Implement file upload backend

src/lib.rs

@@ -13,6 +13,7 @@ pub mod users;
 pub mod search;
 pub mod fileserv;
 pub mod error_template;
+pub mod upload;
 pub mod util;
 
 use cfg_if::cfg_if;

src/upload.rs

@@ -0,0 +1,274 @@
+use leptos::*;
+use server_fn::{codec::{MultipartData, MultipartFormData}, error::NoCustomError};
+use time::Date;
+
+use cfg_if::cfg_if;
+
+cfg_if! {
+	if #[cfg(feature = "ssr")] {
+		use multer::Field;
+		use crate::database::get_db_conn;
+		use diesel::prelude::*;
+		use log::*;
+	}
+}
+
+/// Extract the text from a multipart field
+#[cfg(feature = "ssr")]
+async fn extract_field(field: Field<'static>) -> Result<String, ServerFnError> {
+	let field = match field.text().await {
+		Ok(field) => field,
+		Err(e) => Err(ServerFnError::<NoCustomError>::ServerError(format!("Error reading field: {}", e)))?,
+	};
+
+	Ok(field)
+}
+
+/// Validate the artist ids in a multipart field
+/// Expects a field with a comma-separated list of artist ids, and ensures each is a valid artist id in the database
+#[cfg(feature = "ssr")]
+async fn validate_artist_ids(artist_ids: Field<'static>) -> Result<Vec<i32>, ServerFnError> {
+    use crate::models::Artist;
+	use diesel::result::Error::NotFound;
+
+	// Extract the artist id from the field
+	match artist_ids.text().await {
+		Ok(artist_ids) => {
+			let artist_ids = artist_ids.split(',');
+
+			artist_ids.map(|artist_id| {
+				// Parse the artist id as an integer
+				if let Ok(artist_id) = artist_id.parse::<i32>() {
+					// Check if the artist exists
+					let db_con = &mut get_db_conn();
+					let artist = crate::schema::artists::dsl::artists.find(artist_id).first::<Artist>(db_con);
+
+					match artist {
+						Ok(_) => Ok(artist_id),
+						Err(NotFound) => Err(ServerFnError::<NoCustomError>::
+							ServerError("Artist does not exist".to_string())),
+						Err(e) => Err(ServerFnError::<NoCustomError>::
+							ServerError(format!("Error finding artist id: {}", e))),
+					}
+				} else {
+					Err(ServerFnError::<NoCustomError>::ServerError("Error parsing artist id".to_string()))
+				}
+			}).collect()
+		},
+
+		Err(e) => Err(ServerFnError::<NoCustomError>::ServerError(format!("Error reading artist id: {}", e))),
+	}
+}
+
+/// Validate the album id in a multipart field
+/// Expects a field with an album id, and ensures it is a valid album id in the database
+#[cfg(feature = "ssr")]
+async fn validate_album_id(album_id: Field<'static>) -> Result<i32, ServerFnError> {
+	use crate::models::Album;
+	use diesel::result::Error::NotFound;
+
+	// Extract the album id from the field
+	match album_id.text().await {
+		Ok(album_id) => {
+			// Parse the album id as an integer
+			if let Ok(album_id) = album_id.parse::<i32>() {
+				// Check if the album exists
+				let db_con = &mut get_db_conn();
+				let album = crate::schema::albums::dsl::albums.find(album_id).first::<Album>(db_con);
+
+				match album {
+					Ok(_) => Ok(album_id),
+					Err(NotFound) => Err(ServerFnError::<NoCustomError>::
+						ServerError("Album does not exist".to_string())),
+					Err(e) => Err(ServerFnError::<NoCustomError>::
+						ServerError(format!("Error finding album id: {}", e))),
+				}
+			} else {
+				Err(ServerFnError::<NoCustomError>::ServerError("Error parsing album id".to_string()))
+			}
+		},
+		Err(e) => Err(ServerFnError::<NoCustomError>::ServerError(format!("Error reading album id: {}", e))),
+	}
+}
+
+/// Validate the track number in a multipart field
+/// Expects a field with a track number, and ensures it is a valid track number (non-negative integer)
+#[cfg(feature = "ssr")]
+async fn validate_track_number(track_number: Field<'static>) -> Result<i32, ServerFnError> {
+	match track_number.text().await {
+		Ok(track_number) => {
+			if let Ok(track_number) = track_number.parse::<i32>() {
+				if track_number < 0 {
+					return Err(ServerFnError::<NoCustomError>::
+						ServerError("Track number must be positive or 0".to_string()));
+				} else {
+					Ok(track_number)
+				}
+			} else {
+				return Err(ServerFnError::<NoCustomError>::ServerError("Error parsing track number".to_string()));
+			}
+		},
+		Err(e) => Err(ServerFnError::<NoCustomError>::ServerError(format!("Error reading track number: {}", e)))?,
+	}
+}
+
+/// Validate the release date in a multipart field
+/// Expects a field with a release date, and ensures it is a valid date in the format [year]-[month]-[day]
+#[cfg(feature = "ssr")]
+async fn validate_release_date(release_date: Field<'static>) -> Result<Date, ServerFnError> {
+	match release_date.text().await {
+		Ok(release_date) => {
+			let date_format = time::macros::format_description!("[year]-[month]-[day]");
+			let release_date = Date::parse(&release_date.trim(), date_format);
+
+			match release_date {
+				Ok(release_date) => Ok(release_date),
+				Err(_) => Err(ServerFnError::<NoCustomError>::ServerError("Invalid release date".to_string())),
+			}
+		},
+		Err(e) => Err(ServerFnError::<NoCustomError>::ServerError(format!("Error reading release date: {}", e))),
+	}
+}
+
+/// Handle the file upload form
+#[server(input = MultipartFormData, endpoint = "/upload")]
+pub async fn upload(data: MultipartData) -> Result<(), ServerFnError> {
+	// Safe to unwrap - "On the server side, this always returns Some(_). On the client side, always returns None."
+	let mut data = data.into_inner().unwrap();
+
+	let mut title = None;
+	let mut artist_ids = None;
+	let mut album_id = None;
+	let mut track = None;
+	let mut release_date = None;
+	let mut file_name = None;
+	let mut duration = None;
+
+	// Fetch the fields from the form data
+	while let Ok(Some(mut field)) = data.next_field().await {
+		let name = field.name().unwrap_or_default().to_string();
+
+		println!("Field name: {}", name);
+
+		match name.as_str() {
+			"title" => { title = Some(extract_field(field).await?); },
+			"artist_ids" => { artist_ids = Some(validate_artist_ids(field).await?); },
+			"album_id" => { album_id = Some(validate_album_id(field).await?); },
+			"track_number" => { track = Some(validate_track_number(field).await?); },
+			"release_date" => { release_date = Some(validate_release_date(field).await?); },
+			"file" => {
+				use symphonia::core::codecs::CODEC_TYPE_MP3;
+				use crate::util::audio::extract_metadata;
+				use std::fs::OpenOptions;
+				use std::io::{Seek, Write};
+
+				// Some logging is done here where there is high potential for bugs / failures,
+				// or behavior that we may wish to change in the future
+
+				// Create file name
+				let title = title.clone().ok_or(ServerFnError::<NoCustomError>::
+					ServerError("Title field required and must precede file field".to_string()))?;
+
+				let clean_title = title.replace(" ", "_").replace("/", "_");
+				let date_format = time::macros::format_description!("[year]-[month]-[day]_[hour]:[minute]:[second]");
+				let date_str = time::OffsetDateTime::now_utc().format(date_format).unwrap_or_default();
+				let upload_path = format!("assets/audio/upload-{}_{}.mp3", date_str, clean_title);
+				file_name = Some(format!("upload-{}_{}.mp3", date_str, clean_title));
+
+				debug!("Saving uploaded file {}", upload_path);
+
+				// Save file to disk
+				// Use these open options to create the file, write to it, then read from it
+				let mut file = OpenOptions::new()
+					.read(true)
+					.write(true)
+					.create(true)
+					.open(upload_path.clone())?;
+
+				while let Some(chunk) = field.chunk().await? {
+					file.write(&chunk)?;
+				}
+
+				file.flush()?;
+
+				// Rewind the file so the duration can be measured
+				file.rewind()?;
+
+				// Get the codec and duration of the file
+				let (file_codec, file_duration) = extract_metadata(file)
+					.map_err(|e| {
+						let msg = format!("Error measuring duration of audio file {}: {}", upload_path, e);
+						warn!("{}", msg);
+						ServerFnError::<NoCustomError>::ServerError(msg)
+					})?;
+
+				if file_codec != CODEC_TYPE_MP3 {
+					let msg = format!("Invalid uploaded audio file codec: {}", file_codec);
+					warn!("{}", msg);
+					return Err(ServerFnError::<NoCustomError>::ServerError(msg));
+				}
+
+				duration = Some(file_duration);
+			},
+			_ => {
+				warn!("Unknown file upload field: {}", name);
+			}
+		}
+	}
+
+	// Unwrap mandatory fields
+	let title = title.ok_or(ServerFnError::<NoCustomError>::ServerError("Missing title".to_string()))?;
+	let artist_ids = artist_ids.unwrap_or(vec![]);
+	let file_name = file_name.ok_or(ServerFnError::<NoCustomError>::ServerError("Missing file".to_string()))?;
+	let duration = duration.ok_or(ServerFnError::<NoCustomError>::ServerError("Missing duration".to_string()))?;
+	let duration = i32::try_from(duration).map_err(|e| ServerFnError::<NoCustomError>::
+		ServerError(format!("Error converting duration to i32: {}", e)))?;
+
+	// Create the song
+	use crate::models::Song;
+	let song = Song {
+		id: None,
+		title,
+		album_id,
+		track,
+		duration,
+		release_date,
+		storage_path: file_name,
+		image_path: None,
+	};
+
+	// Save the song to the database
+	let db_con = &mut get_db_conn();
+	let song = song.insert_into(crate::schema::songs::table)
+		.get_result::<Song>(db_con)
+		.map_err(|e| {
+			let msg = format!("Error saving song to database: {}", e);
+			warn!("{}", msg);
+			ServerFnError::<NoCustomError>::ServerError(msg)
+		})?;
+
+	// Save the song's artists to the database
+	let song_id = song.id.ok_or_else(|| {
+		let msg = "Error saving song to database: song id not found after insertion".to_string();
+		warn!("{}", msg);
+		ServerFnError::<NoCustomError>::ServerError(msg)
+	})?;
+
+	use crate::schema::song_artists;
+	use diesel::ExpressionMethods;
+
+	let artist_ids = artist_ids.into_iter().map(|artist_id| {
+		(song_artists::song_id.eq(song_id), song_artists::artist_id.eq(artist_id))
+	}).collect::<Vec<_>>();
+
+	diesel::insert_into(crate::schema::song_artists::table)
+		.values(&artist_ids)
+		.execute(db_con)
+		.map_err(|e| {
+			let msg = format!("Error saving song artists to database: {}", e);
+			warn!("{}", msg);
+			ServerFnError::<NoCustomError>::ServerError(msg)
+		})?;
+
+	Ok(())
+}