local function is_water(pos)
	local nn = minetest.get_node(pos).name
	return minetest.get_item_group(nn, "water") ~= 0
end


local function get_sign(i)
	if i == 0 then
		return 0
	else
		return i / math.abs(i)
	end
end


local function get_velocity(v, yaw, y)
	local x = -math.sin(yaw) * v
	local z = math.cos(yaw) * v
	return { x = x, y = y, z = z }
end


local function get_v(v)
	return math.sqrt(v.x ^ 2 + v.z ^ 2)
end
local function reg_salvag(color)
	local salvag_item_name = "summer:salvag_" .. color .. "_item"
	local salvag_ent_name = "summer:salvag_" .. color .. "_entity"

	--
	-- Boat entity
	--

	local salvag = {
		physical = true,
		collisionbox = { -0.5, -0.35, -0.5, 0.5, 0.3, 0.5 },
		visual = "mesh",
		mesh = "salvagl.obj",
		textures = { "summer_salvag_" .. color .. ".png" },

		driver = nil,
		v = 0,
		last_v = 0,
		removed = false
	}


	function salvag.on_rightclick(self, clicker)
		if not clicker or not clicker:is_player() then
			return
		end
		local name = clicker:get_player_name()
		if self.driver and clicker == self.driver then
			self.driver = nil
			clicker:set_detach()
			default.player_attached[name] = false
			default.player_set_animation(clicker, "stand", 30)
			local pos = clicker:getpos()
			pos = { x = pos.x, y = pos.y + 0.2, z = pos.z }
			minetest.after(0.1, function()
				clicker:setpos(pos)
			end)
		elseif not self.driver then
			local attach = clicker:get_attach()
			if attach and attach:get_luaentity() then
				local luaentity = attach:get_luaentity()
				if luaentity.driver then
					luaentity.driver = nil
				end
				clicker:set_detach()
			end
			self.driver = clicker
			clicker:set_attach(self.object, "",
				{ x = 0, y = 11, z = -3 }, { x = 0, y = 0, z = 0 })
			default.player_attached[name] = true
			minetest.after(0.2, function()
				default.player_set_animation(clicker, "sit", 30)
			end)
			self.object:setyaw(clicker:get_look_yaw() - math.pi / 2)
		end
	end

	function salvag.on_activate(self, staticdata, dtime_s)
		self.object:set_armor_groups({ immortal = 1 })
		if staticdata then
			self.v = tonumber(staticdata)
		end
		self.last_v = self.v
	end

	function salvag.get_staticdata(self)
		return tostring(self.v)
	end

	function salvag.on_punch(self, puncher)
		if not puncher or not puncher:is_player() or self.removed then
			return
		end
		if self.driver and puncher == self.driver then
			self.driver = nil
			puncher:set_detach()
			default.player_attached[puncher:get_player_name()] = false
		end
		if not self.driver then
			self.removed = true
			-- delay remove to ensure player is detached
			minetest.after(0.1, function()
				self.object:remove()
			end)
			if not minetest.setting_getbool("creative_mode") then
				local inv = puncher:get_inventory()
				if inv:room_for_item("main", "summer:salvag_" .. color .. "_item") then
					inv:add_item("main", "summer:salvag_" .. color .. "_item")
				else
					minetest.add_item(self.object:getpos(), salvag_item_name)
				end
			end
		end
	end

	function salvag.on_step(self, dtime)
		self.v = get_v(self.object:getvelocity()) * get_sign(self.v)
		if self.driver then
			local ctrl = self.driver:get_player_control()
			local yaw = self.object:getyaw()
			if ctrl.up then
				self.v = self.v + 0.1
			elseif ctrl.down then
				self.v = self.v - 0.1
			end
			if ctrl.left then
				if self.v < 0 then
					self.object:setyaw(yaw - (1 + dtime) * 0.03)
				else
					self.object:setyaw(yaw + (1 + dtime) * 0.03)
				end
			elseif ctrl.right then
				if self.v < 0 then
					self.object:setyaw(yaw + (1 + dtime) * 0.03)
				else
					self.object:setyaw(yaw - (1 + dtime) * 0.03)
				end
			end
		end
		local velo = self.object:getvelocity()
		if self.v == 0 and velo.x == 0 and velo.y == 0 and velo.z == 0 then
			self.object:setpos(self.object:getpos())
			return
		end
		local s = get_sign(self.v)
		self.v = self.v - 0.02 * s
		if s ~= get_sign(self.v) then
			self.object:setvelocity({ x = 0, y = 0, z = 0 })
			self.v = 0
			return
		end
		if math.abs(self.v) > 5 then
			self.v = 5 * get_sign(self.v)
		end

		local p = self.object:getpos()
		p.y = p.y - 0.5
		local new_velo = { x = 0, y = 0, z = 0 }
		local new_acce = { x = 0, y = 0, z = 0 }
		if not is_water(p) then
			local nodedef = minetest.registered_nodes[minetest.get_node(p).name]
			if (not nodedef) or nodedef.walkable then
				self.v = 0
				new_acce = { x = 0, y = 1, z = 0 }
			else
				new_acce = { x = 0, y = -9.8, z = 0 }
			end
			new_velo = get_velocity(self.v, self.object:getyaw(),
				self.object:getvelocity().y)
			self.object:setpos(self.object:getpos())
		else
			p.y = p.y + 1
			if is_water(p) then
				local y = self.object:getvelocity().y
				if y >= 5 then
					y = 5
				elseif y < 0 then
					new_acce = { x = 0, y = 20, z = 0 }
				else
					new_acce = { x = 0, y = 5, z = 0 }
				end
				new_velo = get_velocity(self.v, self.object:getyaw(), y)
				self.object:setpos(self.object:getpos())
			else
				new_acce = { x = 0, y = 0, z = 0 }
				if math.abs(self.object:getvelocity().y) < 1 then
					local pos = self.object:getpos()
					pos.y = math.floor(pos.y) + 0.5
					self.object:setpos(pos)
					new_velo = get_velocity(self.v, self.object:getyaw(), 0)
				else
					new_velo = get_velocity(self.v, self.object:getyaw(),
						self.object:getvelocity().y)
					self.object:setpos(self.object:getpos())
				end
			end
		end
		self.object:setvelocity(new_velo)
		self.object:setacceleration(new_acce)
	end

	minetest.register_entity("summer:salvag_" .. color .. "", salvag)


	minetest.register_craftitem(salvag_item_name, {
		description = "salvagente (" .. color .. ")",
		inventory_image = "summer_salvag_" .. color .. "_inv.png",
		wield_image = "summer_salvag_" .. color .. "_inv.png",
		wield_scale = { x = 2, y = 2, z = 1 },
		liquids_pointable = true,

		on_place = function(itemstack, placer, pointed_thing)
			if pointed_thing.type ~= "node" then
				return
			end
			if not is_water(pointed_thing.under) then
				return
			end
			pointed_thing.under.y = pointed_thing.under.y + 0.5
			minetest.add_entity(pointed_thing.under, "summer:salvag_" .. color .. "")
			if not minetest.setting_getbool("creative_mode") then
				itemstack:take_item()
			end
			return itemstack
		end,
	})
	minetest.register_craft({
		output = salvag_item_name,
		recipe = {
			{ "",                        "",                        "" },
			{ "group:leaves",            "wool:" .. color,          "group:leaves" },
			{ "default:paper",           "group:leaves",            "default:paper" },
		},
	})



	if minetest.get_modpath("cannabis") then
		minetest.register_craft({
			output = salvag_item_name,
			recipe = {
				{ "",                        "",                        "" },
				{ "cannabis:canapa_plastic", "wool:" .. color,          "cannabis:canapa_plastic" },
				{ "cannabis:canapa_plastic", "cannabis:canapa_plastic", "cannabis:canapa_plastic" },
			},
		})
	end
end

colors = {
	"black", "red", "green", "blue", "yellow", "violet", "orange",
}

for _, color in ipairs(colors) do
	reg_salvag(color)
end