------------------------------------------------------------
-- Copyright (c) 2016 tacigar
-- https://github.com/tacigar/maidroid
------------------------------------------------------------

local _aux = maidroid._aux

-- aux function to generate serialnumber for inventories
local gen_inv_serialnumber = (function ()
	local serialnumber = 0
	return function ()
		serialnumber = serialnumber + 1
		return serialnumber - 1
	end
end) ()

local main_invsize = 16
local main_invname = "main"
local module_invsize = 1
local module_invname = "module"

-- key = modulename, value = moduledef
maidroid.registered_modules = {}

function maidroid.register_module(module_name, def)
	maidroid.registered_modules[module_name] = def
	minetest.register_craftitem(module_name, {
		description = def.description,
		stack_max = 1,
		inventory_image = def.inventory_image,
	})
end

-- animation frame
maidroid.animations = {
	stand = {x = 0, y = 79},
	lay = {x = 162, y = 166},
	walk = {x = 168, y = 187},
	mine = {x = 189, y = 198},
	walk_mine = {x = 200, y = 219},
	sit = {x = 81, y = 160},
}

function maidroid.register_maidroid(product_name, def)
	minetest.register_entity(product_name, {
		hp_max = def.hp_max or 1,
		physical = true,
		weight = def.weight or 5,
		collistionbox = def.collistionbox or { -0.35, -0.5, -0.35, 0.35, 1.1, 0.35 },
		visual = "mesh",
		visual_size = {x = 10, y = 10},
		mesh = def.mesh or "maidroid.b3d",
		textures = def.textures or {"maidroid.png"},
		is_visible = true,
		makes_footstep_sound = true,
		module = nil,
		invname = "",

		on_activate = function(self, staticdata)
			self.invname = "maidroid"..tostring(gen_inv_serialnumber())
			local inv = minetest.create_detached_inventory(self.invname, {
				on_put = function(inv, listname, index, stack, player)
					if listname == module_invname then
						local module_name = stack:get_name()
						local module_def = maidroid.registered_modules[module_name]
						self.module = module_def
						module_def.initialize(self)
					end
				end,
				allow_put = function(inv, listname, index, stack, player)
					local item_name = stack:get_name()
					local is_module = maidroid.registered_modules[item_name]
					if listname == main_invname
					or (listname == module_invname and is_module) then
						return stack:get_count()
					end
					return 0
				end,
				on_take = function(inv, listname, index, stack, player)
					if listname == module_invname then
						local module_name = stack:get_name()
						local module_def = maidroid.registered_modules[module_name]
						self.module = nil
						module_def.finalize(self)
					end
				end,
			})
			inv:set_size(main_invname, main_invsize)
			inv:set_size(module_invname, module_invsize)
			-- process staticdata
			if staticdata ~= "" then
				local data = minetest.deserialize(staticdata)
				if data.inv.module ~= "" then
					module_stack = ItemStack(data.inv.module)
					module_stack:set_count(1)
					inv:add_item(module_invname, module_stack)
					self.module = maidroid.registered_modules[data.inv.module]
				end
				for _, item in ipairs(data.inv.main) do
					local itemstack = ItemStack(item.name)
					itemstack:set_count(item.count)
					inv:add_item(main_invname, itemstack)
				end
			end
			-- initialize module
			if self.module then self.module.initialize(self)
			else
				self.object:setvelocity{x = 0, y = 0, z = 0}
				self.object:setacceleration{x = 0, y = -10, z = 0}
			end
		end,

		on_step = function(self, dtime)
			if self.module then self.module.on_step(self, dtime) end
		end,

		on_punch = function(self, puncher, time_from_last_punch, tool_capabilities, dir)
		end,

		on_rightclick = function(self, clicker)
			local formspec = "size[8,9]"
			.."list[detached:"..self.invname..";"..main_invname..";0,0;4,4;]"
			.."label[5,0;MODULE]"
			.."list[detached:"..self.invname..";"..module_invname..";6,0;1,1;]"
			.."list[current_player;"..main_invname..";0,5;8,1;]"
			.."list[current_player;"..main_invname..";0,6.2;8,3;8]"
			minetest.show_formspec(clicker:get_player_name(), self.invname, formspec)
		end,

		get_staticdata = function(self)
			local inv = _aux.get_maidroid_inventory(self)
			local staticdata = {}
			staticdata.inv = {}
			local module_name = inv:get_list(module_invname)[1]:get_name()
			staticdata.inv.module = module_name or ""
			staticdata.inv.main = {}
			for _, item in ipairs(inv:get_list(main_invname)) do
				local count = item:get_count()
				local itemname = item:get_name()
				if count ~= 0 then
					local itemdata = { count = count, name = itemname }
					table.insert(staticdata.inv.main, itemdata)
				end
			end
			return minetest.serialize(staticdata)
		end,
	})

	-- register spawn egg
	minetest.register_craftitem(product_name.."_spawn_egg", {
		description = def.description.." Spawn Egg",
		inventory_image = def.inventory_image,
		stack_max = 1,
		on_use = function(itemstack, user, pointed_thing)
			if pointed_thing.above ~= nil then
				minetest.add_entity(pointed_thing.above, product_name)
				return itemstack
			end
			return nil
		end
	})
end