/**
 * 服务端 API：QMT 连接配置域（从 api.js 拆分，2026-08-31）
 *
 * 端点：
 *   qmt-connections / add / update / remove / activate / set-default / test
 *   active-host
 *
 * 热切换编排：激活/更新/删除连接导致生效地址变化时，同步 dataSource.setBaseUrl + marketFeed.setBaseUrl
 * （技术约束-008：按请求读取 baseUrl，改字段即生效）
 *
 * 2026-08-31：移除 subscribe-ws / unsubscribe-ws / tick-snapshot（架构演进后无人调用，
 *  订阅与快照统一由 QuoteSync/QuoteHub 内部处理，不再暴露为 HTTP 端点（R-015 迭代 13）
 */

import {
  getQmtConnections, getActiveQmtConnection,
  addQmtConnection, updateQmtConnection, removeQmtConnection,
  activateQmtConnection, setDefaultQmtConnection,
} from '../settings.js';

/** QMT 连接端点方法表 */
export const QMT_METHODS = new Set([
  'qmt-connections',
  'qmt-connections/add',
  'qmt-connections/update',
  'qmt-connections/remove',
  'qmt-connections/activate',
  'qmt-connections/set-default',
  'qmt-connections/test',
  'qmt-connections/active-host',
  'qmt-connections/mcp-status', // R-020/迭代18：QMT MCP 状态（probe / 缓存）
]);

/** 服务端代理测试连接：GET {baseUrl}/health（浏览器跨域规避，Q3 手动测试） */
async function testQmtConnection(ctx, args) {
  const baseUrl = String(args?.baseUrl ?? '').trim().replace(/\/+$/, '');
  if (!/^https?:\/\//i.test(baseUrl)) {
    throw Object.assign(new Error('HTTP 地址格式无效（需以 http:// 或 https:// 开头）'), { code: 'qmt-invalid-url' });
  }
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), 15000);
  const startedAt = Date.now();
  try {
    const res = await fetch(baseUrl + '/health', { signal: controller.signal });
    const latencyMs = Date.now() - startedAt;
    let status = null;
    try { status = (await res.json())?.status ?? null; } catch { /* 非 JSON 响应按 status=null */ }
    return { ok: res.ok, latencyMs, httpStatus: res.status, status, reachable: res.ok };
  } catch (err) {
    return {
      ok: false,
      latencyMs: Date.now() - startedAt,
      reachable: false,
      error: err.name === 'AbortError' ? '请求超时（15s）' : (err?.message ?? String(err)),
    };
  } finally {
    clearTimeout(timer);
  }
}

/**
 * 处理 QMT 连接端点
 * @param {string} method
 * @param {object} args
 * @param {object} runtime { manager, settings, dataSource, marketCache }
 */
export async function handleQmt(method, args, { ctx, settings, dataSource, marketFeed, qmtHealthMonitor, mcpManager }) {
  switch (method) {
    case 'qmt-connections': {
      const state = getQmtConnections(settings);
      return { ...state, active: getActiveQmtConnection(state) };
    }
    case 'qmt-connections/add':
      return await addQmtConnection(settings, { name: args.name, baseUrl: args.baseUrl });
    case 'qmt-connections/update': {
      const before = getQmtConnections(settings);
      const value = await updateQmtConnection(settings, args.id, { name: args.name, baseUrl: args.baseUrl });
      // 编辑的是激活配置且地址变化 → 立即热切换（技术约束-008）
      if (before.activeId === args.id && value.baseUrl !== dataSource.baseUrl) {
        dataSource.setBaseUrl(value.baseUrl);
        marketFeed?.setBaseUrl(value.baseUrl);
        qmtHealthMonitor?.probe(); // 切换后立即补探健康
        ctx?.logger?.info('[one-divine-lot] 激活配置地址已变更，数据源热切换 → ' + value.baseUrl);
        // R-020/迭代18：MCP 目标地址随激活地址变更重挂
        mcpManager?.resync(value.baseUrl).catch(() => {});
      }
      return value;
    }
    case 'qmt-connections/remove': {
      const result = await removeQmtConnection(settings, args.id);
      // 生效连接因删除发生变化 → 立即热切换（产品约束-005 删除边界）
      const afterState = getQmtConnections(settings);
      const active = getActiveQmtConnection(afterState);
      if (active && active.baseUrl !== dataSource.baseUrl) {
        dataSource.setBaseUrl(active.baseUrl);
        marketFeed?.setBaseUrl(active.baseUrl);
        qmtHealthMonitor?.probe(); // 切换后立即补探健康
        ctx?.logger?.info('[one-divine-lot] 激活配置已删除，自动切换 → ' + active.name + ' (' + active.baseUrl + ')');
      }
      // R-020/迭代18：激活已变（或列表清空）→ MCP 跟随新激活 / 卸载
      mcpManager?.resync(active?.baseUrl).catch(() => {});
      return { ...afterState, active, removedWasActive: result.removedWasActive, removedWasDefault: result.removedWasDefault };
    }
    case 'qmt-connections/activate': {
      const state = await activateQmtConnection(settings, args.id);
      const active = getActiveQmtConnection(state);
      if (active && active.baseUrl !== dataSource.baseUrl) {
        dataSource.setBaseUrl(active.baseUrl);
        marketFeed?.setBaseUrl(active.baseUrl);
        qmtHealthMonitor?.probe(); // 切换后立即补探健康
        ctx?.logger?.info('[one-divine-lot] QMT 连接激活: ' + active.name + ' (' + active.baseUrl + ')');
      }
      // R-020/迭代18：激活切换 → MCP 实例跟随（卸旧挂新，url=新激活 baseUrl+/mcp）
      mcpManager?.resync(active?.baseUrl).catch(() => {});
      return { ...state, active };
    }
    case 'qmt-connections/set-default':
      return await setDefaultQmtConnection(settings, args.id);
    case 'qmt-connections/test': {
      // 支持传未保存的 baseUrl（表单先测后存），或传 id 用已存配置地址
      let url = args.baseUrl;
      if (!url && args.id) {
        const state = getQmtConnections(settings);
        url = state.list.find((c) => c.id === args.id)?.baseUrl;
      }
      return await testQmtConnection(ctx, { baseUrl: url });
    }
    case 'qmt-connections/active-host': {
      // R-005：返回激活配置的 host 与 ws 地址
      const state = getQmtConnections(settings);
      const active = getActiveQmtConnection(state) ?? { baseUrl: dataSource.baseUrl, name: '(fallback)' };
      const baseUrl = String(active.baseUrl ?? '').replace(/\/+$/, '');
      let host = '';
      let wsUrl = '';
      try {
        const u = new URL(baseUrl);
        host = u.host; // 含端口，如 100.110.38.78:8610
        wsUrl = 'ws://' + u.host + '/ws';
      } catch { /* baseUrl 非法时返回空 */ }
      return { name: active.name, baseUrl, host, wsUrl, activeId: state.activeId ?? '' };
    }
    case 'qmt-connections/mcp-status': {
      // R-020/迭代18：MCP 状态（缓存秒回；refresh=true 即时探测）
      if (!mcpManager) return { state: 'disabled', error: 'mcpManager 不可用', checkedAt: 0 };
      if (args.refresh) return await mcpManager.probe();
      return mcpManager.getStatus();
    }
    default:
      throw Object.assign(new Error('unknown qmt method: ' + method), { code: 'not-found' });
  }
}