import { Sparkles, WandSparkles } from "lucide-react";
import { useCallback, useEffect, useState } from "react";

import { platformApiClient } from "../api/client";
import type { AuditEventResponse, RunEndpointResponse } from "../api/types";
import { EmptyState, ErrorState, LoadingState } from "../components/StateViews";
import { cx } from "../utils/classes";

type ModuleState<T> = { status: "loading" } | { status: "error"; reason: string } | { status: "ready"; data: T };

export function MaintenancePage() {
  const [endpoints, setEndpoints] = useState<ModuleState<RunEndpointResponse[]>>({ status: "loading" });
  const [events, setEvents] = useState<ModuleState<AuditEventResponse[]>>({ status: "loading" });

  const refreshEndpoints = useCallback(async () => {
    setEndpoints({ status: "loading" });
    try {
      const response = await platformApiClient.listRunEndpoints();
      setEndpoints({ status: "ready", data: response.items });
    } catch (error) {
      setEndpoints({ status: "error", reason: error instanceof Error ? error.message : "加载失败" });
    }
  }, []);

  const refreshEvents = useCallback(async () => {
    setEvents({ status: "loading" });
    try {
      const response = await platformApiClient.listAuditEvents();
      setEvents({ status: "ready", data: response.items });
    } catch (error) {
      setEvents({ status: "error", reason: error instanceof Error ? error.message : "加载失败" });
    }
  }, []);

  useEffect(() => {
    void refreshEndpoints();
    void refreshEvents();
  }, [refreshEndpoints, refreshEvents]);

  return (
    <div className="maintenance-page">
      <header className="page-header">
        <div>
          <p className="page-kicker">平台管理员</p>
          <h1 className="page-title">
            <WandSparkles size={22} style={{ verticalAlign: "-3px" }} /> 系统维护
          </h1>
        </div>
        <button
          type="button"
          className="icon-command"
          onClick={() => {
            void refreshEndpoints();
            void refreshEvents();
          }}
        >
          <Sparkles size={16} />
          <span>刷新</span>
        </button>
      </header>

      <section className="console-panel" aria-label="run endpoints">
        <div className="panel-header">
          <h2>运行节点</h2>
        </div>
        {endpoints.status === "loading" && <LoadingState label="正在加载运行节点…" compact />}
        {endpoints.status === "error" && (
          <ErrorState title="运行节点加载失败" reason={endpoints.reason} diagnosticId="maintenance-endpoints" onRetry={() => void refreshEndpoints()} compact />
        )}
        {endpoints.status === "ready" && endpoints.data.length === 0 && (
          <EmptyState title="暂无运行节点" description="还没有运行端注册到平台。" actionLabel="刷新" onAction={() => void refreshEndpoints()} />
        )}
        {endpoints.status === "ready" && endpoints.data.length > 0 && (
          <div className="resource-list">
            {endpoints.data.map((endpoint) => (
              <article key={endpoint.id} className="resource-list-item">
                <div>
                  <strong>{endpoint.displayName}</strong>
                  <span className="provider-id">{endpoint.id}</span>
                </div>
                <span className={cx("status-pill", endpoint.status === "online" ? "status-active" : endpoint.status === "offline" ? "status-error" : "status-disabled")}>
                  {endpoint.status === "online" ? "在线" : endpoint.status === "offline" ? "离线" : endpoint.status}
                </span>
                <span>
                  任务 {endpoint.capacity.runningJobs}/{endpoint.capacity.maxJobs}（排队 {endpoint.capacity.queuedJobs}）
                </span>
                <span>心跳 {new Date(endpoint.lastHeartbeatAt).toLocaleString()}</span>
              </article>
            ))}
          </div>
        )}
      </section>

      <section className="console-panel" aria-label="audit events">
        <div className="panel-header">
          <h2>审计事件</h2>
        </div>
        {events.status === "loading" && <LoadingState label="正在加载审计事件…" compact />}
        {events.status === "error" && (
          <ErrorState title="审计事件加载失败" reason={events.reason} diagnosticId="maintenance-audit" onRetry={() => void refreshEvents()} compact />
        )}
        {events.status === "ready" && events.data.length === 0 && (
          <EmptyState title="暂无审计事件" description="平台还没有记录任何审计事件。" actionLabel="刷新" onAction={() => void refreshEvents()} />
        )}
        {events.status === "ready" && events.data.length > 0 && (
          <div className="operation-list">
            {events.data.slice(0, 30).map((event) => (
              <div key={event.id} className="operation-item">
                <div className="operation-item-head">
                  <strong>{event.summary || `${event.action} ${event.resourceKind}`}</strong>
                  <span className={cx("status-pill", event.result === "success" ? "status-active" : "status-error")}>{event.result}</span>
                </div>
                <div className="operation-meta">
                  <span>
                    事件 <code>{event.id}</code>
                  </span>
                  <span>操作者 {event.actorId}</span>
                  <span>
                    资源 {event.resourceKind}/{event.resourceId}
                  </span>
                  <span>{new Date(event.createdAt).toLocaleString()}</span>
                </div>
              </div>
            ))}
          </div>
        )}
      </section>
    </div>
  );
}