 'axios';
import {ArrowLeft, GitBranch, Save} from 'lucide-react';
import {useRouter, useSearchParams} from 'next/navigation';
import {toast} from 'sonner';

import {Badge} from '@/components/ui/badge';
import {Button} from '@/components/ui/button';
import {Label} from '@/components/ui/label';
import {Skeleton} from '@/components/ui/skeleton';
import {Switch} from '@/components/ui/switch';
import {services, type WAFRule, type WAFRuleGraph, type WAFRuleNode} from '@/lib/services';

import {getErrorMessage} from '../../components/helpers';
import {validateGraph} from './components/graph-validation';
import {NodeProperties} from './components/node-properties';
import {RuleFlowCanvas} from './components/rule-flow-canvas';
import {UnsavedChanges} from './components/unsaved-changes';
import {findGraphErrorTarget, type GraphErrorTarget} from './components/editor-behavior';

export default function WAFRuleEditorPage() {
  return <Suspense fallback={<EditorSkeleton/>}><EditorContent/></Suspense>;
}

function EditorContent() {
  const router = useRouter();
  const searchParams = useSearchParams();
  const queryClient = useQueryClient();
  const id = Number(searchParams.get('id'));
  const [graph, setGraph] = useState<WAFRuleGraph>();
  const [revision, setRevision] = useState(0);
  const [selectedId, setSelectedId] = useState<string>();
  const [selectedEdgeId, setSelectedEdgeId] = useState<string>();
  const [focusTarget, setFocusTarget] = useState<GraphErrorTarget>();
  const [dirty, setDirty] = useState(false);
  const [conflict, setConflict] = useState(false);
  const ruleQueryKey = ['waf-rule', id] as const;

  const ruleQuery = useQuery({queryKey: ruleQueryKey, queryFn: () => services.openflareWaf.getRule(id), enabled: Number.isFinite(id) && id > 0});
  const ipGroupsQuery = useQuery({queryKey: ['waf-ip-groups'], queryFn: () => services.openflareWaf.listIPGroups()});
  useEffect(() => { if (ruleQuery.data && !dirty) { setGraph(ruleQuery.data.graph); setRevision(ruleQuery.data.revision); } }, [dirty, ruleQuery.data]);
  const issues = useMemo(() => graph ? validateGraph(graph) : [], [graph]);
  const selected = graph?.nodes.find((node) => node.id === selectedId);

  const saveMutation = useMutation({
    mutationFn: () => services.openflareWaf.saveRuleGraph(id, {revision, graph: graph!}),
    onSuccess: (rule) => { setGraph(rule.graph); setRevision(rule.revision); setDirty(false); setConflict(false); queryClient.setQueryData(['waf-rule', id], rule); toast.success('规则图已保存'); },
    onError: (error) => {
      if (axios.isAxiosError(error) && error.response?.status === 409) { setConflict(true); toast.error('规则已在其他页面更新，请重新加载'); return; }
      const payload = axios.isAxiosError(error) ? error.response?.data : error;
      const target = graph ? findGraphErrorTarget(payload, graph.nodes.map((node) => node.id), graph.edges.map((edge) => edge.id)) : undefined;
      if (target?.kind === 'node') { setSelectedEdgeId(undefined); setSelectedId(target.id); }
      if (target?.kind === 'edge') { setSelectedId(undefined); setSelectedEdgeId(target.id); }
      setFocusTarget(target ? {...target} : undefined);
      toast.error('保存失败，请检查标记的节点和连线');
    },
  });

  const metaMutation = useMutation({
    mutationFn: (enabled: boolean) => services.openflareWaf.updateRuleMeta(id, {
      name: ruleQuery.data!.name,
      enabled,
    }),
    onMutate: async (enabled) => {
      await queryClient.cancelQueries({queryKey: ruleQueryKey});
      const previous = queryClient.getQueryData<WAFRule>(ruleQueryKey);
      queryClient.setQueryData<WAFRule>(ruleQueryKey, (current) =>
        current ? {...current, enabled} : current,
      );
      return {previous};
    },
    onError: (error, _enabled, context) => {
      if (context?.previous) {
        queryClient.setQueryData(ruleQueryKey, context.previous);
      }
      toast.error(getErrorMessage(error));
    },
    onSuccess: (rule) => {
      queryClient.setQueryData(ruleQueryKey, rule);
      void queryClient.invalidateQueries({queryKey: ruleQueryKey, refetchType: 'none'});
      void queryClient.invalidateQueries({queryKey: ['openflare', 'waf', 'rule-groups']});
      void queryClient.invalidateQueries({queryKey: ['openflare', 'config-versions', 'diff']});
      toast.success(rule.enabled ? '规则已启用' : '规则已停用');
    },
  });

  const changeGraph = useCallback((next: WAFRuleGraph, persistent = true) => { setGraph(next); if (persistent) { setDirty(true); setConflict(false); } }, []);
  const changeNode = useCallback((next: WAFRuleNode) => { if (!graph) return; changeGraph({...graph, nodes: graph.nodes.map((node) => node.id === next.id ? next : node)}); }, [changeGraph, graph]);
  const leave = () => { if (!dirty || window.confirm('存在未保存的更改，确定离开吗？')) router.push('/waf'); };

  if (!Number.isFinite(id) || id <= 0) return <div className="w-full px-1 py-6"><p className="text-sm text-destructive">缺少有效的规则 ID。</p></div>;
  if (ruleQuery.isError) return <div className="flex w-full flex-col items-start gap-3 px-1 py-6"><p className="text-sm text-destructive">规则加载失败，请重试。</p><Button variant="outline" onClick={() => void ruleQuery.refetch()}>重新加载</Button></div>;
  if (ruleQuery.isLoading || !graph || !ruleQuery.data) return <EditorSkeleton/>;

  return (
    <div className="flex h-[calc(100dvh-4rem)] w-full flex-col px-1 py-6">
      <UnsavedChanges dirty={dirty}/>
      <header className="mb-4 flex items-center justify-between gap-4">
        <div className="flex min-w-0 items-center gap-2"><GitBranch className="size-5 text-primary"/><h1 className="text-2xl font-semibold tracking-tight">{ruleQuery.data.name}</h1><Badge variant={ruleQuery.data.enabled ? 'default' : 'secondary'}>{ruleQuery.data.enabled ? '已启用' : '已停用'}</Badge><Badge variant={issues.length === 0 ? 'outline' : 'destructive'}>{issues.length === 0 ? '图校验通过' : `${issues.length} 个问题`}</Badge>{dirty && <Badge variant="secondary">未保存</Badge>}</div>
        <div className="flex shrink-0 items-center gap-2">
          <div className="flex items-center gap-2">
            <Switch
              id="rule-enabled"
              checked={ruleQuery.data.enabled}
              disabled={dirty || issues.length > 0 || saveMutation.isPending || metaMutation.isPending}
              onCheckedChange={(enabled) => metaMutation.mutate(enabled)}
            />
            <Label htmlFor="rule-enabled">启用规则</Label>
          </div>
          <Button variant="outline" onClick={leave}><ArrowLeft data-icon="inline-start"/>返回</Button>
          {conflict && <Button variant="outline" onClick={() => { setDirty(false); setConflict(false); void ruleQuery.refetch(); }}>重新加载</Button>}
          <Button disabled={!dirty || issues.length > 0 || saveMutation.isPending} onClick={() => saveMutation.mutate()}><Save data-icon="inline-start"/>{saveMutation.isPending ? '保存中...' : '保存'}</Button>
        </div>
      </header>
      <div className="flex min-h-0 flex-1 overflow-hidden rounded-xl border bg-background shadow-sm"><RuleFlowCanvas graph={graph} issues={issues} selectedId={selectedId} selectedEdgeId={selectedEdgeId} focusTarget={focusTarget} onGraphChange={changeGraph} onSelect={setSelectedId} onSelectEdge={setSelectedEdgeId}/><NodeProperties node={selected} ipGroups={ipGroupsQuery.data ?? []} onChange={changeNode}/></div>
    </div>
  );
}

function EditorSkeleton() { return <div className="flex w-full flex-col gap-4 px-1 py-6"><div className="flex items-center gap-2"><Skeleton className="size-5"/><Skeleton className="h-8 w-64"/></div><Skeleton className="h-[70dvh] w-full"/></div>; }