-- Gizmos in the 3D viewport (FORGE.md):  the selected entity carries three arms along the world
-- axes, and dragging an arm's handle moves the entity along that axis alone -- the pointer's
-- travel along the arm, as a fraction of the arm, is the distance moved.
FORGE_LIBRARY = true
dofile("Forge/Forge.singe")

local font = fontLoad("Singe/FreeSansBold.ttf", 15)
local out  = singeGetDataPath()
local work = out .. "gizmo.game"

fontSelect(font)
fontQuality(FONT_QUALITY_BLENDED)
overlaySetResolution(720, 480)

local source = assert(io.open("testScripts/author/railshooter.game", "r"))
local copy   = assert(io.open(work, "w"))

copy:write(source:read("a"))
source:close()
copy:close()

if not forgeBegin(work) then
	debugPrint("GIZMO FAIL could not open " .. work)
	singeQuit()
end

local frames = 0
local stage  = 0


local function handle(axis)
	for _, item in ipairs(forgeGizmoHandles()) do
		if item.axis == axis then
			return item
		end
	end

	return nil
end


local function step()
	local room = forgeRoom()

	if stage == 1 then
		for index, entry in ipairs(room.entities) do
			if entry.id == "wallL" then
				forgeSelect(index)
			end
		end
		local arms = forgeGizmoHandles()

		debugPrint("GIZMO the selected wall shows " .. #arms .. " arms")
		if #arms ~= 4 then
			debugPrint("GIZMO FAIL expected three axis arms and the turn handle")
		end

	elseif stage == 2 then
		-- Drag the Y handle the length of its own arm:  the wall rises one arm's length (1.5) and
		-- nothing else about it changes.
		local entry = room.entities[FORGE.selected]
		local was   = { x = entry.x, y = entry.y, z = entry.z }
		local arm   = handle("y")

		forgePress(arm.tx, arm.ty)
		forgeDrag(arm.tx + (arm.tx - arm.sx), arm.ty + (arm.ty - arm.sy))
		forgeRelease()
		debugPrint(string.format("GIZMO the Y arm took the wall from %.1f to %.1f;  x %.1f to %.1f, z %.1f to %.1f", was.y, entry.y, was.x, entry.x, was.z, entry.z))
		if math.abs(entry.y - (was.y + 1.5)) > 0.2 or entry.x ~= was.x or entry.z ~= was.z then
			debugPrint("GIZMO FAIL the Y drag did not move along Y alone")
		end

	elseif stage == 3 then
		-- And the X handle, dragged half an arm back.
		local entry = room.entities[FORGE.selected]
		local was   = entry.x
		local arm   = handle("x")

		forgePress(arm.tx, arm.ty)
		forgeDrag(arm.tx - (arm.tx - arm.sx) / 2, arm.ty - (arm.ty - arm.sy) / 2)
		forgeRelease()
		debugPrint(string.format("GIZMO the X arm took the wall from %.1f to %.1f", was, entry.x))
		if math.abs(entry.x - (was - 0.75)) > 0.2 then
			debugPrint("GIZMO FAIL the X drag did not move half an arm back")
		end
		forgeKey(0, SCANCODE.U.value)
		forgeKey(0, SCANCODE.U.value)
		-- Undo puts a copy of the description in place, so the room is looked up again.
		local back = forgeRoom().entities[FORGE.selected]

		debugPrint(string.format("GIZMO two undos:  the wall is back at x %.1f, y %.1f", back.x, back.y))
		if back.x ~= -6 or back.y ~= 1.5 then
			debugPrint("GIZMO FAIL undo did not put the wall back")
		end

	elseif stage == 4 then
		-- The turn handle:  dragged a quarter turn round the entity on screen.
		local entry = forgeRoom().entities[FORGE.selected]
		local arm   = handle("ry")
		local dx, dy = arm.tx - arm.sx, arm.ty - arm.sy

		forgePress(arm.tx, arm.ty)
		forgeDrag(arm.sx - dy, arm.sy + dx)
		forgeRelease()
		debugPrint(string.format("GIZMO the turn handle set ry to %s", tostring(entry.ry)))
		if (entry.ry == nil) or (math.abs(((entry.ry - 270 + 180) % 360) - 180) > 15) then
			debugPrint("GIZMO FAIL a quarter turn clockwise on screen should read about 270")
		end
		debugPrint("GIZMO RESULT done")
	end
end


function onOverlayUpdate()
	frames = frames + 1
	if frames % 14 == 0 and stage < 5 then
		stage = stage + 1
		step()
	end
	forgeDraw(nil, nil)
	colorForeground(255, 255, 255, 255)
	fontPrint(210, 8, "gizmos, stage " .. stage)
	if frames == 20 or frames == 34 then
		singeScreenshot()
	end
	if frames > 80 then
		singeQuit()
	end

	return OVERLAY_UPDATED
end