using Larkdown.Parser.Ast;
using Larkdown.Parser.Lexer;
using System;
using System.Collections.Generic;
using System.Text;

namespace Larkdown.Parser
{
    public class Parser
    {
		public Parser()
		{
		}

		public Ast.Ast Parse(string source)
		{
			var ast = new Ast.Ast();
			var lexer = new Lexer.Lexer(source);
			var node = new TextNode(0);

			foreach (var token in lexer.Tokens())
			{
				switch (token.Type)
				{
					case TokenType.Empty:
						if (!node.IsEmpty())
						{
							ast.Add(node);
						}
						node = new TextNode(0);
						break;

					case TokenType.Indentation:
						if (token.Content.Length != node.Indent)
						{
							if (!node.IsEmpty())
							{
								ast.Add(node);
							}
							node = new TextNode(token.Content.Length);
						}
						break;

					case TokenType.Text:
						node.AddText(token.Content);
						break;
				}
			}

			if (!node.IsEmpty())
			{
				ast.Add(node);
			}

			return ast;
		}
    }
}