-- Enhanced main inventory methods
local maininvClass = {}
maininvClass.__index = maininvClass

-- Clear the inventory
function maininvClass:remove_all()
	for idx = 1, self.inventory:get_size("main") do
		self.inventory:set_stack("main", idx, "")
	end
end

-- Save inventory content to a slot (file)
function maininvClass:save_to_slot(slot)
	local savedata = {}
	for idx, stack in ipairs(self.inventory:get_list("main")) do
		if not stack:is_empty() then
			savedata[idx] = stack:to_string()
		end
	end
	local path = minetest.get_worldpath().."/smart_inventory_creative_"..self.playername.."_slot_"..tostring(slot)
	local fd = io.open( path, 'w' )
	if( fd ) then
		fd:write( minetest.serialize(savedata))
		fd:close()
	end
end

-- Get restore the inventory content from a slot (file)
function maininvClass:restore_from_slot(slot)
	local savedata
	local path = minetest.get_worldpath().."/smart_inventory_creative_"..self.playername.."_slot_"..tostring(slot)
	local fd = io.open( path, 'r' )
	if( fd ) then
		local data = fd:read("*all");
		fd:close()
		if data then
			savedata = minetest.deserialize( data );
		end
	end
	if savedata then
		for idx = 1, self.inventory:get_size("main") do
			self.inventory:set_stack("main", idx, savedata[idx])
		end
	end
end

-- Add a item to inventory
function maininvClass:add_item(item)
	self.inventory:add_item("main", item)
end

-- Get inventory content as consolidated table
function maininvClass:get_items()
	local items_in_inventory = {}

	for _, stack in ipairs(self.inventory:get_list("main")) do
		local itemname = stack:get_name()
		if itemname and itemname ~= "" then
			if not items_in_inventory[itemname] then
				items_in_inventory[itemname] = stack:get_count()
			else
				items_in_inventory[itemname] = items_in_inventory[itemname] + stack:get_count()
			end
		end
	end

-- add items in crafting field to the available items in inventory
	for _, stack in ipairs(self.inventory:get_list("craft")) do
		local itemname = stack:get_name()
		if itemname and itemname ~= "" then
			if not items_in_inventory[itemname] then
				items_in_inventory[itemname] = stack:get_count()
			else
				items_in_inventory[itemname] = items_in_inventory[itemname] + stack:get_count()
			end
		end
	end

	return items_in_inventory
end

-- try to get empty stacks by move items to other stacky up to max_size
function maininvClass:compress()
	for idx1 = self.inventory:get_size("main"), 1, -1 do
		local stack1 = self.inventory:get_stack("main", idx1)
		if not stack1:is_empty() then
			for idx2 = 1, idx1 do
				local stack2 = self.inventory:get_stack("main", idx2)
				if idx1 ~= idx2  and stack1:get_name() == stack2:get_name() then
					stack1 = stack2:add_item(stack1)
					self.inventory:set_stack("main", idx1, stack1)
					self.inventory:set_stack("main", idx2, stack2)
					if stack1:is_empty() then
						break
					end
				end
			end
		end
	end
end

-- move all items from crafting inventory back to main inventory
function maininvClass:sweep_crafting_inventory()
	for idx = 1, self.inventory:get_size("craft") do
		local stack = self.inventory:get_stack("craft", idx)
		if not stack:is_empty() then
			local left = self.inventory:add_item("main", stack)
			self.inventory:set_stack("craft", idx, left)
		end
	end
end

-- Swap row to the top. Asumption the inventory is 8x4, the row number should be 2, 3 or 4
function maininvClass:swap_row_to_top(row)
	local width = 8
	for idx1 = 1, width do
		local idx2 = (row -1) * width + idx1
		local stack1 = self.inventory:get_stack("main", idx1)
		local stack2 = self.inventory:get_stack("main", idx2)
		self.inventory:set_stack("main", idx2, stack1)
		self.inventory:set_stack("main", idx1, stack2)
	end
end

-- player inventory class
local maininv = {}
function maininv.get(playername)
	local self = setmetatable({}, maininvClass)
	self.playername = playername
	self.inventory = minetest.get_player_by_name(playername):get_inventory()
	return self
end

return maininv