--[[
RECOMMENDED VERSION
VERSION 1.2.1
Copyright thelastpenguin™
	You may use this for any purpose as long as:
	-	You don't remove this copyright notice.
	-	You don't claim this to be your own.
	-	You properly credit the author, thelastpenguin™, if you publish your work based on (and/or using) this.

	If you modify the code for any purpose, the above still applies to the modified code.

	The author is not held responsible for any d amages incured from the use of pON, you use it at your own risk.
DATA TYPES SUPPORTED:
 - tables  - 		k,v - pointers
 - strings - 		k,v - pointers
 - numbers -		k,v
 - booleans- 		k,v
 - Vectors - 		k,v
 - Angles  -		k,v
 - Entities- 		k,v
 - Players - 		k,v

CHANGE LOG
V 1.1.0
 - Added Vehicle, NPC, NextBot, Player, Weapon
V 1.2.0
 - Added custom handling for k,v tables without any array component.
V 1.2.1
 - fixed deserialization bug.
V 1.3.0
 - added custom handling of strings without any escaped characters.
V 1.4.0
 - added detection of numbers without requiring 'n' datatype. (10 datatypes one for each num it could start with)

THANKS TO...
 - VERCAS for the inspiration.
]]


local pon = {};
_G.pon = pon;

local type, count = type, table.Count ;
local tonumber = tonumber ;

do
	local encode = {};

	local tryCache ;

	local cacheSize = 0;

	encode['table'] = function( self, tbl, output, cache )

		if( cache[ tbl ] )then
			output[ #output + 1 ] = '('..cache[tbl]..')';
			return ;
		else
			cacheSize = cacheSize + 1;
			cache[ tbl ] = cacheSize;
		end
		-- CALCULATE COMPONENT SIZES
		local nSize = #tbl;
		local kvSize = count( tbl ) - nSize;

		if( nSize == 0 and kvSize > 0 )then
			output[ #output + 1 ] = '[';
		else
			output[ #output + 1 ] = '{';

			if nSize > 0 then
				for i = 1, nSize do
					local v = tbl[ i ];
					if v == nil then continue end
					local tv = type( v );
					-- HANDLE POINTERS
					if( tv == 'string' )then
						local pid = cache[ v ];
						if( pid )then
							output[ #output + 1 ] = '('..pid..')';
						else
							cacheSize = cacheSize + 1;
							cache[ v ] = cacheSize;

							self.string( self, v, output, cache );
						end
					else
						self[ tv ]( self, v, output, cache );
					end
				end
			end
		end

		if( kvSize > 0 )then
			if( nSize > 0 )then
				output[ #output + 1 ] = '~';
			end
			for k,v in next, tbl do
				if( type( k ) ~= 'number' or k < 1 or k > nSize )then
					local tk, tv = type( k ), type( v );

					-- THE KEY
					if( tk == 'string' )then
						local pid = cache[ k ];
						if( pid )then
							output[ #output + 1 ] = '('..pid..')';
						else
							cacheSize = cacheSize + 1;
							cache[ k ] = cacheSize;

							self.string( self, k, output, cache );
						end
					else
						self[ tk ]( self, k, output, cache );
					end

					-- THE VALUE
					if( tv == 'string' )then
						local pid = cache[ v ];
						if( pid )then
							output[ #output + 1 ] = '('..pid..')';
						else
							cacheSize = cacheSize + 1;
							cache[ v ] = cacheSize;

							self.string( self, v, output, cache );
						end
					else
						self[ tv ]( self, v, output, cache );
					end

				end
			end
		end
		output[ #output + 1 ] = '}';
	end
	--    ENCODE STRING
	local gsub = string.gsub ;
	encode['string'] = function( self, str, output )
		--if tryCache( str, output ) then return end
		local estr, count = gsub( str, ";", "\\;");
		if( count == 0 )then
			output[ #output + 1 ] = '\''..str..';';
		else
			output[ #output + 1 ] = '"'..estr..'";';
		end
	end
	--    ENCODE NUMBER
	encode['number'] = function( self, num, output )
		output[ #output + 1 ] = tonumber( num )..';';
	end
	--    ENCODE BOOLEAN
	encode['boolean'] = function( self, val, output )
		output[ #output + 1 ] = val and 't' or 'f'
	end
	--    ENCODE VECTOR
	encode['Vector'] = function( self, val, output )
		output[ #output + 1 ] = ('v'..val.x..','..val.y)..(','..val.z..';');
	end
	--    ENCODE ANGLE
	encode['Angle'] = function( self, val, output )
		output[ #output + 1 ] = ('a'..val.p..','..val.y)..(','..val.r..';');
	end
	encode['Entity'] = function( self, val, output )
		output[ #output + 1] = 'E'..(IsValid( val ) and (val:EntIndex( )..';') or '#');
	end
	encode['Player']  = encode['Entity'];
	encode['Vehicle'] = encode['Entity'];
	encode['Weapon']	= encode['Entity'];
	encode['NPC']     = encode['Entity'];
	encode['NextBot'] = encode['Entity'];

	do
		local empty, concat = table.Empty, table.concat ;
		function pon.encode( tbl )
			local output = {};
			cacheSize = 0;
			encode[ 'table' ]( encode, tbl, output, {} );
			local res = concat( output );

			return res;
		end
	end
end

do
	local tonumber = tonumber ;
	local find, sub, gsub, Explode = string.find, string.sub, string.gsub, string.Explode ;
	local Vector, Angle, Entity = Vector, Angle, Entity ;

	local decode = {};
	decode['{'] = function( self, index, str, cache )

		local cur = {};
		cache[ #cache + 1 ] = cur;

		local k, v, tk, tv = 1, nil, nil, nil;
		while( true )do
			tv = sub( str, index, index );
			if( not tv or tv == '~' )then
				index = index + 1;
				break ;
			end
			if( tv == '}' )then
				return index + 1, cur;
			end

			-- READ THE VALUE
			index = index + 1;
			index, v = self[ tv ]( self, index, str, cache );
			cur[ k ] = v;

			k = k + 1;
		end

		while( true )do
			tk = sub( str, index, index );
			if( not tk or tk == '}' )then
				index = index + 1;
				break ;
			end

			-- READ THE KEY

			index = index + 1;
			index, k = self[ tk ]( self, index, str, cache );

			-- READ THE VALUE
			tv = sub( str, index, index );
			index = index + 1;
			index, v = self[ tv ]( self, index, str, cache );

			cur[ k ] = v;
		end

		return index, cur;
	end
	decode['['] = function( self, index, str, cache )

		local cur = {};
		cache[ #cache + 1 ] = cur;

		local k, v, tk, tv = 1, nil, nil, nil;
		while( true )do
			tk = sub( str, index, index );
			if( not tk or tk == '}' )then
				index = index + 1;
				break ;
			end

			-- READ THE KEY

			index = index + 1;
			index, k = self[ tk ]( self, index, str, cache );
			-- READ THE VALUE
			tv = sub( str, index, index );
			index = index + 1;
			index, v = self[ tv ]( self, index, str, cache );

			cur[ k ] = v;
		end

		return index, cur;
	end

	-- STRING
	decode['"'] = function( self, index, str, cache )
		local finish = find( str, '";', index, true );
		local res = gsub( sub( str, index, finish - 1 ), '\\;', ';' );
		index = finish + 2;

		cache[ #cache + 1 ] = res;
		return index, res;
	end
	-- STRING NO ESCAPING NEEDED
	decode['\''] = function( self, index, str, cache )
		local finish = find( str, ';', index, true );
		local res = sub( str, index, finish - 1 )
		index = finish + 1;

		cache[ #cache + 1 ] = res;
		return index, res;
	end

	-- NUMBER
	decode['n'] = function( self, index, str, cache )
		index = index - 1;
		local finish = find( str, ';', index, true );
		local num = tonumber( sub( str, index, finish - 1 ) );
		index = finish + 1;
		return index, num;
	end
	decode['0'] = decode['n'];
	decode['1'] = decode['n'];
	decode['2'] = decode['n'];
	decode['3'] = decode['n'];
	decode['4'] = decode['n'];
	decode['5'] = decode['n'];
	decode['6'] = decode['n'];
	decode['7'] = decode['n'];
	decode['8'] = decode['n'];
	decode['9'] = decode['n'];
	decode['-'] = decode['n'];

	-- POINTER
	decode['('] = function( self, index, str, cache )
		local finish = find( str, ')', index, true );
		local num = tonumber( sub( str, index, finish - 1 ) );
		index = finish + 1;
		return index, cache[ num ];
	end

	-- BOOLEAN. ONE DATA TYPE FOR YES, ANOTHER FOR NO.
	decode[ 't' ] = function( self, index )
		return index, true;
	end
	decode[ 'f' ] = function( self, index )
		return index, false;
	end

	-- VECTOR
	decode[ 'v' ] = function( self, index, str, cache )
		local finish =  find( str, ';', index, true );
		local vecStr = sub( str, index, finish - 1 );
		index = finish + 1; -- update the index.
		local segs = Explode( ',', vecStr, false );
		return index, Vector( tonumber( segs[1] ), tonumber( segs[2] ), tonumber( segs[3] ) );
	end
	-- ANGLE
	decode[ 'a' ] = function( self, index, str, cache )
		local finish =  find( str, ';', index, true );
		local angStr = sub( str, index, finish - 1 );
		index = finish + 1; -- update the index.
		local segs = Explode( ',', angStr, false );
		return index, Angle( tonumber( segs[1] ), tonumber( segs[2] ), tonumber( segs[3] ) );
	end
	-- ENTITY
	decode[ 'E' ] = function( self, index, str, cache )
		if( str[index] == '#' )then
			index = index + 1;
			return NULL ;
		else
			local finish = find( str, ';', index, true );
			local num = tonumber( sub( str, index, finish - 1 ) );
			index = finish + 1;
			return index, Entity( num );
		end
	end
	-- PLAYER
	decode[ 'P' ] = function( self, index, str, cache )
		local finish = find( str, ';', index, true );
		local num = tonumber( sub( str, index, finish - 1 ) );
		index = finish + 1;
		return index, Entity( num ) or NULL;
	end

	function pon.decode( data )
		local _, res = decode[sub(data,1,1)]( decode, 2, data, {});
		return res;
	end
end