Tell me something interesting

private async Task RandomWikiArticle()
{
    try
    {
        var http = new HttpClient();
        string rand_page_str, title, selected_page_str, content;
        int unvalid_seq, idx1, idx2;
        
        do
        {
            var rand_page = await http.GetAsync("http://en.wikipedia.org/wiki/Special:Random");
            rand_page_str = await rand_page.Content.ReadAsStringAsync();
            unvalid_seq = rand_page_str.IndexOf("\\u");
            idx2 = rand_page_str.IndexOf(" - Wikipedia");
        } while(idx2 == -1 || unvalid_seq != -1);

        idx1 = rand_page_str.IndexOf("<title>") + "<title>".Length;
        title = rand_page_str.Substring(idx1, idx2 - idx1).Replace(' ', '_');
        var selected_page = await http.GetAsync("https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts&exintro=&explaintext=&exsentences=2&titles=" + title);
        selected_page_str = await selected_page.Content.ReadAsStringAsync();
        idx1 = selected_page_str.IndexOf("extract\":\"") + "extract\":\"".Length;
        idx2 = selected_page_str.IndexOf("\"}}}}");
        content = selected_page_str.Substring(idx1, idx2 - idx1);

        while(content.IndexOf(" (") != -1)
        {
            idx1 = content.IndexOf(" (");
            if(content.IndexOf("))") != -1)
            {
                idx2 = content.IndexOf("))") + 2;
                content = content.Remove(idx1, idx2 - idx1);
            }
            else
            {
                idx2 = content.IndexOf(")") + 1;
                content = content.Remove(idx1, idx2 - idx1);
            }
        }

        while(content.IndexOf("\\n") != -1)
        {
            idx1 = content.IndexOf("\\n");
            content = content.Remove(idx1, 2);
        }

        content = content.Replace("  ", " ");
        content = content.Replace("   ", " ");
        content = content.Replace("\\\"", "\"");
        await GUIOutput(content, true);
    }
    catch
    {
        await GUIOutput("I'm sorry, I couldn't retrieve the informations from the web.", true);
    }
    
    state = AssistantState.BACKGROUND_DEFAULT;
}