Add delete and update

1 files changed, 87 insertions, 5 deletions

diff --git a/src/handlers.rs b/src/handlers.rs
index 3f815a5..a49d29a 100644
--- a/src/handlers.rs
+++ b/src/handlers.rs
@@ -1,5 +1,5 @@
 use axum::{
-    extract::{Query, State},
+    extract::{Path, Query, State},
     http::StatusCode,
     response::Json,
 };
@@ -7,17 +7,36 @@ use chrono::NaiveTime;
 use sqlx::PgPool;
 use uuid::Uuid;
 
-use crate::error::AppError;
-use crate::models::{DateQuery, MeasurementData, MeasurementView, Unit};
+use crate::models::{AllQuery, DateQuery, MeasurementData, MeasurementView, Unit};
+use crate::{error::AppError, models::MetricType};
 
 pub async fn index() -> &'static str {
     "Hello World!"
 }
 
-pub async fn all(State(pool): State<PgPool>) -> Result<Json<Vec<MeasurementView>>, AppError> {
+pub async fn all(
+    State(pool): State<PgPool>,
+    Query(options): Query<AllQuery>,
+) -> Result<Json<Vec<MeasurementView>>, AppError> {
+    let limit = match options.limit {
+        Some(x) if (x > 0) => Some(x),
+        None => None,
+        _ => return Err(AppError::BadRequest),
+    };
+    // SQL can't bind ASC/DESC as a parameter. The CASE yields measured_at only when
+    // `reverse` is true (sorted DESC) and NULL otherwise, so that key ties for every
+    // row and the ASC key decides the order. If this gets slow, use an if/else with a
+    // separate ASC and DESC query and add an index on measured_at.
     let rows = sqlx::query_as!(
         MeasurementView,
-        "SELECT id, measured_at, metric_type, value, unit FROM measurement"
+        "
+        SELECT id, measured_at, metric_type, value, unit FROM measurement
+        ORDER BY CASE WHEN $2 THEN measured_at END DESC,
+                 measured_at ASC
+        LIMIT $1
+        ",
+        limit,
+        options.reverse.unwrap_or(false)
     )
     .fetch_all(&pool)
     .await?;
@@ -92,3 +111,66 @@ pub async fn units(State(pool): State<PgPool>) -> Result<Json<Vec<Unit>>, AppErr
             .await?,
     ))
 }
+
+pub async fn metric_types(State(pool): State<PgPool>) -> Result<Json<Vec<MetricType>>, AppError> {
+    Ok(Json(
+        sqlx::query_scalar("SELECT enum_range(NULL::metric_type)")
+            .fetch_one(&pool)
+            .await?,
+    ))
+}
+
+pub async fn measurement_by_id(
+    State(pool): State<PgPool>,
+    Path(id): Path<Uuid>,
+) -> Result<Json<MeasurementView>, AppError> {
+    let measurement = sqlx::query_as!(
+        MeasurementView,
+        "
+        SELECT id, measured_at, metric_type, value, unit FROM measurement
+        WHERE id = $1
+        ",
+        id
+    )
+    .fetch_one(&pool)
+    .await?;
+    Ok(Json(measurement))
+}
+
+pub async fn delete(
+    State(pool): State<PgPool>,
+    Path(id): Path<Uuid>,
+) -> Result<StatusCode, AppError> {
+    sqlx::query!("DELETE FROM measurement WHERE id = $1", id)
+        .execute(&pool)
+        .await?;
+    Ok(StatusCode::NO_CONTENT)
+}
+
+pub async fn update(
+    State(pool): State<PgPool>,
+    Path(id): Path<Uuid>,
+    Json(data): Json<MeasurementData>,
+) -> Result<StatusCode, AppError> {
+    let result = sqlx::query!(
+        "
+        UPDATE measurement
+        SET measured_at = $1,
+            metric_type = $2,
+            value = $3,
+            unit = $4
+        WHERE id = $5
+        ",
+        data.measured_at,
+        data.metric_type,
+        data.value,
+        data.unit,
+        id
+    )
+    .execute(&pool)
+    .await?;
+    if result.rows_affected() == 0 {
+        return Err(AppError::NotFound);
+    }
+    Ok(StatusCode::NO_CONTENT)
+}