/// Handle the response code.
extern crate opentdb;

use opentdb::api_request::ApiRequest;
use opentdb::api_response::ApiResponse;
use opentdb::enums::response_code::ResponseCode;

fn main() {
    // This token should have been extensively used before, but
    // for purposes of demonstration we'll just create a new one.
    let token: String = opentdb::session_new(None)
        .expect("New Session Creation failed")
        .token;

    let rq: ApiRequest = opentdb::builder().token(token.to_string()).build();
    // This will still work, because when the ResponseCode is non-zero (ResponseCode::Success),
    // the response will just be an empty JSON array, and this perfectly decodable by ApiResponse.
    let rs: ApiResponse = opentdb::send_and_parse(rq).unwrap();

    match rs.response_code {
        ResponseCode::Success => {
            // Nothing to do but deal with the Api Response.
        },
        ResponseCode::NoResults => {
            // Retry the request with fewer questions or a less specific category.
            // You can also try calling `opentdb::session_reset(token);` to allow for
            // more questions to be returned.
        },
        ResponseCode::InvalidParameter => {
            // Most probably one of the folowing cases is true:
            //
            // (1) The API has been updated and this library is no longer compatible with it, report as a bug.
            // (2) The library just flat out has a bug in it, and it needs to be fixed.
            // (3) Something unknown has happened.
            //
            // Whatever it is, we can't really recover from this. You can panic!() or deal with this however you see fit.
            panic!("Library encountered an error.");
        },
        ResponseCode::TokenNotFound => {
            // Session Tokens only maintain active for 6 hours after last use. You've probably
            // kept it stored for too long. You will have to request a new token.
            let _token = opentdb::session_new(None).unwrap();
            // Store token somewhere.
        },
        ResponseCode::TokenEmpty => {
            // We need to retry the request after this.
            opentdb::session_reset(&token, None).unwrap();
            // Retry the request with the same token.
        },
        ResponseCode::Unknown => {
            // This response may exist if the API has introduced new codes but they are not
            // yet mapped to the library. You can deal with them yourself here, panic,
            // or do something else.
            panic!("Unknown problem.");
        }
    }

    // You don't *NEED* to deal with the Response Code other than ResponseCode::TokenEmpty,
    // and even this is a stretch if you a very basic app that does not filter out much
    // (because OpenTDB has >3000 items, you will not run out any time soon.)
    //
    // the API will return an empty array, and if there's nothing in there, there's no questions left.
    //
    // You may also choose to look at `rs.results.len()`
    //
    // The following will still just entirely work:
    //
    // for results in rs.results {
    //     println!("  [{}] Question: {}", results.category, results.question);
    // }

    println!("Response Code: {:?}", rs.response_code);
}