local meta = {}

-- Create a Group metatable
function Group( group )
    local ret = setmetatable( group or {}, meta )
    ret.count = 0
    ret.funcs = {}
    ret.args = {}
    ret.instant = false
    return ret
end

-- Create a Group metatable which will run the functions instantly
function GroupInstant( group )
    local ret = setmetatable( group or {}, meta )
    ret.count = 0
    ret.funcs = {}
    ret.args = {}
    ret.instant = true
    return ret
end

-- If the Group is Instant, use this
meta._run_now = function( self, ... )
    local ret = {}
    local key = self.key -- Get string key
    self.key = nil
    for i=1,#self do
        local obj = self[i]
        ret[i] = { obj[key]( obj, ... ) } -- Call function, save returns
    end
    return ret
end

-- If the Group is normal, use this
meta._run_later = function( self, ... )
    self.args[self.count] = { ... } -- Add arguments to buffer
end

local rawget = rawget

meta.__index = function( self,key )
    if (rawget(self,key) != nil) then
        return rawget( self,key )-- The Group has this function or variable, get it.
    elseif (rawget(meta, key) != nil) then
        return rawget( meta,key )-- The metatable has this function or variable, get it.
    else -- This function is to be run on the objs
        if (self.instant) then -- The Group is instant, run now
            self.key = key -- temporary variable
            return self._run_now
        else -- The Group is normal, add to buffer
            self.count = self.count + 1
            self.funcs[self.count] = key
            return self._run_later
        end
    end
end

meta.__call = function( self, func )
    self.count = self.count + 1
    self.funcs[self.count] = func
end

-- Run function, used by normal Groups
meta.Run = function( self )
    local ret = {}
    local runid = self.count <= 10 and self.count or "more"
    for i=1, #self do
        local obj = self[i]
        ret[i] = self["_run"..runid]( self, obj ) -- Call function(s), get return(s)
    end

    -- Reset buffers
    self.funcs = {}
    self.args = {}

    return ret
end

-- Add an obj to the Group
meta.__add = function( self, op2 )
    self[#self+1] = op2
end

-- Remove an obj from the Group
meta.__sub = function( self, op2 )
    for i=#self,1,-1 do
        if (self[i] == op2) then
            table.remove( self, i )
        end
    end
end

-- Helper function for below
local function run( self, obj, idx )
    local func = self.funcs[idx]
    if (type(func) == "string") then
        return obj[func](obj,unpack(self.args[idx]))
    else
        return func(obj)
    end
end

-- _run functions used by normal Groups (by the Run function)
meta._run1 = function( self, obj )
    return { run( self,obj,1 ) }
end
meta._run2 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    return ret
end
meta._run3 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    ret[3] = { run( self,obj,3 ) }
    return ret
end
meta._run4 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    ret[3] = { run( self,obj,3 ) }
    ret[4] = { run( self,obj,4 ) }
    return ret
end
meta._run5 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    ret[3] = { run( self,obj,3 ) }
    ret[4] = { run( self,obj,4 ) }
    ret[5] = { run( self,obj,5 ) }
    return ret
end
meta._run6 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    ret[3] = { run( self,obj,3 ) }
    ret[4] = { run( self,obj,4 ) }
    ret[5] = { run( self,obj,5 ) }
    ret[6] = { run( self,obj,6 ) }
end
meta._run7 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    ret[3] = { run( self,obj,3 ) }
    ret[4] = { run( self,obj,4 ) }
    ret[5] = { run( self,obj,5 ) }
    ret[6] = { run( self,obj,6 ) }
    ret[7] = { run( self,obj,7 ) }
    return ret
end
meta._run8 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    ret[3] = { run( self,obj,3 ) }
    ret[4] = { run( self,obj,4 ) }
    ret[5] = { run( self,obj,5 ) }
    ret[6] = { run( self,obj,6 ) }
    ret[7] = { run( self,obj,7 ) }
    ret[8] = { run( self,obj,8 ) }
    return ret
end
meta._run9 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    ret[3] = { run( self,obj,3 ) }
    ret[4] = { run( self,obj,4 ) }
    ret[5] = { run( self,obj,5 ) }
    ret[6] = { run( self,obj,6 ) }
    ret[7] = { run( self,obj,7 ) }
    ret[8] = { run( self,obj,8 ) }
    ret[9] = { run( self,obj,9 ) }
    return ret
end
meta._run10 = function( self, obj )
    local ret = {}
    ret[1] = { run( self,obj,1 ) }
    ret[2] = { run( self,obj,2 ) }
    ret[3] = { run( self,obj,3 ) }
    ret[4] = { run( self,obj,4 ) }
    ret[5] = { run( self,obj,5 ) }
    ret[6] = { run( self,obj,6 ) }
    ret[7] = { run( self,obj,7 ) }
    ret[8] = { run( self,obj,8 ) }
    ret[9] = { run( self,obj,9 ) }
    ret[10] = { run( self,obj,10 ) }
    return ret
end
-- If we have more than 10 functions, run them in a secondary loop
meta._runmore = function( self, obj )
    local ret = {}
    for i=1,self.count do
        ret[i] = { run( self,obj,i ) }
    end
    return ret
end