/*
Copyright (c) 2013 Andrey Penechko

Boost Software License - Version 1.0 - August 17th, 2003

Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license the "Software" to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:

The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.

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, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/

module anchovy.gui.jsonguiskinparser;

import std.array;
import std.conv;
import std.json;
import std.stdio;

import anchovy.core.types;

import anchovy.gui;


//version = debug_parser;

class SkinParserException : Exception
{
	this(string msg, string file = __FILE__, size_t line = __LINE__)
	{
		super(msg, file, line);
	}
}

alias JSONValue[string] jsonObject;
alias JSONValue[] jsonArray;

static string[JSON_TYPE] jsonTypeNames;
static this()
{
	jsonTypeNames =
		[JSON_TYPE.STRING : "string",
		 JSON_TYPE.INTEGER : "int",
		 JSON_TYPE.UINTEGER : "uint",
		 JSON_TYPE.FLOAT : "float",
		 JSON_TYPE.OBJECT : "object",
		 JSON_TYPE.ARRAY : "array",
		 JSON_TYPE.TRUE : "true",
		 JSON_TYPE.FALSE : "false",
		 JSON_TYPE.NULL : "null",];
}

static const string returnDefault = "if (value.type == JSON_TYPE.NULL) return defaultValue;";

class JsonGuiSkinParser
{
	string[] warnings;
	string[] errors;

	void warn(string message)
	{
		warnings ~= message;
	}

	GuiSkin parse(string skinData)
	{
		GuiSkin skin = new GuiSkin();

		try
		{
			auto jsonValue = parseJSON(skinData);

			skin.name = getValue!string("name", jsonValue);
			skin.textureFilename = getValue!string("image", jsonValue);
			skin.fontInfos = parseFonts(getValue!jsonArray("fonts", jsonValue));
			
			foreach(i, ref value; getValue!jsonArray("styles", jsonValue))
			{
				string styleName = getValue!string("name", value);

				if (styleName == "")
				{
					warn("No style name was specified for style no " ~ to!string(i + 1) ~ " in skin " ~ skin.name);
					continue;
				}

				skin.styles[styleName] = parseStyle(value, styleName);
			}

		}
		catch(JSONException exception)
		{
			throw new SkinParserException(exception.msg);
		}

		if (!warnings.empty)
		{
			foreach(warning; warnings)
				writeln("Warning: ", warning);
				
			warnings = [];
		}

		return skin;
	}

	/**
	 * len 	Result
	 * 1 	Поля будут установлены одновременно от каждого края элемента.
	 * 2 	Первое значение устанавливает поля от верхнего и нижнего края, второе — от левого и правого.
	 * 3 	Первое значение задает поле от верхнего края, второе — одновременно от левого и правого края, а третье — от нижнего края.
	 * 4 	Поочередно устанавливается поля от верхнего, правого, нижнего и левого края.
	 */

	GuiStyle parseStyle(ref JSONValue value, string styleName)
	{
		expect(JSON_TYPE.OBJECT, value);
		
		GuiStyle parsedStyle = new GuiStyle();
		GuiStyleState nullState;

		parsedStyle.states["normal"] = parseStyleState(value, nullState);
		parsedStyle.fontName = getValue!string("font", value, "normal");

		jsonArray states = getValue!jsonArray("states", value);

		foreach(i, ref state; states)
		{
			string stateName = getValue!string("state", state);

			if (stateName == "")
			{
				warn("No state name was specified for state no "~to!string(i+1)~" in style "~styleName);
				continue;
			}

			version(debug_parser) writeln("stateName: ", stateName);

			parsedStyle.states[stateName] = parseStyleState(state, parsedStyle.states["normal"]);
		}

		return parsedStyle;
	}

	GuiStyleState parseStyleState(ref JSONValue stateValue, ref GuiStyleState globalState)
	{
		GuiStyleState parsedStyleState;
		expect(JSON_TYPE.OBJECT, stateValue);

		jsonArray fixedBordersValue = getValue!jsonArray("fixedBorders", stateValue);
		parsedStyleState.fixedBorders = RectOffset(parseRectOffset(fixedBordersValue, globalState.fixedBorders.arrayof));

		jsonArray contentPaddingValue = getValue!jsonArray("contentPadding", stateValue);
		parsedStyleState.contentPadding = RectOffset(parseRectOffset(contentPaddingValue, globalState.contentPadding.arrayof));

		jsonArray rectValue = getValue!jsonArray("rect", stateValue);
		parsedStyleState.atlasRect = Rect(parseRect(rectValue, globalState.atlasRect.arrayof));

		jsonArray outlineValue = getValue!jsonArray("outline", stateValue);
		parsedStyleState.outline = RectOffset(parseRectOffset(outlineValue, globalState.outline.arrayof));

		jsonArray minSize = getValue!jsonArray("minSize", stateValue);
		parsedStyleState.minSize = parseSize(minSize, ivec2(parsedStyleState.atlasRect.width, parsedStyleState.atlasRect.height));

		jsonArray maxSize = getValue!jsonArray("maxSize", stateValue);
		parsedStyleState.maxSize = parseSize(maxSize, ivec2(0, 0));

		return parsedStyleState;
	}

	FontInfo[] parseFonts(jsonArray inArray)
	{
		FontInfo[] outFonts;

		foreach(font; inArray)
		{
			outFonts ~= FontInfo(getValue!string("name", font),
			                     getValue!string("file", font),
			                     getValue!uint("size", font),
			                     getValue!int("verticalOffset", font));
		}

		version(debug_parser) writeln(outFonts);

		return outFonts;
	}

private:

	int[4] parseRect(jsonArray inArray, int[4] defaultValue = [0, 0, 0, 0])
	{
		if (inArray.length == 0) return defaultValue;
		
		int[4] outArray;

		foreach(i, ref element; inArray)
		{
			if (i > 3)
			{
				warn("Rect with more than 4 values found");
				break;
			}

			outArray[i] = getValue!int(element);
		}

		return outArray;
	}

	ivec2 parsePoint(jsonArray inArray, ivec2 defaultValue = ivec2(0, 0))
	{
		if (inArray.length == 0)
			return defaultValue;

		if (inArray.length == 1)
			return ivec2(getValue!int(inArray[0]), 0);

		return ivec2(getValue!int(inArray[0]), getValue!int(inArray[1]));
	}

	ivec2 parseSize(jsonArray inArray, ivec2 defaultValue = ivec2(0, 0))
	{
		if (inArray.length == 0)
			return defaultValue;

		if (inArray.length == 1)
		{
			uint size = getValue!uint(inArray[0]);

			return ivec2(size, size);
		}

		return ivec2(getValue!uint(inArray[0]), getValue!uint(inArray[1]));
	}

	int[4] parseRectOffset(jsonArray inArray, int[4] defaultValue = [0, 0, 0, 0])
	{
		if (inArray.length == 0)
		{
			return defaultValue;
		}
		else if (inArray.length == 1)
		{
			int val = getValue!int(inArray[0]);

			return [val, val, val, val];
		}
		else if (inArray.length == 2)
		{
			int vert = getValue!int(inArray[0]);
			int hor = getValue!int(inArray[1]);

			return [hor, hor, vert, vert];
		}
		else if (inArray.length == 3)
		{
			int top = getValue!int(inArray[0]);
			int hor = getValue!int(inArray[1]);
			int bottom = getValue!int(inArray[2]);

			return [hor, hor, top, bottom];
		}
		else
		{
			int top = getValue!int(inArray[0]);
			int right = getValue!int(inArray[1]);
			int bottom = getValue!int(inArray[2]);
			int left = getValue!int(inArray[3]);

			if (inArray.length > 4) warn("Rect with more than 4 values found");

			return [left, right, top, bottom];
		}
	}

	void expect(JSON_TYPE type, ref JSONValue value, string file = __FILE__, size_t line = __LINE__)
	{
		if(value.type != type && value.type != JSON_TYPE.NULL)
		{
			throw new SkinParserException("Wrong JSON type. " ~
			                              jsonTypeNames[value.type] ~
			                              " found while " ~
			                              jsonTypeNames[type] ~
			                              " expected", file, line);
		}
	}

	T getValue(T)(string key, ref JSONValue objectValue, T defaultValue = T.init)
	{
     	JSONValue* targetValue = key in objectValue.object;

	 	if (targetValue is null)
	 	{
	 		return defaultValue;
	 	}
	 	else
	 	{
	 		return getValue!T(*targetValue, defaultValue);
	 	}
	}

	T getValue(T)(ref JSONValue value, T defaultValue = T.init)
	{
		static if (is(T : string))
		{
			expect(JSON_TYPE.STRING, value);
			mixin(returnDefault);
			return value.str;
		}
		else static if (is(T : int))
		{
			expect(JSON_TYPE.INTEGER, value);
			mixin(returnDefault);
			return cast(int)value.integer;
		}
		else static if (is(T : uint))
		{
			expect(JSON_TYPE.UINTEGER, value);
			mixin(returnDefault);
			return cast(uint)value.uinteger;
		}
		else static if(is(T : float))
		{
			expect(JSON_TYPE.FLOAT, value);
			mixin(returnDefault);
			return cast(float)value.floating;
		}
		else static if(is(T : jsonObject))
		{
			expect(JSON_TYPE.OBJECT, value);
			mixin(returnDefault);
			return value.object;
		}
		else static if(is(T : jsonArray))
		{
			expect(JSON_TYPE.ARRAY, value);
			mixin(returnDefault);
			return value.array;
		}
		else static if(is(T : bool))
		{
			if(value.type == JSON_TYPE.TRUE)
				return true;
			else if (value.type == JSON_TYPE.FALSE)
				return false;
			else if (value.type == JSON_TYPE.NULL)
				return defaultValue;
			else throw new SkinParserException("Wrong JSON type. " ~
			                                   jsonTypeNames[value.type] ~
			                                   " found while boolean expected");
		}
	}
}