local savegen = {}

function savegen:new()

	local save = {}

	save.settings = {}
	save.settings.eid = true
	save.settings.visual = true
	save.settings.showonmodded = true
	save.settings.showonblind = false
	save.settings.maxid = 732

	save.seen = {}
	for i=1, save.settings.maxid do
		save.seen[i] = false
	end

	save.seenmodded = {}

	function save:touchid(id)
		-- Non-modded
		self.seen[id] = true
	end

	function save:touchname(name)
		-- Modded, save by name
		self.seenmodded[name] = true
	end

	function save:dump(json)
		local data = {}
		if self.settings then
			data.settings = {}
			data.settings.eid = self.settings.eid
			data.settings.visual = self.settings.visual
			data.settings.showonblind = self.settings.showonblind
			data.settings.showonmodded = self.settings.showonmodded
		end
		if self.seen then
			data.seen = {}
			for i=1, #save.seen do
				data.seen[i] = self.seen[i]
			end
		end
		if self.seenmodded then
			data.seenmodded = {}
			for i,v in pairs(self.seenmodded) do
				data.seenmodded[i] = v
			end
		end

		return json.encode(data)
	end

	function save:load(json, text)
		if save:islegacysave(text) then
			save:legacyload(text)
			return save
		else
			local data = json.decode(text)
			if data.settings then
				save.settings.eid = data.settings.eid
				save.settings.visual = data.settings.visual
				save.settings.showonblind = data.settings.showonblind
				save.settings.showonmodded = data.settings.showonmodded
			end
			if data.seen then
				for i=1, #data.seen do
					save.seen[i] = data.seen[i]
				end
			end
			if data.seenmodded then
				for i,v in pairs(data.seenmodded) do
					save.seenmodded[i] = v
				end
			end
		end
	end

	function save:islegacysave(text)
		-- Check if legacy (before modded items support) save
		for i=1, math.min(#text,self.settings.maxid+3) do
			local digit = string.sub(text,i,i)
			if digit~="0" and digit~="1" then
				-- Not a legacy save
				return false
			end
		end
		return true
	end

	function save:legacyload(text)
		-- Pre modded items support
		-- Change attributes based on the text
		-- Symbol to bool
		local f = function(x, i)
			return x:sub(i,i)=="1"
		end
		if (#text>=3) then
			-- First 3 are the settings
			self.settings.eid = f(text,1)
			self.settings.visual = f(text,2)
			self.settings.showonblind = f(text,3)
		end
		local offset = 3
		for id=1, self.settings.maxid do
			self.seen[id] = f(text,offset+id)
		end
	end

	return save
end

return savegen