route history requests based on project

either to track changes or to project history service

services/web/app/coffee/Features/History/HistoryController.coffee

@@ -2,6 +2,7 @@ logger = require "logger-sharelatex"
 request = require "request"
 settings = require "settings-sharelatex"
 AuthenticationController = require "../Authentication/AuthenticationController"
+ProjectDetailsHandler = require "../Project/ProjectDetailsHandler"
 
 module.exports = HistoryController =
 	initializeProject: (callback = (error, history_id) ->) ->
@@ -27,11 +28,22 @@ module.exports = HistoryController =
 				error = new Error("project-history returned a non-success status code: #{res.statusCode}")
 				callback error
 
+	selectHistoryApi: (req, res, next = (error) ->) ->
+		project_id = req.params?.Project_id
+		# find out which type of history service this project uses
+		ProjectDetailsHandler.getDetails project_id, (err, project) ->
+			return next(err) if err?
+			if project?.overleaf?.history?
+				req.useProjectHistory = true
+			else
+				req.useProjectHistory = false
+			next()
+
 	proxyToHistoryApi: (req, res, next = (error) ->) ->
 		user_id = AuthenticationController.getLoggedInUserId req
-		url = HistoryController.buildHistoryServiceUrl() + req.url
+		url = HistoryController.buildHistoryServiceUrl(req.useProjectHistory) + req.url
 
-		logger.log url: url, "proxying to track-changes api"
+		logger.log url: url, "proxying to history api"
 		getReq = request(
 			url: url
 			method: req.method
@@ -40,11 +52,13 @@ module.exports = HistoryController =
 		)
 		getReq.pipe(res)
 		getReq.on "error", (error) ->
-			logger.error err: error, "track-changes API error"
+			logger.error url: url, err: error, "history API error"
 			next(error)
 
-	buildHistoryServiceUrl: () ->
-		if settings.apis.project_history?.enabled
+	buildHistoryServiceUrl: (useProjectHistory) ->
+		# choose a history service, either document-level (trackchanges)
+		# or project-level (project_history)
+		if settings.apis.project_history?.enabled && useProjectHistory
 			return settings.apis.project_history.url
 		else
 			return settings.apis.trackchanges.url

services/web/app/coffee/router.coffee

@@ -194,9 +194,9 @@ module.exports = class Router
 
 		webRouter.post '/project/:Project_id/rename', AuthorizationMiddlewear.ensureUserCanAdminProject, ProjectController.renameProject
 
-		webRouter.get  "/project/:Project_id/updates", AuthorizationMiddlewear.ensureUserCanReadProject, HistoryController.proxyToHistoryApi
-		webRouter.get  "/project/:Project_id/doc/:doc_id/diff", AuthorizationMiddlewear.ensureUserCanReadProject, HistoryController.proxyToHistoryApi
-		webRouter.post "/project/:Project_id/doc/:doc_id/version/:version_id/restore", AuthorizationMiddlewear.ensureUserCanReadProject, HistoryController.proxyToHistoryApi
+		webRouter.get  "/project/:Project_id/updates", AuthorizationMiddlewear.ensureUserCanReadProject, HistoryController.selectHistoryApi, HistoryController.proxyToHistoryApi
+		webRouter.get  "/project/:Project_id/doc/:doc_id/diff", AuthorizationMiddlewear.ensureUserCanReadProject, HistoryController.selectHistoryApi, HistoryController.proxyToHistoryApi
+		webRouter.post "/project/:Project_id/doc/:doc_id/version/:version_id/restore", AuthorizationMiddlewear.ensureUserCanReadProject, HistoryController.selectHistoryApi, HistoryController.proxyToHistoryApi
 
 		webRouter.get  '/Project/:Project_id/download/zip', AuthorizationMiddlewear.ensureUserCanReadProject, ProjectDownloadsController.downloadProject
 		webRouter.get  '/project/download/zip', AuthorizationMiddlewear.ensureUserCanReadMultipleProjects, ProjectDownloadsController.downloadMultipleProjects

services/web/test/UnitTests/coffee/History/HistoryControllerTests.coffee

@@ -15,6 +15,7 @@ describe "HistoryController", ->
 			"settings-sharelatex": @settings = {}
 			"logger-sharelatex": @logger = {log: sinon.stub(), error: sinon.stub()}
 			"../Authentication/AuthenticationController": @AuthenticationController
+			"../Project/ProjectDetailsHandler": @ProjectDetailsHandler = {}
 		@settings.apis =
 			trackchanges:
 				enabled: false
@@ -22,6 +23,29 @@ describe "HistoryController", ->
 			project_history:
 				url: "http://project_history.example.com"
 
+	describe "selectHistoryApi", ->
+		beforeEach ->
+			@req = { url: "/mock/url", method: "POST" }
+			@res = "mock-res"
+			@next = sinon.stub()
+
+		describe "for a project with project history", ->
+			beforeEach ->
+				@ProjectDetailsHandler.getDetails = sinon.stub().callsArgWith(1, null, {overleaf:{history:{}}})
+				@HistoryController.selectHistoryApi @req, @res, @next
+
+			it "should set the flag for project history to true", ->
+				@req.useProjectHistory.should.equal true
+
+		describe "for any other project ", ->
+			beforeEach ->
+				@ProjectDetailsHandler.getDetails = sinon.stub().callsArgWith(1, null, {})
+				@HistoryController.selectHistoryApi @req, @res, @next
+
+			it "should not set the flag for project history to false", ->
+				@req.useProjectHistory.should.equal false
+
+
 	describe "proxyToHistoryApi", ->
 		beforeEach ->
 			@req = { url: "/mock/url", method: "POST" }
@@ -33,10 +57,13 @@ describe "HistoryController", ->
 				on: (event, handler) -> @events[event] = handler
 			@request.returns @proxy
 
-		describe "successfully", ->
-			describe "with project history enabled", ->
+		describe "with project history enabled", ->
+			beforeEach ->
+				@settings.apis.project_history.enabled = true
+
+			describe "for a project with the project history flag", ->
 				beforeEach ->
-					@settings.apis.project_history.enabled = true
+					@req.useProjectHistory = true
 					@HistoryController.proxyToHistoryApi @req, @res, @next
 
 				it "should get the user id", ->
@@ -59,9 +86,53 @@ describe "HistoryController", ->
 						.calledWith(@res)
 						.should.equal true
 
-			describe "with project history disabled", ->
+			describe "for a project without the project history flag", ->
 				beforeEach ->
-					@settings.apis.project_history.enabled = false
+					@req.useProjectHistory = false
+					@HistoryController.proxyToHistoryApi @req, @res, @next
+
+				it "should get the user id", ->
+					@AuthenticationController.getLoggedInUserId
+						.calledWith(@req)
+						.should.equal true
+
+				it "should call the track changes api", ->
+					@request
+						.calledWith({
+							url: "#{@settings.apis.trackchanges.url}#{@req.url}"
+							method: @req.method
+							headers:
+								"X-User-Id": @user_id
+						})
+						.should.equal true
+
+				it "should pipe the response to the client", ->
+					@proxy.pipe
+						.calledWith(@res)
+						.should.equal true
+
+		describe "with project history disabled", ->
+			beforeEach ->
+				@settings.apis.project_history.enabled = false
+
+			describe "for a project with the project history flag", ->
+				beforeEach ->
+					@req.useProjectHistory = true
+					@HistoryController.proxyToHistoryApi @req, @res, @next
+
+				it "should call the track changes api", ->
+					@request
+						.calledWith({
+							url: "#{@settings.apis.trackchanges.url}#{@req.url}"
+							method: @req.method
+							headers:
+								"X-User-Id": @user_id
+						})
+						.should.equal true
+
+			describe "for a project without the project history flag", ->
+				beforeEach ->
+					@req.useProjectHistory = false
 					@HistoryController.proxyToHistoryApi @req, @res, @next
 
 				it "should call the track changes api", ->