chore: Release departure version 0.2.2

improves performance

Cargo.toml

@@ -1,14 +1,25 @@
 [package]
 name = "departure"
-version = "0.1.0"
+version = "0.2.2"
 edition = "2021"
 
 [dependencies]
-scraper = { version = "*", default-features = false }
-anyhow = { version = "*", default-features = false }
-ureq = { version = "*", default-features = false , features = ["tls"]}
+anyhow = "1.0.68"
+chrono = { version = "0.4.23", default-features = false, features = ["clock"] }
+ureq = { version = "2.5.0", default-features = false, features = ["tls"] }
+
+serde = { version = "1.0.151", features = ["serde_derive"], default-features = false }
+serde_derive = "1.0.151"
+serde_json = "1.0.91"
 
 [profile.release]
 strip = true
 lto = true
 opt-level = "z"
+
+[dev-dependencies]
+criterion = "0.4.0"
+
+[[bench]]
+name = "benchmark"
+harness = false

README.md

@@ -1,2 +1,7 @@
 # departure
 
+DVB Abfahrtsmonitor
+
+## Demo
+
+https://asciinema.org/a/cprkgCrl3PrFwhI3vSm4Nw1TJ

benches/benchmark.rs

@@ -0,0 +1,19 @@
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+
+use departure::response::Response;
+
+use std::fs::read_to_string;
+
+fn load_json() -> String {
+    read_to_string("benches/reply.json").unwrap()
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    let content = load_json();
+    c.bench_function("parse JSON", |b| {
+        b.iter(|| serde_json::from_str::<'_, Response>(black_box(&content)))
+    });
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);

benches/reply.json

@@ -0,0 +1 @@
+{"Name":"Forschungszentrum","Status":{"Code":"Ok"},"Place":"Rossendorf (Dresden)","ExpirationTime":"\/Date(1672832857580+0100)\/","Departures":[{"Id":"voe:27753: :R:j23","DlId":"de:vvo:27-753","LineName":"753","Direction":"Radeberg Bahnhof","Platform":{"Name":"1","Type":"Platform"},"Mot":"IntercityBus","RealTime":"\/Date(1672832760000-0000)\/","ScheduledTime":"\/Date(1672832400000-0000)\/","State":"Delayed","RouteChanges":[],"Diva":{"Number":"27753","Network":"voe"},"CancelReasons":[]},{"Id":"voe:15261:b:R:j23","DlId":"de:vvo:15-261-b","LineName":"261","Direction":"Sebnitz Busbahnhof","Platform":{"Name":"2","Type":"Platform"},"Mot":"PlusBus","RealTime":"\/Date(1672833120000-0000)\/","ScheduledTime":"\/Date(1672833060000-0000)\/","State":"Delayed","RouteChanges":[],"Diva":{"Number":"15261b","Network":"voe"},"CancelReasons":[]}]}

src/args.rs

@@ -0,0 +1,25 @@
+use std::env::args;
+
+use anyhow::{Context, Result};
+
+pub struct Args {
+    pub name: String,
+    pub number_stops: usize,
+}
+
+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/extractor.rs

@@ -1,88 +0,0 @@
-use anyhow::{bail, Context, Result};
-use scraper::{ElementRef, Html, Selector};
-
-pub(crate) struct Extractor {
-    time: Selector,
-    departure: Selector,
-    delay: Selector,
-}
-
-impl Extractor {
-    pub(crate) fn new() -> Self {
-        Self {
-            time: Self::get_time_selector(),
-            departure: Self::get_departure_selector(),
-            delay: Self::get_delay_selector(),
-        }
-    }
-
-    fn get_time_selector() -> Selector {
-        Selector::parse("div.col.c2of12.tour p").unwrap()
-    }
-
-    fn get_departure_selector() -> Selector {
-        Selector::parse("li[data-filter][data-departure-id][data-departure-time]").unwrap()
-    }
-
-    fn get_delay_selector() -> Selector {
-        Selector::parse("span.late").unwrap()
-    }
-
-    pub(crate) fn get_departures<'a>(&'a self, html: &'a Html) -> impl Iterator<Item = ElementRef> {
-        // `Select` does not implement DoubleEndedIterator, so we need to collect it first
-        let mut result = html.select(&self.departure).collect::<Vec<_>>();
-        result.reverse();
-        // we seem to extract the blocks twice with slightly different layout, so we discard half of them
-        result.truncate(result.len() / 2);
-        result.into_iter()
-    }
-
-    pub(crate) fn get_transport_line(departure_block: scraper::ElementRef) -> Result<&str> {
-        let val = departure_block.value();
-        let result = val
-            .attr("data-filter")
-            .context("accessing 'data-filter'")?
-            .trim();
-        Ok(result)
-    }
-
-    pub(crate) fn extract_delay(
-        departure_block: scraper::ElementRef,
-        late_selector: &Selector,
-    ) -> Option<String> {
-        departure_block
-            .select(late_selector)
-            .next()
-            .map(|content| content.inner_html())
-    }
-
-    pub(crate) fn get_times(&self, departure: scraper::ElementRef) -> Result<String> {
-        let delay = Self::extract_delay(departure, &self.delay);
-        for time_block in departure
-            .select(&self.time)
-            .next()
-            .context("extracting time block")?
-            .children()
-        {
-            let value = time_block.value();
-
-            if value.is_text() {
-                let scheduled_time = value
-                    .as_text()
-                    .context("extracting text of scheduled time")?
-                    .trim();
-                if !scheduled_time.is_empty() {
-                    let mut result = "Abfahrt: ".to_owned();
-                    result.push_str(scheduled_time);
-
-                    if let Some(late_text) = &delay {
-                        result.push_str(" | Verspätet: ");
-                        result.push_str(late_text);
-                    }
-                    return Ok(result);
-                }
-            }
-        }
-        bail!("could not get the times")
-    }
-}

src/lib.rs

@@ -0,0 +1,7 @@
+mod args;
+mod query;
+pub mod response;
+
+pub use args::Args;
+pub use query::get_departures_for_station;
+pub use response::format_departures;

src/main.rs

@@ -1,21 +1,11 @@
-mod extractor;
-mod query;
+use anyhow::{Context, Result};
 
-use anyhow::Result;
-use scraper::Html;
-
-use extractor::Extractor;
+use departure::{format_departures, get_departures_for_station, Args};
 
 fn main() -> Result<()> {
-    let message = query::query_server()?;
-    let html = Html::parse_document(&message);
-
-    let extractor = Extractor::new();
-
-    for departure in extractor.get_departures(&html) {
-        println!("{}", Extractor::get_transport_line(departure)?);
-        println!("{}", extractor.get_times(departure)?);
-        println!();
-    }
+    let args = Args::try_get().context("parsing args")?;
+    let response = get_departures_for_station(args).context("getting departures")?;
+    let formatted = format_departures(response);
+    println!("{formatted}");
     Ok(())
 }

src/query.rs

@@ -1,11 +1,91 @@
-use anyhow::{anyhow, Result};
+use std::collections::HashMap;
 
-pub(crate) const SIEDLUNG: &str =
-    "https://www.vvo-online.de/de/fahrplan/aktuelle-abfahrten-ankuenfte/abfahrten?stopid=33006765";
+use anyhow::{bail, Context, Result};
 
-pub(crate) fn query_server() -> Result<String> {
-    match ureq::get(SIEDLUNG).call() {
-        Ok(response) => Ok(response.into_string().map_err(|e| anyhow!(e))?),
-        Err(e) => Err(anyhow!(e)),
+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(args: Args) -> Result<Response> {
+    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 number_stops = args.number_stops.to_string();
+    let kv_pair = get_key_value_pair_for_departure(&stopid, &number_stops);
+
+    let json_string = create_json_request(DEPARTURE_MONITOR, kv_pair)
+        .context("creating JSON request")?
+        .into_string()
+        .context("converting JSON reply to string")?;
+
+    let result = serde_json::from_str(&json_string)?;
+    Ok(result)
+}
+
+fn get_stopid_from_station_name(station_name: String) -> Result<String> {
+    let kv_pair = get_key_value_pair_for_stopid(&station_name);
+
+    let json_string = create_json_request(POINT_FINDER, kv_pair)
+        .context("creating JSON request")?
+        .into_string()
+        .context("converting JSON reply to string")?;
+
+    let response: PointFinderResponse = serde_json::from_str(&json_string)?;
+    print_station_name(&response);
+
+    let result = response.point.stopid;
+    Ok(result)
+}
+
+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

@@ -0,0 +1,122 @@
+use std::fmt::{Debug, Display};
+
+use anyhow::{Context, Result};
+use chrono::{DateTime, Local, TimeZone, Utc};
+use serde::{de, Deserialize, Deserializer};
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "PascalCase")]
+pub struct Departure {
+    line_name: String,
+    direction: String,
+    #[serde(default, deserialize_with = "deserialize_realtime")]
+    real_time: Option<DateTime<Local>>,
+    #[serde(deserialize_with = "deserialize_timestamp")]
+    scheduled_time: DateTime<Local>,
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "PascalCase")]
+pub struct Response {
+    pub departures: Vec<Departure>,
+}
+
+/// Deserialize a timestamp in the form of '/Date(1671713820000-0000)/'
+fn deserialize_timestamp<'de, D>(deserializer: D) -> Result<DateTime<Local>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let s = String::deserialize(deserializer)?;
+    let timestamp: i64 = s
+        .trim_start_matches("/Date(")
+        .trim_end_matches(")/")
+        .split('-')
+        .next()
+        .ok_or_else(|| de::Error::custom("Invalid timestamp format"))?
+        .parse()
+        .map_err(de::Error::custom)?;
+    let result = Utc.timestamp_millis_opt(timestamp).unwrap();
+
+    let local_tz = chrono::offset::Local::now().timezone();
+    Ok(result.with_timezone(&local_tz))
+}
+
+fn deserialize_realtime<'de, D>(deserializer: D) -> Result<Option<DateTime<Local>>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    match deserialize_timestamp(deserializer) {
+        Ok(inner) => Ok(Some(inner)),
+        Err(_) => Ok(None),
+    }
+}
+
+impl Display for Departure {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(&format!("{} {}\n", &self.line_name, &self.direction))?;
+
+        let scheduled_time = self.scheduled_time.format("%H:%M");
+        f.write_str(&format!("departure: {}", &scheduled_time))?;
+
+        if let Some(real_time) = self.real_time {
+            let actual_time = real_time.format("%H:%M");
+            if real_time != self.scheduled_time {
+                f.write_str(&format!(" | delayed: {actual_time} "))?;
+            }
+        }
+        Ok(())
+    }
+}
+
+pub fn format_departures(response: Response) -> String {
+    let departures: Vec<String> = response.departures.iter().map(|d| d.to_string()).collect();
+    departures.join("\n\n")
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "PascalCase")]
+pub struct PointFinderResponse {
+    #[serde(deserialize_with = "deserialize_points", rename = "Points")]
+    pub point: Point,
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "PascalCase")]
+pub struct Point {
+    pub stopid: String,
+    pub name: String,
+    pub area: String,
+}
+
+impl From<(&str, &str, &str)> for Point {
+    fn from(value: (&str, &str, &str)) -> Self {
+        Self {
+            stopid: value.0.into(),
+            name: value.1.into(),
+            area: value.2.into(),
+        }
+    }
+}
+
+/// Deserialize a Point Response in the form of
+/// '\"33000742|||Helmholtzstraße|5655904|4621157|0||\"'
+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")?;
+    let name = iter.next().context("getting stop name from line")?;
+    Ok((stopid, name, area).into())
+}
+
+fn deserialize_points<'de, D>(deserializer: D) -> Result<Point, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let stops: Vec<String> = Vec::deserialize(deserializer)?;
+    let first_stop_line = stops
+        .first()
+        .ok_or_else(|| de::Error::custom("could not get first stop"))?;
+    let point = extract_data_from_response(first_stop_line).map_err(de::Error::custom)?;
+    Ok(point)
+}