using System;
using System.Collections.Specialized;
using System.Web;

namespace CommonTool
{
    /// <summary>
    /// URl帮助类
    /// </summary>
    public class UriUtil
    {
        /// <summary>
        /// 在URL后面追加参数
        /// </summary>
        /// <param name="url"></param>
        /// <param name="key"></param>
        /// <param name="value"></param>
        /// <returns></returns>
        public static string GetAppendedQueryString(string url, string key, string value)
        {
			return url.Contains("?") ? $"{url}&{key}={value}" : $"{url}?{key}={value}";
        }

        public static string RemoveParameter(string url, string key)
        {

            url = url.ToLower();
            key = key.ToLower();
            if (!url.Contains(key + "=")) return url;

            Uri uri = new Uri(url);
            NameValueCollection collection = HttpUtility.ParseQueryString(uri.Query);
            if (collection.Count == 0) return url;

            var val = collection[key];
            string fragmentToRemove = $"{key}={val}";

            string result = url.ToLower().Replace("&" + fragmentToRemove, string.Empty).Replace("?" + fragmentToRemove, string.Empty);
            return result;
        }

        /// <summary>
        /// 根据URL的相对地址获取决定路径
        /// <para>eg: /Home/About ==>http://192.168.0.1/Home/About</para>
        /// </summary>
        /// <returns>System.String.</returns>
        public static string GetAbsolutePathForRelativePath(string relativePath)
        {
            HttpRequest request = HttpContext.Current.Request;
            string returnUrl =
	            $"{request.Url.AbsoluteUri.Replace(request.Url.PathAndQuery, string.Empty)}{VirtualPathUtility.ToAbsolute(relativePath)}";
            return returnUrl;
        }
    }
}