import { useCallback, useEffect, useState } from "react";
import "../../styles/pages/provider-health.css";
import {
  CheckCircleOutlined,
  CloseCircleOutlined,
  ExclamationCircleOutlined,
  ReloadOutlined,
} from "@ant-design/icons";
import { providerHealthClient, type ProviderHealthResponse } from "../../api/providerHealthClient";
import WorkspacePageShell from "../../components/WorkspacePageShell";
import type { WebUserSession } from "../../types";

interface ProviderHealthPageProps {
  session: WebUserSession | null;
  onOpenLogin: () => void;
}

const STATUS_ICON: Record<string, React.ReactNode> = {
  healthy: <CheckCircleOutlined style={{ color: "#10b981" }} />,
  arrears: <CloseCircleOutlined style={{ color: "#ef4444" }} />,
  denied: <CloseCircleOutlined style={{ color: "#ef4444" }} />,
  error: <ExclamationCircleOutlined style={{ color: "#f59e0b" }} />,
  timeout: <ExclamationCircleOutlined style={{ color: "#f59e0b" }} />,
  no_key: <ExclamationCircleOutlined style={{ color: "#f59e0b" }} />,
  unknown: <ExclamationCircleOutlined style={{ color: "#9ca3af" }} />,
};

const STATUS_LABEL: Record<string, string> = {
  healthy: "正常",
  arrears: "欠费",
  denied: "权限拒绝",
  error: "异常",
  timeout: "超时",
  no_key: "无密钥",
  unknown: "未知",
};

export default function ProviderHealthPage({ session, onOpenLogin }: ProviderHealthPageProps) {
  const isAdmin = session?.user?.role === "admin";
  const [data, setData] = useState<ProviderHealthResponse | null>(null);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const load = useCallback(async () => {
    setLoading(true);
    setError(null);
    try {
      const result = await providerHealthClient.getStatus();
      setData(result);
    } catch (err) {
      setError(err instanceof Error ? err.message : "加载失败");
    } finally {
      setLoading(false);
    }
  }, []);

  useEffect(() => {
    if (isAdmin) void load();
  }, [isAdmin, load]);

  if (!session) {
    return (
      <WorkspacePageShell title="服务商健康" fullWidth className="provider-health-page page-motion">
        <section className="provider-health-access">
          <p>请登录管理员账号后查看。</p>
          <button type="button" onClick={onOpenLogin}>登录</button>
        </section>
      </WorkspacePageShell>
    );
  }

  if (!isAdmin) {
    return (
      <WorkspacePageShell title="服务商健康" fullWidth className="provider-health-page page-motion">
        <section className="provider-health-access">
          <p>当前账号没有管理员权限。</p>
        </section>
      </WorkspacePageShell>
    );
  }

  return (
    <WorkspacePageShell title="服务商健康" fullWidth className="provider-health-page page-motion">
      <div className="provider-health-page__inner">
        <section className="provider-health-toolbar">
          <div>
            <h2>服务商健康监控</h2>
            <p>各 AI 服务商的健康状态、调用统计与密钥池负载。</p>
          </div>
          <button type="button" disabled={loading} onClick={() => void load()}>
            <ReloadOutlined /> 刷新
          </button>
        </section>

        {error ? <p className="provider-health-error">{error}</p> : null}

        {/* Health status cards */}
        <div className="provider-health-grid">
          {data?.health ? Object.entries(data.health).map(([provider, entry]) => (
            <div key={provider} className="provider-health-card">
              <div className="provider-health-card__header">
                {STATUS_ICON[entry.status] || STATUS_ICON.unknown}
                <strong>{provider}</strong>
                <span className={`provider-health-card__status provider-health-card__status--${entry.status}`}>
                  {STATUS_LABEL[entry.status] || entry.status}
                </span>
              </div>
              {entry.lastCheck ? (
                <small className="provider-health-card__time">
                  上次检查: {new Date(entry.lastCheck).toLocaleString("zh-CN")}
                </small>
              ) : null}
              {entry.lastError ? (
                <p className="provider-health-card__error">{entry.lastError}</p>
              ) : null}
            </div>
          )) : null}
        </div>

        {/* Call stats table */}
        {data?.callStats?.length ? (
          <section className="provider-health-section">
            <h3>最近 1h 调用统计</h3>
            <table className="provider-health-table">
              <thead>
                <tr><th>服务商</th><th>模型</th><th>状态</th><th>调用数</th><th>平均耗时</th><th>总成本</th></tr>
              </thead>
              <tbody>
                {data.callStats.map((row, i) => (
                  <tr key={i}>
                    <td>{row.provider}</td>
                    <td>{row.model}</td>
                    <td>{row.status}</td>
                    <td>{row.count}</td>
                    <td>{row.avg_ms ? `${Math.round(Number(row.avg_ms))}ms` : "-"}</td>
                    <td>{row.total_cost ? `¥${Number(row.total_cost).toFixed(2)}` : "-"}</td>
                  </tr>
                ))}
              </tbody>
            </table>
          </section>
        ) : null}

        {/* Key pool stats */}
        {data?.keyStats?.length ? (
          <section className="provider-health-section">
            <h3>密钥池负载</h3>
            <table className="provider-health-table">
              <thead>
                <tr><th>服务商</th><th>总密钥</th><th>活跃密钥</th><th>当前负载</th></tr>
              </thead>
              <tbody>
                {data.keyStats.map((row, i) => (
                  <tr key={i}>
                    <td>{row.provider}</td>
                    <td>{row.total_keys}</td>
                    <td>{row.active_keys}</td>
                    <td>{row.current_load}</td>
                  </tr>
                ))}
              </tbody>
            </table>
          </section>
        ) : null}
      </div>
    </WorkspacePageShell>
  );
}