feat(api): add api endpoint to retrieve teachers for a given class

src/api/mod.rs

@@ -20,7 +20,8 @@ pub fn get_routes() -> Router {
         "/api",
         Router::new()
             .route("/pdf", get(pdf))
-            .route("/classi", get(get_classes)),
+            .route("/classi", get(get_classes))
+            .route("/professori", get(get_teachers)),
     )
 }
 
@@ -118,6 +119,49 @@ pub async fn get_classes(Query(params): Query<FilterByTeacherQuery>) -> impl Int
     )
 }
 
+#[derive(Deserialize)]
+pub struct FilterByClassQuery {
+    id: u8,
+    classe: String,
+}
+
+pub async fn get_teachers(Query(params): Query<FilterByClassQuery>) -> impl IntoResponse {
+    let filename = download_pdf(params.id).await.unwrap();
+    let csv_content = fs::read_to_string(&filename).unwrap();
+
+    let mut rdr = csv::Reader::from_reader(csv_content.as_bytes());
+    let header = get_header(rdr.headers().unwrap());
+
+    let mut result: HashMap<String, Vec<String>> = HashMap::new();
+
+    for record in rdr.records() {
+        let record = record.unwrap();
+        for (i, cell) in record.iter().enumerate() {
+            if cell == params.classe {
+                for (day, range) in header.weekdays.clone() {
+                    if range.contains(&i) {
+                        let value = result.entry(day).or_insert_with(|| {
+                            let mut v = Vec::new();
+                            v.resize(range.end - range.start, String::new());
+                            v
+                        });
+                        value[i - range.start] = record[header.teacher as usize].to_string();
+                    }
+                }
+            }
+        }
+    }
+
+    if !result.is_empty() {
+        (StatusCode::OK, Json(json!(result)))
+    } else {
+        (
+            StatusCode::UNPROCESSABLE_ENTITY,
+            Json(json!({ "errore": "classe non trovata"})),
+        )
+    }
+}
+
 pub fn get_header(record: &StringRecord) -> Header {
     let mut docente: u8 = 0;
     let mut weekdays = HashMap::new();