import type { HttpClient } from './index.js';
import type { HttpClientConfig } from './options.js';

/** 规格化 URL */
function normalizeUrl(url: string, config: HttpClientConfig): string {
    if (!url) url = config.apiUrl;
    if (url.startsWith('ws://') || url.startsWith('wss://')) {
        return url;
    }
    if (url.startsWith('http://') || url.startsWith('https://')) {
        return url.replace(/^http/, 'ws');
    }
    if (url.startsWith('/')) {
        return `${config.apiUrl}${url}`.replace(/^http/, 'ws');
    }
    throw new Error(`Url must starts with '/', 'ws://', 'wss://', 'http://' or 'https://'`);
}

/** 获取构造函数 */
function getConstructor(config: HttpClientConfig): typeof WebSocket {
    return config.webSocket ?? WebSocket;
}

/** 建立 WebSocket */
export type Ws = (url: string, protocols?: string | string[]) => WebSocket;

/** 建立 WebSocket */
export function createWs(client: HttpClient): Ws {
    return (url, protocols) => {
        const { config } = client;
        const wsUrl = normalizeUrl(url, config);
        const ws = new (getConstructor(config))(wsUrl, protocols);
        return ws;
    };
}