feat(services/autumn): scaffold implementation of api

crates/services/autumn/src/api.rs

@@ -0,0 +1,160 @@
+use axum::{
+    extract::{DefaultBodyLimit, Multipart, Path},
+    http::StatusCode,
+    response::{IntoResponse, Response},
+    routing::{get, post},
+    Json, Router,
+};
+use axum_typed_multipart::{FieldData, TryFromMultipart, TypedMultipart};
+use revolt_config::config;
+use serde::{Deserialize, Serialize};
+use utoipa::ToSchema;
+
+use tempfile::NamedTempFile;
+
+pub async fn router() -> Router {
+    let config = config().await;
+
+    Router::new().route("/", get(root)).route(
+        "/:tag",
+        post(upload_file).layer(DefaultBodyLimit::max(
+            config.features.limits.global.body_limit_size,
+        )),
+    )
+}
+
+/// Successful root response
+#[derive(Serialize, Debug, ToSchema)]
+pub struct RootResponse {
+    autumn: &'static str,
+    version: &'static str,
+}
+
+/// Capture crate version from Cargo
+static CRATE_VERSION: &str = env!("CARGO_PKG_VERSION");
+
+/// Root response from service
+#[utoipa::path(
+    get,
+    path = "/",
+    responses(
+        (status = 200, description = "Echo response", body = RootResponse)
+    )
+)]
+async fn root() -> Json<RootResponse> {
+    Json(RootResponse {
+        autumn: "Hello, I am a file server!",
+        version: CRATE_VERSION,
+    })
+}
+
+/// Available tags to upload to
+#[derive(Deserialize, Debug, ToSchema)]
+#[allow(non_camel_case_types)]
+pub enum Tag {
+    attachments,
+    avatars,
+    backgrounds,
+    icons,
+    banners,
+    emojis,
+}
+
+/// Request body for upload
+#[derive(ToSchema, TryFromMultipart)]
+pub struct UploadPayload {
+    #[schema(format = Binary)]
+    #[allow(dead_code)]
+    #[form_data(limit = "unlimited")] // handled by axum
+    file: FieldData<NamedTempFile>,
+}
+
+/// Successful upload response
+#[derive(Serialize, Debug, ToSchema)]
+pub struct UploadResponse {
+    /// ID to attach uploaded file to object
+    id: &'static str,
+}
+
+/// Upload a file
+///
+/// Available tags and restrictions:
+///
+/// | Tag | Size | Resolution | Type |
+/// | :-: | --: | :-- | :-: |
+/// | attachments | 20 MB | - | Any |
+/// | avatars | 4 MB | 40 MP or 10,000px | Image |
+/// | backgrounds | 6 MB | 40 MP or 10,000px | Image |
+/// | icons | 2.5 MB | 40 MP or 10,000px | Image |
+/// | banners | 6 MB | 40 MP or 10,000px | Image |
+/// | emojis | 500 KB | 40 MP or 10,000px | Image |
+#[utoipa::path(
+    post,
+    path = "/{tag}",
+    responses(
+        (status = 200, description = "Upload was successful", body = UploadResponse)
+    ),
+    params(
+        ("tag" = Tag, Path, description = "Tag to upload to (e.g. attachments, icons, ...)")
+    ),
+    request_body(content_type = "multipart/form-data", content = UploadPayload),
+)]
+async fn upload_file(
+    Path(tag): Path<Tag>,
+    TypedMultipart(UploadPayload { file }): TypedMultipart<UploadPayload>,
+) -> axum::response::Result<Json<UploadResponse>> {
+    Ok(Json(UploadResponse { id: "aaa" }))
+}
+
+/// Fetch preview of file
+///
+/// Depending on the given tag, the file will be re-processed to fit the criteria:
+///
+/// | Tag | Image Resolution <sup>†</sup> |
+/// | :-: | --- |
+/// | attachments | Up to 1280px on any axis |
+/// | avatars | Up to 128px on any axis |
+/// | backgrounds | Up to 1280x720px |
+/// | icons | Up to 128px on any axis |
+/// | banners | Up to 480px on any axis |
+/// | emojis | Up to 128px on any axis |
+///
+/// <sup>†</sup> aspect ratio will always be preserved
+#[utoipa::path(
+    get,
+    path = "/{tag}/{file_id}",
+    responses(
+        (status = 200, description = "Generated preview", body = Vec<u8>)
+    ),
+    params(
+        ("tag" = Tag, Path, description = "Tag to fetch from (e.g. attachments, icons, ...)"),
+        ("file_id" = String, Path, description = "File identifier")
+    ),
+)]
+async fn fetch_preview(
+    Path(tag): Path<Tag>,
+    Path(file_id): Path<String>,
+) -> axum::response::Result<Response> {
+    todo!()
+}
+
+/// Fetch original file
+#[utoipa::path(
+    get,
+    path = "/{tag}/{file_id}/{file_name}",
+    responses(
+        (status = 200, description = "Generated preview", body = Vec<u8>)
+    ),
+    params(
+        ("tag" = Tag, Path, description = "Tag to fetch from (e.g. attachments, icons, ...)"),
+        ("file_id" = String, Path, description = "File identifier"),
+        ("file_name" = String, Path, description = "File name")
+    ),
+)]
+async fn fetch_file(
+    Path(tag): Path<Tag>,
+    Path(file_id): Path<String>,
+    Path(file_name): Path<String>,
+) -> axum::response::Result<Response> {
+    todo!()
+}