Add initial (buggy) fetch implementation

Cargo.toml

@@ -6,7 +6,10 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+musicbrainz_rs = "0.5.0"
 nanoserde = "0.1.32"
+pico-args = { version = "0.5.0", features = ["eq-separator", "short-space-opt", "combined-flags"] }
+tokio = { version = "1.27.0", features = ["full"] }
 
 [dev-dependencies]
 criterion = "0.4.0"

benches/bench_library.rs

@@ -15,10 +15,6 @@ fn bench_random_library(c: &mut Criterion) {
     bench_random_library_with_sizes(c, "massive", 1000, 2500);
 }
 
-fn bench_supermassive_random_library(c: &mut Criterion) {
-    bench_random_library_with_sizes(c, "supermassive", 2500, 7500);
-}
-
 // benchmark helpers
 
 fn bench_random_library_with_sizes(c: &mut Criterion, size: &str, artists: usize, songs: usize) {
@@ -70,9 +66,4 @@ fn random_library(artists: usize, songs_per_artist: usize) -> Library {
 // entrypoint
 
 criterion_group!(benches, bench_random_library);
-criterion_group! {
-    name = slow_benches;
-    config = Criterion::default().sample_size(20);
-    targets = bench_supermassive_random_library
-}
-criterion_main!(benches, slow_benches);
+criterion_main!(benches);

justfile

@@ -0,0 +1,11 @@
+bench:
+    cargo bench --profile release -- "#rnd"
+
+bench-supermassive:
+    cargo bench --profile release -- "#spr"
+
+bench-all:
+    cargo bench --profile release
+
+flamegraph:
+    cargo flamegraph --bench bench_library --root --open -- --bench --profile-time 10

src/fetch.rs

@@ -0,0 +1,111 @@
+use std::collections::HashSet;
+
+use musicbrainz_rs::{
+    config,
+    entity::{
+        artist::{Artist, ArtistSearchQuery, ArtistType},
+        recording::Recording,
+        relations::{Relation, RelationContent},
+    },
+    prelude::*,
+};
+
+use crate::library;
+
+const USER_AGENT: &str = "cover/0.1.0 ( mat@mat.services )";
+
+pub async fn fetch_library(
+    names: impl IntoIterator<Item = String>,
+) -> Result<library::Library, Error> {
+    config::set_user_agent(USER_AGENT);
+    let mut artists = vec![];
+    for name in names {
+        let artist = fetch_artist(name).await?;
+        println!("{artist:#?}");
+        artists.push(artist);
+    }
+    Ok(library::Library::new(artists))
+}
+
+async fn fetch_artist(name: String) -> Result<library::Artist, Error> {
+    let query = ArtistSearchQuery::query_builder().artist(&name).build();
+    let result = Artist::search(query)
+        .with_artist_relations()
+        .execute()
+        .await?;
+    let artist = result.entities.first().expect("Failed to load {name}");
+    let artist = Artist::fetch()
+        .id(&artist.id)
+        .with_artist_relations()
+        .execute()
+        .await?;
+    let members =
+        if artist.artist_type.is_some() && is_plural_artist(artist.artist_type.as_ref().unwrap()) {
+            artist
+                .relations
+                .as_ref()
+                .expect("Failed to load relations")
+                .iter()
+                .flat_map(member_from_relation)
+                .collect()
+        } else {
+            vec![artist.name.clone()]
+        };
+    let recordings = Recording::browse()
+        .by_artist(&artist.id)
+        .with_work_relations()
+        .with_work_level_relations()
+        .execute()
+        .await?;
+    let catalog = recordings
+        .entities
+        .into_iter()
+        .map(|recording| convert_recording(&artist, &members, recording));
+    Ok(library::Artist::new(name, members.clone(), catalog))
+}
+
+fn is_plural_artist(kind: &ArtistType) -> bool {
+    matches!(
+        kind,
+        ArtistType::Choir | ArtistType::Group | ArtistType::Orchestra
+    )
+}
+
+fn member_from_relation(relation: &Relation) -> Option<String> {
+    if relation.relation_type == "member of band" {
+        let artist = extract_artist(relation);
+        Some(artist.name.clone())
+    } else {
+        None
+    }
+}
+
+fn convert_recording(artist: &Artist, members: &[String], recording: Recording) -> library::Song {
+    let writers = get_writers(members, &recording);
+    library::Song {
+        title: recording.title,
+        performer: artist.name.clone(),
+        writers,
+    }
+}
+
+fn get_writers(members: &[String], recording: &Recording) -> HashSet<String> {
+    recording.relations.as_ref().map_or_else(
+        || HashSet::from_iter(members.iter().cloned()),
+        |relations| relations.iter().flat_map(writer_from_relation).collect(),
+    )
+}
+
+fn writer_from_relation(relation: &Relation) -> Option<String> {
+    match relation.relation_type.as_str() {
+        "writer" | "composer" => Some(extract_artist(relation).name.clone()),
+        _ => None,
+    }
+}
+
+fn extract_artist(relation: &Relation) -> &Artist {
+    match &relation.content {
+        RelationContent::Artist(artist) => artist,
+        _ => unreachable!("Bad relation"),
+    }
+}

src/lib.rs

@@ -1 +1,2 @@
+pub mod fetch;
 pub mod library;

src/main.rs

@@ -1,16 +1,40 @@
-use std::{env, fs};
+use std::fs;
+use std::process::exit;
 
 use nanoserde::DeJson;
+use pico_args::Arguments;
 
-use cover::library::Library;
+use cover::fetch::fetch_library;
 
-fn main() {
-    let file_path = env::args()
-        .nth(1)
-        .expect("Usage: cover path/to/library.json");
-    let json = fs::read_to_string(file_path).expect("Failed to open library file");
-    let library: Library =
-        DeJson::deserialize_json(&json).expect("Failed to deserialize library file");
+const USAGE: &str = "Usage:
+# process library.json
+ $ cover json path/to/library.json
+# fetch artists from musicbrainz
+ $ cover fetch 'Taylor Swift' 'black midi'";
+
+#[tokio::main]
+async fn main() {
+    let mut args = Arguments::from_env();
+    let library = match args.subcommand().unwrap().as_deref() {
+        Some("json") => {
+            let file_path = args
+                .finish()
+                .into_iter()
+                .next()
+                .unwrap()
+                .into_string()
+                .unwrap();
+            let json = fs::read_to_string(file_path).expect("Failed to open library file");
+            DeJson::deserialize_json(&json).expect("Failed to deserialize library file")
+        }
+        Some("fetch") => fetch_library(args.finish().into_iter().flat_map(|s| s.into_string()))
+            .await
+            .unwrap(),
+        _ => {
+            eprintln!("{USAGE}");
+            exit(1);
+        }
+    };
     for cover in library.library_covers() {
         println!("Found cover!");
         println!(