refactor: reduced duplication in db types

Author: harshkhandeparkar

backend/src/db/mod.rs

@@ -70,7 +70,7 @@ impl Database {
         query: &str,
         exam_filter: ExamFilter,
         exam_filter_str: String,
-    ) -> Result<Vec<qp::SearchQP>, sqlx::Error> {
+    ) -> Result<Vec<qp::BaseQP>, sqlx::Error> {
         let (query_sql, use_exam_arg) = queries::get_qp_search_query(exam_filter);
         let query = sqlx::query_as(&query_sql).bind(query);
 
@@ -80,11 +80,11 @@ impl Database {
             query
         };
 
-        let papers: Vec<models::DBSearchQP> = query.fetch_all(&self.connection).await?;
+        let papers: Vec<models::DBBaseQP> = query.fetch_all(&self.connection).await?;
 
         Ok(papers
             .iter()
-            .map(|qp| qp::SearchQP::from(qp.clone()))
+            .map(|qp| qp::BaseQP::from(qp.clone()))
             .collect())
     }
 
@@ -125,24 +125,24 @@ impl Database {
         let current_details = self.get_paper_by_id(id).await?;
 
         // Construct the final values to be inserted into the db
-        let course_code = course_code.unwrap_or(current_details.course_code);
-        let course_name = course_name.unwrap_or(current_details.course_name);
-        let year = year.unwrap_or(current_details.year);
+        let course_code = course_code.unwrap_or(current_details.qp.course_code);
+        let course_name = course_name.unwrap_or(current_details.qp.course_name);
+        let year = year.unwrap_or(current_details.qp.year);
         let semester: String = semester
             .map(|sem| Semester::try_from(&sem))
             .transpose()?
-            .unwrap_or(current_details.semester)
+            .unwrap_or(current_details.qp.semester)
             .into();
         let exam: String = exam
             .map(|exam| Exam::try_from(&exam))
             .transpose()?
-            .unwrap_or(current_details.exam)
+            .unwrap_or(current_details.qp.exam)
             .into();
         let approve_status = approve_status.unwrap_or(current_details.approve_status);
 
         // Set the new filelink
-        let old_filelink = current_details.filelink;
-        let new_filelink = if current_details.from_library {
+        let old_filelink = current_details.qp.filelink;
+        let new_filelink = if current_details.qp.from_library {
             old_filelink.clone()
         } else if approve_status {
             env_vars.paths.get_slug(
@@ -186,9 +186,9 @@ impl Database {
         Ok((tx, old_filelink, new_qp))
     }
 
-    /// Adds a new upload paper's details to the database. Sets the `from_library` field to false.
-    ///
-    /// Returns the database transaction and the id of the uploaded paper
+    // /// Adds a new upload paper's details to the database. Sets the `from_library` field to false.
+    // ///
+    // /// Returns the database transaction and the id of the uploaded paper
     // pub async fn add_uploaded_paper<'c>(
     //     &self,
     //     file_details:
@@ -276,9 +276,9 @@ impl Database {
     }
 
     // /// Updates filelink for an uploaded question paper uploaded using the [crate::db::Database::update_uploaded_filelink] function. Takes the same transaction that the previous function used.
-    pub async fn update_uploaded_filelink<'c>(
+    pub async fn update_uploaded_filelink(
         &self,
-        tx: &mut Transaction<'c, Postgres>,
+        tx: &mut Transaction<'_, Postgres>,
         id: i32,
         file_link: &str,
     ) -> Result<(), color_eyre::eyre::Error> {

backend/src/db/models.rs

@@ -10,8 +10,8 @@ use super::qp;
 use sqlx::{prelude::FromRow, types::chrono};
 
 #[derive(FromRow, Clone)]
-/// The fields of a question paper sent to the search endpoint
-pub struct DBSearchQP {
+/// Base/common fields of a question paper
+pub struct DBBaseQP {
     id: i32,
     filelink: String,
     from_library: bool,
@@ -25,37 +25,24 @@ pub struct DBSearchQP {
 #[derive(FromRow, Clone)]
 /// The fields of a question paper sent to the admin dashboard endpoint
 pub struct DBAdminDashboardQP {
-    id: i32,
-    filelink: String,
-    from_library: bool,
-    course_code: String,
-    course_name: String,
-    year: i32,
-    semester: String,
-    exam: String,
+    #[sqlx(flatten)]
+    qp: DBBaseQP,
     upload_timestamp: chrono::NaiveDateTime,
     approve_status: bool,
 }
 
 impl From<DBAdminDashboardQP> for qp::AdminDashboardQP {
     fn from(value: DBAdminDashboardQP) -> Self {
         Self {
-            id: value.id,
-            filelink: value.filelink,
-            from_library: value.from_library,
-            course_code: value.course_code,
-            course_name: value.course_name,
-            year: value.year,
-            semester: (&value.semester).try_into().unwrap_or(Semester::Unknown),
-            exam: (&value.exam).try_into().unwrap_or(qp::Exam::Unknown),
+            qp: value.qp.into(),
             upload_timestamp: value.upload_timestamp.to_string(),
             approve_status: value.approve_status,
         }
     }
 }
 
-impl From<DBSearchQP> for qp::SearchQP {
-    fn from(value: DBSearchQP) -> Self {
+impl From<DBBaseQP> for qp::BaseQP {
+    fn from(value: DBBaseQP) -> Self {
         Self {
             id: value.id,
             filelink: value.filelink,

backend/src/qp.rs

@@ -118,9 +118,14 @@ impl Serialize for ExamSem {
     }
 }
 
+pub trait WithUrl: Sized {
+    /// Returns the question paper with the full static files URL in the `filelink` field instead of just the slug. See the [`crate::pathutils`] module for what a slug is.
+    fn with_url(self, env_vars: &EnvVars) -> Result<Self, color_eyre::eyre::Error>;
+}
+
 #[derive(Serialize, Clone)]
 /// The fields of a question paper sent from the search endpoint
-pub struct SearchQP {
+pub struct BaseQP {
     pub id: i32,
     pub filelink: String,
     pub from_library: bool,
@@ -136,29 +141,26 @@ pub struct SearchQP {
 ///
 /// This includes fields such as `approve_status` and `upload_timestamp` that would only be relevant to the dashboard.
 pub struct AdminDashboardQP {
-    pub id: i32,
-    pub filelink: String,
-    pub from_library: bool,
-    pub course_code: String,
-    pub course_name: String,
-    pub year: i32,
-    pub semester: Semester,
-    pub exam: Exam,
+    #[serde(flatten)]
+    pub qp: BaseQP,
     pub upload_timestamp: String,
     pub approve_status: bool,
 }
 
-#[duplicate_item(
-    QP;
-    [ SearchQP ];
-    [ AdminDashboardQP ];
-)]
-impl QP {
-    /// Returns the question paper with the full static files URL in the `filelink` field instead of just the slug. See the [`crate::pathutils`] module for what a slug is.
-    pub fn with_url(self, env_vars: &EnvVars) -> Result<Self, color_eyre::eyre::Error> {
+impl WithUrl for BaseQP {
+    fn with_url(self, env_vars: &EnvVars) -> Result<Self, color_eyre::eyre::Error> {
         Ok(Self {
             filelink: env_vars.paths.get_url_from_slug(&self.filelink)?,
             ..self
         })
     }
 }
+
+impl WithUrl for AdminDashboardQP {
+    fn with_url(self, env_vars: &EnvVars) -> Result<Self, color_eyre::eyre::Error> {
+        Ok(Self {
+            qp: self.qp.with_url(env_vars)?,
+            ..self
+        })
+    }
+}

backend/src/routing/handlers.rs

@@ -23,7 +23,7 @@ use serde::Deserialize;
 use crate::{
     auth::{self, Auth},
     pathutils::PaperCategory,
-    qp::{self, AdminDashboardQP},
+    qp::{self, AdminDashboardQP, WithUrl},
 };
 
 use super::{AppError, BackendResponse, RouterState, Status};
@@ -61,7 +61,7 @@ pub async fn get_unapproved(
 pub async fn search(
     State(state): State<RouterState>,
     Query(params): Query<HashMap<String, String>>,
-) -> HandlerReturn<Vec<qp::SearchQP>> {
+) -> HandlerReturn<Vec<qp::BaseQP>> {
     let response = if let Some(query) = params.get("query") {
         let exam_query_str = params
             .get("exam")
@@ -77,7 +77,7 @@ pub async fn search(
             let papers = papers
                 .iter()
                 .map(|paper| paper.clone().with_url(&state.env_vars))
-                .collect::<Result<Vec<qp::SearchQP>, color_eyre::eyre::Error>>()?;
+                .collect::<Result<Vec<qp::BaseQP>, color_eyre::eyre::Error>>()?;
 
             Ok(BackendResponse::ok(
                 format!("Successfully fetched {} papers.", papers.len()),
@@ -179,7 +179,7 @@ pub async fn edit(
 
     // Copy the actual file
     let old_filepath = state.env_vars.paths.get_path_from_slug(&old_filelink);
-    let new_filepath = state.env_vars.paths.get_path_from_slug(&new_qp.filelink);
+    let new_filepath = state.env_vars.paths.get_path_from_slug(&new_qp.qp.filelink);
 
     if old_filepath != new_filepath {
         if let Err(e) = fs::copy(old_filepath, new_filepath).await {