Add file uploads

Good luck getting them, though

src/app/api/files.rs

@@ -0,0 +1,92 @@
+use std::path::PathBuf;
+
+use axum::{
+    extract::{BodyStream, State},
+    routing::post,
+    Json, Router,
+};
+use futures_util::TryStreamExt;
+use serde::Serialize;
+use sha2::{Digest, Sha256};
+use sqlx::PgPool;
+use tokio::{
+    fs::{self, File},
+    io,
+};
+use tokio_util::io::StreamReader;
+use tracing::{error, field, info, instrument};
+use ulid::Ulid;
+
+use crate::error::AppError;
+
+pub fn router(db: PgPool) -> Router {
+    Router::new().route("/", post(upload_file)).with_state(db)
+}
+
+#[derive(Debug, Serialize)]
+struct UploadedFile {
+    id: Ulid,
+    hash: String,
+}
+
+#[instrument(skip(body))]
+async fn upload_file(
+    State(_db): State<PgPool>,
+    body: BodyStream,
+) -> Result<Json<UploadedFile>, AppError> {
+    let id_temp = Ulid::new();
+    let file_path_temp = PathBuf::from("temp").join(id_temp.to_string());
+    let mut hasher = Sha256::new();
+
+    {
+        let mut file_temp = File::create(&file_path_temp).await?;
+
+        let better_body = body
+            .inspect_ok(|b| hasher.update(b))
+            .map_err(|err| io::Error::new(io::ErrorKind::Other, err));
+        let mut reader = StreamReader::new(better_body);
+
+        if let Err(err) = io::copy(&mut reader, &mut file_temp).await {
+            error!(
+                err = field::display(&err),
+                file_path = field::debug(&file_path_temp),
+                "failed to copy file, removing",
+            );
+
+            drop(file_temp);
+            if let Err(err) = fs::remove_file(file_path_temp).await {
+                error!(
+                    err = field::display(err),
+                    "failed to remove failed upload file",
+                );
+            }
+
+            return Err(err.into());
+        }
+    }
+
+    let hash = hasher.finalize();
+    let hash_hex = hex::encode(hash);
+    let file_path_hash = PathBuf::from("files").join(&hash_hex);
+
+    if fs::try_exists(&file_path_hash).await? {
+        info!(hash = hash_hex, "file already exists");
+        if let Err(err) = fs::remove_file(&file_path_temp).await {
+            error!(err = field::display(&err), "failed to remove temp file");
+        }
+    } else if let Err(err) = fs::rename(&file_path_temp, &file_path_hash).await {
+        error!(err = field::display(&err), "failed to move finished file");
+        if let Err(err) = fs::remove_file(&file_path_temp).await {
+            error!(
+                err = field::display(&err),
+                "failed to remove file after failed rename",
+            );
+        }
+        return Err(err.into());
+    }
+
+    Ok(Json(UploadedFile {
+        id: id_temp,
+        hash: hash_hex,
+    }))
+}

src/app/api/mod.rs

@@ -1,8 +1,11 @@
+mod files;
 mod links;
 
 use axum::Router;
 use sqlx::PgPool;
 
 pub fn router(db: PgPool) -> Router {
-    Router::new().nest("/links", links::router(db))
+    Router::new()
+        .nest("/files", files::router(db.clone()))
+        .nest("/links", links::router(db))
 }