using System;
using System.Text;
using sharp.extensions;

namespace sharp.json
{
	public class JSONString : JSON
	{
		static System.Tuple<char,char>[] escapeCharacters = {
			System.Tuple.Create('\\','\\'),
			System.Tuple.Create('/','/'),
			System.Tuple.Create('"','"'),
			System.Tuple.Create('b','\b'),
			System.Tuple.Create('f','\f'),
			System.Tuple.Create('n','\n'),
			System.Tuple.Create('r','\r'),
			System.Tuple.Create('t','\t'),
		};

		string value;

		public JSONString()
			:base(JSONTypes.String)
		{
			this.value = "";
		}

		public JSONString(String value)
			:base(JSONTypes.String)
		{
			this.value = value;
		}

		public override string String
		{
			get { return this.value; }
		}

		public override double Double
		{
			get { return Double.Parse(this.value); }
		}

		public override long Integer
		{
			get { return long.Parse(this.value); }
		}


		public override string[] prettyPrint()
		{
			return new string[] { ToString() }; 
		}

		public override string ToString()
		{
			return String.Format("\"{0}\"",escape(this.value));
		}

		public static string escape(string source){
			StringBuilder sb = new StringBuilder();
			foreach (char ch in source){
				if ((ch >= 0x20) && (ch < 128)){
					sb.Append(ch);
				} else if (ch < 0x20){
					foreach (System.Tuple<char,char> repl in escapeCharacters){
						if (repl.Item2 == ch){
							sb.Append("\\");
							sb.Append(repl.Item1);
							break;
						}
					}
				} else {
					int iv = (int)ch;
					sb.Append("\\u");
					sb.Append("____");
					Console.WriteLine("JSON WARNING: UNICODE ESCAPE SEQUENCES ARE NOT IMPLEMENTED YET");
				}
			}
			return sb.ToString();
		}

		public static string unescape(string source)
		{
			StringBuilder sb = new StringBuilder();
			CharEnumerator ce = source.GetEnumerator();
			char[] hex = new char[4];
				
			while (ce.MoveNext()){

				if (ce.Current == '\\'){
					ce.MoveNext();

					foreach (System.Tuple<char, char> repl in escapeCharacters)
					{
						if (repl.Item1 == ce.Current)
						{
							sb.Append(repl.Item2);
							break;
						}
					}

					if (ce.Current == 'u'){
						for (int n = 0; n < 4;n++){
							ce.MoveNext();
							hex[3 - n] = ce.Current;
						}
						sb.Append((char)( HexString.toBytes(hex).toUInt32()[0] ));
					}

				} else {
					sb.Append(ce.Current);
				}
			}
			return sb.ToString();
		}
	}
}