/**
 * SecureStorage - OS Keyring/Keychain Management UI
 *
 * Allows users to view, add, and delete securely stored credentials
 * using the OS keyring (Windows DPAPI, macOS Keychain, Linux Secret Service).
 */
import { useState, useEffect } from 'react';
import {
  Key,
  Plus,
  Trash2,
  Eye,
  EyeOff,
  RefreshCw,
  AlertCircle,
  CheckCircle,
  Shield,
  ShieldOff,
} from 'lucide-react';
import { secureStorage, isSecureStorageAvailable } from '../../lib/secure-storage';

interface StoredKey {
  key: string;
  hasValue: boolean;
  preview?: string;
}

// Known storage keys used by the application
const KNOWN_KEYS = [
  { key: 'zclaw_api_key', label: 'API Key', description: 'LLM API 密钥' },
  { key: 'zclaw_device_keys_private', label: 'Device Private Key', description: '设备私钥 (Ed25519)' },
  { key: 'zclaw_gateway_token', label: 'Gateway Token', description: 'Gateway 认证令牌' },
  { key: 'zclaw_feishu_secret', label: '飞书 Secret', description: '飞书应用密钥' },
  { key: 'zclaw_discord_token', label: 'Discord Token', description: 'Discord Bot Token' },
  { key: 'zclaw_slack_token', label: 'Slack Token', description: 'Slack Bot Token' },
  { key: 'zclaw_telegram_token', label: 'Telegram Token', description: 'Telegram Bot Token' },
];

export function SecureStorage() {
  const [isAvailable, setIsAvailable] = useState<boolean | null>(null);
  const [storedKeys, setStoredKeys] = useState<StoredKey[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [showAddForm, setShowAddForm] = useState(false);
  const [newKey, setNewKey] = useState('');
  const [newValue, setNewValue] = useState('');
  const [showValue, setShowValue] = useState<Record<string, boolean>>({});
  const [revealedValues, setRevealedValues] = useState<Record<string, string>>({});
  const [isSaving, setIsSaving] = useState(false);
  const [isDeleting, setIsDeleting] = useState<string | null>(null);
  const [message, setMessage] = useState<{ type: 'success' | 'error'; text: string } | null>(null);

  const loadStoredKeys = async () => {
    setIsLoading(true);
    try {
      const available = await isSecureStorageAvailable();
      setIsAvailable(available);

      const keys: StoredKey[] = [];
      for (const knownKey of KNOWN_KEYS) {
        const value = await secureStorage.get(knownKey.key);
        keys.push({
          key: knownKey.key,
          hasValue: !!value,
          preview: value ? `${value.slice(0, 8)}${value.length > 8 ? '...' : ''}` : undefined,
        });
      }
      setStoredKeys(keys);
    } catch (error) {
      console.error('Failed to load stored keys:', error);
    } finally {
      setIsLoading(false);
    }
  };

  useEffect(() => {
    loadStoredKeys();
  }, []);

  const handleReveal = async (key: string) => {
    if (revealedValues[key]) {
      // Hide if already revealed
      setRevealedValues((prev) => {
        const next = { ...prev };
        delete next[key];
        return next;
      });
      setShowValue((prev) => ({ ...prev, [key]: false }));
    } else {
      // Reveal the value
      const value = await secureStorage.get(key);
      if (value) {
        setRevealedValues((prev) => ({ ...prev, [key]: value }));
        setShowValue((prev) => ({ ...prev, [key]: true }));
      }
    }
  };

  const handleAddKey = async () => {
    if (!newKey.trim() || !newValue.trim()) {
      setMessage({ type: 'error', text: '请填写密钥名称和值' });
      return;
    }

    setIsSaving(true);
    setMessage(null);
    try {
      await secureStorage.set(newKey.trim(), newValue.trim());
      setMessage({ type: 'success', text: '密钥已保存' });
      setNewKey('');
      setNewValue('');
      setShowAddForm(false);
      await loadStoredKeys();
    } catch (error) {
      setMessage({ type: 'error', text: `保存失败: ${error instanceof Error ? error.message : '未知错误'}` });
    } finally {
      setIsSaving(false);
    }
  };

  const handleDeleteKey = async (key: string) => {
    if (!confirm(`确定要删除密钥 "${key}" 吗？此操作无法撤销。`)) {
      return;
    }

    setIsDeleting(key);
    setMessage(null);
    try {
      await secureStorage.delete(key);
      setMessage({ type: 'success', text: '密钥已删除' });
      setRevealedValues((prev) => {
        const next = { ...prev };
        delete next[key];
        return next;
      });
      await loadStoredKeys();
    } catch (error) {
      setMessage({ type: 'error', text: `删除失败: ${error instanceof Error ? error.message : '未知错误'}` });
    } finally {
      setIsDeleting(null);
    }
  };

  const getKeyLabel = (key: string) => {
    const known = KNOWN_KEYS.find((k) => k.key === key);
    return known ? known.label : key;
  };

  const getKeyDescription = (key: string) => {
    const known = KNOWN_KEYS.find((k) => k.key === key);
    return known?.description;
  };

  return (
    <div className="max-w-3xl">
      <div className="flex justify-between items-center mb-6">
        <div>
          <h1 className="text-xl font-bold text-gray-900 dark:text-white">安全存储</h1>
          <p className="text-xs text-gray-500 dark:text-gray-400 mt-1">
            使用系统密钥库 (Keyring/Keychain) 安全存储敏感信息
          </p>
        </div>
        <div className="flex gap-2 items-center">
          {isAvailable !== null && (
            <span className={`text-xs flex items-center gap-1 ${isAvailable ? 'text-green-600' : 'text-amber-600'}`}>
              {isAvailable ? (
                <>
                  <Shield className="w-3 h-3" /> Keyring 可用
                </>
              ) : (
                <>
                  <ShieldOff className="w-3 h-3" /> 使用加密本地存储
                </>
              )}
            </span>
          )}
          <button
            onClick={loadStoredKeys}
            disabled={isLoading}
            className="text-xs text-white bg-orange-500 hover:bg-orange-600 px-3 py-1.5 rounded-lg flex items-center gap-1 transition-colors disabled:opacity-50"
          >
            <RefreshCw className={`w-3 h-3 ${isLoading ? 'animate-spin' : ''}`} /> 刷新
          </button>
        </div>
      </div>

      {/* Status Banner */}
      {isAvailable === false && (
        <div className="mb-6 p-4 bg-amber-50 dark:bg-amber-900/20 border border-amber-200 dark:border-amber-800 rounded-lg">
          <div className="flex items-start gap-2">
            <AlertCircle className="w-4 h-4 text-amber-500 mt-0.5" />
            <div className="text-xs text-amber-700 dark:text-amber-300">
              <p className="font-medium">Keyring 不可用</p>
              <p className="mt-1">
                系统密钥库不可用，将使用 AES-GCM 加密的本地存储作为后备方案。
                建议在 Tauri 环境中运行以获得最佳安全性。
              </p>
            </div>
          </div>
        </div>
      )}

      {/* Message */}
      {message && (
        <div className={`mb-4 p-3 rounded-lg flex items-center gap-2 ${
          message.type === 'success'
            ? 'bg-green-50 dark:bg-green-900/20 text-green-700 dark:text-green-300'
            : 'bg-red-50 dark:bg-red-900/20 text-red-700 dark:text-red-300'
        }`}>
          {message.type === 'success' ? (
            <CheckCircle className="w-4 h-4" />
          ) : (
            <AlertCircle className="w-4 h-4" />
          )}
          {message.text}
        </div>
      )}

      {/* Stored Keys List */}
      <div className="bg-white dark:bg-gray-800 rounded-xl border border-gray-200 dark:border-gray-700 mb-6 shadow-sm">
        {isLoading ? (
          <div className="h-40 flex items-center justify-center text-sm text-gray-400">
            <RefreshCw className="w-4 h-4 animate-spin mr-2" />
            加载中...
          </div>
        ) : storedKeys.length > 0 ? (
          <div className="divide-y divide-gray-100 dark:divide-gray-700">
            {storedKeys.map((item) => (
              <div key={item.key} className="p-4">
                <div className="flex items-center gap-4">
                  <div className={`w-10 h-10 rounded-xl flex items-center justify-center ${
                    item.hasValue
                      ? 'bg-gradient-to-br from-green-500 to-emerald-500 text-white'
                      : 'bg-gray-200 dark:bg-gray-700 text-gray-400'
                  }`}>
                    <Key className="w-4 h-4" />
                  </div>
                  <div className="flex-1 min-w-0">
                    <div className="text-sm font-medium text-gray-900 dark:text-white">
                      {getKeyLabel(item.key)}
                    </div>
                    <div className="text-xs text-gray-500 dark:text-gray-400 mt-0.5">
                      {getKeyDescription(item.key) || item.key}
                    </div>
                    {item.hasValue && (
                      <div className="text-xs text-gray-400 dark:text-gray-500 mt-1 font-mono">
                        {showValue[item.key] ? (
                          <span className="break-all">{revealedValues[item.key]}</span>
                        ) : (
                          <span>{item.preview}</span>
                        )}
                      </div>
                    )}
                  </div>
                  <div className="flex items-center gap-2">
                    {item.hasValue && (
                      <>
                        <button
                          onClick={() => handleReveal(item.key)}
                          className="p-2 text-gray-400 hover:text-blue-600 dark:hover:text-blue-400 hover:bg-gray-100 dark:hover:bg-gray-700 rounded-lg transition-colors"
                          title={showValue[item.key] ? '隐藏' : '显示'}
                        >
                          {showValue[item.key] ? (
                            <EyeOff className="w-4 h-4" />
                          ) : (
                            <Eye className="w-4 h-4" />
                          )}
                        </button>
                        <button
                          onClick={() => handleDeleteKey(item.key)}
                          disabled={isDeleting === item.key}
                          className="p-2 text-gray-400 hover:text-red-600 dark:hover:text-red-400 hover:bg-gray-100 dark:hover:bg-gray-700 rounded-lg transition-colors disabled:opacity-50"
                          title="删除"
                        >
                          {isDeleting === item.key ? (
                            <RefreshCw className="w-4 h-4 animate-spin" />
                          ) : (
                            <Trash2 className="w-4 h-4" />
                          )}
                        </button>
                      </>
                    )}
                    {!item.hasValue && (
                      <span className="text-xs text-gray-400 dark:text-gray-500 px-2">未设置</span>
                    )}
                  </div>
                </div>
              </div>
            ))}
          </div>
        ) : (
          <div className="h-40 flex items-center justify-center text-sm text-gray-400">
            暂无存储的密钥
          </div>
        )}
      </div>

      {/* Add New Key */}
      <div className="mb-6">
        {!showAddForm ? (
          <button
            onClick={() => setShowAddForm(true)}
            className="w-full p-4 border-2 border-dashed border-gray-300 dark:border-gray-600 rounded-xl text-gray-500 dark:text-gray-400 hover:border-orange-400 hover:text-orange-500 transition-colors flex items-center justify-center gap-2"
          >
            <Plus className="w-4 h-4" />
            <span className="text-sm">添加新密钥</span>
          </button>
        ) : (
          <div className="bg-white dark:bg-gray-800 rounded-xl border border-gray-200 dark:border-gray-700 p-4 shadow-sm">
            <h3 className="text-sm font-medium text-gray-900 dark:text-white mb-4">添加新密钥</h3>
            <div className="space-y-3">
              <div>
                <label className="block text-xs font-medium text-gray-700 dark:text-gray-300 mb-1">
                  密钥名称
                </label>
                <input
                  type="text"
                  value={newKey}
                  onChange={(e) => setNewKey(e.target.value)}
                  placeholder="例如: zclaw_custom_key"
                  className="w-full px-3 py-2 border border-gray-300 dark:border-gray-600 rounded-lg bg-white dark:bg-gray-900 text-gray-900 dark:text-white text-sm focus:ring-2 focus:ring-blue-500 focus:border-transparent"
                />
              </div>
              <div>
                <label className="block text-xs font-medium text-gray-700 dark:text-gray-300 mb-1">
                  密钥值
                </label>
                <input
                  type="password"
                  value={newValue}
                  onChange={(e) => setNewValue(e.target.value)}
                  placeholder="输入密钥值"
                  className="w-full px-3 py-2 border border-gray-300 dark:border-gray-600 rounded-lg bg-white dark:bg-gray-900 text-gray-900 dark:text-white text-sm focus:ring-2 focus:ring-blue-500 focus:border-transparent"
                />
              </div>
              <div className="flex gap-2 pt-2">
                <button
                  onClick={() => {
                    setShowAddForm(false);
                    setNewKey('');
                    setNewValue('');
                    setMessage(null);
                  }}
                  className="flex-1 px-4 py-2 border border-gray-300 dark:border-gray-600 rounded-lg text-gray-700 dark:text-gray-300 hover:bg-gray-50 dark:hover:bg-gray-700 text-sm"
                >
                  取消
                </button>
                <button
                  onClick={handleAddKey}
                  disabled={isSaving || !newKey.trim() || !newValue.trim()}
                  className="flex-1 px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 disabled:opacity-50 flex items-center justify-center gap-2 text-sm"
                >
                  {isSaving ? (
                    <>
                      <RefreshCw className="w-3 h-3 animate-spin" />
                      保存中...
                    </>
                  ) : (
                    <>
                      <CheckCircle className="w-3 h-3" />
                      保存
                    </>
                  )}
                </button>
              </div>
            </div>
          </div>
        )}
      </div>

      {/* Info Section */}
      <div className="p-4 bg-gray-50 dark:bg-gray-800/50 rounded-lg border border-gray-200 dark:border-gray-700">
        <h3 className="text-sm font-medium text-gray-900 dark:text-white mb-2">关于安全存储</h3>
        <ul className="text-xs text-gray-500 dark:text-gray-400 space-y-1">
          <li>• Windows: 使用 DPAPI 加密</li>
          <li>• macOS: 使用 Keychain 存储</li>
          <li>• Linux: 使用 Secret Service API (gnome-keyring, kwallet 等)</li>
          <li>• 后备方案: AES-GCM 加密的 localStorage</li>
        </ul>
      </div>
    </div>
  );
}
