add number stops from args

src/args.rs

@@ -2,9 +2,24 @@ use std::env::args;
 
 use anyhow::{Context, Result};
 
-pub fn get_station_name_from_args() -> Result<String> {
+pub struct Args {
-    args()
+    pub name: String,
-        .into_iter()
+    pub number_stops: usize,
-        .nth(1)
+}
-        .context("getting station name from args")
+
+impl Args {
+    pub fn try_get() -> Result<Self> {
+        let mut iter = args().into_iter().skip(1);
+        let name = iter.next().context("getting station name")?;
+        let number_stops = get_number_stops(iter.next()).context("getting number of stops")?;
+
+        Ok(Self { name, number_stops })
+    }
+}
+
+fn get_number_stops(arg: Option<String>) -> Result<usize> {
+    match arg {
+        Some(s) => s.parse().context("parsing number"),
+        None => Ok(5),
+    }
 }

src/lib.rs

@@ -2,6 +2,6 @@ mod args;
 mod query;
 pub mod response;
 
-pub use args::get_station_name_from_args;
+pub use args::Args;
 pub use query::get_departures_for_station;
 pub use response::format_departures;

src/main.rs

@@ -1,10 +1,10 @@
-use anyhow::Result;
+use anyhow::{Context, Result};
 
-use departure::{format_departures, get_departures_for_station, get_station_name_from_args};
+use departure::{format_departures, get_departures_for_station, Args};
 
 fn main() -> Result<()> {
-    let station_name = get_station_name_from_args()?;
+    let args = Args::try_get().context("parsing args")?;
-    let response = get_departures_for_station(station_name)?;
+    let response = get_departures_for_station(args).context("getting departures")?;
     let formatted = format_departures(response);
     println!("{formatted}");
     Ok(())

src/query.rs

@@ -1,52 +1,91 @@
-use anyhow::Result;
+use std::collections::HashMap;
-use ureq::Request;
 
-use crate::response::{PointFinderResponse, Response};
+use anyhow::{bail, Context, Result};
+
+use crate::{
+    response::{PointFinderResponse, Response},
+    Args,
+};
 
 const DEPARTURE_MONITOR: &str = "https://webapi.vvo-online.de/dm";
 const POINT_FINDER: &str = "https://webapi.vvo-online.de/tr/pointfinder";
 
-pub fn get_departures_for_station(station_name: String) -> Result<Response> {
+pub fn get_departures_for_station(args: Args) -> Result<Response> {
-    let stopid = get_stopid_from_station_name(station_name)?;
+    let stopid = match get_stopid_from_station_name(args.name) {
+        Ok(value) => value,
+        Err(e) => bail!(
+            "could not resolve stop ID. Check the spelling of the stop name\nserde error: {e}"
+        ),
+    };
 
-    let json_string = create_json_request(DEPARTURE_MONITOR)
+    let number_stops = args.number_stops.to_string();
-        .send_string(&format!(
+    let kv_pair = get_key_value_pair_for_departure(&stopid, &number_stops);
-            "{{
+
-            \"stopid\":\"{stopid}\",
+    let json_string = create_json_request(DEPARTURE_MONITOR, kv_pair)
-            \"limit\":5
+        .context("creating JSON request")?
-            }}"
+        .into_string()
-        ))?
+        .context("converting JSON reply to string")?;
-        .into_string()?;
 
     let result = serde_json::from_str(&json_string)?;
     Ok(result)
 }
 
 fn get_stopid_from_station_name(station_name: String) -> Result<String> {
-    let json_string = create_json_request(POINT_FINDER)
+    let kv_pair = get_key_value_pair_for_stopid(&station_name);
-        .send_string(&format!(
+
-            "{{
+    let json_string = create_json_request(POINT_FINDER, kv_pair)
-            \"query\":\"{station_name}\",
+        .context("creating JSON request")?
-            \"limit\":1,
+        .into_string()
-            \"regionalOnly\":\"true\",
+        .context("converting JSON reply to string")?;
-            \"stopsOnly\":\"true\"
-        }}"
-        ))?
-        .into_string()?;
 
     let response: PointFinderResponse = serde_json::from_str(&json_string)?;
-    print!("{}", response.point.name);
+    print_station_name(&response);
-    if let Some(area) = response.point.area {
-        print!(", {area}");
-    }
-    println!("\n");
 
     let result = response.point.stopid;
     Ok(result)
 }
 
-fn create_json_request(url: &str) -> Request {
+fn print_station_name(response: &PointFinderResponse) {
+    print!("{}", response.point.name);
+    let area = &response.point.area;
+    if !area.is_empty() {
+        print!(", {area}");
+    }
+    println!("\n");
+}
+
+fn create_json_request(url: &str, kv_pair: HashMap<&str, &str>) -> Result<ureq::Response> {
     ureq::post(url)
         .set("Content-Type", "application/json")
         .set("charset", "UTF-8")
+        .send_string(&create_json_body(kv_pair))
+        .context("sending JSON to server")
+}
+
+fn create_json_body(kv_pair: HashMap<&str, &str>) -> String {
+    let mut result = String::from("{");
+    for (k, v) in kv_pair {
+        result.push_str(&format!("\"{k}\":\"{v}\","))
+    }
+    result.push('}');
+    result
+}
+
+fn get_key_value_pair_for_departure<'a>(
+    stopid: &'a str,
+    number_stops: &'a str,
+) -> HashMap<&'a str, &'a str> {
+    let mut result = HashMap::new();
+    result.insert("stopid", stopid);
+    result.insert("limit", number_stops);
+    result
+}
+
+fn get_key_value_pair_for_stopid(name: &str) -> HashMap<&str, &str> {
+    let mut result = HashMap::new();
+    result.insert("query", name);
+    result.insert("limit", "1");
+    result.insert("regionalOnly", "true");
+    result.insert("stopsOnly", "true");
+    result
 }

src/response.rs

@@ -85,15 +85,15 @@ pub struct PointFinderResponse {
 pub struct Point {
     pub stopid: String,
     pub name: String,
-    pub area: Option<String>,
+    pub area: String,
 }
 
-impl From<(&str, &str, Option<&str>)> for Point {
+impl From<(&str, &str, &str)> for Point {
-    fn from(value: (&str, &str, Option<&str>)) -> Self {
+    fn from(value: (&str, &str, &str)) -> Self {
         Self {
             stopid: value.0.into(),
             name: value.1.into(),
-            area: value.2.map(|s| s.into()),
+            area: value.2.into(),
         }
     }
 }
@@ -104,7 +104,7 @@ fn extract_data_from_response(line: &str) -> Result<Point> {
     let mut iter = line.trim_start_matches("\\\"").split_terminator('|');
 
     let stopid = iter.next().context("getting stopid from line")?;
-    let area = iter.nth(1).context("getting area from line").ok();
+    let area = iter.nth(1).context("getting area from line")?;
     let name = iter.next().context("getting stop name from line")?;
     Ok((stopid, name, area).into())
 }