'use client';

import React, { useCallback, useEffect, useState } from 'react';
import { Bot, Plus, RefreshCw, Trash2, Loader2, AlertCircle, Tags, ChevronDown } from 'lucide-react';

import { addAgent, deleteAgent, listAgents, refreshAgents } from '@/lib/api';
import { useChatStore } from '@/lib/store';
import type { UiAgentDescriptor } from '@/types';
import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Collapsible, CollapsibleContent, CollapsibleTrigger } from '@/components/ui/collapsible';
import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger } from '@/components/ui/dialog';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Textarea } from '@/components/ui/textarea';

const EMPTY_FORM = {
  id: '',
  name: '',
  description: '',
  base_url: '',
  endpoint: '',
  card_url: '',
  auth_env: '',
  auth_mode: 'none',
  auth_audience: '',
  auth_scopes: '',
  tags: '',
  aliases: '',
};

export default function AgentsPage() {
  const cachedAgents = useChatStore((s) => s.agentRegistry);
  const setCachedAgents = useChatStore((s) => s.setAgentRegistry);
  const [agents, setAgents] = useState<UiAgentDescriptor[]>(cachedAgents);
  const [loading, setLoading] = useState(cachedAgents.length === 0);
  const [refreshing, setRefreshing] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [dialogOpen, setDialogOpen] = useState(false);
  const [submitting, setSubmitting] = useState(false);
  const [advancedOpen, setAdvancedOpen] = useState(false);
  const [form, setForm] = useState(EMPTY_FORM);

  const load = useCallback(async (background = false) => {
    if (background) {
      setRefreshing(true);
    } else {
      setLoading(true);
    }
    setError(null);
    try {
      const data = await listAgents();
      const nextAgents = Array.isArray(data) ? data : [];
      setAgents(nextAgents);
      setCachedAgents(nextAgents);
    } catch (err: any) {
      setError(err.message || '加载智能体失败');
    } finally {
      if (background) {
        setRefreshing(false);
      } else {
        setLoading(false);
      }
    }
  }, [setCachedAgents]);

  useEffect(() => {
    void load(cachedAgents.length > 0);
  }, [cachedAgents.length, load]);

  const handleRefresh = async () => {
    setError(null);
    setRefreshing(true);
    try {
      const data = await refreshAgents();
      const nextAgents = data.agents || [];
      setAgents(nextAgents);
      setCachedAgents(nextAgents);
    } catch (err: any) {
      setError(err.message || '刷新智能体失败');
    } finally {
      setRefreshing(false);
    }
  };

  const handleDialogOpenChange = (open: boolean) => {
    setDialogOpen(open);
    if (!open) {
      setAdvancedOpen(false);
      setForm(EMPTY_FORM);
    }
  };

  const handleCreate = async (e: React.FormEvent) => {
    e.preventDefault();
    const hasAddress = [form.base_url, form.endpoint, form.card_url].some((value) => value.trim());
    if (!hasAddress) {
      setError('请至少填写 A2A 部署地址、接口地址或卡片地址');
      return;
    }
    setSubmitting(true);
    setError(null);
    try {
      await addAgent({
        id: form.id || undefined,
        name: form.name || undefined,
        description: form.description || undefined,
        protocol: 'a2a',
        base_url: form.base_url || undefined,
        endpoint: form.endpoint || undefined,
        card_url: form.card_url || undefined,
        auth_env: form.auth_env || undefined,
        auth_mode: form.auth_mode || 'none',
        auth_audience: form.auth_mode === 'none' ? undefined : form.auth_audience || undefined,
        auth_scopes: form.auth_mode === 'none'
          ? []
          : form.auth_scopes.split(',').map((item) => item.trim()).filter(Boolean),
        tags: form.tags.split(',').map((item) => item.trim()).filter(Boolean),
        aliases: form.aliases.split(',').map((item) => item.trim()).filter(Boolean),
      });
      handleDialogOpenChange(false);
      await load();
    } catch (err: any) {
      setError(err.message || '新增智能体失败');
    } finally {
      setSubmitting(false);
    }
  };

  const handleDelete = async (agentId: string) => {
    try {
      await deleteAgent(agentId);
      await load();
    } catch (err: any) {
      setError(err.message || '删除智能体失败');
    }
  };

  if (loading) {
    return (
      <div className="flex items-center justify-center py-20">
        <Loader2 className="w-6 h-6 animate-spin text-muted-foreground" />
      </div>
    );
  }

  return (
    <div className="max-w-6xl mx-auto p-6 space-y-6">
      <div className="flex items-center justify-between gap-4 flex-wrap">
        <div>
          <h1 className="text-2xl font-bold flex items-center gap-2">
            <Bot className="w-6 h-6" />
            智能体
          </h1>
          <p className="text-sm text-muted-foreground mt-1">
            管理工作区智能体，并查看来自插件、技能和内置能力的可委派目标。
          </p>
        </div>
        <div className="flex items-center gap-2">
          <Button variant="outline" size="sm" onClick={handleRefresh}>
            <RefreshCw className={`w-4 h-4 mr-2 ${refreshing ? 'animate-spin' : ''}`} />
            刷新
          </Button>
          <Dialog open={dialogOpen} onOpenChange={handleDialogOpenChange}>
            <DialogTrigger asChild>
              <Button size="sm">
                <Plus className="w-4 h-4 mr-2" />
                新增智能体
              </Button>
            </DialogTrigger>
            <DialogContent className="sm:max-w-2xl">
              <DialogHeader>
                <DialogTitle>新增工作区智能体</DialogTitle>
              </DialogHeader>
              <form className="space-y-4" onSubmit={handleCreate}>
                <div className="space-y-2">
                  <Label htmlFor="base_url">A2A 部署地址</Label>
                  <Input
                    id="base_url"
                    value={form.base_url}
                    onChange={(e) => setForm((s) => ({ ...s, base_url: e.target.value }))}
                    placeholder="https://agent.example.com 或 agent.example.com:19090"
                  />
                  <p className="text-xs text-muted-foreground leading-relaxed">
                    默认只需要填写部署地址。保存时会自动读取
                    <code className="mx-1">/.well-known/agent-card</code>
                    、<code className="mx-1">/.well-known/agent-card.json</code>
                    和<code className="mx-1">/.well-known/agent.json</code>
                    ，并补齐 ID、名称、描述、接口地址等信息。
                  </p>
                </div>
                <Collapsible open={advancedOpen} onOpenChange={setAdvancedOpen}>
                  <CollapsibleTrigger asChild>
                    <Button type="button" variant="outline" className="w-full justify-between">
                      高级设置（可选）
                      <ChevronDown className={`w-4 h-4 transition-transform ${advancedOpen ? 'rotate-180' : ''}`} />
                    </Button>
                  </CollapsibleTrigger>
                  <CollapsibleContent className="space-y-4 pt-4">
                    <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
                      <div className="space-y-2">
                        <Label htmlFor="id">ID</Label>
                        <Input id="id" value={form.id} onChange={(e) => setForm((s) => ({ ...s, id: e.target.value }))} placeholder="留空则从 A2A card 自动生成" />
                      </div>
                      <div className="space-y-2">
                        <Label htmlFor="name">名称</Label>
                        <Input id="name" value={form.name} onChange={(e) => setForm((s) => ({ ...s, name: e.target.value }))} placeholder="留空则从 A2A card 自动填充" />
                      </div>
                    </div>
                    <div className="space-y-2">
                      <Label htmlFor="description">描述</Label>
                      <Textarea id="description" value={form.description} onChange={(e) => setForm((s) => ({ ...s, description: e.target.value }))} rows={3} placeholder="留空则从 A2A card 自动填充" />
                    </div>
                    <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
                      <div className="space-y-2">
                        <Label htmlFor="endpoint">接口地址</Label>
                        <Input id="endpoint" value={form.endpoint} onChange={(e) => setForm((s) => ({ ...s, endpoint: e.target.value }))} placeholder="https://agent.example.com/rpc" />
                      </div>
                      <div className="space-y-2">
                        <Label htmlFor="card_url">卡片地址</Label>
                        <Input id="card_url" value={form.card_url} onChange={(e) => setForm((s) => ({ ...s, card_url: e.target.value }))} placeholder="https://agent.example.com/.well-known/agent-card" />
                      </div>
                    </div>
                    <div className="grid grid-cols-1 sm:grid-cols-3 gap-4">
                      <div className="space-y-2">
                        <Label htmlFor="auth_mode">鉴权模式</Label>
                        <select
                          id="auth_mode"
                          value={form.auth_mode}
                          onChange={(e) => setForm((s) => ({ ...s, auth_mode: e.target.value }))}
                          className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm"
                        >
                          <option value="none">none</option>
                          <option value="oauth_backend_token">oauth_backend_token</option>
                        </select>
                      </div>
                      <div className="space-y-2">
                        <Label htmlFor="auth_audience">Audience</Label>
                        <Input id="auth_audience" value={form.auth_audience} onChange={(e) => setForm((s) => ({ ...s, auth_audience: e.target.value }))} placeholder="planner 或 a2a:planner" />
                      </div>
                      <div className="space-y-2">
                        <Label htmlFor="auth_scopes">Scopes</Label>
                        <Input id="auth_scopes" value={form.auth_scopes} onChange={(e) => setForm((s) => ({ ...s, auth_scopes: e.target.value }))} placeholder="run_task" />
                      </div>
                    </div>
                    <div className="space-y-2">
                      <Label htmlFor="auth_env">认证环境变量</Label>
                      <Input id="auth_env" value={form.auth_env} onChange={(e) => setForm((s) => ({ ...s, auth_env: e.target.value }))} placeholder="例如：MY_AGENT_TOKEN" />
                    </div>
                    <div className="grid grid-cols-1 sm:grid-cols-2 gap-4">
                      <div className="space-y-2">
                        <Label htmlFor="tags">标签</Label>
                        <Input id="tags" value={form.tags} onChange={(e) => setForm((s) => ({ ...s, tags: e.target.value }))} placeholder="例如：评审, 代码, 安全" />
                      </div>
                      <div className="space-y-2">
                        <Label htmlFor="aliases">别名</Label>
                        <Input id="aliases" value={form.aliases} onChange={(e) => setForm((s) => ({ ...s, aliases: e.target.value }))} placeholder="例如：reviewer, audit-agent" />
                      </div>
                    </div>
                  </CollapsibleContent>
                </Collapsible>
                <div className="rounded-md border border-border/70 bg-muted/30 px-3 py-2 text-xs text-muted-foreground">
                  如果远端 card 需要额外鉴权信息，或者服务没有暴露标准
                  <code className="mx-1">.well-known</code>
                  路径，再展开高级设置手动补充。
                </div>
                <div className="flex justify-end gap-2">
                  <Button type="button" variant="outline" onClick={() => handleDialogOpenChange(false)}>
                    取消
                  </Button>
                  <Button type="submit" disabled={submitting}>
                    {submitting ? <Loader2 className="w-4 h-4 animate-spin mr-2" /> : <Plus className="w-4 h-4 mr-2" />}
                    保存
                  </Button>
                </div>
              </form>
            </DialogContent>
          </Dialog>
        </div>
      </div>

      {error && (
        <Card className="border-destructive">
          <CardContent className="pt-6">
            <div className="flex items-center gap-2 text-destructive text-sm">
              <AlertCircle className="w-4 h-4" />
              {error}
            </div>
          </CardContent>
        </Card>
      )}

      <div className="grid grid-cols-1 xl:grid-cols-2 gap-4">
        {agents.map((agent) => {
          const isWorkspace = agent.source === 'workspace';
          return (
            <Card key={agent.id}>
              <CardHeader className="pb-3">
                <div className="flex items-start justify-between gap-4">
                  <div className="min-w-0 flex-1">
                    <CardTitle className="text-base truncate">{agent.name}</CardTitle>
                    <p className="text-xs text-muted-foreground mt-1 font-mono">{agent.id}</p>
                    <p className="text-sm text-muted-foreground mt-2 leading-relaxed">
                      {agent.description || '—'}
                    </p>
                  </div>
                  <div className="flex items-center gap-2 flex-wrap justify-end">
                    <Badge variant="outline">{agent.source === 'workspace' ? '工作区' : agent.source === 'plugin' ? '插件' : agent.source === 'skill' ? '技能' : '内置'}</Badge>
                    <Badge variant="secondary">{agent.protocol || '本地'}</Badge>
                    {agent.support_streaming && <Badge className="bg-sky-600">流式</Badge>}
                    {agent.support_group && <Badge className="bg-emerald-600">群组</Badge>}
                  </div>
                </div>
              </CardHeader>
              <CardContent className="space-y-3 pt-0">
                <div className="grid grid-cols-1 gap-2 text-xs text-muted-foreground">
                  {agent.base_url && <div><span className="font-medium text-foreground">基础地址：</span> {agent.base_url}</div>}
                  {agent.endpoint && <div><span className="font-medium text-foreground">接口地址：</span> {agent.endpoint}</div>}
                  {agent.card_url && <div><span className="font-medium text-foreground">卡片地址：</span> {agent.card_url}</div>}
                  {agent.auth_env && <div><span className="font-medium text-foreground">认证变量：</span> {agent.auth_env}</div>}
                  {agent.auth_mode && agent.auth_mode !== 'none' && <div><span className="font-medium text-foreground">鉴权模式：</span> {agent.auth_mode}</div>}
                  {agent.auth_audience && <div><span className="font-medium text-foreground">Audience：</span> {agent.auth_audience}</div>}
                  {(agent.auth_scopes || []).length > 0 && <div><span className="font-medium text-foreground">Scopes：</span> {(agent.auth_scopes || []).join(', ')}</div>}
                </div>
                {(agent.tags.length > 0 || agent.aliases.length > 0) && (
                  <div className="space-y-2">
                    {agent.tags.length > 0 && (
                      <div className="flex items-start gap-2 flex-wrap">
                        <Tags className="w-3.5 h-3.5 mt-0.5 text-muted-foreground" />
                        {agent.tags.map((tag) => (
                          <Badge key={tag} variant="outline" className="text-xs">{tag}</Badge>
                        ))}
                      </div>
                    )}
                    {agent.aliases.length > 0 && (
                      <div className="flex items-center gap-2 flex-wrap text-xs text-muted-foreground">
                        <span className="font-medium text-foreground">别名：</span>
                        {agent.aliases.map((alias) => (
                          <code key={alias} className="px-2 py-0.5 rounded bg-muted">{alias}</code>
                        ))}
                      </div>
                    )}
                  </div>
                )}
                <div className="flex justify-end">
                  {isWorkspace ? (
                    <Button variant="outline" size="sm" onClick={() => handleDelete(agent.id)}>
                      <Trash2 className="w-4 h-4 mr-2" />
                      删除
                    </Button>
                  ) : (
                    <span className="text-xs text-muted-foreground">只读来源</span>
                  )}
                </div>
              </CardContent>
            </Card>
          );
        })}
      </div>
    </div>
  );
}