refactor show_question_details

Cargo.lock

@@ -1026,7 +1026,7 @@ dependencies = [
 
 [[package]]
 name = "qchgk_web"
-version = "0.1.0"
+version = "0.1.1"
 dependencies = [
  "ledb",
  "ledb-derive",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "qchgk_web"
-version = "0.1.0"
+version = "0.1.1"
 authors = ["Dmitry <b4tm4n@mail.ru>"]
 edition = "2021"
 

src/main.rs

@@ -9,11 +9,6 @@ extern crate serde_json;
 extern crate ledb_derive;
 extern crate ledb_types;
 
-//#[macro_use]
-//extern crate tera;
-
-//use tera::Context;
-
 #[macro_use]
 extern crate rocket;
 extern crate rocket_contrib;
@@ -28,6 +23,18 @@ use rand::Rng;
 
 use ledb::{Options, Storage};
 
+trait ErrorEmpty {
+    type Output;
+    fn err_empty(self) -> Result<Self::Output, ()>;
+}
+
+impl<T, E> ErrorEmpty for Result<T, E> {
+    type Output = T;
+    fn err_empty(self) -> Result<Self::Output, ()> {
+        self.map_err(|_| ())
+    }
+}
+
 #[derive(Debug, Default, Clone, Serialize, Deserialize, Document)]
 struct BatchInfo {
     #[document(primary)]
@@ -120,66 +127,53 @@ fn random_question_id(database_distribution: &Uniform<u32>) -> u32 {
     rng.sample(database_distribution)
 }
 
-fn get_question(storage: &Storage, id: u32) -> Result<Option<Question>, ()> {
-    if 0 == id {
-        return Ok(None);
-    }
-
-    let collection = storage
+fn get_question(storage: &Storage, id: u32) -> Result<Question, ()> {
+    storage
         .collection("questions")
-        .expect("collection \"questions\"");
-    let last_id = collection.last_id().expect("\"questions\" last_id");
-
-    if id > last_id {
-        Err(())
-    } else {
-        let question = collection.get::<Question>(id);
-        if question.is_err() {
-            Err(())
-        } else {
-            Ok(question.unwrap())
-        }
-    }
+        .err_empty()?
+        .get::<Question>(id)
+        .err_empty()?
+        .ok_or(())
 }
 
-fn show_question_details(
-    template_name: &'static str,
-    data: &AppState,
-    id: u32,
-) -> Result<Template, Redirect> {
-    let question = get_question(&data.storage, id);
-
-    if question.is_ok() {
-        let question = question.unwrap();
-
-        if question.is_some() {
-            let question = question.unwrap();
+fn show_question_details(template_name: &'static str, data: &AppState, id: u32) -> Template {
+    match get_question(&data.storage, id) {
+        Ok(question) => {
             let mut context = serde_json::to_value(question).expect("question serialize");
             if context.is_object() {
                 let next_id = random_question_id(&data.database_distribution);
                 context["next"] = serde_json::to_value(next_id).expect("question id serialize");
             }
-            Ok(Template::render(template_name, &context))
-        } else {
-            Err(Redirect::permanent("/q/"))
+            Template::render(template_name, &context)
         }
-    } else {
+        Err(_) => {
             use std::collections::HashMap;
             let context: HashMap<String, String> = HashMap::new();
-        Ok(Template::render("404", &context))
+            Template::render("404", &context)
+        }
     }
 }
 
 #[get("/q/<id>")]
-fn show_question(data: State<AppState>, id: u32) -> Result<Template, Redirect> {
+fn show_question(data: State<AppState>, id: u32) -> Template {
     show_question_details("question", data.inner(), id)
 }
 
 #[get("/q/<id>/a")]
-fn show_answer(data: State<AppState>, id: u32) -> Result<Template, Redirect> {
+fn show_answer(data: State<AppState>, id: u32) -> Template {
     show_question_details("answer", data.inner(), id)
 }
 
+#[get("/q/0")]
+fn question0() -> Redirect {
+    Redirect::to("/")
+}
+
+#[get("/q/0/a")]
+fn answer0() -> Redirect {
+    Redirect::to("/")
+}
+
 #[get("/")]
 fn index(data: State<AppState>) -> Redirect {
     let id = random_question_id(&data.database_distribution);
@@ -211,7 +205,10 @@ fn rocket() -> Rocket {
     rocket::ignite()
         .manage(state)
         .register(catchers![not_found])
-        .mount("/", routes![index, show_question, show_answer])
+        .mount(
+            "/",
+            routes![index, show_question, show_answer, question0, answer0],
+        )
         .mount("/q", routes![index])
         .mount("/q/static", StaticFiles::from("static/"))
         .attach(Template::fairing())