How to integrate 2 branches programatically

I have 2 branches in my depot.

  //depot/project/mainline/...
  //depot/project/staging/...

I am using an in-house tool that manages the build of the project, and would like to create a build step that automatically promotes all the files from mainline into staging. I have been trying to write it using p4.net API, following the following example. I am able to run powershell commands from the build tool. My plan was to write a c# console application, compile it using the tool, and then execute it as a build step. Unfortunately I am getting nowhere with that example. I am able to create a client, create a branch spec and even sync the files down, but I for the life of me cant figure out how to submit the integrate. I feel like I am trying to over-engineer a solution thought. This is something that should be easy to do. I am attaching my broken code below. If it dose not make sense, its because I am using trial and error to figure stuff out and didn't make a final pass through it yet. That said, if i don't need to use the p4 api, all the better. The only requirement is that there be no user input required to run the commands. If there is a merge conflict, I want to automatically accept the source.

Thanks

        string uri = "server";
        string user = "user";
        string pass = null;
        string ws_client = "Project-Temp-"+ Guid.NewGuid().ToString();


        Server server = new Server(new ServerAddress(uri));
        Repository rep = new Repository(server);
        Connection con = rep.Connection;

        con.UserName = user;
        con.Client = new Client();
        con.Client.Name = ws_client;
        con.Client.ViewMap = new ViewMap();

        con.Connect(null);
        Credential cred = con.Login(pass, null, null);
        rep.DeleteClient(con.Client, null);
        rep.CreateClient(con.Client);
        con.Client.ViewMap.Clear();
        con.Client.ViewMap.Add("//depot/project/...", String.Format("//{0}/...", con.Client.Name), MapType.Include);
        rep.UpdateClient(con.Client);

        var files = con.Client.SyncFiles(new SyncFilesCmdOptions(SyncFilesCmdFlags.None, -1));

        ViewMap vm = new ViewMap();
        vm.Add(new MapEntry(MapType.Include,new ClientPath("//depot/project/mainline/..."), new ClientPath("//depot/project/staging/...")));
        string msg = "Mainline to Staging";
        BranchSpec bs = new BranchSpec("Project-Temp", user, DateTime.Now, DateTime.Now, msg, true, vm, null, null);
        int change = -1;
        IntegrateFilesCmdOptions BranchOptions = new IntegrateFilesCmdOptions(IntegrateFilesCmdFlags.None, change, -1, "Project-Temp", null, null);
        rep.CreateBranchSpec(bs);
        rep.UpdateClient(con.Client);


        var integrated = con.Client.IntegrateFiles(BranchOptions);
        con.Client.ResolveFiles(files, new ResolveCmdOptions(ResolveFilesCmdFlags.AutomaticYoursMode, change));


        rep.DeleteClient(con.Client, null);

From the command line this is:

p4 integrate //depot/project/mainline/... //depot/project/staging/...
p4 resolve -am
p4 resolve -at
p4 resolve -ay
p4 submit -d "Integrate."

The "resolve -am" automerges all files without conflicts. The "resolve -at" accepts the source of all remaining files. On the very off chance there are source files that can't be accepted (e.g. the source revisions have been obliterated, or the source and target actions are incompatible), the "resolve -ay" ignores them.