/**
 * Plugin Runtime — channelRuntime acquisition and readiness gate
 *
 * Mirrors the pattern established by openclaw-weixin v2.1.1 runtime.ts:
 *   1. register() stores the PluginRuntime via setClawlinkPluginRuntime()
 *   2. startAccount() resolves channelRuntime via resolveClawlinkChannelRuntime()
 *      with a three-level fallback: ctx-injected → global → async wait
 *
 * Reference: docs/reference/plugins/openclaw-weixin/src/runtime.ts
 */

import type { PluginRuntime } from 'openclaw/plugin-sdk/core';

import { logger } from '../util/logger.js';

// ── Module-level singleton ──

let pluginRuntime: PluginRuntime | null = null;

export type PluginChannelRuntime = PluginRuntime['channel'];

// ── Public API ──

/**
 * Store the PluginRuntime received during register().
 * Called once from index.ts register().
 */
export function setClawlinkPluginRuntime(next: PluginRuntime): void {
  pluginRuntime = next;
  logger.info('[plugin-runtime] setClawlinkPluginRuntime called, runtime set');
}

/**
 * Synchronous getter — throws if not initialized.
 * Use only when you are certain register() has completed.
 */
export function getClawlinkPluginRuntime(): PluginRuntime {
  if (!pluginRuntime) {
    throw new Error('ClawLink PluginRuntime not initialized');
  }
  return pluginRuntime;
}

// ── Async wait ──

const WAIT_INTERVAL_MS = 100;
const DEFAULT_TIMEOUT_MS = 10_000;

/**
 * Async polling wait for the runtime to become available.
 * Used during startAccount() if register() hasn't completed yet.
 */
export async function waitForClawlinkPluginRuntime(
  timeoutMs = DEFAULT_TIMEOUT_MS,
): Promise<PluginRuntime> {
  const start = Date.now();
  while (!pluginRuntime) {
    if (Date.now() - start > timeoutMs) {
      throw new Error('ClawLink PluginRuntime initialization timeout');
    }
    await new Promise((resolve) => setTimeout(resolve, WAIT_INTERVAL_MS));
  }
  return pluginRuntime;
}

// ── Three-level fallback resolver ──

/**
 * Resolve PluginRuntime['channel'] with three-level fallback:
 *
 *   1. Gateway-injected channelRuntime on ctx (new OpenClaw versions)
 *   2. Module-global from register()
 *   3. Async wait for register() to complete
 *
 * This matches openclaw-weixin's resolveWeixinChannelRuntime() exactly.
 */
export async function resolveClawlinkChannelRuntime(params: {
  channelRuntime?: PluginChannelRuntime;
  waitTimeoutMs?: number;
}): Promise<PluginChannelRuntime> {
  if (params.channelRuntime) {
    logger.debug('[plugin-runtime] channelRuntime from gateway context');
    return params.channelRuntime;
  }
  if (pluginRuntime) {
    logger.debug('[plugin-runtime] channelRuntime from register() global');
    return pluginRuntime.channel;
  }
  logger.warn(
    '[plugin-runtime] no channelRuntime on ctx and no global runtime yet; waiting for register()',
  );
  const pr = await waitForClawlinkPluginRuntime(params.waitTimeoutMs ?? DEFAULT_TIMEOUT_MS);
  return pr.channel;
}