feat: add logic for journey->train identifier resolving, add recording of journeys, build api bearer auth

src/api/db_vendo_navigator.rs

@@ -0,0 +1,71 @@
+use chrono::DateTime;
+use url::Url;
+use urlencoding::encode;
+use crate::error::train_order_api_error::ResolveTripNumberError;
+use crate::model::db_vendo_navigator_api::TrainOrdering;
+use crate::model::travelynx::TrainType;
+
+pub async fn get_railcar_identifier_by_journey(
+    train_type: TrainType,
+    trip_number: usize,
+    station_uic: usize,
+    departure_time: usize
+) -> Result<u64, ResolveTripNumberError> {
+    let train_ordering = query_train_order_api(train_type, trip_number, station_uic, departure_time).await?;
+    println!("Received train ordering response {:?}", train_ordering);
+    find_railcar_identifier(train_ordering)
+}
+
+fn find_railcar_identifier(train_ordering: TrainOrdering) -> Result<u64, ResolveTripNumberError> {
+    let trainset = train_ordering.train_sets.first()
+        .ok_or(ResolveTripNumberError::Api("No items in field 'fahrzeuggruppe'".to_string()))?;
+    let identifier_str = trainset.identifier.to_owned();
+    let train_type = &trainset.journey.train_type;
+    let identifier = crop_first_n_chars(identifier_str.as_str(), train_type.to_string().len())
+        .to_string().parse::<u64>()?;
+    Ok(identifier)
+}
+
+async fn query_train_order_api(
+    train_type: TrainType,
+    trip_number: usize,
+    station_uic: usize,
+    departure_time: usize
+) -> reqwest::Result<TrainOrdering> {
+    println!("Resolving trip {train_type} {trip_number} from {station_uic} at {departure_time}");
+    let client = reqwest::ClientBuilder::new()
+        .build()?;
+    let api_url = build_api_url(train_type, trip_number, station_uic, departure_time);
+    println!("Fetching {api_url}");
+    client.get(api_url)
+        .header("Accept", "application/x.db.vendo.mob.wagenreihung.v3+json")
+        .header("X-Correlation-ID", "ABCDE")
+        .send()
+        .await?
+        .json::<TrainOrdering>()
+        .await
+}
+
+fn build_api_url(
+    train_type: TrainType,
+    trip_number: usize,
+    station_uic: usize,
+    departure_time: usize
+) -> Url {
+    let train_trip = format!("{}_{}", train_type.to_string(), trip_number);
+    let departure = DateTime::from_timestamp(departure_time as i64, 0)
+        .expect("invalid departure time");
+    Url::parse(format!(
+        "https://app.vendo.noncd.db.de/mob/zuglaeufe/{}/halte/by-abfahrt/{}_{}/wagenreihung",
+        train_trip,
+        station_uic,
+        encode(departure.to_rfc3339().as_str())
+    ).as_str()).unwrap()
+}
+
+fn crop_first_n_chars(s: &str, count: usize) -> &str {
+    match s.char_indices().skip(count).next() {
+        Some((pos, _)) => &s[pos..],
+        None => ""
+    }
+}