local com = nrequire("cl_common.lua")
local col = nrequire("config/colortheme.lua")

local inv = {}

local width = ScrW()
--local height = ScrH()
local iconsize = ((width / 4) - 20) / 5


local function default_paint(self,w,h)
	--Draw a box
	surface.SetDrawColor(col.ui.border)
	surface.DrawOutlinedRect( 0, 0, w, h )
	--xpcall(self.DrawModel,function() end,self)
end


--[[
local function calcposition(width,height,x,y)
	return (y * width) + x
end
]]

local function shapebounds(shape)
	local maxx = 0
	local maxy = 0
	for rn, row in pairs(shape) do
		if #row > maxx then maxx = #row end
		maxy = rn
	end
	return maxx, maxy
end

--Run a function on all the panels in a shape
local function runonshape(self,shape,x,y,func)
	for i = 1,#shape do
		for j = 1, #shape[i] do
			if shape[i][j] then
				func(self.gridpanels[x + i - 1][y + j - 1])
			end
		end
	end
end

--Draw the item in a position
local function drawitemat(self,x,y,item)
	local tp = self.gridpanels[x][y]
	if tp == nil then
		error("Unable to continue, could not find item at (" .. x .. "," .. y .. ")")
	end
	tp:Droppable("item")
	runonshape(self,item.Shape,x,y,function(panel)
		panel:SetVisible(false)
	end)
	tp:SetVisible(true)
	local sx,sy = shapebounds(item.Shape)
	tp:SetSize(iconsize * sx, iconsize * sy)
	tp:SetText(item.Name)
	tp.DoClick = function()
		if item.GetOptions then
			local dm = DermaMenu()
			com.CreateMenuFor(dm,item:GetOptions())
			dm:Open()
		end
	end
	if item.DoOnPanel then
		item:DoOnPanel(tp)
	end
	if item.Paint then
		tp.PaintOver = item.Paint
	end
end

--Reset the position, using the item and it's shape
local function undrawitemat(self,x,y)
	local item = self:Get({x,y})
	local dpn = self.gridpanels[x][y]
	dpn:Droppable("")
	dpn:SetText("")
	if dpn:GetModel() then
		dpn.Entity:Remove()
	end
	for k,v in pairs(dpn:GetChildren()) do v:Remove() end
	runonshape(self,item.Shape,x,y,function(panel)
		panel:SetVisible(true)
		panel:SetSize(iconsize,iconsize)
		panel.PaintOver = default_paint
		panel.DoClick = function() end
	end)
end

inv.DrawOnDPanel = function(self,panel)
	local DScrollPanel = vgui.Create( "DScrollPanel",panel)
	DScrollPanel:SetPos( 0, 0 )
	DScrollPanel:Dock(FILL)

	local grid = vgui.Create( "DGrid", DScrollPanel )
	grid:SetPos(0, 0)
	grid:SetCols(self.width)
	grid:SetColWide(iconsize)
	grid:SetRowHeight(iconsize)
	self.grid = grid

	self.gridpanels = {}

	--Create the full grid of dpanels
	for x = 1, self.width do
		for y = 1, self.height do
			local dp = vgui.Create("DModelPanel")
			function dp:LayoutEntity( Entity ) return end -- disables default rotation
			dp:SetSize(iconsize,iconsize)
			dp.PaintOver = default_paint
			dp:SetText("")
			--dp:Droppable("item")
			dp:Receiver("item",com.generatereceiver(),{"one","two","three"})
			dp.info = {}
			dp.info.owner = self.Owner
			dp.info.id = self.id
			dp.info.pos = {x,y}
			dp.info.inv = self
			grid:AddItem(dp)
			self.gridpanels[x] = self.gridpanels[x] or {}
			self.gridpanels[x][y] = dp
		end
	end

	--Go through the items, and set the dpanels appropriately.
	for k,v in pairs(self.tracker) do
		if type(v) == "table" then
			local px = k % self.width
			local py = math.ceil(k / self.height)
			drawitemat(self,px,py,v)
		end
	end

	local observer = {}
	observer.Put = function(obs,position,item)
		drawitemat(self,position[1],position[2],item)
	end
	observer.Remove = function(obs,position)
		undrawitemat(self,position[1],position[2])
	end
	return observer
end

return inv