/**
 * SearXNGSettings — SearXNG 元搜索配置 Tab
 *
 * 从 SettingsModal.tsx 提取（v0.4.1 拆分）。
 * 功能：SearXNG 实例配置（12 项）+ 连接测试。
 *
 * v0.6.4 P3-7 重构（批量草稿模型统一）：原先 12 个字段各自经 useConfig
 * "逐键实时落库" —— 数字输入每敲一个字符就触发一次 IPC 写 + reloadAdapter 副作用，
 * 且 SearXNG 的数字字段无范围 guard 会把中间态写进配置。现改为与 LLMSettings 同一
 * 草稿范式：mount 时一次读入 → 本地草稿编辑（dirty 标记）→ 显式"保存"批量提交。
 * 启用开关保持即时生效（它是功能总开关，语义上属于立即动作而非表单字段）。
 */

import { useCallback, useEffect, useMemo, useState } from 'react';
import {
  Button,
  TextField,
  Select,
  MenuItem,
  Stack,
  Typography,
  Divider,
  Chip,
  Switch,
  Alert,
  Box,
  FormControlLabel,
  InputLabel,
  FormControl,
  IconButton,
  CircularProgress,
} from '@mui/material';
import { Eye, EyeOff, Save } from 'lucide-react';

interface DraftConfig {
  url: string;
  engines: string;
  language: string;
  safesearch: number;
  time_range: string;
  max_results: number;
  auth_key: string;
  auth_type: string;
  format: string;
  fetch_count: number;
  fetch_mode: string;
}

type DraftKey = keyof DraftConfig;

const DRAFT_DEFAULTS: DraftConfig = {
  url: '',
  engines: '',
  language: 'zh-CN',
  safesearch: 1,
  time_range: '',
  max_results: 0,
  auth_key: '',
  auth_type: 'bearer',
  format: 'json',
  fetch_count: 0,
  fetch_mode: 'sequential',
};

/** 配置键 → 草稿字段的映射与读取类型转换 */
const KEY_MAP: Array<{ key: string; field: DraftKey; type: 'string' | 'number' }> = [
  { key: 'searxng.url', field: 'url', type: 'string' },
  { key: 'searxng.engines', field: 'engines', type: 'string' },
  { key: 'searxng.language', field: 'language', type: 'string' },
  { key: 'searxng.safesearch', field: 'safesearch', type: 'number' },
  { key: 'searxng.time_range', field: 'time_range', type: 'string' },
  { key: 'searxng.max_results', field: 'max_results', type: 'number' },
  { key: 'searxng.auth_key', field: 'auth_key', type: 'string' },
  { key: 'searxng.auth_type', field: 'auth_type', type: 'string' },
  { key: 'searxng.format', field: 'format', type: 'string' },
  { key: 'searxng.fetch_count', field: 'fetch_count', type: 'number' },
  { key: 'searxng.fetch_mode', field: 'fetch_mode', type: 'string' },
];

export function SearXNGSettings() {
  const [enabled, setEnabledState] = useState<boolean>(false);
  const [enabledLoaded, setEnabledLoaded] = useState(false);
  const [draft, setDraft] = useState<DraftConfig>(DRAFT_DEFAULTS);
  /** 首次加载完成（或最近一次成功保存）时的草稿快照 —— dirty 判定基准 */
  const [baseline, setBaseline] = useState<DraftConfig | null>(null);
  const [loaded, setLoaded] = useState(false);
  const [saving, setSaving] = useState(false);
  const [savedNotice, setSavedNotice] = useState(false);

  const [showKey, setShowKey] = useState(false);
  const [testing, setTesting] = useState(false);
  const [testResult, setTestResult] = useState<{ success: boolean; message: string } | null>(null);

  // ===== mount：一次性读入全部配置（12 次 IPC 并行，替代原逐键写路径）=====
  useEffect(() => {
    let cancelled = false;
    void (async () => {
      const entries = await Promise.all(
        KEY_MAP.map(async ({ key }) => ({ key, value: await window.metona?.config?.get(key) })),
      );
      if (cancelled) return;
      const next = { ...DRAFT_DEFAULTS };
      for (const entry of entries) {
        const spec = KEY_MAP.find((k) => k.key === entry.key)!;
        if (entry.value === null || entry.value === undefined) continue;
        (next[spec.field] as unknown) =
          spec.type === 'number' ? Number(entry.value) : String(entry.value);
      }
      setDraft(next);
      // 精确 dirty 基准：以加载时快照对比，而非"任何交互即 dirty"
      setBaseline(next);
      setLoaded(true);
    })();
    void window.metona?.config
      ?.get('searxng.enabled')
      .then((v) => {
        if (!cancelled) {
          setEnabledState(v === true);
          setEnabledLoaded(true);
        }
      })
      .catch(() => setEnabledLoaded(true));
    return () => {
      cancelled = true;
    };
  }, []);

  const updateField = useCallback(<K extends DraftKey>(field: K, value: DraftConfig[K]) => {
    setSavedNotice(false);
    setDraft((prev) => ({ ...prev, [field]: value }));
  }, []);

  // v0.6.4 P3-7: dirty 精确判定 —— 当前草稿与基线快照逐字段比较
  const dirty = useMemo(() => {
    if (!loaded || !baseline) return false;
    return KEY_MAP.some(({ field }) => draft[field] !== baseline[field]);
  }, [draft, baseline, loaded]);

  const handleSave = async () => {
    setSaving(true);
    try {
      await window.metona?.config?.setBatch(
        KEY_MAP.map(({ key, field }) => ({ key, value: draft[field] as string | number })),
      );
      setBaseline(draft);
      setSavedNotice(true);
      import('@metona-team/metona-toast')
        .then((mod) => mod.default.success('SearXNG 配置已保存'))
        .catch(() => {});
    } catch (err) {
      console.error('[SearXNGSettings]', err);
      import('@metona-team/metona-toast')
        .then((mod) => mod.default.error('保存失败'))
        .catch(() => {});
    }
    setSaving(false);
  };

  // ===== 数字输入安全钳制（v0.6.4: 原 useConfig 无 guard 导致中间态逐键落库）=====
  const clampNumber = (value: number, min: number, max: number): number =>
    Number.isFinite(value) ? Math.min(max, Math.max(min, Math.trunc(value))) : min;

  const handleToggleEnabled = async (checked: boolean): Promise<void> => {
    // 总开关保持即时落库（立即动作语义），并向前端状态同步
    setEnabledState(checked);
    try {
      await window.metona?.config?.set('searxng.enabled', checked);
    } catch (err) {
      console.error('[SearXNGSettings] toggle failed:', err);
      setEnabledState(!checked);
      import('@metona-team/metona-toast')
        .then((mod) => mod.default.error('开关保存失败'))
        .catch(() => {});
    }
  };

  const urlError = !!draft.url && !/^https?:\/\//.test(draft.url);

  const handleTest = async () => {
    if (!draft.url.trim() || urlError) return;
    setTesting(true);
    setTestResult(null);
    try {
      const result = await window.metona?.searxng?.testConnection(
        draft.url.trim(),
        draft.auth_key,
        draft.auth_type,
      );
      if (result?.success) {
        setTestResult({ success: true, message: `连接成功（${result.latencyMs}ms）` });
      } else {
        setTestResult({
          success: false,
          message: result?.error || `连接失败（HTTP ${result?.statusCode}）`,
        });
      }
    } catch (e) {
      setTestResult({ success: false, message: (e as Error).message });
    }
    setTesting(false);
  };

  if (!enabledLoaded || !loaded) {
    return (
      <Stack spacing={1} sx={{ alignItems: 'center', py: 3 }}>
        <CircularProgress size={18} />
        <Typography variant="caption" sx={{ color: 'text.disabled' }}>
          正在读取配置...
        </Typography>
      </Stack>
    );
  }

  return (
    <Stack spacing={2}>
      {/* 标题 + 状态徽章 */}
      <Stack direction="row" sx={{ justifyContent: 'space-between', alignItems: 'center' }}>
        <Typography variant="subtitle2" sx={{ fontWeight: 600 }}>
          SearXNG 元搜索
        </Typography>
        <Chip
          label={enabled ? '已启用' : '未启用'}
          size="small"
          color={enabled ? 'success' : 'default'}
          variant={enabled ? 'filled' : 'outlined'}
        />
      </Stack>
      <Typography variant="body2" sx={{ color: 'text.secondary' }}>
        SearXNG 是开源元搜索引擎，支持 70+
        搜索引擎聚合。启用后替代内置四引擎搜索通道，未启用时回退到 Bing + 百度 + 搜狗 + 360 搜索。
      </Typography>

      {/* 启用开关（即时生效的总开关） */}
      <FormControlLabel
        control={
          <Switch
            checked={enabled}
            onChange={(e) => void handleToggleEnabled(e.target.checked)}
            size="small"
            slotProps={{ input: { 'aria-label': '启用 SearXNG' } }}
          />
        }
        label={<Typography variant="body2">启用 SearXNG</Typography>}
      />

      <Divider />

      {/* API 地址 + 连接测试 */}
      <Stack direction="row" spacing={1} sx={{ alignItems: 'flex-start' }}>
        <TextField
          size="small"
          label="API 地址"
          value={draft.url}
          onChange={(e) => updateField('url', e.target.value)}
          placeholder="如 https://searxng.example.com"
          error={urlError}
          helperText={
            urlError ? '需以 http:// 或 https:// 开头' : '实例根地址（不含 /search 路径）'
          }
          sx={{ flex: 1 }}
        />
        <Button
          variant="outlined"
          size="small"
          onClick={handleTest}
          disabled={!draft.url.trim() || urlError || testing}
          sx={{ mt: 0.5, minWidth: 90, height: 40 }}
        >
          {testing ? <CircularProgress size={14} /> : '测试连接'}
        </Button>
      </Stack>

      {/* 测试结果 */}
      {testResult && (
        <Alert
          severity={testResult.success ? 'success' : 'error'}
          sx={{ py: 0.5, '& .MuiAlert-message': { fontSize: 12 } }}
        >
          {testResult.message}
        </Alert>
      )}

      {/* 搜索引擎 */}
      <TextField
        size="small"
        label="搜索引擎（逗号分隔）"
        value={draft.engines}
        onChange={(e) => updateField('engines', e.target.value)}
        placeholder="如 google,bing,duckduckgo（留空使用实例默认）"
      />

      {/* 语言 + 安全搜索 */}
      <Box sx={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 2 }}>
        <FormControl size="small">
          <InputLabel>语言</InputLabel>
          <Select
            value={draft.language}
            label="语言"
            onChange={(e) => updateField('language', e.target.value)}
          >
            <MenuItem value="zh-CN">简体中文</MenuItem>
            <MenuItem value="zh-TW">繁體中文</MenuItem>
            <MenuItem value="en">English</MenuItem>
            <MenuItem value="ja">日本語</MenuItem>
            <MenuItem value="ko">한국어</MenuItem>
            <MenuItem value="auto">自动检测</MenuItem>
          </Select>
        </FormControl>
        <FormControl size="small">
          <InputLabel>安全搜索</InputLabel>
          <Select
            value={draft.safesearch}
            label="安全搜索"
            onChange={(e) => updateField('safesearch', Number(e.target.value))}
          >
            <MenuItem value={0}>关闭</MenuItem>
            <MenuItem value={1}>中等</MenuItem>
            <MenuItem value={2}>严格</MenuItem>
          </Select>
        </FormControl>
      </Box>

      {/* 时间范围 + 返回格式 */}
      <Box sx={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 2 }}>
        <FormControl size="small">
          <InputLabel>时间范围</InputLabel>
          <Select
            value={draft.time_range}
            label="时间范围"
            onChange={(e) => updateField('time_range', e.target.value)}
          >
            <MenuItem value="">不限</MenuItem>
            <MenuItem value="day">一天</MenuItem>
            <MenuItem value="week">一周</MenuItem>
            <MenuItem value="month">一月</MenuItem>
            <MenuItem value="year">一年</MenuItem>
          </Select>
        </FormControl>
        <FormControl size="small">
          <InputLabel>返回格式</InputLabel>
          <Select
            value={draft.format}
            label="返回格式"
            onChange={(e) => updateField('format', e.target.value)}
          >
            <MenuItem value="json">JSON（结构化解析）</MenuItem>
            <MenuItem value="html">HTML（原始网页）</MenuItem>
          </Select>
        </FormControl>
      </Box>

      {/* 最大结果数 + 自动抓取条数 */}
      <Box sx={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 2 }}>
        <TextField
          size="small"
          label="最大结果数"
          type="number"
          value={draft.max_results}
          onChange={(e) =>
            updateField('max_results', clampNumber(Number(e.target.value), 0, 50))
          }
          placeholder="0 表示使用默认"
          slotProps={{ htmlInput: { min: 0, max: 50 } }}
        />
        <TextField
          size="small"
          label="自动抓取条数"
          type="number"
          value={draft.fetch_count}
          onChange={(e) =>
            updateField('fetch_count', clampNumber(Number(e.target.value), 0, 8))
          }
          placeholder="0 表示由 AI 决定"
          slotProps={{ htmlInput: { min: 0, max: 8 } }}
        />
      </Box>

      {/* 抓取类型 */}
      <FormControl size="small">
        <InputLabel>抓取类型</InputLabel>
        <Select
          value={draft.fetch_mode}
          label="抓取类型"
          onChange={(e) => updateField('fetch_mode', e.target.value)}
        >
          <MenuItem value="sequential">顺序抓取</MenuItem>
          <MenuItem value="random">随机抓取</MenuItem>
        </Select>
      </FormControl>

      <Divider />

      {/* 认证设置 */}
      <Typography variant="caption" sx={{ fontWeight: 600, color: 'text.secondary' }}>
        认证设置
      </Typography>
      <Box sx={{ display: 'grid', gridTemplateColumns: '1fr 2fr', gap: 2 }}>
        <FormControl size="small">
          <InputLabel>认证类型</InputLabel>
          <Select
            value={draft.auth_type}
            label="认证类型"
            onChange={(e) => updateField('auth_type', e.target.value)}
          >
            <MenuItem value="bearer">Bearer Token</MenuItem>
            <MenuItem value="basic">Basic Auth</MenuItem>
          </Select>
        </FormControl>
        <TextField
          size="small"
          label={draft.auth_type === 'bearer' ? 'Token' : '用户名:密码'}
          type={showKey ? 'text' : 'password'}
          value={draft.auth_key}
          onChange={(e) => updateField('auth_key', e.target.value)}
          placeholder={draft.auth_type === 'bearer' ? '访问令牌原值' : 'username:password'}
          slotProps={{
            input: {
              endAdornment: (
                <IconButton
                  size="small"
                  onClick={() => setShowKey(!showKey)}
                  aria-label={showKey ? '隐藏密钥' : '显示密钥'}
                >
                  {showKey ? <EyeOff size={14} /> : <Eye size={14} />}
                </IconButton>
              ),
            },
          }}
        />
      </Box>
      <Typography variant="caption" sx={{ color: 'text.disabled' }}>
        {draft.auth_type === 'bearer'
          ? 'Bearer: 直接填写令牌原值，原样透传到 Authorization 头。建议配合 HTTPS 使用。'
          : 'Basic: 填写 username:password 明文串，系统自动 Base64 编码。必须配合 HTTPS 使用。'}
      </Typography>

      {/* 保存区（批量草稿提交 + 变更提示） */}
      <Divider />
      <Stack direction="row" spacing={1} sx={{ alignItems: 'center' }}>
        <Button
          variant="contained"
          size="small"
          startIcon={<Save size={14} />}
          disabled={!dirty || saving}
          onClick={() => void handleSave()}
        >
          {saving ? '保存中...' : '保存更改'}
        </Button>
        {dirty && (
          <Typography variant="caption" sx={{ color: 'warning.main' }}>
            有未保存的修改
          </Typography>
        )}
        {!dirty && savedNotice && (
          <Typography variant="caption" sx={{ color: 'text.disabled' }}>
            已保存
          </Typography>
        )}
      </Stack>
    </Stack>
  );
}