merge impl-v2: plugin

plugin/src/ApiContext.lua

@@ -0,0 +1,119 @@
+local Promise = require(script.Parent.Parent.modules.Promise)
+
+local Config = require(script.Parent.Config)
+local Version = require(script.Parent.Version)
+local Http = require(script.Parent.Http)
+local HttpError = require(script.Parent.HttpError)
+
+local ApiContext = {}
+ApiContext.__index = ApiContext
+
+-- TODO: Audit cases of errors and create enum values for each of them.
+ApiContext.Error = {
+	ServerIdMismatch = "ServerIdMismatch",
+}
+
+setmetatable(ApiContext.Error, {
+	__index = function(_, key)
+		error("Invalid API.Error name " .. key, 2)
+	end
+})
+
+function ApiContext.new(url, onMessage)
+	assert(type(url) == "string")
+	assert(type(onMessage) == "function")
+
+	local context = {
+		url = url,
+		onMessage = onMessage,
+		serverId = nil,
+		connected = false,
+		messageCursor = -1,
+	}
+
+	setmetatable(context, ApiContext)
+
+	return context
+end
+
+function ApiContext:connect()
+	return Http.get(self.url)
+		:andThen(function(response)
+			local body = response:json()
+
+			if body.protocolVersion ~= Config.protocolVersion then
+				local message = (
+					"Found a Rojo dev server, but it's using a different protocol version, and is incompatible." ..
+					"\nMake sure you have matching versions of both the Rojo plugin and server!" ..
+					"\n\nYour client is version %s, with protocol version %s. It expects server version %s." ..
+					"\nYour server is version %s, with protocol version %s." ..
+					"\n\nGo to https://github.com/LPGhatguy/rojo for more details."
+				):format(
+					Version.display(Config.version), Config.protocolVersion,
+					Config.expectedApiContextVersionString,
+					body.serverVersion, body.protocolVersion
+				)
+
+				return Promise.reject(message)
+			end
+
+			self.serverId = body.serverId
+			self.connected = true
+		end)
+end
+
+function ApiContext:readAll()
+	if not self.connected then
+		return Promise.reject()
+	end
+
+	return Http.get(self.url .. "/read_all")
+		:andThen(function(response)
+			local body = response:json()
+
+			if body.serverId ~= self.serverId then
+				return Promise.reject("server changed ID")
+			end
+
+			self.messageCursor = body.messageCursor
+
+			return body.instances
+		end, function(err)
+			self.connected = false
+
+			return Promise.reject(err)
+		end)
+end
+
+function ApiContext:retrieveMessages()
+	if not self.connected then
+		return Promise.reject()
+	end
+
+	return Http.get(self.url .. "/subscribe/" .. self.messageCursor)
+		:andThen(function(response)
+			local body = response:json()
+
+			if body.serverId ~= self.serverId then
+				return Promise.reject("server changed ID")
+			end
+
+			for _, message in ipairs(body.messages) do
+				self.onMessage(message)
+			end
+
+			self.messageCursor = body.messageCursor
+
+			return self:retrieveMessages()
+		end, function(err)
+			if err.type == HttpError.Error.Timeout then
+				return self:retrieveMessages()
+			end
+
+			self.connected = false
+
+			return Promise.reject(err)
+		end)
+end
+
+return ApiContext