ref, feat(scheduler) global project refactor, add scheduler

backend/api_server/src/blog/api/get_post.rs

@@ -0,0 +1,153 @@
+use axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    Json,
+};
+use serde_json::{json, Value};
+use sqlx::{query, Error, PgPool, Row};
+use std::str::FromStr;
+use tracing::error;
+use uuid::Uuid;
+
+pub async fn get_post(
+    State(db_connection): State<PgPool>,
+    Path(post_id): Path<String>,
+) -> Result<Json<Value>, (StatusCode, Json<Value>)> {
+    let post_id = match Uuid::from_str(post_id.as_str()) {
+        Ok(id) => id,
+        Err(e) => {
+            error!(
+                "Failed to parse UUID <{}>: {}",
+                post_id.as_str(),
+                e.to_string()
+            );
+            return Err((
+                StatusCode::BAD_REQUEST,
+                Json::from(json!(("error", e.to_string()))),
+            ));
+        }
+    };
+
+    let post = match query(
+        r#"
+SELECT jsonb_strip_nulls(to_jsonb(t.*)) - 'post_id' AS post
+FROM post t
+WHERE post_id = $1;
+"#,
+    )
+    .bind(post_id)
+    .fetch_one(&db_connection)
+    .await
+    {
+        Ok(value) => value.get::<Value, _>("post"),
+        Err(e) => {
+            error!(
+                "Database error on Reading `base post information` from table `post`: <{}>: {}",
+                post_id.to_string(),
+                e.to_string()
+            );
+            return match e {
+                Error::RowNotFound => Err((
+                    StatusCode::BAD_REQUEST,
+                    Json::from(json!({"error": e.to_string()})),
+                )),
+                _ => Err((
+                    StatusCode::INTERNAL_SERVER_ERROR,
+                    Json::from(json!({"error": e.to_string()})),
+                )),
+            };
+        }
+    };
+
+    let tags: Vec<_> = match query("SELECT tag FROM Tag WHERE post_id = $1;")
+        .bind(post_id)
+        .fetch_all(&db_connection)
+        .await
+    {
+        Ok(tags) => tags.iter().map(|tag| tag.get::<String, _>("tag")).collect(),
+        Err(e) => {
+            error!("Database query error :{}", e.to_string());
+            return Err((
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json::from(json!({"error": e.to_string()})),
+            ));
+        }
+    };
+
+    let meta = match query(
+        r#"
+SELECT jsonb_strip_nulls(to_jsonb(t.*)) - 'post_id' AS meta
+FROM meta t
+WHERE post_id = $1;
+        "#,
+    )
+    .bind(post_id)
+    .fetch_one(&db_connection)
+    .await
+    {
+        Ok(value) => value.get::<Value, _>("meta"),
+        Err(e) => {
+            error!(
+                "Database error on Reading `{}` from table `{}`: <{}>: {}",
+                "post meta data",
+                "meta",
+                post_id.to_string(),
+                e.to_string()
+            );
+            return Err((
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json::from(json!({"error": e.to_string()})),
+            ));
+        }
+    };
+
+    let adjacent = match query(r"
+WITH target_post AS (SELECT t.date FROM meta t WHERE post_id = $1),
+     prev AS (SELECT post_id, t.title, t.sub_title, t.header_img
+              FROM meta t
+              WHERE t.date < (SELECT date FROM target_post)
+              ORDER BY t.date DESC
+              LIMIT 1),
+     next AS (SELECT post_id, t.title, t.sub_title, t.header_img
+              FROM meta t
+              WHERE t.date > (SELECT date FROM target_post)
+              ORDER BY t.date
+              LIMIT 1)
+SELECT json_strip_nulls(json_build_object(
+        'prev',
+        (SELECT json_build_object('id', post_id, 'title', title, 'sub_title', sub_title, 'header_img', header_img)
+         FROM prev),
+        'next',
+        (SELECT json_build_object('id', post_id, 'title', title, 'sub_title', sub_title, 'header_img', header_img)
+         FROM next)
+                        )) AS result;
+"
+    )
+        .bind(post_id)
+        .fetch_one(&db_connection)
+        .await
+    {
+        Ok(res) => {res.get::<Value, _>("result")}
+        Err(e) => {
+            error!(
+                "Database error on Reading `{}` from table `{}`: <{}>: {}",
+                "adjoint posts data",
+                "meta",
+                post_id.to_string(),
+                e.to_string()
+            );
+            return Err((
+                StatusCode::INTERNAL_SERVER_ERROR,
+                Json::from(json!({"error": e.to_string()})),
+            ));
+        }
+
+    };
+
+    let mut res = post.as_object().unwrap().to_owned();
+    res.insert("tags".to_string(), tags.into());
+    res.insert("meta".to_string(), meta);
+    res.insert("adj".to_string(), adjacent);
+
+    Ok(Json::from(json!(res)))
+}