import axios, { type AxiosRequestConfig } from "axios";
import { showErrorNative } from "../host/dialog";
import { getSession, setSession } from "../host/session";
import type { SessionState } from "../host/types";

export const API_QUEUE_CALLER_PATH = "/api/queue/caller";
const DEFAULT_API_PORT = 8845;
const AUTH_LOGIN_PATH = "/auth/login";
const AUTH_REFRESH_PATH = "/auth/refresh";

type ApiEnvelope<T = unknown> = {
  code: number;
  msg?: string;
  message?: string;
  data: T;
};

type RefreshTokenResponse = {
  queueToken?: string;
  refreshToken?: string;
};

type RetryableAxiosRequestConfig = AxiosRequestConfig & {
  _retry?: boolean;
  _skipAuthRefresh?: boolean;
};

let refreshTokenPromise: Promise<string | null> | null = null;

/**
 * 根据配置中的服务器地址拼出后端 baseURL。
 */
export function buildBaseUrlFromServerIp(serverIp: string): string {
  const raw = serverIp.trim();
  if (!raw) {
    return "";
  }

  if (raw.startsWith("http://") || raw.startsWith("https://")) {
    return `${raw.replace(/\/$/, "")}${API_QUEUE_CALLER_PATH}`;
  }

  const hostPort = raw.replace(/^\/+/, "");
  const hasPort = /:\d+$/.test(hostPort) || /^\[.+\]:\d+$/.test(hostPort);
  if (hasPort) {
    return `http://${hostPort}${API_QUEUE_CALLER_PATH}`;
  }

  return `http://${hostPort}:${DEFAULT_API_PORT}${API_QUEUE_CALLER_PATH}`;
}

const instance = axios.create({
  baseURL: "",
  timeout: 10000,
  headers: {
    "Content-Type": "application/json",
  },
});

function isApiSuccessCode(code: unknown): boolean {
  return code === 200 || code === 0;
}

function getApiMessage(payload: unknown): string {
  const data = (payload ?? {}) as { message?: unknown; msg?: unknown };
  if (typeof data.message === "string" && data.message.trim() !== "") {
    return data.message;
  }
  if (typeof data.msg === "string" && data.msg.trim() !== "") {
    return data.msg;
  }
  return "请求失败";
}

function isAuthEndpoint(url?: string): boolean {
  if (!url) {
    return false;
  }
  return url.includes(AUTH_LOGIN_PATH) || url.includes(AUTH_REFRESH_PATH);
}

function setAuthHeader(config: AxiosRequestConfig, queueToken: string): void {
  const headers = (config.headers ?? {}) as Record<string, string>;
  headers.Authorization = `Bearer ${queueToken}`;
  config.headers = headers;
}

async function refreshQueueToken(): Promise<string | null> {
  if (refreshTokenPromise) {
    return refreshTokenPromise;
  }

  refreshTokenPromise = (async () => {
    const sessionState = await getSession();
    const refreshToken = sessionState.refreshToken;
    if (!refreshToken) {
      return null;
    }

    const response = await axios.request<ApiEnvelope<RefreshTokenResponse>>({
      baseURL: instance.defaults.baseURL,
      timeout: instance.defaults.timeout,
      method: "POST",
      url: AUTH_REFRESH_PATH,
      data: { refreshToken },
      headers: { "Content-Type": "application/json" },
    });

    const payload = response.data;
    if (!isApiSuccessCode(payload?.code) || !payload?.data?.queueToken) {
      return null;
    }

    const refreshedQueueToken = payload.data.queueToken;
    await setSession({
      ...sessionState,
      queueToken: refreshedQueueToken,
      refreshToken: payload.data.refreshToken ?? refreshToken,
    });

    return refreshedQueueToken;
  })();

  try {
    return await refreshTokenPromise;
  } finally {
    refreshTokenPromise = null;
  }
}

function canRefreshAndRetry(config?: RetryableAxiosRequestConfig): boolean {
  if (!config) {
    return false;
  }
  if (config._retry || config._skipAuthRefresh) {
    return false;
  }
  return !isAuthEndpoint(config.url);
}

async function retryWithRefreshedToken(config: RetryableAxiosRequestConfig): Promise<any> {
  const nextToken = await refreshQueueToken();
  if (!nextToken) {
    throw new Error("会话已过期，请重新登录");
  }

  const retryConfig: RetryableAxiosRequestConfig = {
    ...config,
    _retry: true,
  };
  setAuthHeader(retryConfig, nextToken);
  return instance.request(retryConfig);
}

/**
 * 将配置中的服务器地址应用到 axios 实例。
 */
export function applyServerIpToHttp(serverIp: string): void {
  if (import.meta.env.DEV) {
    instance.defaults.baseURL = API_QUEUE_CALLER_PATH;
    return;
  }

  instance.defaults.baseURL = buildBaseUrlFromServerIp(serverIp);
}

instance.interceptors.request.use(
  async (config) => {
    if (!instance.defaults.baseURL) {
      throw new Error("未配置服务器地址，请先完成服务地址设置");
    }

    let token: string | null = null;

    try {
      const sessionState: SessionState = await getSession();
      token = sessionState.queueToken;
    } catch {
      token = null;
    }

    if (token && !isAuthEndpoint(config.url)) {
      setAuthHeader(config, token);
    }

    return config;
  },
  async (error) => {
    throw error;
  },
);

instance.interceptors.response.use(
  async (response) => {
    const { data } = response;
    const payload = data as ApiEnvelope;

    if (!isApiSuccessCode(payload?.code)) {
      const requestConfig = response.config as RetryableAxiosRequestConfig;
      if (payload?.code === 401 && canRefreshAndRetry(requestConfig)) {
        return retryWithRefreshedToken(requestConfig);
      }

      const message = getApiMessage(payload);
      await showErrorNative(message);
      throw new Error(message);
    }

    return payload.data;
  },
  async (error) => {
    if (error.response) {
      const requestConfig = error.config as RetryableAxiosRequestConfig;
      if (error.response.status === 401 && canRefreshAndRetry(requestConfig)) {
        try {
          return await retryWithRefreshedToken(requestConfig);
        } catch {
          await showErrorNative("未授权，请重新登录");
          throw error;
        }
      }

      switch (error.response.status) {
        case 400:
          await showErrorNative("请求错误");
          break;
        case 401:
          await showErrorNative("未授权，请重新登录");
          break;
        case 403:
          await showErrorNative("拒绝访问");
          break;
        case 404:
          await showErrorNative("请求地址不存在");
          break;
        case 500:
          await showErrorNative("服务器内部错误");
          break;
        case 502:
          await showErrorNative("网关错误");
          break;
        case 503:
          await showErrorNative("服务不可用");
          break;
        default:
          await showErrorNative("请求失败");
      }
    } else if (error.request) {
      await showErrorNative("网络连接异常");
    } else {
      await showErrorNative(error.message);
    }

    throw error;
  },
);

export const http = {
  /**
   * 发送原生 axios 请求。
   */
  request<T = unknown>(config: AxiosRequestConfig): Promise<T> {
    return instance.request(config);
  },

  /**
   * 发送 GET 请求。
   */
  get<T = unknown>(url: string, params?: unknown, config?: AxiosRequestConfig): Promise<T> {
    return instance.get(url, { params, ...config });
  },

  /**
   * 发送 POST 请求。
   */
  post<T = unknown>(url: string, data?: unknown, config?: AxiosRequestConfig): Promise<T> {
    return instance.post(url, data, config);
  },

  /**
   * 发送 PUT 请求。
   */
  put<T = unknown>(url: string, data?: unknown, config?: AxiosRequestConfig): Promise<T> {
    return instance.put(url, data, config);
  },

  /**
   * 发送 DELETE 请求。
   */
  delete<T = unknown>(url: string, params?: unknown, config?: AxiosRequestConfig): Promise<T> {
    return instance.delete(url, { params, ...config });
  },

  /**
   * 发送 PATCH 请求。
   */
  patch<T = unknown>(url: string, data?: unknown, config?: AxiosRequestConfig): Promise<T> {
    return instance.patch(url, data, config);
  },
};