﻿/*
 * Copyright (c) 2013 Calvin Rien
 *
 * Based on the JSON parser by Patrick van Bergen
 * http://techblog.procurios.nl/k/618/news/view/14605/14863/How-do-I-write-my-own-parser-for-JSON.html
 *
 * Simplified it so that it doesn't throw exceptions
 * and can be used in Unity iPhone with maximum code stripping.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;

// Example usage:
//
//  using UnityEngine;
//  using System.Collections;
//  using System.Collections.Generic;
//  using MiniJSON;
//
//  public class MiniJSONTest : MonoBehaviour {
//      void Start () {
//          var jsonString = "{ \"array\": [1.44,2,3], " +
//                          "\"object\": {\"key1\":\"value1\", \"key2\":256}, " +
//                          "\"string\": \"The quick brown fox \\\"jumps\\\" over the lazy dog \", " +
//                          "\"unicode\": \"\\u3041 Men\u00fa sesi\u00f3n\", " +
//                          "\"int\": 65536, " +
//                          "\"float\": 3.1415926, " +
//                          "\"bool\": true, " +
//                          "\"null\": null }";
//
//          var dict = Json.Deserialize(jsonString) as Dictionary<string,object>;
//
//          Debug.Log("deserialized: " + dict.GetType());
//          Debug.Log("dict['array'][0]: " + ((List<object>) dict["array"])[0]);
//          Debug.Log("dict['string']: " + (string) dict["string"]);
//          Debug.Log("dict['float']: " + (double) dict["float"]); // floats come out as doubles
//          Debug.Log("dict['int']: " + (long) dict["int"]); // ints come out as longs
//          Debug.Log("dict['unicode']: " + (string) dict["unicode"]);
//
//          var str = Json.Serialize(dict);
//
//          Debug.Log("serialized: " + str);
//      }
//  }

/// <summary>
/// This class encodes and decodes JSON strings.
/// Spec. details, see http://www.json.org/
///
/// JSON uses Arrays and Objects. These correspond here to the datatypes IList and IDictionary.
/// All numbers are parsed to doubles.
/// </summary>
public static class AirbridgeJson
{
	/// <summary>
	/// Parses the string json into a value
	/// </summary>
	/// <param name="json">A JSON string.</param>
	/// <returns>An List&lt;object&gt;, a Dictionary&lt;string, object&gt;, a double, an integer,a string, null, true, or false</returns>
	public static object Deserialize(string json)
	{
		// save the string for debug information
		if (json == null)
		{
			return null;
		}

		return Parser.Parse(json);
	}

	sealed class Parser : IDisposable
	{
		const string WORD_BREAK = "{}[],:\"";

		public static bool IsWordBreak(char c)
		{
			return Char.IsWhiteSpace(c) || WORD_BREAK.IndexOf(c) != -1;
		}

		enum TOKEN
		{
			NONE,
			CURLY_OPEN,
			CURLY_CLOSE,
			SQUARED_OPEN,
			SQUARED_CLOSE,
			COLON,
			COMMA,
			STRING,
			NUMBER,
			TRUE,
			FALSE,
			NULL
		};

		StringReader json;

		Parser(string jsonString)
		{
			json = new StringReader(jsonString);
		}

		public static object Parse(string jsonString)
		{
			using (var instance = new Parser(jsonString))
			{
				return instance.ParseValue();
			}
		}

		public void Dispose()
		{
			json.Dispose();
			json = null;
		}

		Dictionary<string, object> ParseObject()
		{
			Dictionary<string, object> table = new Dictionary<string, object>();

			// ditch opening brace
			json.Read();

			// {
			while (true)
			{
				switch (NextToken)
				{
					case TOKEN.NONE:
						return null;
					case TOKEN.COMMA:
						continue;
					case TOKEN.CURLY_CLOSE:
						return table;
					default:
						// name
						string name = ParseString();
						if (name == null)
						{
							return null;
						}

						// :
						if (NextToken != TOKEN.COLON)
						{
							return null;
						}
						// ditch the colon
						json.Read();

						// value
						table[name] = ParseValue();
						break;
				}
			}
		}

		List<object> ParseArray()
		{
			List<object> array = new List<object>();

			// ditch opening bracket
			json.Read();

			// [
			var parsing = true;
			while (parsing)
			{
				TOKEN nextToken = NextToken;

				switch (nextToken)
				{
					case TOKEN.NONE:
						return null;
					case TOKEN.COMMA:
						continue;
					case TOKEN.SQUARED_CLOSE:
						parsing = false;
						break;
					default:
						object value = ParseByToken(nextToken);

						array.Add(value);
						break;
				}
			}

			return array;
		}

		object ParseValue()
		{
			TOKEN nextToken = NextToken;
			return ParseByToken(nextToken);
		}

		object ParseByToken(TOKEN token)
		{
			switch (token)
			{
				case TOKEN.STRING:
					return ParseString();
				case TOKEN.NUMBER:
					return ParseNumber();
				case TOKEN.CURLY_OPEN:
					return ParseObject();
				case TOKEN.SQUARED_OPEN:
					return ParseArray();
				case TOKEN.TRUE:
					return true;
				case TOKEN.FALSE:
					return false;
				case TOKEN.NULL:
					return null;
				default:
					return null;
			}
		}

		string ParseString()
		{
			StringBuilder s = new StringBuilder();
			char c;

			// ditch opening quote
			json.Read();

			bool parsing = true;
			while (parsing)
			{

				if (json.Peek() == -1)
				{
					parsing = false;
					break;
				}

				c = NextChar;
				switch (c)
				{
					case '"':
						parsing = false;
						break;
					case '\\':
						if (json.Peek() == -1)
						{
							parsing = false;
							break;
						}

						c = NextChar;
						switch (c)
						{
							case '"':
							case '\\':
							case '/':
								s.Append(c);
								break;
							case 'b':
								s.Append('\b');
								break;
							case 'f':
								s.Append('\f');
								break;
							case 'n':
								s.Append('\n');
								break;
							case 'r':
								s.Append('\r');
								break;
							case 't':
								s.Append('\t');
								break;
							case 'u':
								var hex = new char[4];

								for (int i = 0; i < 4; i++)
								{
									hex[i] = NextChar;
								}

								s.Append((char)Convert.ToInt32(new string(hex), 16));
								break;
						}
						break;
					default:
						s.Append(c);
						break;
				}
			}

			return s.ToString();
		}

		object ParseNumber()
		{
			string number = NextWord;

			if (number.IndexOf('.') == -1)
			{
				long parsedInt;
				Int64.TryParse(number, out parsedInt);
				return parsedInt;
			}

			double parsedDouble;
			Double.TryParse(number, out parsedDouble);
			return parsedDouble;
		}

		void EatWhitespace()
		{
			while (Char.IsWhiteSpace(PeekChar))
			{
				json.Read();

				if (json.Peek() == -1)
				{
					break;
				}
			}
		}

		char PeekChar
		{
			get
			{
				return Convert.ToChar(json.Peek());
			}
		}

		char NextChar
		{
			get
			{
				return Convert.ToChar(json.Read());
			}
		}

		string NextWord
		{
			get
			{
				StringBuilder word = new StringBuilder();

				while (!IsWordBreak(PeekChar))
				{
					word.Append(NextChar);

					if (json.Peek() == -1)
					{
						break;
					}
				}

				return word.ToString();
			}
		}

		TOKEN NextToken
		{
			get
			{
				EatWhitespace();

				if (json.Peek() == -1)
				{
					return TOKEN.NONE;
				}

				switch (PeekChar)
				{
					case '{':
						return TOKEN.CURLY_OPEN;
					case '}':
						json.Read();
						return TOKEN.CURLY_CLOSE;
					case '[':
						return TOKEN.SQUARED_OPEN;
					case ']':
						json.Read();
						return TOKEN.SQUARED_CLOSE;
					case ',':
						json.Read();
						return TOKEN.COMMA;
					case '"':
						return TOKEN.STRING;
					case ':':
						return TOKEN.COLON;
					case '0':
					case '1':
					case '2':
					case '3':
					case '4':
					case '5':
					case '6':
					case '7':
					case '8':
					case '9':
					case '-':
						return TOKEN.NUMBER;
				}

				switch (NextWord)
				{
					case "false":
						return TOKEN.FALSE;
					case "true":
						return TOKEN.TRUE;
					case "null":
						return TOKEN.NULL;
				}

				return TOKEN.NONE;
			}
		}
	}

	/// <summary>
	/// Converts a IDictionary / IList object or a simple type (string, int, etc.) into a JSON string
	/// </summary>
	/// <param name="json">A Dictionary&lt;string, object&gt; / List&lt;object&gt;</param>
	/// <returns>A JSON encoded string, or null if object 'json' is not serializable</returns>
	public static string Serialize(object obj)
	{
		return Serializer.Serialize(obj);
	}

	sealed class Serializer
	{
		StringBuilder builder;

		Serializer()
		{
			builder = new StringBuilder();
		}

		public static string Serialize(object obj)
		{
			var instance = new Serializer();

			instance.SerializeValue(obj);

			return instance.builder.ToString();
		}

		void SerializeValue(object value)
		{
			IList asList;
			IDictionary asDict;
			string asStr;

			if (value == null)
			{
				builder.Append("null");
			}
			else if ((asStr = value as string) != null)
			{
				SerializeString(asStr);
			}
			else if (value is bool)
			{
				builder.Append((bool)value ? "true" : "false");
			}
			else if ((asList = value as IList) != null)
			{
				SerializeArray(asList);
			}
			else if ((asDict = value as IDictionary) != null)
			{
				SerializeObject(asDict);
			}
			else if (value is char)
			{
				SerializeString(new string((char)value, 1));
			}
			else
			{
				SerializeOther(value);
			}
		}

		void SerializeObject(IDictionary obj)
		{
			bool first = true;

			builder.Append('{');

			foreach (object e in obj.Keys)
			{
				if (!first)
				{
					builder.Append(',');
				}

				SerializeString(e.ToString());
				builder.Append(':');

				SerializeValue(obj[e]);

				first = false;
			}

			builder.Append('}');
		}

		void SerializeArray(IList anArray)
		{
			builder.Append('[');

			bool first = true;

			foreach (object obj in anArray)
			{
				if (!first)
				{
					builder.Append(',');
				}

				SerializeValue(obj);

				first = false;
			}

			builder.Append(']');
		}

		void SerializeString(string str)
		{
			builder.Append('\"');

			char[] charArray = str.ToCharArray();
			foreach (var c in charArray)
			{
				switch (c)
				{
					case '"':
						builder.Append("\\\"");
						break;
					case '\\':
						builder.Append("\\\\");
						break;
					case '\b':
						builder.Append("\\b");
						break;
					case '\f':
						builder.Append("\\f");
						break;
					case '\n':
						builder.Append("\\n");
						break;
					case '\r':
						builder.Append("\\r");
						break;
					case '\t':
						builder.Append("\\t");
						break;
					default:
						int codepoint = Convert.ToInt32(c);
						if ((codepoint >= 32) && (codepoint <= 126))
						{
							builder.Append(c);
						}
						else
						{
							builder.Append("\\u");
							builder.Append(codepoint.ToString("x4"));
						}
						break;
				}
			}

			builder.Append('\"');
		}

		void SerializeOther(object value)
		{
            // NOTE: Modified decimal cases for fix precision problem.
            // by wontak@ab180.co
            if (value is float)
            {
                string text = ((float)value).ToString("R");
                if (!text.Contains("."))
                {
                    text += ".0";
                }
                builder.Append(text); 
			}
			else if (value is int
				|| value is uint
				|| value is long
				|| value is sbyte
				|| value is byte
				|| value is short
				|| value is ushort
				|| value is ulong)
			{
				builder.Append(value);
			}
			else if (value is double
				|| value is decimal)
			{
                string text = Convert.ToDouble(value).ToString("R");
                if (!text.Contains("."))
                {
                    text += ".0";
                }
                builder.Append(text);
			}
			else
			{
				SerializeString(value.ToString());
			}
		}
	}
}