/**
 * LLMSettings — LLM 配置 Tab
 *
 * 从 SettingsModal.tsx 提取（v0.4.1 拆分）。
 * 功能：主 Provider / 故障转移 Provider / 上下文窗口配置，批量保存。
 */

import { useState, useEffect, useCallback, useRef } from 'react';
import {
  Autocomplete,
  Box,
  Button,
  Chip,
  LinearProgress,
  TextField,
  Select,
  MenuItem,
  Stack,
  Typography,
  Divider,
  InputLabel,
  FormControl,
  IconButton,
  CircularProgress,
  FormControlLabel,
  Switch,
} from '@mui/material';
import { Eye, EyeOff } from 'lucide-react';
import { useAgentStore } from '@renderer/stores/agent-store';
import { PROVIDER_LABELS } from '@renderer/lib/constants';
import { PROVIDER_URLS } from './useConfig';

/** v0.7.2 P3-9: 动态模型条目（渲染端子集，与 global.d.ts MetonaModelInfoLite 对齐） */
interface ModelOption {
  id: string;
  name?: string;
  supportsToolCalling?: boolean;
  supportsThinking?: boolean;
  description?: string;
}

export function LLMSettings() {
  // 改为本地 state + Save 按钮统一提交，避免 onChange 实时落库导致：
  // 1. 改 Base URL 时被回滚卡死（useConfig seqRef 机制与连续输入冲突）
  // 2. 每按一个字符就触发一次 IPC + DB + reloadAdapter，浪费且会打断输入
  // 3. 错误提示笼统（不指向具体字段）
  const [provider, setProvider] = useState<string>('');
  const [model, setModel] = useState<string>('');
  const [apiKey, setApiKey] = useState<string>('');
  const [baseURL, setBaseURL] = useState<string>('');
  const [numCtx, setNumCtx] = useState<number | null>(null);
  // v0.3.1: DeepSeek/Agnes/MiMo contextWindow 可配置（不再写死）
  const [dsCtxWindow, setDsCtxWindow] = useState<number>(1000000);
  const [agnesCtxWindow, setAgnesCtxWindow] = useState<number>(1000000);
  const [mimoCtxWindow, setMimoCtxWindow] = useState<number>(1000000);
  // P3: OpenAI/Anthropic contextWindow
  const [oaCtxWindow, setOaCtxWindow] = useState<number>(128000);
  const [anthropicCtxWindow, setAnthropicCtxWindow] = useState<number>(200000);
  // P1: 故障转移 Provider 配置
  const [fbProvider, setFbProvider] = useState<string>('');
  const [fbModel, setFbModel] = useState<string>('');
  const [fbApiKey, setFbApiKey] = useState<string>('');
  const [fbBaseURL, setFbBaseURL] = useState<string>('');
  const [showKey, setShowKey] = useState(false);
  const [showFbKey, setShowFbKey] = useState(false);
  const [loaded, setLoaded] = useState(false);
  const [saving, setSaving] = useState(false);
  // v0.5.4: 多模态总开关（未开启时禁止上传图片，即使模型支持）
  const [multimodalEnabled, setMultimodalEnabled] = useState(false);
  // v0.5.0: DeepSeek 余额显示（复用主进程 getBalance，原为适配器死代码）
  const [balance, setBalance] = useState<{
    currency: string;
    totalBalance: string;
    grantedBalance: string;
    toppedUpBalance: string;
  } | null>(null);
  const [balanceError, setBalanceError] = useState<string | null>(null);
  const [balanceLoading, setBalanceLoading] = useState(false);

  // ===== v0.7.2 P3-9: 动态模型列表 =====
  const [modelOptions, setModelOptions] = useState<ModelOption[]>([]);
  const [modelsLoading, setModelsLoading] = useState(false);
  const [modelsError, setModelsError] = useState<string | null>(null);
  const [modelsLoaded, setModelsLoaded] = useState(false);

  // ===== v0.7.2 P3-10: Ollama 模型下载 =====
  const [pullModelName, setPullModelName] = useState('');
  const [pulling, setPulling] = useState(false);
  const [pullStatus, setPullStatus] = useState<{ label: string; percent: number | null } | null>(
    null,
  );

  const loadModels = useCallback(async () => {
    if (!window.metona?.llm?.listModels) return;
    setModelsLoading(true);
    setModelsError(null);
    try {
      const r = await window.metona.llm.listModels();
      if (r.success && r.data) {
        setModelOptions(r.data);
        setModelsLoaded(true);
      } else {
        setModelOptions([]);
        setModelsError(r.error ?? '获取模型列表失败');
      }
    } catch (err) {
      setModelOptions([]);
      setModelsError((err as Error).message);
    } finally {
      setModelsLoading(false);
    }
  }, []);

  const handlePull = useCallback(async () => {
    const name = pullModelName.trim();
    if (!name || pulling || !window.metona?.llm?.pullModel) return;
    setPulling(true);
    setPullStatus({ label: '连接 Ollama 服务…', percent: null });
    try {
      const r = await window.metona.llm.pullModel(name);
      if (r.success) {
        import('@metona-team/metona-toast')
          .then((mod) => mod.default.success(`模型 ${name} 下载完成`))
          .catch(() => {});
      } else if (!r.aborted) {
        import('@metona-team/metona-toast')
          .then((mod) => mod.default.error(`模型下载失败：${r.error ?? '未知错误'}`))
          .catch(() => {});
      }
    } catch (err) {
      import('@metona-team/metona-toast')
        .then((mod) => mod.default.error(`模型下载失败：${(err as Error).message}`))
        .catch(() => {});
    } finally {
      // onOllamaPullEnded 也会复位（时序竞态下双保险），此处兜底同步复位
      setPulling(false);
      setPullStatus(null);
    }
  }, [pullModelName, pulling]);

  const handlePullCancel = useCallback(async () => {
    if (!window.metona?.llm?.cancelPullModel) return;
    try {
      await window.metona.llm.cancelPullModel();
    } catch (err) {
      console.error('[LLMSettings] cancelPullModel failed:', err);
    }
  }, []);

  // 订阅下载进度/结束事件（全局单任务广播，无需按 model 过滤）
  const pullingRef = useRef(false);
  pullingRef.current = pulling;
  useEffect(() => {
    if (!window.metona?.llm?.onOllamaPullProgress) return;
    const offProgress = window.metona.llm.onOllamaPullProgress((d) => {
      const percent =
        d.total != null && d.completed != null && d.total > 0
          ? Math.min(100, (d.completed / d.total) * 100)
          : null;
      setPullStatus({ label: d.status, percent });
    });
    const offEnded = window.metona.llm.onOllamaPullEnded(() => {
      if (!pullingRef.current) return;
      setPulling(false);
      setPullStatus(null);
      // 本地库新增了模型 — 刷新已加载的列表（未加载过则保持未加载语义）
      void loadModels();
    });
    return () => {
      offProgress();
      offEnded();
    };
  }, [loadModels]);

  const loadBalance = useCallback(async () => {
    if (!window.metona?.llm?.getBalance) return;
    setBalanceLoading(true);
    setBalanceError(null);
    try {
      const r = await window.metona.llm.getBalance();
      if (r.success && r.data) {
        setBalance(r.data);
      } else {
        setBalance(null);
        setBalanceError(r.error ?? '查询失败');
      }
    } catch (err) {
      setBalance(null);
      setBalanceError((err as Error).message);
    } finally {
      setBalanceLoading(false);
    }
  }, []);

  // DeepSeek Provider 且配置加载完成后自动查询一次（仅一次，避免频繁请求 API）
  // 依赖故意不含 apiKey —— 仅在加载完成与 Provider 切换时查询，apiKey 输入变化不重复请求
  useEffect(() => {
    if (loaded && provider === 'deepseek' && apiKey.trim()) {
      void loadBalance();
    } else {
      setBalance(null);
      setBalanceError(null);
    }
  }, [loaded, provider]);

  // 初始化：一次性加载所有 LLM 配置字段
  useEffect(() => {
    let cancelled = false;
    const load = async () => {
      if (!window.metona?.config?.get) {
        setLoaded(true);
        return;
      }
      try {
        const results = await Promise.all([
          window.metona.config.get('llm.provider'),
          window.metona.config.get('llm.model'),
          window.metona.config.get('llm.apiKey'),
          window.metona.config.get('llm.baseURL'),
          window.metona.config.get('ollama.numCtx'),
          window.metona.config.get('deepseek.contextWindow'),
          window.metona.config.get('agnes.contextWindow'),
          window.metona.config.get('mimo.contextWindow'),
          window.metona.config.get('openai.contextWindow'),
          window.metona.config.get('anthropic.contextWindow'),
          // P1: 故障转移配置
          window.metona.config.get('llm.fallbackProvider'),
          window.metona.config.get('llm.fallbackModel'),
          window.metona.config.get('llm.fallbackApiKey'),
          window.metona.config.get('llm.fallbackBaseURL'),
          // v0.5.4: 多模态开关
          window.metona.config.get('llm.multimodalEnabled'),
        ]);
        if (cancelled) return;
        const [p, m, k, u, nc, ds, ag, mi, oa, an, fbp, fbm, fbk, fbu, mm] = results;
        setProvider((p as string) ?? '');
        setModel((m as string) ?? '');
        setApiKey((k as string) ?? '');
        setBaseURL((u as string) ?? '');
        setNumCtx((nc as number | null) ?? null);
        if (typeof ds === 'number' && ds > 0) setDsCtxWindow(ds);
        if (typeof ag === 'number' && ag > 0) setAgnesCtxWindow(ag);
        if (typeof mi === 'number' && mi > 0) setMimoCtxWindow(mi);
        if (typeof oa === 'number' && oa > 0) setOaCtxWindow(oa);
        if (typeof an === 'number' && an > 0) setAnthropicCtxWindow(an);
        setFbProvider((fbp as string) ?? '');
        setFbModel((fbm as string) ?? '');
        setFbApiKey((fbk as string) ?? '');
        setFbBaseURL((fbu as string) ?? '');
        setMultimodalEnabled(mm === true);
      } catch (err) {
        console.error('[LLMSettings]', err);
      } finally {
        if (!cancelled) setLoaded(true);
      }
    };
    load();
    return () => {
      cancelled = true;
    };
  }, []);

  // 同步 Provider/Model 到 Agent Store（含 contextWindow）
  // 注意：仅同步运行时状态，不落库
  useEffect(() => {
    useAgentStore.getState().setProvider(provider, model);
  }, [provider, model]);

  // v0.3.1: contextWindow 变化时同步到 Agent Store（支持所有 Provider）
  useEffect(() => {
    if (provider === 'ollama') {
      if (numCtx != null && numCtx > 0) useAgentStore.setState({ contextWindow: numCtx });
    } else if (provider === 'deepseek') {
      if (dsCtxWindow != null && dsCtxWindow > 0)
        useAgentStore.setState({ contextWindow: dsCtxWindow });
    } else if (provider === 'agnes') {
      if (agnesCtxWindow != null && agnesCtxWindow > 0)
        useAgentStore.setState({ contextWindow: agnesCtxWindow });
    } else if (provider === 'mimo') {
      if (mimoCtxWindow != null && mimoCtxWindow > 0)
        useAgentStore.setState({ contextWindow: mimoCtxWindow });
    } else if (provider === 'openai') {
      if (oaCtxWindow != null && oaCtxWindow > 0)
        useAgentStore.setState({ contextWindow: oaCtxWindow });
    } else if (provider === 'anthropic') {
      if (anthropicCtxWindow != null && anthropicCtxWindow > 0)
        useAgentStore.setState({ contextWindow: anthropicCtxWindow });
    }
  }, [
    provider,
    numCtx,
    dsCtxWindow,
    agnesCtxWindow,
    mimoCtxWindow,
    oaCtxWindow,
    anthropicCtxWindow,
  ]);

  // ===== 字段级 inline 校验 =====
  // Base URL：非空时必须以 http:// 或 https:// 开头（避免漏写协议头导致发消息时报 Invalid URL）
  const urlError = !!baseURL && !/^https?:\/\/.+/.test(baseURL);
  // Model：非空时不允许包含空格（OpenAI API 会把空格后的部分当作额外参数）
  const modelHasSpace = !!model && /\s/.test(model);
  // contextWindow / numCtx：必须为有限正数且不低于最小值
  const numCtxError = numCtx != null && (!Number.isFinite(numCtx) || numCtx < 512);
  const dsCtxError = !Number.isFinite(dsCtxWindow) || dsCtxWindow < 4096;
  const agnesCtxError = !Number.isFinite(agnesCtxWindow) || agnesCtxWindow < 4096;
  const mimoCtxError = !Number.isFinite(mimoCtxWindow) || mimoCtxWindow < 4096;
  const oaCtxError = !Number.isFinite(oaCtxWindow) || oaCtxWindow < 4096;
  const anthropicCtxError = !Number.isFinite(anthropicCtxWindow) || anthropicCtxWindow < 4096;

  // 是否存在阻断保存的错误（API Key 为空只警告，不阻断 — 允许先填其他字段再回来填 key）
  const hasBlockingError =
    urlError ||
    modelHasSpace ||
    numCtxError ||
    (provider === 'deepseek' && dsCtxError) ||
    (provider === 'agnes' && agnesCtxError) ||
    (provider === 'mimo' && mimoCtxError) ||
    (provider === 'openai' && oaCtxError) ||
    (provider === 'anthropic' && anthropicCtxError);

  // 切换 Provider 时：清空 apiKey + 清空 model + 自动填充默认 URL
  // 不同 Provider 的 key/model 互不通用，避免用旧值调用新 API 导致 401 / model not found
  const handleProviderChange = (newProvider: string) => {
    const oldProvider = provider;
    setProvider(newProvider);
    // 切换 Provider 时清空 apiKey（不同 Provider 的 key 格式不同）
    if (oldProvider !== newProvider && apiKey) {
      setApiKey('');
    }
    // 切换 Provider 时清空 model（不同 Provider 支持的模型名不同，如 deepseek-v4-pro 不适用于 ollama）
    if (oldProvider !== newProvider && model) {
      setModel('');
    }
    // 自动填充默认 URL（仅在 URL 为空或与旧 provider 默认 URL 匹配时覆盖）
    const currentUrl = baseURL.trim();
    const isDefaultUrl = Object.values(PROVIDER_URLS).includes(currentUrl);
    if (isDefaultUrl || !currentUrl) {
      setBaseURL(PROVIDER_URLS[newProvider] ?? '');
    }
  };

  const handleSave = async () => {
    if (hasBlockingError) {
      import('@metona-team/metona-toast')
        .then((mod) => mod.default.error('请修正表单中的错误后再保存'))
        .catch(() => {});
      return;
    }
    setSaving(true);
    try {
      const setBatch = window.metona?.config?.setBatch;
      if (!setBatch) {
        import('@metona-team/metona-toast')
          .then((mod) => mod.default.error('配置 API 不可用'))
          .catch(() => {});
        return;
      }
      // v0.3.9: 批量保存，避免串行保存中间态触发 reloadAdapter 失败
      const entries: Array<{ key: string; value: unknown }> = [
        { key: 'llm.provider', value: provider },
        { key: 'llm.model', value: model },
        { key: 'llm.apiKey', value: apiKey },
        { key: 'llm.baseURL', value: baseURL },
        // v0.5.4: 多模态总开关
        { key: 'llm.multimodalEnabled', value: multimodalEnabled },
        { key: 'ollama.numCtx', value: numCtx },
        { key: 'deepseek.contextWindow', value: dsCtxWindow },
        { key: 'agnes.contextWindow', value: agnesCtxWindow },
        { key: 'mimo.contextWindow', value: mimoCtxWindow },
        { key: 'openai.contextWindow', value: oaCtxWindow },
        { key: 'anthropic.contextWindow', value: anthropicCtxWindow },
        // P1: 故障转移 Provider（主 Provider 失败时切换）
        { key: 'llm.fallbackProvider', value: fbProvider },
        { key: 'llm.fallbackModel', value: fbModel },
        { key: 'llm.fallbackApiKey', value: fbApiKey },
        { key: 'llm.fallbackBaseURL', value: fbBaseURL },
      ];
      const r = await setBatch(entries);
      if (r && !r.success) {
        import('@metona-team/metona-toast')
          .then((mod) => mod.default.error(r.error ?? '配置保存失败'))
          .catch(() => {});
      } else {
        // v0.5.4: 保存成功后同步多模态开关到 Agent Store（立即生效，控制上传入口）
        useAgentStore.getState().setMultimodalEnabled(multimodalEnabled);
        import('@metona-team/metona-toast')
          .then((mod) => mod.default.success('配置已保存'))
          .catch(() => {});
        // v0.7.2 P3-9: 保存成功后配置与引擎 adapter 一致 —— 若列表已加载过则静默刷新，
        // 保证候选列表与刚保存的 Provider/BaseURL 同源
        if (modelsLoaded) void loadModels();
      }
    } catch (err) {
      import('@metona-team/metona-toast')
        .then((mod) => mod.default.error(`保存失败：${(err as Error).message}`))
        .catch(() => {});
    } finally {
      setSaving(false);
    }
  };

  if (!loaded) {
    return (
      <Stack spacing={2}>
        <Typography variant="subtitle2" sx={{ fontWeight: 600 }}>
          LLM 配置
        </Typography>
        <Typography variant="caption" sx={{ color: 'text.secondary' }}>
          加载中...
        </Typography>
      </Stack>
    );
  }

  const apiKeyEmpty = provider !== 'ollama' && !apiKey.trim();

  return (
    <Stack spacing={2}>
      <Typography variant="subtitle2" sx={{ fontWeight: 600 }}>
        LLM 配置
      </Typography>
      <FormControl size="small">
        <InputLabel>Provider</InputLabel>
        <Select
          value={provider}
          label="Provider"
          onChange={(e) => handleProviderChange(e.target.value)}
        >
          <MenuItem value="deepseek">DeepSeek</MenuItem>
          <MenuItem value="agnes">Agnes AI</MenuItem>
          <MenuItem value="mimo">MiMo (小米)</MenuItem>
          <MenuItem value="ollama">Ollama (本地)</MenuItem>
          <MenuItem value="openai">OpenAI</MenuItem>
          <MenuItem value="anthropic">Anthropic</MenuItem>
        </Select>
      </FormControl>
      <TextField
        size="small"
        label="API Base URL"
        value={baseURL}
        onChange={(e) => setBaseURL(e.target.value)}
        placeholder="如 https://api.deepseek.com"
        error={urlError}
        helperText={urlError ? '需以 http:// 或 https:// 开头' : ' '}
      />
      {/* v0.7.2 P3-9: 模型名称 — 自由输入 + 动态模型列表候选（freeSolo） */}
      <Autocomplete
        freeSolo
        size="small"
        disableClearable
        options={modelOptions}
        getOptionLabel={(option) => (typeof option === 'string' ? option : option.id)}
        inputValue={model}
        onInputChange={(_, newValue) => setModel(newValue)}
        loading={modelsLoading}
        renderOption={(props, option) => {
          const { key, ...optionProps } = props as { key: string } & Record<string, unknown>;
          const opt = option as ModelOption;
          return (
            <Box component="li" key={key} {...optionProps}>
              <Stack sx={{ minWidth: 0 }}>
                <Stack direction="row" spacing={0.5} sx={{ alignItems: 'center' }}>
                  <Typography variant="body2" sx={{ fontFamily: 'monospace', fontSize: 12 }}>
                    {opt.id}
                  </Typography>
                  {opt.supportsToolCalling === true && (
                    <Chip
                      label="tools"
                      size="small"
                      variant="outlined"
                      sx={{ height: 16, fontSize: 9 }}
                    />
                  )}
                  {opt.supportsThinking === true && (
                    <Chip
                      label="thinking"
                      size="small"
                      variant="outlined"
                      sx={{ height: 16, fontSize: 9 }}
                    />
                  )}
                </Stack>
                {opt.description && (
                  <Typography variant="caption" sx={{ color: 'text.secondary', fontSize: 10 }}>
                    {opt.description}
                  </Typography>
                )}
              </Stack>
            </Box>
          );
        }}
        renderInput={(params) => (
          <TextField
            {...params}
            size="small"
            label="模型名称"
            placeholder="如 deepseek-v4-pro、gpt-4o、claude-sonnet-4-5"
            error={modelHasSpace}
            helperText={
              modelHasSpace
                ? '模型名称不能包含空格'
                : modelsError
                  ? modelsError
                  : modelsLoaded
                    ? ' '
                    : '可手动输入，或点击下方按钮获取模型列表'
            }
          />
        )}
      />
      <Stack direction="row" spacing={1} sx={{ alignItems: 'center' }}>
        <Button
          size="small"
          variant="outlined"
          onClick={loadModels}
          disabled={modelsLoading}
          startIcon={modelsLoading ? <CircularProgress size={12} /> : undefined}
          sx={{ minWidth: 120, fontSize: 11 }}
        >
          获取模型列表
        </Button>
        <Typography variant="caption" sx={{ color: 'text.disabled', fontSize: 10 }}>
          基于「已保存」的配置查询（修改后请先保存）
        </Typography>
      </Stack>
      {/* v0.5.4: 多模态总开关 — 未开启时即使模型支持也不能上传图片 */}
      <FormControlLabel
        control={
          <Switch
            size="small"
            checked={multimodalEnabled}
            onChange={(e) => setMultimodalEnabled(e.target.checked)}
          />
        }
        label={
          <Stack>
            <Typography variant="body2">启用多模态（图片输入）</Typography>
            <Typography variant="caption" sx={{ color: 'text.disabled' }}>
              开启后可在输入框上传图片；DeepSeek 需 vision
              系列模型。历史会话图片会随上下文回传（最近 10 张）
            </Typography>
          </Stack>
        }
        sx={{ alignItems: 'flex-start', m: 0 }}
      />
      {provider !== 'ollama' && (
        <>
          <TextField
            size="small"
            label="API Key"
            type={showKey ? 'text' : 'password'}
            value={apiKey}
            onChange={(e) => setApiKey(e.target.value)}
            placeholder="sk-..."
            error={apiKeyEmpty}
            helperText={
              apiKeyEmpty
                ? `必填，未填 ${PROVIDER_LABELS[provider] ?? provider} 的 API Key 会 401`
                : ' '
            }
            slotProps={{
              input: {
                endAdornment: (
                  <IconButton size="small" onClick={() => setShowKey(!showKey)}>
                    {showKey ? <EyeOff size={14} /> : <Eye size={14} />}
                  </IconButton>
                ),
              },
            }}
          />
        </>
      )}
      {provider === 'ollama' && (
        <TextField
          size="small"
          label="上下文长度 (num_ctx)"
          type="number"
          value={numCtx ?? ''}
          onChange={(e) => {
            const v = e.target.value;
            setNumCtx(v === '' ? null : Number(v));
          }}
          placeholder="默认由模型决定（如 2048、4096、128000）"
          slotProps={{ htmlInput: { min: 512, step: 512 } }}
          error={numCtxError}
          helperText={numCtxError ? '最小值为 512' : ' '}
        />
      )}
      {/* ===== v0.7.2 P3-10: Ollama 模型下载（adapter.pullModel 首次接线 UI） ===== */}
      {provider === 'ollama' && (
        <Stack
          spacing={1}
          sx={{
            p: 1.5,
            borderRadius: 1.5,
            bgcolor: 'secondary.main',
            border: '1px solid',
            borderColor: 'divider',
          }}
        >
          <Typography variant="caption" sx={{ fontWeight: 600 }}>
            下载 Ollama 模型
          </Typography>
          <Stack direction="row" spacing={1} sx={{ alignItems: 'center' }}>
            <TextField
              size="small"
              fullWidth
              value={pullModelName}
              onChange={(e) => setPullModelName(e.target.value)}
              placeholder="模型名，如 qwen3:8b"
              disabled={pulling}
              slotProps={{ input: { sx: { fontFamily: 'monospace', fontSize: 12 } } }}
            />
            {pulling ? (
              <Button
                size="small"
                color="error"
                variant="outlined"
                onClick={handlePullCancel}
                sx={{ flexShrink: 0 }}
              >
                取消
              </Button>
            ) : (
              <Button
                size="small"
                variant="contained"
                onClick={handlePull}
                disabled={!pullModelName.trim()}
                sx={{ flexShrink: 0 }}
              >
                下载
              </Button>
            )}
          </Stack>
          {pulling && pullStatus && (
            <Stack direction="row" spacing={1} sx={{ alignItems: 'center' }}>
              <LinearProgress
                variant={pullStatus.percent != null ? 'determinate' : 'indeterminate'}
                value={pullStatus.percent ?? undefined}
                sx={{ flex: 1, height: 6, borderRadius: 3 }}
              />
              <Typography
                variant="caption"
                noWrap
                sx={{ minWidth: 140, textAlign: 'right', color: 'text.secondary', fontSize: 10 }}
              >
                {pullStatus.percent != null ? `${pullStatus.percent.toFixed(0)}% · ` : ''}
                {pullStatus.label}
              </Typography>
            </Stack>
          )}
          <Typography variant="caption" sx={{ color: 'text.disabled', fontSize: 10 }}>
            从 Ollama 服务拉取模型（大模型下载耗时取决于网络，可随时取消）；完成后获取模型列表即可见
          </Typography>
        </Stack>
      )}
      {/* v0.3.1: DeepSeek/Agnes 上下文窗口配置（用于 Engine 压缩判断和 UI 显示，不传给 API） */}
      {provider === 'deepseek' && (
        <TextField
          size="small"
          label="上下文窗口 (contextWindow)"
          type="number"
          value={dsCtxWindow}
          onChange={(e) => setDsCtxWindow(Number(e.target.value) || 1000000)}
          placeholder="如 64000、128000、1000000"
          slotProps={{ htmlInput: { min: 4096, step: 4096 } }}
          error={dsCtxError}
          helperText={dsCtxError ? '最小值为 4096' : '用于上下文压缩判断，不传给 API'}
        />
      )}

      {/* v0.5.0: DeepSeek 账户余额显示 */}
      {provider === 'deepseek' && (
        <Stack
          direction="row"
          spacing={1}
          sx={{
            alignItems: 'center',
            px: 1.5,
            py: 1,
            borderRadius: 1.5,
            bgcolor: 'secondary.main',
            border: '1px solid',
            borderColor: 'divider',
          }}
        >
          <Typography variant="caption" sx={{ fontWeight: 600, color: 'text.secondary' }}>
            账户余额
          </Typography>
          {balanceLoading ? (
            <Typography variant="caption" sx={{ color: 'text.secondary' }}>
              查询中...
            </Typography>
          ) : balance ? (
            <Typography variant="caption" sx={{ fontFamily: 'monospace', fontWeight: 600 }}>
              {balance.totalBalance} {balance.currency}
              <Typography component="span" variant="caption" sx={{ color: 'text.disabled', ml: 1 }}>
                （赠送 {balance.grantedBalance} + 充值 {balance.toppedUpBalance}）
              </Typography>
            </Typography>
          ) : (
            <Typography
              variant="caption"
              sx={{ color: balanceError ? 'error.main' : 'text.disabled' }}
            >
              {balanceError ?? '未查询（需已保存 API Key）'}
            </Typography>
          )}
          <Button
            size="small"
            variant="outlined"
            onClick={loadBalance}
            disabled={balanceLoading || !apiKey.trim()}
            sx={{ ml: 'auto', minWidth: 64, fontSize: 11 }}
          >
            刷新
          </Button>
        </Stack>
      )}
      {provider === 'agnes' && (
        <TextField
          size="small"
          label="上下文窗口 (contextWindow)"
          type="number"
          value={agnesCtxWindow}
          onChange={(e) => setAgnesCtxWindow(Number(e.target.value) || 1000000)}
          placeholder="如 64000、128000、1000000"
          slotProps={{ htmlInput: { min: 4096, step: 4096 } }}
          error={agnesCtxError}
          helperText={agnesCtxError ? '最小值为 4096' : '用于上下文压缩判断，不传给 API'}
        />
      )}
      {provider === 'mimo' && (
        <TextField
          size="small"
          label="上下文窗口 (contextWindow)"
          type="number"
          value={mimoCtxWindow}
          onChange={(e) => setMimoCtxWindow(Number(e.target.value) || 1000000)}
          placeholder="如 65536、131072、1000000"
          slotProps={{ htmlInput: { min: 4096, step: 4096 } }}
          error={mimoCtxError}
          helperText={mimoCtxError ? '最小值为 4096' : '默认 1000000（1M），用于上下文压缩判断'}
        />
      )}
      {provider === 'openai' && (
        <TextField
          size="small"
          label="上下文窗口 (contextWindow)"
          type="number"
          value={oaCtxWindow}
          onChange={(e) => setOaCtxWindow(Number(e.target.value) || 128000)}
          placeholder="如 128000、200000、1000000"
          slotProps={{ htmlInput: { min: 4096, step: 4096 } }}
          error={oaCtxError}
          helperText={oaCtxError ? '最小值为 4096' : 'gpt-4o 默认 128K，gpt-4.1 默认 1M'}
        />
      )}
      {provider === 'anthropic' && (
        <TextField
          size="small"
          label="上下文窗口 (contextWindow)"
          type="number"
          value={anthropicCtxWindow}
          onChange={(e) => setAnthropicCtxWindow(Number(e.target.value) || 200000)}
          placeholder="如 200000"
          slotProps={{ htmlInput: { min: 4096, step: 4096 } }}
          error={anthropicCtxError}
          helperText={anthropicCtxError ? '最小值为 4096' : 'Claude 默认 200K'}
        />
      )}

      {/* ===== P1: 故障转移 Provider（主 Provider 请求失败时自动切换） ===== */}
      <Divider />
      <Typography variant="subtitle2" sx={{ fontWeight: 600 }}>
        故障转移（可选）
      </Typography>
      <Typography variant="caption" sx={{ color: 'text.secondary' }}>
        主 Provider 请求失败（重试耗尽或密钥失效）时自动切换到备用 Provider 重发。留空禁用。
      </Typography>
      <FormControl size="small">
        <InputLabel>备用 Provider</InputLabel>
        <Select
          value={fbProvider}
          label="备用 Provider"
          onChange={(e) => {
            const v = e.target.value;
            setFbProvider(v);
            setFbModel('');
            setFbApiKey('');
            setFbBaseURL(PROVIDER_URLS[v] ?? '');
          }}
        >
          <MenuItem value="">
            <em>禁用</em>
          </MenuItem>
          <MenuItem value="deepseek">DeepSeek</MenuItem>
          <MenuItem value="agnes">Agnes AI</MenuItem>
          <MenuItem value="mimo">MiMo (小米)</MenuItem>
          <MenuItem value="ollama">Ollama (本地)</MenuItem>
          <MenuItem value="openai">OpenAI</MenuItem>
          <MenuItem value="anthropic">Anthropic</MenuItem>
        </Select>
      </FormControl>
      {fbProvider && (
        <>
          <TextField
            size="small"
            label="备用 Base URL"
            value={fbBaseURL}
            onChange={(e) => setFbBaseURL(e.target.value)}
            placeholder="如 https://api.deepseek.com"
          />
          <TextField
            size="small"
            label="备用模型名称"
            value={fbModel}
            onChange={(e) => setFbModel(e.target.value)}
            placeholder="如 deepseek-v4-flash"
          />
          {fbProvider !== 'ollama' && (
            <TextField
              size="small"
              label="备用 API Key"
              type={showFbKey ? 'text' : 'password'}
              value={fbApiKey}
              onChange={(e) => setFbApiKey(e.target.value)}
              placeholder="sk-..."
              slotProps={{
                input: {
                  endAdornment: (
                    <IconButton size="small" onClick={() => setShowFbKey(!showFbKey)}>
                      {showFbKey ? <EyeOff size={14} /> : <Eye size={14} />}
                    </IconButton>
                  ),
                },
              }}
            />
          )}
        </>
      )}

      {/* Save 按钮：批量提交，取消 onChange 实时落库 */}
      <Stack direction="row" spacing={1} sx={{ mt: 1, alignItems: 'center' }}>
        <Button
          variant="contained"
          size="small"
          onClick={handleSave}
          disabled={saving || hasBlockingError}
          startIcon={saving ? <CircularProgress size={12} /> : undefined}
        >
          {saving ? '保存中...' : '保存配置'}
        </Button>
        {hasBlockingError && (
          <Typography variant="caption" sx={{ color: 'error.main', fontSize: 11 }}>
            请修正表单错误后再保存
          </Typography>
        )}
      </Stack>
    </Stack>
  );
}