metadata

local unpack = unpack or table.unpack

function parse(path)
	if fs.exists(path) then
		local handle = fs.open(path, "r")
		if handle then
			local data = {}
			local fn, err = loadstring(handle.readAll())
			handle.close()
			if fn then
				setfenv(fn, data)
				local success, err = pcall(fn)
				if success then
					return data
				else
					return nil, err
				end
			else
				return nil, err
			end
		else
			return nil, "could not read metadata"
		end
	else
		return nil, "no metadata found"
	end
end

function getMetaFolderForPath(path)
	local drive = fs.getDrive(path)
	if drive == "hdd" or drive == "rom" then
		return "/.meta", path
	elseif drive then
		local mountPath = disk.getMountPath(drive)
		local metaPath = fs.combine(mountPath, ".meta")
		if string.sub(mountPath, 1, 1) ~= "/" then mountPath = "/"..mountPath end
		if string.sub(path, 1, 1) ~= "/" then path = "/"..path end
		local pathRemainder = string.match(path, fs.combine(mountPath, "(.*)"))
		return metaPath, pathRemainder
	else
		return "/.meta", path
	end
end

function getForFile(path)
	return metadata.parse(fs.combine(metadata.getMetaFolderForPath(path)))
end

function getForFolder(path)
	if fs.exists(path) and fs.isDir(path) then
		local data = {}
		for _, file in ipairs(fs.list(fs.combine(metadata.getMetaFolderForPath(path), path))) do
			data[fs.combine(path, file)] = metadata.parse(fs.combine(fs.combine(metadata.getMetaFolderForPath(path), path), file))
		end
		return data
	end
end

local function walkFolder(path, meta)
	local path = path or "/"
	local data = meta or {}
	if fs.exists(path) and fs.isDir(path) then
		for _, file in ipairs(fs.list(path)) do
			local current = fs.combine(path, file)
			if fs.isDir(current) then
				walkFolder(current, data)
			else
				data[current] = metadata.getForFile(current)
			end
		end
		return data
	end
end

function load()
	if fs.exists(".meta") and fs.isDir(".meta") then
		return walkFolder()
	else
		return nil, "no metadata available"
	end
end

function prepare(meta)
	local str = ""
	for k, v in pairs(meta) do
		if type(k) == "string" then
			if type(v) == "number" or type(v) == "string" or type(v) == "boolean" then
				str = str..k.." = "..tostring(v).."\n"
			elseif type(v) == "table" then
				str = str..k.." = "..textutils.serialize(v).."\n"
			end
		end
	end
	return str
end

local function makeFolders(path)
	local folders = ""
	repeat
		local newFolder = string.match(path, folders.."([^/]+/)")
		if not newFolder then break end
		folders = folders..newFolder
		if not fs.exists(folders) then fs.makeDir(folders) end
	until false
end

function save(path, meta)
	if meta then
		local data = prepare(meta)
		local path = fs.combine(metadata.getMetaFolderForPath(path))
		makeFolders(path)
		local handle = fs.open(path, "w")
		if handle then
			handle.write(data)
			handle.close()
		else
			return nil, "could not open metadata file"
		end
	else
		return nil, "no metadata to write"
	end
end

function saveAll(meta)
	if meta then
		for k, v in pairs(meta) do
			metadata.save(k, v)
		end
	end
end