Google Core Reporting凭据标识

I've read up on the Core Reporting docs, I've gone through different tutorials, and none of this makes sense.

Just from the point of trying to replicate demos, I'm still lost. The simple, SIMPLE demo I'm working with asks for this 0Auth 2.0 info:

// $client->setClientId('insert_your_oauth2_client_id');
// $client->setClientSecret('insert_your_oauth2_client_secret');
// $client->setRedirectUri('insert_your_oauth2_redirect_uri');
// $client->setDeveloperKey('insert_your_developer_key');

The JSON file I downloaded from https://code.google.com/apis/console?api=analytics, supplies some of that info:

{
    "web":{
        "auth_uri":"https://accounts.google.com/o/oauth2/auth",
        "token_uri":"https://accounts.google.com/o/oauth2/token",
        "client_email":"*********@developer.gserviceaccount.com",
        "redirect_uris":["https://www.**********.com/oauth2callback"],
         "client_x509_cert_url":"https://www.googleapis.com/robot/v1/metadata/x509/**********@developer.gserviceaccount.com",
        "client_id":"**********.apps.googleusercontent.com",
        "auth_provider_x509_cert_url":"https://www.googleapis.com/oauth2/v1/certs",
        "javascript_origins":["https://www.**********.com"]
    }
}

CliendId and RedirectUri, got it, no prob. ClientSecret and DeveloperKey? I don't even see those listed ANYWHERE. I assume it could mean the Public and Private keys that you download, but even then, I have no idea how to access the PKCS #12 file or whatever that is.

I am hopelessly lost and the google documentation just keeps pulling me around in circles and never mentions what these pieces are and how to get them.

I didn't do anything to fix this. It just started working one day. I assume it was some kind of bug with Google's API that they got around to fixing, but I never found any other instances of the bug in other forums or help sites.