local glPush				 = gl.PushMatrix
local glPop					 = gl.PopMatrix
local glColor                = gl.Color
local glDepthTest            = gl.DepthTest
local glDepthMask            = gl.DepthMask
local glTranslate			 = gl.Translate
local glUnitShape			 = gl.UnitShape

local cmdStack = {}
local myTeam = Spring.GetMyTeamID()

function widget:GameFrame(f)

	for unitID, params in pairs(cmdStack) do -- for each unit
		local cmd = params
		local gap = cmd.gap
		repeat
			Spring.Echo("gap: "..cmd.gap)
			Spring.GiveOrderToUnit(unitID, CMD.INSERT,{gap * -1, cmd.id, 0, unpack(cmd.params)}, CMD.OPT_ALT)
			cmd = cmd.prev
			if cmd then gap = gap + cmd.gap end
		until not cmd
		cmdStack[unitID] = nil
	end
end

-- draw the building on the frame the actual order is not yet issued to avoid confusion
function widget:DrawWorldPreUnit()
	--if true then return end
	for unitID, params in pairs(cmdStack) do
		local cmd = params
		repeat
			local p = cmd.params
			glColor(1,1,1,0.5)
			glDepthTest(true)
			glDepthMask(true)
			glPush()
				glTranslate(p[1], p[2], p[3])
				glUnitShape(cmd.id * -1, myTeam)
			glPop()
			glColor(1,1,1,1)
			glDepthMask(false)
			glDepthTest(false)
			cmd = cmd.prev
		until not cmd
	end
end

function widget:CommandNotify(cmdId, cmdParams, cmdOptions)

	local selectedUnits = Spring.GetSelectedUnits()

	for i = 1, #selectedUnits do
		local unitID = selectedUnits[i]
		if cmdStack[unitID] then
			if cmdOptions.shift then
				-- this cant be done right now because terraform orders always end up after other commands no matter what
				-- so we just ignore other queued orders altogether unless they override the que
				--cmdStack[unitID].gap = cmdStack[unitID].gap + 1
			else
				cmdStack[unitID] = nil
			end
		end
	end

	if currentTerraformSelectedIndex > 1 then
		if cmdId < 0 then
			local unitDefId = -cmdId

			if unitDefId == 37 or unitDefId == 275 then

				local commandPos = {}
				commandPos.x = cmdParams[1]
				commandPos.y = cmdParams[2]
				commandPos.z = cmdParams[3]

				local terraformHowMuch = 0 + currentTerraformSelectedValue

				local unitWidth = 10
				local unitHeight = 10

				local rect = GetTerraRectByParams(commandPos.x, commandPos.z, unitWidth, unitHeight, commandPos.y + terraformHowMuch, 0, 0)


				local myTeamId = Spring.GetMyTeamID()
				local volumeSelection = 0
				local terraformParams = GetTerraParameters(1, rect, selectedUnits, myTeamId, volumeSelection)

				for i = 1, #selectedUnits do
					-- check for unit validty here, ie isBuilder etc
					local unitID = selectedUnits[i]
					Spring.GiveOrderToUnit(unitID, CMD_TERRAFORM_INTERNAL, terraformParams, {"shift"})
					if cmdStack[unitID] and cmdOptions.shift then
						local last = cmdStack[unitID]
						last.gap = last.gap + 1
						cmdStack[unitID] = {params = cmdParams, id = cmdId, prev = last, gap = 1}
					else
						cmdStack[unitID] = {params = cmdParams, id = cmdId, gap = 1}
					end
					-- +2
				end

				return true
			else
				-- +1
			end
		else
			-- +1
		end
	end
	return false
end