public void ExecuteCommand(string input)
{
if (string.IsNullOrEmpty(input))
{
throw new ArgumentNullException();
}
const string noPost = "Nothing posted yet";
const char separator = ' ';
string[] splitted = input.Split(separator);
bool noActionInTheInput = splitted.Length == 1;
var username = splitted[0];
var action = noActionInTheInput ? "read" : splitted[1];
switch (action)
{
case "->":
var message = string.Join(" ", splitted.Skip(2));
_createPostCommand.Execute(username, message);
break;
case "follows":
var usernameToFollow = splitted[2];
_followUserCommand.Execute(username, usernameToFollow);
break;
case "wall":
var wallPosts = _wallQuery.Execute(username);
if (wallPosts.Any())
{
wallPosts.ToList().ForEach(post =>
_writer.Write($"{post.Username} - {post.Message} ({post.WhenPosted})"));
}
else
{
_writer.Write(noPost);
}
break;
case "read":
var userPosts = _getPostListByUserQuery.Execute(username);
if (userPosts.Any())
{
userPosts.ToList()
.ForEach(post => _writer.Write($"{post.Message} ({post.WhenPosted})"));
}
else
{
_writer.Write(noPost);
}
break;
default:
throw new Exception("Invalid command");
}
}
