/**
 * 配置处理模块
 * @module config
 */

import type { 
  PITBotAccountConfig, 
  ResolvedPITBotAccount 
} from "./types.js";
import type { OpenClawConfig } from "openclaw/plugin-sdk";
import { createLogger } from "./utils/logger.js";

const MODULE = "config";

/**
 * 默认账户 ID
 */
export const DEFAULT_ACCOUNT_ID = "default";

/**
 * 获取 PIT Bot 账户 ID 列表
 * @param cfg OpenClaw 配置
 * @returns 账户 ID 列表
 */
export function listPITBotAccountIds(cfg: OpenClawConfig): string[] {
  const accounts = cfg.getSection<{ accounts?: Record<string, unknown> }>("channels.pit-bot");
  const ids: string[] = [];

  if (accounts && typeof accounts.accounts === "object") {
    for (const [id, account] of Object.entries(accounts.accounts)) {
      if (account && typeof account === "object" && !Array.isArray(account)) {
        ids.push(id);
      }
    }
  }

  // 如果没有配置账户，返回默认账户
  if (ids.length === 0) {
    ids.push(DEFAULT_ACCOUNT_ID);
  }

  return ids;
}

/**
 * 解析 PIT Bot 账户
 * @param cfg OpenClaw 配置
 * @param accountId 账户 ID
 * @returns 解析后的账户配置
 * @throws 如果配置无效
 */
export function resolvePITBotAccount(
  cfg: OpenClawConfig, 
  accountId: string
): ResolvedPITBotAccount {
  const log = createLogger(MODULE);
  
  const section = cfg.getSection<{
    enabled?: boolean;
    routerUrl?: string;
    authToken?: string;
    name?: string;
    reconnectInterval?: number;
    heartbeatInterval?: number;
    heartbeatTimeout?: number;
    ackTimeout?: number;
    maxQueueSize?: number;
    accounts?: Record<string, PITBotAccountConfig>;
  }>("channels.pit-bot");

  if (!section) {
    throw new Error(`[pit-bot] Configuration section 'channels.pit-bot' not found`);
  }

  // 获取全局默认配置
  const defaults: PITBotAccountConfig = {
    enabled: section.enabled ?? true,
    routerUrl: section.routerUrl,
    authToken: section.authToken,
    name: section.name,
    reconnectInterval: section.reconnectInterval ?? 5000,
    heartbeatInterval: section.heartbeatInterval ?? 30000,
    heartbeatTimeout: section.heartbeatTimeout ?? 10000,
    ackTimeout: section.ackTimeout ?? 30000,
    maxQueueSize: section.maxQueueSize ?? 100,
  };

  // 获取特定账户配置
  let accountConfig: PITBotAccountConfig = {};
  
  if (section.accounts && typeof section.accounts === "object") {
    const specificConfig = section.accounts[accountId];
    if (specificConfig && typeof specificConfig === "object") {
      accountConfig = specificConfig;
    }
  }

  // 合并配置（账户配置覆盖默认配置）
  const mergedConfig: PITBotAccountConfig = {
    ...defaults,
    ...accountConfig,
  };

  // 解析认证 Token
  const { authToken, secretSource } = resolveAuthToken(mergedConfig.authToken, accountId, log);

  // 验证必需字段
  const routerUrl = mergedConfig.routerUrl;
  if (!routerUrl || typeof routerUrl !== "string") {
    throw new Error(
      `[pit-bot:${accountId}] Missing required config: 'routerUrl'. ` +
      `Please set channels.pit-bot.routerUrl or channels.pit-bot.accounts.${accountId}.routerUrl`
    );
  }

  if (!authToken) {
    log.warn(`No auth token configured for account ${accountId}. Connection may fail.`);
  }

  return {
    accountId,
    name: mergedConfig.name,
    enabled: mergedConfig.enabled ?? true,
    routerUrl,
    authToken: authToken ?? "",
    secretSource,
    config: mergedConfig,
  };
}

/**
 * 应用 PIT Bot 账户配置
 * @param cfg OpenClaw 配置
 * @param accountId 账户 ID
 * @param config 新配置
 */
export function applyPITBotAccountConfig(
  cfg: OpenClawConfig, 
  accountId: string, 
  config: PITBotAccountConfig
): void {
  const key = `channels.pit-bot.accounts.${accountId}`;
  cfg.set(key, config);
}

/**
 * 解析认证 Token
 * 支持环境变量引用和环境变量名
 */
function resolveAuthToken(
  configToken: string | undefined, 
  accountId: string,
  log: { warn: (msg: string) => void }
): { authToken: string | null; secretSource: "config" | "env" | "none" } {
  // 1. 如果配置中直接设置了 Token
  if (configToken && typeof configToken === "string") {
    // 检查是否是环境变量引用 ${VAR_NAME}
    const envMatch = configToken.match(/^\$\{(.+)\}$/);
    if (envMatch) {
      const envVar = envMatch[1];
      const token = process.env[envVar];
      if (!token) {
        log.warn(`Environment variable ${envVar} is not set for account ${accountId}`);
        return { authToken: null, secretSource: "env" };
      }
      return { authToken: token, secretSource: "env" };
    }
    return { authToken: configToken, secretSource: "config" };
  }

  // 2. 尝试从标准环境变量名获取
  const envVarName = accountId === DEFAULT_ACCOUNT_ID 
    ? "PIT_ROUTER_TOKEN" 
    : `PIT_ROUTER_TOKEN_${accountId.toUpperCase()}`;
  
  const envToken = process.env[envVarName];
  if (envToken) {
    return { authToken: envToken, secretSource: "env" };
  }

  // 3. 无 Token
  return { authToken: null, secretSource: "none" };
}

/**
 * 验证配置
 */
export function validateConfig(config: PITBotAccountConfig): { valid: boolean; errors: string[] } {
  const errors: string[] = [];

  if (!config.routerUrl) {
    errors.push("routerUrl is required");
  } else if (!isValidUrl(config.routerUrl)) {
    errors.push(`routerUrl is invalid: ${config.routerUrl}`);
  }

  if (config.reconnectInterval !== undefined && config.reconnectInterval < 1000) {
    errors.push("reconnectInterval must be at least 1000ms");
  }

  if (config.heartbeatInterval !== undefined && config.heartbeatInterval < 1000) {
    errors.push("heartbeatInterval must be at least 1000ms");
  }

  return {
    valid: errors.length === 0,
    errors,
  };
}

/**
 * 验证 URL
 */
function isValidUrl(url: string): boolean {
  try {
    new URL(url);
    return true;
  } catch {
    return false;
  }
}