Add pagination

7 files changed, 80 insertions, 12 deletions

diff --git a/src/config.rs b/src/config.rs
new file mode 100644
index 0000000..6449a3f
--- /dev/null
+++ b/src/config.rs
@@ -0,0 +1 @@
+pub static PAGE_LIMIT: i64 = 20;
diff --git a/src/main.rs b/src/main.rs
index 1c9d63a..59ffb24 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,9 @@
+mod config;
 mod db;
 mod errors;
 mod logger;
 mod models;
+mod pagination;
 mod routes;
 
 use axum::{
diff --git a/src/models/model.rs b/src/models/model.rs
index e3fc7ac..a87cddb 100644
--- a/src/models/model.rs
+++ b/src/models/model.rs
@@ -1,4 +1,6 @@
+use crate::config::PAGE_LIMIT;
 use crate::db::get_client;
+
 use crate::errors::AppError;
 use sqlx::types::JsonValue;
 
@@ -111,18 +113,32 @@ impl Model {
     }
 
     /// List all models
-    pub async fn list() -> Result<Vec<ModelUser>, AppError> {
+    pub async fn list(page: i64) -> Result<Vec<ModelUser>, AppError> {
         let pool = unsafe { get_client() };
         let rows = sqlx::query_as!(
             ModelUser,
             r#"SELECT
             models.*,
             json_build_object('id', users.id, 'email', users.email, 'username', users.username, 'is_staff', users.is_staff) as author
-            FROM models JOIN users ON users.id = models.author_id"#
+            FROM models JOIN users ON users.id = models.author_id
+            LIMIT $1 OFFSET $2
+            "#,
+            PAGE_LIMIT,
+            PAGE_LIMIT * page
         )
         .fetch_all(pool)
         .await?;
 
         Ok(rows)
     }
+
+    /// Return the number of models.
+    pub async fn count() -> Result<i64, AppError> {
+        let pool = unsafe { get_client() };
+        let row = sqlx::query!(r#"SELECT COUNT(id) as count FROM models"#)
+            .fetch_one(pool)
+            .await?;
+
+        Ok(row.count.unwrap())
+    }
 }
diff --git a/src/models/user.rs b/src/models/user.rs
index 71b35b6..22bd130 100644
--- a/src/models/user.rs
+++ b/src/models/user.rs
@@ -1,3 +1,4 @@
+use crate::config::PAGE_LIMIT;
 use crate::db::get_client;
 use crate::errors::AppError;
 
@@ -113,15 +114,29 @@ impl User {
     }
 
     /// List all users
-    pub async fn list() -> Result<Vec<UserList>, AppError> {
+    pub async fn list(page: i64) -> Result<Vec<UserList>, AppError> {
         let pool = unsafe { get_client() };
         let rows = sqlx::query_as!(
             UserList,
-            r#"SELECT id, email, username, is_staff FROM users"#
+            r#"SELECT id, email, username, is_staff FROM users
+            LIMIT $1 OFFSET $2
+            "#,
+            PAGE_LIMIT,
+            PAGE_LIMIT * page
         )
         .fetch_all(pool)
         .await?;
 
         Ok(rows)
     }
+
+    /// Return the number of users.
+    pub async fn count() -> Result<i64, AppError> {
+        let pool = unsafe { get_client() };
+        let row = sqlx::query!(r#"SELECT COUNT(id) as count FROM users"#)
+            .fetch_one(pool)
+            .await?;
+
+        Ok(row.count.unwrap())
+    }
 }
diff --git a/src/pagination.rs b/src/pagination.rs
new file mode 100644
index 0000000..1f902b4
--- /dev/null
+++ b/src/pagination.rs
@@ -0,0 +1,7 @@
+use serde::Deserialize;
+
+#[derive(Deserialize, Debug)]
+pub struct Pagination {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub page: Option<i64>,
+}
diff --git a/src/routes/model.rs b/src/routes/model.rs
index a5cd2b3..4ac2688 100644
--- a/src/routes/model.rs
+++ b/src/routes/model.rs
@@ -3,18 +3,28 @@ use crate::models::{
     auth::Claims,
     model::{Model, ModelCreate, ModelUser},
 };
-use axum::{routing::get, Json, Router};
+use crate::pagination::Pagination;
+use axum::{extract::Query, routing::get, Json, Router};
+use serde::Serialize;
 
 /// Create routes for `/v1/models/` namespace
 pub fn create_route() -> Router {
     Router::new().route("/", get(list_models).post(create_model))
 }
 
+#[derive(Serialize)]
+struct ModelPagination {
+    count: i64,
+    results: Vec<ModelUser>,
+}
+
 /// List models.
-async fn list_models() -> Result<Json<Vec<ModelUser>>, AppError> {
-    let models = Model::list().await?;
+async fn list_models(pagination: Query<Pagination>) -> Result<Json<ModelPagination>, AppError> {
+    let page = pagination.0.page.unwrap_or_default();
+    let results = Model::list(page).await?;
+    let count = Model::count().await?;
 
-    Ok(Json(models))
+    Ok(Json(ModelPagination { count, results }))
 }
 
 /// Create a model. Checks Authorization token
diff --git a/src/routes/user.rs b/src/routes/user.rs
index 3dfb73a..4ac994c 100644
--- a/src/routes/user.rs
+++ b/src/routes/user.rs
@@ -3,7 +3,13 @@ use crate::models::{
     auth::Claims,
     user::{User, UserCreate, UserList},
 };
-use axum::{extract::Path, routing::get, Json, Router};
+use crate::pagination::Pagination;
+use axum::{
+    extract::{Path, Query},
+    routing::get,
+    Json, Router,
+};
+use serde::Serialize;
 
 /// Create routes for `/v1/users/` namespace
 pub fn create_route() -> Router {
@@ -12,11 +18,22 @@ pub fn create_route() -> Router {
         .route("/:id", get(get_user))
 }
 
+#[derive(Serialize)]
+struct UserPagination {
+    count: i64,
+    results: Vec<UserList>,
+}
+
 /// List users. Checks Authorization token
-async fn list_users(_: Claims) -> Result<Json<Vec<UserList>>, AppError> {
-    let users = User::list().await?;
+async fn list_users(
+    _: Claims,
+    pagination: Query<Pagination>,
+) -> Result<Json<UserPagination>, AppError> {
+    let page = pagination.0.page.unwrap_or_default();
+    let results = User::list(page).await?;
+    let count = User::count().await?;
 
-    Ok(Json(users))
+    Ok(Json(UserPagination { count, results }))
 }
 
 /// Create an user. Checks Authorization token