--
-- Helper functions
--

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


--
-- Sled entity
--

local sled = {
	physical = false,
	collisionbox = {-0.6,-0.25,-0.6, 0.6,0.3,0.6},
	visual = "mesh",
	mesh = "sled.x",
	textures = {"sled.png"},
	
	driver = nil,
	sliding = false,
}

local players_sled = {}

function sled:on_rightclick(clicker)
	if (not self.driver) and snow.sleds then
		players_sled[clicker:get_player_name()] = true
		self.driver = clicker
		self.object:set_attach(clicker, "", {x=0,y=-9,z=0}, {x=0,y=90,z=0})
		clicker:set_physics_override({
			speed = 2, -- multiplier to default value
			jump = 0, -- multiplier to default value
			gravity = 1
		  })   
		local HUD = 
			{
				hud_elem_type = "text", -- see HUD element types
				position = {x=0.5, y=0.89},
				name = "sled",
				scale = {x=2, y=2},
				text = "You are sledding, hold sneak to stop.",
				direction = 0,
			}
			
		clicker:hud_add(HUD)
 	end
end

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

function sled:get_staticdata()
	return tostring(v)
end

function sled:on_punch(puncher, time_from_last_punch, tool_capabilities, direction)
	self.object:remove()
	if puncher and puncher:is_player() then
		puncher:get_inventory():add_item("main", "snow:sled")
	end
end


minetest.register_globalstep(function(dtime)
	for _, player in pairs(minetest.get_connected_players()) do
		if players_sled[player:get_player_name()] then
			default.player_set_animation(player, "sit", 0)
		end
	end
end)


function sled:on_step(dtime)
	if self.driver then
		local p = self.object:getpos()
		p.y = p.y+0.4
		local s = self.object:getpos()
		s.y = s.y -0.5
		local keys = self.driver:get_player_control()
		if keys["sneak"] or is_water(p) or (not minetest.find_node_near(s, 1, {"default:snow","default:snowblock","default:ice","default:dirt_with_snow"})) then
			self.driver:set_physics_override({
				speed = 1, -- multiplier to default value
				jump = 1, -- multiplier to default value
				gravity = 1
		  	})
			players_sled[self.driver:get_player_name()] = false
			self.object:set_detach()
			self.driver:hud_remove("sled")
			self.driver = nil
			self.object:remove()
		end
	end
end

minetest.register_entity("snow:sled", sled)


minetest.register_craftitem("snow:sled", {
	description = "Sled",
	inventory_image = "snow_sled.png",
	wield_image = "snow_sled.png",
	wield_scale = {x=2, y=2, z=1},
	liquids_pointable = true,
	stack_max = 1,
	
 	on_use = function(itemstack, placer)
 		local pos = {x=0,y=-1000, z=0}
 		local name = placer:get_player_name()
 		if not players_sled[name] then
			local sled = minetest.env:add_entity(pos, "snow:sled")
			sled:get_luaentity():on_rightclick(placer)
		end
	end,
})

minetest.register_craft({
	output = "snow:sled",
	recipe = {
		{"", "", ""},
		{"group:stick", "", ""},
		{"group:wood", "group:wood", "group:wood"},
	},
})
minetest.register_craft({
	output = "snow:sled",
	recipe = {
		{"", "", ""},
		{"", "", "group:stick"},
		{"group:wood", "group:wood", "group:wood"},
	},
})