From 65881f717476b60bf7b566bb1148a96f157926de Mon Sep 17 00:00:00 2001
From: "Dr. Matthias Ratajczak" <m.ratajczak@hzdr.de>
Date: Thu, 5 Jan 2023 13:31:51 +0100
Subject: [PATCH] add point finder from args

---
 src/args.rs     | 10 ++++++++++
 src/lib.rs      |  4 +++-
 src/main.rs     |  5 +++--
 src/query.rs    | 48 +++++++++++++++++++++++++++++++++++++++++------
 src/response.rs | 50 ++++++++++++++++++++++++++++++++++++++++++++++++-
 5 files changed, 107 insertions(+), 10 deletions(-)
 create mode 100644 src/args.rs

diff --git a/src/args.rs b/src/args.rs
new file mode 100644
index 0000000..8840ed4
--- /dev/null
+++ b/src/args.rs
@@ -0,0 +1,10 @@
+use std::env::args;
+
+use anyhow::{Context, Result};
+
+pub fn get_station_name_from_args() -> Result<String> {
+    args()
+        .into_iter()
+        .nth(1)
+        .context("getting station name from args")
+}
diff --git a/src/lib.rs b/src/lib.rs
index 850a4f8..7814c44 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,7 @@
+mod args;
 mod query;
 pub mod response;
 
-pub use query::query_server;
+pub use args::get_station_name_from_args;
+pub use query::get_departures_for_station;
 pub use response::format_departures;
diff --git a/src/main.rs b/src/main.rs
index 78ff66c..e0a1a2b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,9 +1,10 @@
 use anyhow::Result;
 
-use departure::{format_departures, query_server};
+use departure::{format_departures, get_departures_for_station, get_station_name_from_args};
 
 fn main() -> Result<()> {
-    let response = query_server()?;
+    let station_name = get_station_name_from_args()?;
+    let response = get_departures_for_station(station_name)?;
     let formatted = format_departures(response);
     println!("{formatted}");
     Ok(())
diff --git a/src/query.rs b/src/query.rs
index 0679836..5bf3ece 100644
--- a/src/query.rs
+++ b/src/query.rs
@@ -1,16 +1,52 @@
 use anyhow::Result;
+use ureq::Request;
 
-use crate::response::Response;
+use crate::response::{PointFinderResponse, Response};
 
 const DEPARTURE_MONITOR: &str = "https://webapi.vvo-online.de/dm";
+const POINT_FINDER: &str = "https://webapi.vvo-online.de/tr/pointfinder";
 
-pub fn query_server() -> Result<Response> {
-    let json_string = ureq::post(DEPARTURE_MONITOR)
-        .set("Content-Type", "application/json")
-        .set("charset", "UTF-8")
-        .send_string("{\"stopid\":\"33006765\",\"limit\":5}")?
+pub fn get_departures_for_station(station_name: String) -> Result<Response> {
+    let stopid = get_stopid_from_station_name(station_name)?;
+
+    let json_string = create_json_request(DEPARTURE_MONITOR)
+        .send_string(&format!(
+            "{{
+            \"stopid\":\"{stopid}\",
+            \"limit\":5
+            }}"
+        ))?
         .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)
+        .send_string(&format!(
+            "{{
+            \"query\":\"{station_name}\",
+            \"limit\":1,
+            \"regionalOnly\":\"true\",
+            \"stopsOnly\":\"true\"
+        }}"
+        ))?
+        .into_string()?;
+
+    let response: PointFinderResponse = serde_json::from_str(&json_string)?;
+    print!("{}", response.point.name);
+    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 {
+    ureq::post(url)
+        .set("Content-Type", "application/json")
+        .set("charset", "UTF-8")
+}
diff --git a/src/response.rs b/src/response.rs
index d3bd135..e5b4783 100644
--- a/src/response.rs
+++ b/src/response.rs
@@ -1,6 +1,6 @@
 use std::fmt::{Debug, Display};
 
-use anyhow::Result;
+use anyhow::{Context, Result};
 use chrono::{DateTime, Local, TimeZone, Utc};
 use serde::{de, Deserialize, Deserializer};
 
@@ -72,3 +72,51 @@ 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: Option<String>,
+}
+
+impl From<(&str, &str, Option<&str>)> for Point {
+    fn from(value: (&str, &str, Option<&str>)) -> Self {
+        Self {
+            stopid: value.0.into(),
+            name: value.1.into(),
+            area: value.2.map(|s| s.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").ok();
+    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)
+}