--[[

	Based primarily on code from:
	TechAge
	=======

	Copyright (C) 2019 Joachim Stolberg

	AGPL v3
	See LICENSE.txt for more information

	mark.lua:

]]--

local marker_region = {}

function techage_forceload.unmark_region(name)
	if marker_region[name] ~= nil then --marker already exists
		--wip: make the area stay loaded somehow
		for _, entity in ipairs(marker_region[name]) do
			entity:remove()
		end
		marker_region[name] = nil
	end
end

function techage_forceload.mark_region(name, pos1, pos2, owner, secs)

	if not name or not pos1 or not pos2 then return end

	techage_forceload.unmark_region(name)

	local sizex, sizey, sizez = (1 + pos2.x - pos1.x) / 2, (1 + pos2.y - pos1.y) / 2, (1 + pos2.z - pos1.z) / 2
	local markers = {}

	--XY plane markers
	for _, z in ipairs({pos1.z - 0.5, pos2.z + 0.5}) do
		local markerpos = {x=pos1.x + sizex - 0.5, y=pos1.y + sizey - 0.5, z=z}
		local marker = minetest.add_entity(markerpos, "techage_forceload:region_cube")
		if marker ~= nil then
			marker:set_properties({
				visual_size={x=sizex * 2, y=sizey * 2},
				--collisionbox = {-sizex, -sizey, -thickness, sizex, sizey, thickness},
				collisionbox = {0,0,0, 0,0,0},
			})
			if owner then
				marker:set_nametag_attributes({text = owner})
			end
			marker:get_luaentity().player_name = name
			table.insert(markers, marker)
		end
	end

	--YZ plane markers
	for _, x in ipairs({pos1.x - 0.5, pos2.x + 0.5}) do
		local markerpos = {x=x, y=pos1.y + sizey - 0.5, z=pos1.z + sizez - 0.5}
		local marker = minetest.add_entity(markerpos, "techage_forceload:region_cube")
		if marker ~= nil then
			marker:set_properties({
				visual_size={x=sizez * 2, y=sizey * 2},
				--collisionbox = {-thickness, -sizey, -sizez, thickness, sizey, sizez},
				collisionbox = {0,0,0, 0,0,0},
			})
			marker:set_yaw(math.pi / 2)
			marker:get_luaentity().player_name = name
			table.insert(markers, marker)
		end
	end

	marker_region[name] = markers
	minetest.after(secs or 20, techage_forceload.unmark_region, name)
end

function techage_forceload.switch_region(name, pos1, pos2)
	if marker_region[name] ~= nil then --marker already exists
		techage_forceload.unmark_region(name)
	else
		techage_forceload.mark_region(name, pos1, pos2)
	end
end

minetest.register_entity(":techage_forceload:region_cube", {
	initial_properties = {
		visual = "upright_sprite",
		textures = {"techage_cube_mark.png"},
		use_texture_alpha = true,
		physical = false,
		glow = 12,
	},
	on_step = function(self)
		if marker_region[self.player_name] == nil then
			self.object:remove()
			return
		end
	end,
	on_punch = function(self)
		techage_forceload.unmark_region(self.player_name)
	end,
})