--[[**
	<description>
	Asynchronously saves the data to the data store.
	</description>
**--]]

function DataStore:SaveAsync()
	return Promise.async(function(resolve, reject)
		if not self.valueUpdated then
			warn(("Data store %s was not saved as it was not updated."):format(self.Name))
			resolve(false)
			return
		end

		if RunService:IsStudio() and not SaveInStudio then
			warn(("Data store %s attempted to save in studio while SaveInStudio is false."):format(self.Name))
			if not SaveInStudioObject then
				warn("You can set the value of this by creating a BoolValue named SaveInStudio in ServerStorage.")
			end
			resolve(false)
			return
		end

		if self.backup then
			warn("This data store is a backup store, and thus will not be saved.")
			resolve(false)
			return
		end

		if self.value ~= nil then
			local save = clone(self.value)

			if self.beforeSave then
				local success, result = pcall(self.beforeSave, save, self)

				if success then
					save = result
				else
					reject(result, Constants.SaveFailure.BeforeSaveError)
					return
				end
			end

			local problem = Verifier.testValidity(save)
			if problem then
				reject(problem, Constants.SaveFailure.InvalidData)
				return
			end

			return self.savingMethod:Set(save):andThen(function()
				resolve(true, save)
			end)
		end
	end):andThen(function(saved, save)
		if saved then
			for _, afterSave in pairs(self.afterSave) do
				local success, err = pcall(afterSave, save, self)

				if not success then
					warn("Error on AfterSave: "..err)
				end
			end

			self.valueUpdated = false
		end
	end)
end

function DataStore:BindToClose(callback)
	table.insert(self.bindToClose, callback)
end

function DataStore:GetKeyValue(key)
	return (self.value or {})[key]
end

function DataStore:SetKeyValue(key, newValue)
	if not self.value then
		self.value = self:Get({})
	end

	self.value[key] = newValue
end

local CombinedDataStore = {}

do
	function CombinedDataStore:BeforeInitialGet(modifier)
		self.combinedBeforeInitialGet = modifier
	end

	function CombinedDataStore:BeforeSave(modifier)
		self.combinedBeforeSave = modifier
	end

	function CombinedDataStore:Get(defaultValue, dontAttemptGet)
		local tableResult = self.combinedStore:Get({})
		local tableValue = tableResult[self.combinedName]

		if not dontAttemptGet then
			if tableValue == nil then
				tableValue = defaultValue
			else
				if self.combinedBeforeInitialGet and not self.combinedInitialGot then
					tableValue = self.combinedBeforeInitialGet(tableValue)
				end
			end
		end

		self.combinedInitialGot = true
		tableResult[self.combinedName] = clone(tableValue)
		self.combinedStore:Set(tableResult, true)
		return clone(tableValue)
	end

	function CombinedDataStore:Set(value, dontCallOnUpdate)
		local tableResult = self.combinedStore:GetTable({})
		tableResult[self.combinedName] = value
		self.combinedStore:Set(tableResult, dontCallOnUpdate)
		self:_Update(dontCallOnUpdate)
	end

	function CombinedDataStore:Update(updateFunc)
		self:Set(updateFunc(self:Get()))
		self:_Update()
	end

	function CombinedDataStore:Save()
		self.combinedStore:Save()
	end

	function CombinedDataStore:OnUpdate(callback)
		if not self.onUpdateCallbacks then
			self.onUpdateCallbacks = { callback }
		else
			self.onUpdateCallbacks[#self.onUpdateCallbacks + 1] = callback
		end
	end

	function CombinedDataStore:_Update(dontCallOnUpdate)
		if not dontCallOnUpdate then
			for _, callback in pairs(self.onUpdateCallbacks or {}) do
				callback(self:Get(), self)
			end
		end

		self.combinedStore:_Update(true)
	end

	function CombinedDataStore:SetBackup(retries)
		self.combinedStore:SetBackup(retries)
	end
end

local DataStoreMetatable = {}

DataStoreMetatable.__index = DataStore
