Add server

README.md

@@ -7,8 +7,10 @@ https://musicus.org
 ## Repository structure
 
 The subdirectories contain toplevel components of the Musicus system. Currently
-you will only find a Musicus desktop app under `musicus`. The component READMEs
-provide more detailed information.
+you will find:
+
+ * `musicus` – Musicus desktop app for Linux
+ * `musicus_server` – Musicus server
 
 ## License
 

musicus/README.md

@@ -57,4 +57,19 @@ command:
 $ diesel migration run --database-url test.sqlite
 ```
 
-This file should never be edited manually.
+This file should never be edited manually.
+
+## License
+
+Musicus is free and open source software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by the
+Free Software Foundation, either version 3 of the License, or (at your option)
+any later version.
+
+Musicus is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+details.
+
+You should have received a copy of the GNU Affero General Public License along
+with this program. If not, see https://www.gnu.org/licenses/.

musicus_server/.gitignore

@@ -0,0 +1,3 @@
+/.env
+/Cargo.lock
+/target

musicus_server/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "musicus_server"
+version = "0.1.0"
+edition = "2018"
+
+[dependencies]
+actix-web = "3.2.0"
+actix-web-httpauth = "0.5.0"
+anyhow = "1.0.34"
+derive_more = "0.99.11"
+diesel = { version = "1.4.4", features = ["postgres", "r2d2"] }
+dotenv = "0.15.0"
+env_logger = "0.8.1"
+jsonwebtoken = "7.2.0"
+r2d2 = "0.8.9"
+rand = "0.7.3"
+serde = { version = "1.0.117", features = ["derive"] }
+serde_json = "1.0.59"
+sodiumoxide = "0.2.6"

musicus_server/README.md

@@ -0,0 +1,50 @@
+# Musicus Server
+
+This is a server for hosting metadata on classical music.
+
+## Running
+
+The Musicus server should reside behind a reverse proxy (e.g. Nginx) that is
+set up to only use TLS encrypted connections. You will need a running
+[PostgreSQL](https://www.postgresql.org/) service. To set up the database (and
+migrate to future versions) use the Diesel command line utility from within
+the source code repository. This utility and the Musicus server itself use the
+environment variable `MUSICUS_DATABASE_URL` to find the database. A nice way to
+set it up is to use a file called `.env` within the toplevel directory of the
+repository.
+
+```bash
+# Install the Diesel command line utility:
+cargo install diesel_cli --no-default-features --features postgres
+
+# Configure the database URL (replace username and table):
+echo "MUSICUS_DATABASE_URL=\"postgres://username@localhost/table\"" >> .env
+
+# Run migrations:
+~/.cargo/bin/diesel migration run
+
+# Set a secret that will be used to sign access tokens:
+echo "MUSICUS_SECRET=\"$(openssl rand -base64 64)\"" >> .env
+```
+
+## Hacking
+
+The Musicus server is written in [Rust](https://www.rust-lang.org) using the
+[Actix Web](https://actix.rs/) framework for serving requests and
+[Diesel](https://diesel.rs/) for database access. The linked websites should
+provide you with the necessary information to get started.
+
+## License
+
+Musicus is free and open source software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by the
+Free Software Foundation, either version 3 of the License, or (at your option)
+any later version.
+
+Musicus is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+details.
+
+You should have received a copy of the GNU Affero General Public License along
+with this program. If not, see https://www.gnu.org/licenses/.

musicus_server/diesel.toml

@@ -0,0 +1,2 @@
+[print_schema]
+file = "src/database/schema.rs"

musicus_server/migrations/00000000000000_diesel_initial_setup/down.sql

@@ -0,0 +1,6 @@
+-- This file was automatically created by Diesel to setup helper functions
+-- and other internal bookkeeping. This file is safe to edit, any future
+-- changes will be added to existing projects as new migrations.
+
+DROP FUNCTION IF EXISTS diesel_manage_updated_at(_tbl regclass);
+DROP FUNCTION IF EXISTS diesel_set_updated_at();

musicus_server/migrations/00000000000000_diesel_initial_setup/up.sql

@@ -0,0 +1,36 @@
+-- This file was automatically created by Diesel to setup helper functions
+-- and other internal bookkeeping. This file is safe to edit, any future
+-- changes will be added to existing projects as new migrations.
+
+
+
+
+-- Sets up a trigger for the given table to automatically set a column called
+-- `updated_at` whenever the row is modified (unless `updated_at` was included
+-- in the modified columns)
+--
+-- # Example
+--
+-- ```sql
+-- CREATE TABLE users (id SERIAL PRIMARY KEY, updated_at TIMESTAMP NOT NULL DEFAULT NOW());
+--
+-- SELECT diesel_manage_updated_at('users');
+-- ```
+CREATE OR REPLACE FUNCTION diesel_manage_updated_at(_tbl regclass) RETURNS VOID AS $$
+BEGIN
+    EXECUTE format('CREATE TRIGGER set_updated_at BEFORE UPDATE ON %s
+                    FOR EACH ROW EXECUTE PROCEDURE diesel_set_updated_at()', _tbl);
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION diesel_set_updated_at() RETURNS trigger AS $$
+BEGIN
+    IF (
+        NEW IS DISTINCT FROM OLD AND
+        NEW.updated_at IS NOT DISTINCT FROM OLD.updated_at
+    ) THEN
+        NEW.updated_at := current_timestamp;
+    END IF;
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;

musicus_server/migrations/2020-11-09-153819_initial_schema/down.sql

@@ -0,0 +1,19 @@
+DROP TABLE performances;
+
+DROP TABLE recordings;
+
+DROP TABLE ensembles;
+
+DROP TABLE work_sections;
+
+DROP TABLE work_parts;
+
+DROP TABLE instrumentations;
+
+DROP TABLE works;
+
+DROP TABLE instruments;
+
+DROP TABLE persons;
+
+DROP TABLE users;

musicus_server/migrations/2020-11-09-153819_initial_schema/up.sql

@@ -0,0 +1,70 @@
+CREATE TABLE users (
+    username TEXT NOT NULL PRIMARY KEY,
+    password_hash TEXT NOT NULL,
+    email TEXT,
+    is_admin BOOLEAN NOT NULL DEFAULT FALSE,
+    is_editor BOOLEAN NOT NULL DEFAULT FALSE,
+    is_banned BOOLEAN NOT NULL DEFAULT FALSE
+);
+
+CREATE TABLE persons (
+    id BIGINT NOT NULL PRIMARY KEY,
+    first_name TEXT NOT NULL,
+    last_name TEXT NOT NULL,
+    created_by TEXT NOT NULL REFERENCES users(username)
+);
+
+CREATE TABLE instruments (
+    id BIGINT NOT NULL PRIMARY KEY,
+    name TEXT NOT NULL,
+    created_by TEXT NOT NULL REFERENCES users(username)
+);
+
+CREATE TABLE works (
+    id BIGINT NOT NULL PRIMARY KEY,
+    composer BIGINT NOT NULL REFERENCES persons(id),
+    title TEXT NOT NULL,
+    created_by TEXT NOT NULL REFERENCES users(username)
+);
+
+CREATE TABLE instrumentations (
+    id BIGINT NOT NULL PRIMARY KEY,
+    work BIGINT NOT NULL REFERENCES works(id) ON DELETE CASCADE,
+    instrument BIGINT NOT NULL REFERENCES instruments(id) ON DELETE CASCADE
+);
+
+CREATE TABLE work_parts (
+    id BIGINT NOT NULL PRIMARY KEY,
+    work BIGINT NOT NULL REFERENCES works(id) ON DELETE CASCADE,
+    part_index BIGINT NOT NULL,
+    title TEXT NOT NULL,
+    composer BIGINT REFERENCES persons(id)
+);
+
+CREATE TABLE work_sections (
+    id BIGINT NOT NULL PRIMARY KEY,
+    work BIGINT NOT NULL REFERENCES works(id) ON DELETE CASCADE,
+    title TEXT NOT NULL,
+    before_index BIGINT NOT NULL
+);
+
+CREATE TABLE ensembles (
+    id BIGINT NOT NULL PRIMARY KEY,
+    name TEXT NOT NULL,
+    created_by TEXT NOT NULL REFERENCES users(username)
+);
+
+CREATE TABLE recordings (
+    id BIGINT NOT NULL PRIMARY KEY,
+    work BIGINT NOT NULL REFERENCES works(id),
+    comment TEXT NOT NULL,
+    created_by TEXT NOT NULL REFERENCES users(username)
+);
+
+CREATE TABLE performances (
+    id BIGINT NOT NULL PRIMARY KEY,
+    recording BIGINT NOT NULL REFERENCES recordings(id) ON DELETE CASCADE,
+    person BIGINT REFERENCES persons(id),
+    ensemble BIGINT REFERENCES ensembles(id),
+    role BIGINT REFERENCES instruments(id)
+);

musicus_server/src/database/ensembles.rs

@@ -0,0 +1,75 @@
+use super::schema::ensembles;
+use super::DbConn;
+use anyhow::Result;
+use diesel::prelude::*;
+use diesel::{Insertable, Queryable};
+use serde::{Deserialize, Serialize};
+
+/// An ensemble that takes part in recordings.
+#[derive(Insertable, Queryable, Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct Ensemble {
+    pub id: i64,
+    pub name: String,
+
+    #[serde(skip)]
+    pub created_by: String,
+}
+
+/// A structure representing data on an ensemble.
+#[derive(AsChangeset, Deserialize, Debug, Clone)]
+#[table_name = "ensembles"]
+#[serde(rename_all = "camelCase")]
+pub struct EnsembleInsertion {
+    pub name: String,
+}
+
+/// Insert a new ensemble.
+pub fn insert_ensemble(
+    conn: &DbConn,
+    id: u32,
+    data: &EnsembleInsertion,
+    created_by: &str,
+) -> Result<()> {
+    let ensemble = Ensemble {
+        id: id as i64,
+        name: data.name.clone(),
+        created_by: created_by.to_string(),
+    };
+
+    diesel::insert_into(ensembles::table)
+        .values(ensemble)
+        .execute(conn)?;
+
+    Ok(())
+}
+
+/// Update an existing ensemble.
+pub fn update_ensemble(conn: &DbConn, id: u32, data: &EnsembleInsertion) -> Result<()> {
+    diesel::update(ensembles::table)
+        .filter(ensembles::id.eq(id as i64))
+        .set(data)
+        .execute(conn)?;
+
+    Ok(())
+}
+
+/// Get an existing ensemble.
+pub fn get_ensemble(conn: &DbConn, id: u32) -> Result<Option<Ensemble>> {
+    Ok(ensembles::table
+        .filter(ensembles::id.eq(id as i64))
+        .load::<Ensemble>(conn)?
+        .first()
+        .cloned())
+}
+
+/// Delete an existing ensemble.
+pub fn delete_ensemble(conn: &DbConn, id: u32) -> Result<()> {
+    diesel::delete(ensembles::table.filter(ensembles::id.eq(id as i64))).execute(conn)?;
+    Ok(())
+}
+
+/// Get all existing ensembles.
+pub fn get_ensembles(conn: &DbConn) -> Result<Vec<Ensemble>> {
+    Ok(ensembles::table.load::<Ensemble>(conn)?)
+}

musicus_server/src/database/instruments.rs

@@ -0,0 +1,75 @@
+use super::schema::instruments;
+use super::DbConn;
+use anyhow::Result;
+use diesel::prelude::*;
+use diesel::{Insertable, Queryable};
+use serde::{Deserialize, Serialize};
+
+/// An instrument or any other possible role within a recording.
+#[derive(Insertable, Queryable, Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct Instrument {
+    pub id: i64,
+    pub name: String,
+
+    #[serde(skip)]
+    pub created_by: String,
+}
+
+/// A structure representing data on an instrument.
+#[derive(AsChangeset, Deserialize, Debug, Clone)]
+#[table_name = "instruments"]
+#[serde(rename_all = "camelCase")]
+pub struct InstrumentInsertion {
+    pub name: String,
+}
+
+/// Insert a new instrument.
+pub fn insert_instrument(
+    conn: &DbConn,
+    id: u32,
+    data: &InstrumentInsertion,
+    created_by: &str,
+) -> Result<()> {
+    let instrument = Instrument {
+        id: id as i64,
+        name: data.name.clone(),
+        created_by: created_by.to_string(),
+    };
+
+    diesel::insert_into(instruments::table)
+        .values(instrument)
+        .execute(conn)?;
+
+    Ok(())
+}
+
+/// Update an existing instrument.
+pub fn update_instrument(conn: &DbConn, id: u32, data: &InstrumentInsertion) -> Result<()> {
+    diesel::update(instruments::table)
+        .filter(instruments::id.eq(id as i64))
+        .set(data)
+        .execute(conn)?;
+
+    Ok(())
+}
+
+/// Get an existing instrument.
+pub fn get_instrument(conn: &DbConn, id: u32) -> Result<Option<Instrument>> {
+    Ok(instruments::table
+        .filter(instruments::id.eq(id as i64))
+        .load::<Instrument>(conn)?
+        .first()
+        .cloned())
+}
+
+/// Delete an existing instrument.
+pub fn delete_instrument(conn: &DbConn, id: u32) -> Result<()> {
+    diesel::delete(instruments::table.filter(instruments::id.eq(id as i64))).execute(conn)?;
+    Ok(())
+}
+
+/// Get all existing instruments.
+pub fn get_instruments(conn: &DbConn) -> Result<Vec<Instrument>> {
+    Ok(instruments::table.load::<Instrument>(conn)?)
+}

musicus_server/src/database/mod.rs

@@ -0,0 +1,39 @@
+use anyhow::Result;
+use diesel::r2d2;
+use diesel::PgConnection;
+
+pub mod ensembles;
+pub use ensembles::*;
+
+pub mod instruments;
+pub use instruments::*;
+
+pub mod persons;
+pub use persons::*;
+
+pub mod recordings;
+pub use recordings::*;
+
+pub mod users;
+pub use users::*;
+
+pub mod works;
+pub use works::*;
+
+mod schema;
+
+/// A pool of connections to the database.
+pub type DbPool = r2d2::Pool<r2d2::ConnectionManager<PgConnection>>;
+
+/// One database connection from the connection pool.
+pub type DbConn = r2d2::PooledConnection<r2d2::ConnectionManager<PgConnection>>;
+
+/// Create a connection pool for a database. This will look for the database URL in the
+/// "MUSICUS_DATABASE_URL" environment variable and fail, if that is not set.
+pub fn connect() -> Result<DbPool> {
+    let url = std::env::var("MUSICUS_DATABASE_URL")?;
+    let manager = r2d2::ConnectionManager::<PgConnection>::new(url);
+    let pool = r2d2::Pool::new(manager)?;
+
+    Ok(pool)
+}

musicus_server/src/database/persons.rs

@@ -0,0 +1,78 @@
+use super::schema::persons;
+use super::DbConn;
+use anyhow::Result;
+use diesel::prelude::*;
+use diesel::{Insertable, Queryable};
+use serde::{Deserialize, Serialize};
+
+/// A person that is a composer, an interpret or both.
+#[derive(Insertable, Queryable, Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct Person {
+    pub id: i64,
+    pub first_name: String,
+    pub last_name: String,
+
+    #[serde(skip)]
+    pub created_by: String,
+}
+
+/// A structure representing data on a person.
+#[derive(AsChangeset, Deserialize, Debug, Clone)]
+#[table_name = "persons"]
+#[serde(rename_all = "camelCase")]
+pub struct PersonInsertion {
+    pub first_name: String,
+    pub last_name: String,
+}
+
+/// Insert a new person.
+pub fn insert_person(
+    conn: &DbConn,
+    id: u32,
+    data: &PersonInsertion,
+    created_by: &str,
+) -> Result<()> {
+    let person = Person {
+        id: id as i64,
+        first_name: data.first_name.clone(),
+        last_name: data.last_name.clone(),
+        created_by: created_by.to_string(),
+    };
+
+    diesel::insert_into(persons::table)
+        .values(person)
+        .execute(conn)?;
+
+    Ok(())
+}
+
+/// Update an existing person.
+pub fn update_person(conn: &DbConn, id: u32, data: &PersonInsertion) -> Result<()> {
+    diesel::update(persons::table)
+        .filter(persons::id.eq(id as i64))
+        .set(data)
+        .execute(conn)?;
+
+    Ok(())
+}
+
+/// Get an existing person.
+pub fn get_person(conn: &DbConn, id: u32) -> Result<Option<Person>> {
+    Ok(persons::table
+        .filter(persons::id.eq(id as i64))
+        .load::<Person>(conn)?
+        .first()
+        .cloned())
+}
+
+/// Delete an existing person.
+pub fn delete_person(conn: &DbConn, id: u32) -> Result<()> {
+    diesel::delete(persons::table.filter(persons::id.eq(id as i64))).execute(conn)?;
+    Ok(())
+}
+
+/// Get all existing persons.
+pub fn get_persons(conn: &DbConn) -> Result<Vec<Person>> {
+    Ok(persons::table.load::<Person>(conn)?)
+}

musicus_server/src/database/recordings.rs

@@ -0,0 +1,278 @@
+use super::schema::{ensembles, instruments, performances, persons, recordings};
+use super::{get_work_description, DbConn, Ensemble, Instrument, Person, WorkDescription};
+use anyhow::{anyhow, Error, Result};
+use diesel::prelude::*;
+use diesel::{Insertable, Queryable};
+use serde::{Deserialize, Serialize};
+use std::convert::TryInto;
+
+/// A specific recording of a work.
+#[derive(Insertable, Queryable, Debug, Clone)]
+pub struct Recording {
+    pub id: i64,
+    pub work: i64,
+    pub comment: String,
+    pub created_by: String,
+}
+
+/// How a person or ensemble was involved in a recording.
+#[derive(Insertable, Queryable, Debug, Clone)]
+pub struct Performance {
+    pub id: i64,
+    pub recording: i64,
+    pub person: Option<i64>,
+    pub ensemble: Option<i64>,
+    pub role: Option<i64>,
+}
+
+/// A structure for collecting all available information on a performance.
+#[derive(Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct PerformanceDescription {
+    pub person: Option<Person>,
+    pub ensemble: Option<Ensemble>,
+    pub role: Option<Instrument>,
+}
+
+/// A structure for collecting all available information on a recording.
+#[derive(Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct RecordingDescription {
+    pub id: i64,
+    pub work: WorkDescription,
+    pub comment: String,
+    pub performances: Vec<PerformanceDescription>,
+}
+
+/// A structure representing data on a performance.
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct PerformanceInsertion {
+    pub person: Option<i64>,
+    pub ensemble: Option<i64>,
+    pub role: Option<i64>,
+}
+
+/// A bundle of everything needed for adding a new recording to the database.
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct RecordingInsertion {
+    pub work: i64,
+    pub comment: String,
+    pub performances: Vec<PerformanceInsertion>,
+}
+
+/// Insert a new recording.
+pub fn insert_recording(
+    conn: &DbConn,
+    id: u32,
+    data: &RecordingInsertion,
+    created_by: &str,
+) -> Result<()> {
+    conn.transaction::<(), Error, _>(|| {
+        let id = id as i64;
+
+        diesel::insert_into(recordings::table)
+            .values(Recording {
+                id,
+                work: data.work,
+                comment: data.comment.clone(),
+                created_by: created_by.to_string(),
+            })
+            .execute(conn)?;
+
+        insert_recording_data(conn, id, data)?;
+
+        Ok(())
+    })?;
+
+    Ok(())
+}
+
+/// Update an existing recording.
+pub fn update_recording(conn: &DbConn, id: u32, data: &RecordingInsertion) -> Result<()> {
+    conn.transaction::<(), Error, _>(|| {
+        let id = id as i64;
+
+        diesel::delete(performances::table)
+            .filter(performances::recording.eq(id))
+            .execute(conn)?;
+
+        diesel::update(recordings::table)
+            .filter(recordings::id.eq(id))
+            .set((
+                recordings::work.eq(data.work),
+                recordings::comment.eq(data.comment.clone()),
+            ))
+            .execute(conn)?;
+
+        insert_recording_data(conn, id, data)?;
+
+        Ok(())
+    })?;
+
+    Ok(())
+}
+
+/// Helper method to populate other tables related to a recording.
+fn insert_recording_data(conn: &DbConn, id: i64, data: &RecordingInsertion) -> Result<()> {
+    for performance in &data.performances {
+        diesel::insert_into(performances::table)
+            .values(Performance {
+                id: rand::random(),
+                recording: id,
+                person: performance.person,
+                ensemble: performance.ensemble,
+                role: performance.role,
+            })
+            .execute(conn)?;
+    }
+
+    Ok(())
+}
+
+/// Get an existing recording.
+pub fn get_recording(conn: &DbConn, id: u32) -> Result<Option<Recording>> {
+    Ok(recordings::table
+        .filter(recordings::id.eq(id as i64))
+        .load::<Recording>(conn)?
+        .first()
+        .cloned())
+}
+
+/// Retrieve all available information on a recording from related tables.
+pub fn get_description_for_recording(
+    conn: &DbConn,
+    recording: &Recording,
+) -> Result<RecordingDescription> {
+    let mut performance_descriptions: Vec<PerformanceDescription> = Vec::new();
+
+    let performances = performances::table
+        .filter(performances::recording.eq(recording.id))
+        .load::<Performance>(conn)?;
+
+    for performance in performances {
+        performance_descriptions.push(PerformanceDescription {
+            person: match performance.person {
+                Some(id) => Some(
+                    persons::table
+                        .filter(persons::id.eq(id as i64))
+                        .load::<Person>(conn)?
+                        .first()
+                        .cloned()
+                        .ok_or(anyhow!("No person with ID: {}", id))?,
+                ),
+                None => None,
+            },
+            ensemble: match performance.ensemble {
+                Some(id) => Some(
+                    ensembles::table
+                        .filter(ensembles::id.eq(id as i64))
+                        .load::<Ensemble>(conn)?
+                        .first()
+                        .cloned()
+                        .ok_or(anyhow!("No ensemble with ID: {}", id))?,
+                ),
+                None => None,
+            },
+            role: match performance.role {
+                Some(id) => Some(
+                    instruments::table
+                        .filter(instruments::id.eq(id as i64))
+                        .load::<Instrument>(conn)?
+                        .first()
+                        .cloned()
+                        .ok_or(anyhow!("No instrument with ID: {}", id))?,
+                ),
+                None => None,
+            },
+        });
+    }
+
+    let work_id = recording.work.try_into()?;
+    let work =
+        get_work_description(conn, work_id)?.ok_or(anyhow!("Work doesn't exist: {}", work_id))?;
+
+    let recording_description = RecordingDescription {
+        id: recording.id,
+        work,
+        comment: recording.comment.clone(),
+        performances: performance_descriptions,
+    };
+
+    Ok(recording_description)
+}
+
+/// Get an existing recording and all available information from related tables.
+pub fn get_recording_description(conn: &DbConn, id: u32) -> Result<Option<RecordingDescription>> {
+    let recording_description = match get_recording(conn, id)? {
+        Some(recording) => Some(get_description_for_recording(conn, &recording)?),
+        None => None,
+    };
+
+    Ok(recording_description)
+}
+
+/// Get all available information on all recordings where a person is performing.
+pub fn get_recordings_for_person(
+    conn: &DbConn,
+    person_id: u32,
+) -> Result<Vec<RecordingDescription>> {
+    let mut recording_descriptions: Vec<RecordingDescription> = Vec::new();
+
+    let recordings = recordings::table
+        .inner_join(performances::table.on(performances::recording.eq(recordings::id)))
+        .inner_join(persons::table.on(persons::id.nullable().eq(performances::person)))
+        .filter(persons::id.eq(person_id as i64))
+        .select(recordings::table::all_columns())
+        .load::<Recording>(conn)?;
+
+    for recording in recordings {
+        recording_descriptions.push(get_description_for_recording(conn, &recording)?);
+    }
+
+    Ok(recording_descriptions)
+}
+
+/// Get all available information on all recordings where an ensemble is performing.
+pub fn get_recordings_for_ensemble(
+    conn: &DbConn,
+    ensemble_id: u32,
+) -> Result<Vec<RecordingDescription>> {
+    let mut recording_descriptions: Vec<RecordingDescription> = Vec::new();
+
+    let recordings = recordings::table
+        .inner_join(performances::table.on(performances::recording.eq(recordings::id)))
+        .inner_join(ensembles::table.on(ensembles::id.nullable().eq(performances::ensemble)))
+        .filter(ensembles::id.eq(ensemble_id as i64))
+        .select(recordings::table::all_columns())
+        .load::<Recording>(conn)?;
+
+    for recording in recordings {
+        recording_descriptions.push(get_description_for_recording(conn, &recording)?);
+    }
+
+    Ok(recording_descriptions)
+}
+
+/// Get allavailable information on all recordings of a work.
+pub fn get_recordings_for_work(conn: &DbConn, work_id: u32) -> Result<Vec<RecordingDescription>> {
+    let mut recording_descriptions: Vec<RecordingDescription> = Vec::new();
+
+    let recordings = recordings::table
+        .filter(recordings::work.eq(work_id as i64))
+        .load::<Recording>(conn)?;
+
+    for recording in recordings {
+        recording_descriptions.push(get_description_for_recording(conn, &recording)?);
+    }
+
+    Ok(recording_descriptions)
+}
+
+/// Delete an existing recording. This will fail if there are still references to this
+/// recording from other tables that are not directly part of the recording data.
+pub fn delete_recording(conn: &DbConn, id: u32) -> Result<()> {
+    diesel::delete(recordings::table.filter(recordings::id.eq(id as i64))).execute(conn)?;
+    Ok(())
+}

musicus_server/src/database/schema.rs

@@ -0,0 +1,120 @@
+table! {
+    ensembles (id) {
+        id -> Int8,
+        name -> Text,
+        created_by -> Text,
+    }
+}
+
+table! {
+    instrumentations (id) {
+        id -> Int8,
+        work -> Int8,
+        instrument -> Int8,
+    }
+}
+
+table! {
+    instruments (id) {
+        id -> Int8,
+        name -> Text,
+        created_by -> Text,
+    }
+}
+
+table! {
+    performances (id) {
+        id -> Int8,
+        recording -> Int8,
+        person -> Nullable<Int8>,
+        ensemble -> Nullable<Int8>,
+        role -> Nullable<Int8>,
+    }
+}
+
+table! {
+    persons (id) {
+        id -> Int8,
+        first_name -> Text,
+        last_name -> Text,
+        created_by -> Text,
+    }
+}
+
+table! {
+    recordings (id) {
+        id -> Int8,
+        work -> Int8,
+        comment -> Text,
+        created_by -> Text,
+    }
+}
+
+table! {
+    users (username) {
+        username -> Text,
+        password_hash -> Text,
+        email -> Nullable<Text>,
+        is_admin -> Bool,
+        is_editor -> Bool,
+        is_banned -> Bool,
+    }
+}
+
+table! {
+    work_parts (id) {
+        id -> Int8,
+        work -> Int8,
+        part_index -> Int8,
+        title -> Text,
+        composer -> Nullable<Int8>,
+    }
+}
+
+table! {
+    work_sections (id) {
+        id -> Int8,
+        work -> Int8,
+        title -> Text,
+        before_index -> Int8,
+    }
+}
+
+table! {
+    works (id) {
+        id -> Int8,
+        composer -> Int8,
+        title -> Text,
+        created_by -> Text,
+    }
+}
+
+joinable!(ensembles -> users (created_by));
+joinable!(instrumentations -> instruments (instrument));
+joinable!(instrumentations -> works (work));
+joinable!(instruments -> users (created_by));
+joinable!(performances -> ensembles (ensemble));
+joinable!(performances -> instruments (role));
+joinable!(performances -> persons (person));
+joinable!(performances -> recordings (recording));
+joinable!(persons -> users (created_by));
+joinable!(recordings -> users (created_by));
+joinable!(recordings -> works (work));
+joinable!(work_parts -> persons (composer));
+joinable!(work_parts -> works (work));
+joinable!(work_sections -> works (work));
+joinable!(works -> persons (composer));
+joinable!(works -> users (created_by));
+
+allow_tables_to_appear_in_same_query!(
+    ensembles,
+    instrumentations,
+    instruments,
+    performances,
+    persons,
+    recordings,
+    users,
+    work_parts,
+    work_sections,
+    works,
+);

musicus_server/src/database/users.rs

@@ -0,0 +1,61 @@
+use super::schema::users;
+use super::DbConn;
+use anyhow::Result;
+use diesel::prelude::*;
+use serde::Deserialize;
+
+/// A user that can be authenticated to use the API.
+#[derive(Insertable, Queryable, Debug, Clone)]
+pub struct User {
+    pub username: String,
+    pub password_hash: String,
+    pub email: Option<String>,
+    pub is_admin: bool,
+    pub is_editor: bool,
+    pub is_banned: bool,
+}
+
+/// A structure representing data on a user.
+#[derive(AsChangeset, Deserialize, Debug, Clone)]
+#[table_name = "users"]
+#[serde(rename_all = "camelCase")]
+pub struct UserInsertion {
+    pub password_hash: String,
+    pub email: Option<String>,
+}
+
+/// Insert a new user.
+pub fn insert_user(conn: &DbConn, username: &str, data: &UserInsertion) -> Result<()> {
+    let user = User {
+        username: username.to_string(),
+        password_hash: data.password_hash.clone(),
+        email: data.email.clone(),
+        is_admin: false,
+        is_editor: false,
+        is_banned: false,
+    };
+    diesel::insert_into(users::table)
+        .values(user)
+        .execute(conn)?;
+
+    Ok(())
+}
+
+/// Update an existing user.
+pub fn update_user(conn: &DbConn, username: &str, data: &UserInsertion) -> Result<()> {
+    diesel::update(users::table)
+        .filter(users::username.eq(username))
+        .set(data)
+        .execute(conn)?;
+
+    Ok(())
+}
+
+/// Get an existing user.
+pub fn get_user(conn: &DbConn, username: &str) -> Result<Option<User>> {
+    Ok(users::table
+        .filter(users::username.eq(username))
+        .load::<User>(conn)?
+        .first()
+        .cloned())
+}

musicus_server/src/database/works.rs

@@ -0,0 +1,307 @@
+use super::schema::{instrumentations, instruments, persons, work_parts, work_sections, works};
+use super::{get_person, DbConn, Instrument, Person};
+use anyhow::{anyhow, Error, Result};
+use diesel::prelude::*;
+use diesel::{Insertable, Queryable};
+use serde::{Deserialize, Serialize};
+use std::convert::TryInto;
+
+/// A composition by a composer.
+#[derive(Insertable, Queryable, Debug, Clone)]
+pub struct Work {
+    pub id: i64,
+    pub composer: i64,
+    pub title: String,
+    pub created_by: String,
+}
+
+/// Definition that a work uses an instrument.
+#[derive(Insertable, Queryable, Debug, Clone)]
+pub struct Instrumentation {
+    pub id: i64,
+    pub work: i64,
+    pub instrument: i64,
+}
+
+/// A concrete work part that can be recorded.
+#[derive(Insertable, Queryable, Debug, Clone)]
+pub struct WorkPart {
+    pub id: i64,
+    pub work: i64,
+    pub part_index: i64,
+    pub title: String,
+    pub composer: Option<i64>,
+}
+
+/// A heading between work parts.
+#[derive(Insertable, Queryable, Debug, Clone)]
+pub struct WorkSection {
+    pub id: i64,
+    pub work: i64,
+    pub title: String,
+    pub before_index: i64,
+}
+/// A structure for collecting all available information on a work part.
+#[derive(Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct WorkPartDescription {
+    pub title: String,
+    pub composer: Option<Person>,
+}
+
+/// A structure for collecting all available information on a work section.
+#[derive(Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct WorkSectionDescription {
+    pub title: String,
+    pub before_index: i64,
+}
+
+/// A structure for collecting all available information on a work.
+#[derive(Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct WorkDescription {
+    pub id: i64,
+    pub title: String,
+    pub composer: Person,
+    pub instruments: Vec<Instrument>,
+    pub parts: Vec<WorkPartDescription>,
+    pub sections: Vec<WorkSectionDescription>,
+}
+
+/// A structure representing data on a work part.
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct WorkPartInsertion {
+    pub title: String,
+    pub composer: Option<i64>,
+}
+
+/// A structure representing data on a work section.
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct WorkSectionInsertion {
+    pub title: String,
+    pub before_index: i64,
+}
+
+/// A structure representing data on a work.
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct WorkInsertion {
+    pub composer: i64,
+    pub title: String,
+    pub instruments: Vec<i64>,
+    pub parts: Vec<WorkPartInsertion>,
+    pub sections: Vec<WorkSectionInsertion>,
+}
+
+/// Insert a new work.
+pub fn insert_work(conn: &DbConn, id: u32, data: &WorkInsertion, created_by: &str) -> Result<()> {
+    conn.transaction::<(), Error, _>(|| {
+        let id = id as i64;
+
+        diesel::insert_into(works::table)
+            .values(Work {
+                id,
+                composer: data.composer.clone(),
+                title: data.title.clone(),
+                created_by: created_by.to_string(),
+            })
+            .execute(conn)?;
+
+        insert_work_data(conn, id, data)?;
+
+        Ok(())
+    })?;
+
+    Ok(())
+}
+
+/// Update an existing work.
+pub fn update_work(conn: &DbConn, id: u32, data: &WorkInsertion) -> Result<()> {
+    conn.transaction::<(), Error, _>(|| {
+        let id = id as i64;
+
+        diesel::delete(instrumentations::table)
+            .filter(instrumentations::work.eq(id))
+            .execute(conn)?;
+
+        diesel::delete(work_parts::table)
+            .filter(work_parts::work.eq(id))
+            .execute(conn)?;
+
+        diesel::delete(work_sections::table)
+            .filter(work_sections::work.eq(id))
+            .execute(conn)?;
+
+        diesel::update(works::table)
+            .filter(works::id.eq(id))
+            .set((
+                works::composer.eq(data.composer),
+                works::title.eq(data.title.clone()),
+            ))
+            .execute(conn)?;
+
+        insert_work_data(conn, id, data)?;
+
+        Ok(())
+    })?;
+
+    Ok(())
+}
+
+/// Helper method to populate tables related to a work.
+fn insert_work_data(conn: &DbConn, id: i64, data: &WorkInsertion) -> Result<()> {
+    for instrument in &data.instruments {
+        diesel::insert_into(instrumentations::table)
+            .values(Instrumentation {
+                id: rand::random(),
+                work: id,
+                instrument: *instrument,
+            })
+            .execute(conn)?;
+    }
+
+    for (index, part) in data.parts.iter().enumerate() {
+        let part = WorkPart {
+            id: rand::random(),
+            work: id,
+            part_index: index.try_into()?,
+            title: part.title.clone(),
+            composer: part.composer,
+        };
+
+        diesel::insert_into(work_parts::table)
+            .values(part)
+            .execute(conn)?;
+    }
+
+    for section in &data.sections {
+        let section = WorkSection {
+            id: rand::random(),
+            work: id,
+            title: section.title.clone(),
+            before_index: section.before_index,
+        };
+
+        diesel::insert_into(work_sections::table)
+            .values(section)
+            .execute(conn)?;
+    }
+
+    Ok(())
+}
+
+/// Get an already existing work without related rows from other tables.
+fn get_work(conn: &DbConn, id: u32) -> Result<Option<Work>> {
+    Ok(works::table
+        .filter(works::id.eq(id as i64))
+        .load::<Work>(conn)?
+        .first()
+        .cloned())
+}
+
+/// Retrieve all available information on a work from related tables.
+fn get_description_for_work(conn: &DbConn, work: &Work) -> Result<WorkDescription> {
+    let mut instruments: Vec<Instrument> = Vec::new();
+
+    let instrumentations = instrumentations::table
+        .filter(instrumentations::work.eq(work.id))
+        .load::<Instrumentation>(conn)?;
+
+    for instrumentation in instrumentations {
+        instruments.push(
+            instruments::table
+                .filter(instruments::id.eq(instrumentation.instrument))
+                .load::<Instrument>(conn)?
+                .first()
+                .cloned()
+                .ok_or(anyhow!(
+                    "No instrument with ID: {}",
+                    instrumentation.instrument
+                ))?,
+        );
+    }
+
+    let mut part_descriptions: Vec<WorkPartDescription> = Vec::new();
+
+    let work_parts = work_parts::table
+        .filter(work_parts::work.eq(work.id))
+        .load::<WorkPart>(conn)?;
+
+    for work_part in work_parts {
+        part_descriptions.push(WorkPartDescription {
+            title: work_part.title,
+            composer: match work_part.composer {
+                Some(composer) => Some(
+                    persons::table
+                        .filter(persons::id.eq(composer))
+                        .load::<Person>(conn)?
+                        .first()
+                        .cloned()
+                        .ok_or(anyhow!("No person with ID: {}", composer))?,
+                ),
+                None => None,
+            },
+        });
+    }
+
+    let mut section_descriptions: Vec<WorkSectionDescription> = Vec::new();
+
+    let sections = work_sections::table
+        .filter(work_sections::work.eq(work.id))
+        .load::<WorkSection>(conn)?;
+
+    for section in sections {
+        section_descriptions.push(WorkSectionDescription {
+            title: section.title,
+            before_index: section.before_index,
+        });
+    }
+
+    let person_id = work.composer.try_into()?;
+    let person =
+        get_person(conn, person_id)?.ok_or(anyhow!("Person doesn't exist: {}", person_id))?;
+
+    Ok(WorkDescription {
+        id: work.id,
+        composer: person,
+        title: work.title.clone(),
+        instruments,
+        parts: part_descriptions,
+        sections: section_descriptions,
+    })
+}
+
+/// Get an existing work and all available information from related tables.
+pub fn get_work_description(conn: &DbConn, id: u32) -> Result<Option<WorkDescription>> {
+    let work_description = match get_work(conn, id)? {
+        Some(work) => Some(get_description_for_work(conn, &work)?),
+        None => None,
+    };
+
+    Ok(work_description)
+}
+
+/// Delete an existing work. This will fail if there are still other tables that relate to
+/// this work except for the things that are part of the information on the work it
+pub fn delete_work(conn: &DbConn, id: u32) -> Result<()> {
+    diesel::delete(works::table.filter(works::id.eq(id as i64))).execute(conn)?;
+    Ok(())
+}
+
+/// Get all existing works by a composer and related information from other tables.
+pub fn get_work_descriptions(conn: &DbConn, composer_id: u32) -> Result<Vec<WorkDescription>> {
+    let mut work_descriptions: Vec<WorkDescription> = Vec::new();
+
+    let works = works::table
+        .filter(works::composer.eq(composer_id as i64))
+        .load::<Work>(conn)?;
+
+    for work in works {
+        work_descriptions.push(get_description_for_work(conn, &work)?);
+    }
+
+    Ok(work_descriptions)
+}

musicus_server/src/main.rs

@@ -0,0 +1,36 @@
+// Required for database/schema.rs
+#[macro_use]
+extern crate diesel;
+
+use actix_web::{App, HttpServer};
+
+mod database;
+
+mod routes;
+use routes::*;
+
+#[actix_web::main]
+async fn main() -> std::io::Result<()> {
+    dotenv::dotenv().ok();
+    env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info")).init();
+    sodiumoxide::init().expect("Failed to init crypto library!");
+    let db_pool = database::connect().expect("Failed to create database interface!");
+
+    let server = HttpServer::new(move || {
+        App::new()
+            .data(db_pool.clone())
+            .wrap(actix_web::middleware::Logger::new(
+                "%t: %r -> %s; %b B; %D ms",
+            ))
+            .service(register_user)
+            .service(login_user)
+            .service(put_user)
+            .service(get_user)
+            .service(get_person)
+            .service(post_person)
+            .service(put_person)
+            .service(get_persons)
+    });
+
+    server.bind("127.0.0.1:8087")?.run().await
+}

musicus_server/src/routes/auth.rs

@@ -0,0 +1,261 @@
+use super::ServerError;
+use crate::database;
+use crate::database::{DbConn, DbPool, User, UserInsertion};
+use actix_web::{get, post, put, web, HttpResponse};
+use actix_web_httpauth::extractors::bearer::BearerAuth;
+use anyhow::{anyhow, Result};
+use serde::{Deserialize, Serialize};
+use sodiumoxide::crypto::pwhash::argon2id13;
+
+/// Request body data for user registration.
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct UserRegistration {
+    pub username: String,
+    pub password: String,
+    pub email: Option<String>,
+}
+
+/// Request body data for user login.
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct Login {
+    pub username: String,
+    pub password: String,
+}
+
+/// Request body data for changing user details.
+#[derive(Deserialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct PutUser {
+    pub old_password: String,
+    pub new_password: Option<String>,
+    pub email: Option<String>,
+}
+
+/// Response body data for getting a user.
+#[derive(Serialize, Debug, Clone)]
+pub struct GetUser {
+    pub username: String,
+    pub email: Option<String>,
+}
+
+/// Claims for issued JWTs.
+#[derive(Deserialize, Serialize, Debug, Clone)]
+struct Claims {
+    pub iat: u64,
+    pub exp: u64,
+    pub username: String,
+}
+
+/// Register a new user.
+#[post("/users")]
+pub async fn register_user(
+    db: web::Data<DbPool>,
+    data: web::Json<UserRegistration>,
+) -> Result<HttpResponse, ServerError> {
+    web::block(move || {
+        let conn = db.into_inner().get().or(Err(ServerError::Internal))?;
+
+        database::insert_user(
+            &conn,
+            &data.username,
+            &UserInsertion {
+                password_hash: hash_password(&data.password).or(Err(ServerError::Internal))?,
+                email: data.email.clone(),
+            },
+        )
+        .or(Err(ServerError::Internal))
+    })
+    .await?;
+
+    Ok(HttpResponse::Ok().finish())
+}
+
+/// Update an existing user. This doesn't use a JWT for authentication but requires the client to
+/// resent the old password.
+#[put("/users/{username}")]
+pub async fn put_user(
+    db: web::Data<DbPool>,
+    username: web::Path<String>,
+    data: web::Json<PutUser>,
+) -> Result<HttpResponse, ServerError> {
+    let conn = db.into_inner().get().or(Err(ServerError::Internal))?;
+
+    web::block(move || {
+        let user = database::get_user(&conn, &username)
+            .or(Err(ServerError::Internal))?
+            .ok_or(ServerError::Unauthorized)?;
+
+        if verify_password(&data.old_password, &user.password_hash) {
+            let password_hash = match &data.new_password {
+                Some(password) => hash_password(password).or(Err(ServerError::Unauthorized))?,
+                None => user.password_hash.clone(),
+            };
+
+            database::update_user(
+                &conn,
+                &username,
+                &UserInsertion {
+                    email: data.email.clone(),
+                    password_hash,
+                },
+            )
+            .or(Err(ServerError::Internal))?;
+
+            Ok(())
+        } else {
+            Err(ServerError::Forbidden)
+        }
+    })
+    .await?;
+
+    Ok(HttpResponse::Ok().finish())
+}
+
+/// Get an existing user. This requires a valid JWT authenticating that user.
+#[get("/users/{username}")]
+pub async fn get_user(
+    db: web::Data<DbPool>,
+    username: web::Path<String>,
+    auth: BearerAuth,
+) -> Result<HttpResponse, ServerError> {
+    let user = web::block(move || {
+        let conn = db.into_inner().get().or(Err(ServerError::Internal))?;
+        authenticate(&conn, auth.token()).or(Err(ServerError::Unauthorized))
+    })
+    .await?;
+
+    if username.into_inner() != user.username {
+        Err(ServerError::Forbidden)?;
+    }
+
+    Ok(HttpResponse::Ok().json(GetUser {
+        username: user.username,
+        email: user.email,
+    }))
+}
+
+/// Login an already existing user. This will respond with a newly issued JWT.
+#[post("/login")]
+pub async fn login_user(
+    db: web::Data<DbPool>,
+    data: web::Json<Login>,
+) -> Result<HttpResponse, ServerError> {
+    let token = web::block(move || {
+        let conn = db.into_inner().get().or(Err(ServerError::Internal))?;
+
+        let user = database::get_user(&conn, &data.username)
+            .or(Err(ServerError::Internal))?
+            .ok_or(ServerError::Unauthorized)?;
+
+        if verify_password(&data.password, &user.password_hash) {
+            issue_jwt(&user.username).or(Err(ServerError::Internal))
+        } else {
+            Err(ServerError::Unauthorized)
+        }
+    })
+    .await?;
+
+    Ok(HttpResponse::Ok().body(token))
+}
+
+/// Authenticate a user by verifying the provided token. The environemtn variable "MUSICUS_SECRET"
+/// will be used as the secret key and has to be set.
+pub fn authenticate(conn: &DbConn, token: &str) -> Result<User> {
+    let username = verify_jwt(token)?.username;
+    database::get_user(conn, &username)?.ok_or(anyhow!("User doesn't exist: {}", &username))
+}
+
+/// Check whether a token allows the user to create a new item.
+pub fn may_create(conn: &DbConn, token: &str) -> Result<bool> {
+    let user = authenticate(conn, token)?;
+
+    let result = if user.is_banned { false } else { false };
+
+    Ok(result)
+}
+
+/// Check whether a token allows the user to edit an item created by him or somebody else.
+pub fn may_edit(conn: &DbConn, token: &str, created_by: &str) -> Result<bool> {
+    let user = authenticate(conn, token)?;
+
+    let result = if user.is_banned {
+        false
+    } else if user.username == created_by {
+        true
+    } else if user.is_editor {
+        true
+    } else {
+        false
+    };
+
+    Ok(result)
+}
+
+/// Return a hash for a password that can be stored in the database.
+fn hash_password(password: &str) -> Result<String> {
+    let hash = argon2id13::pwhash(
+        password.as_bytes(),
+        argon2id13::OPSLIMIT_INTERACTIVE,
+        argon2id13::MEMLIMIT_INTERACTIVE,
+    )
+    .or(Err(anyhow!("Failed to hash password!")))?;
+
+    // Strip trailing null bytes to facilitate database storage.
+    Ok(std::str::from_utf8(&hash.0)?
+        .trim_end_matches('\u{0}')
+        .to_string())
+}
+
+/// Verify whether a hash is valid for a password.
+fn verify_password(password: &str, hash: &str) -> bool {
+    // Readd the trailing null bytes padding.
+    let mut bytes = [0u8; 128];
+    for (index, byte) in hash.as_bytes().iter().enumerate() {
+        bytes[index] = *byte;
+    }
+
+    argon2id13::pwhash_verify(
+        &argon2id13::HashedPassword::from_slice(&bytes).unwrap(),
+        password.as_bytes(),
+    )
+}
+
+/// Issue a JWT that allows to claim to be a user. This uses the value of the environment variable
+/// "MUSICUS_SECRET" as the secret key. This needs to be set.
+fn issue_jwt(username: &str) -> Result<String> {
+    let now = std::time::SystemTime::now();
+    let expiry = now + std::time::Duration::new(86400, 0);
+
+    let iat = now.duration_since(std::time::UNIX_EPOCH)?.as_secs();
+    let exp = expiry.duration_since(std::time::UNIX_EPOCH)?.as_secs();
+
+    let secret = std::env::var("MUSICUS_SECRET")?;
+
+    let token = jsonwebtoken::encode(
+        &jsonwebtoken::Header::default(),
+        &Claims {
+            iat,
+            exp,
+            username: username.to_string(),
+        },
+        &jsonwebtoken::EncodingKey::from_secret(&secret.as_bytes()),
+    )?;
+
+    Ok(token)
+}
+
+/// Verify a JWT and return the claims that are made by it. This uses the value of the environment
+/// variable "MUSICUS_SECRET" as the secret key. This needs to be set.
+fn verify_jwt(token: &str) -> Result<Claims> {
+    let secret = std::env::var("MUSICUS_SECRET")?;
+
+    let jwt = jsonwebtoken::decode::<Claims>(
+        token,
+        &jsonwebtoken::DecodingKey::from_secret(&secret.as_bytes()),
+        &jsonwebtoken::Validation::default(),
+    )?;
+
+    Ok(jwt.claims)
+}

musicus_server/src/routes/error.rs

@@ -0,0 +1,47 @@
+use actix_web::{dev::HttpResponseBuilder, error, http::StatusCode, HttpResponse};
+use derive_more::{Display, Error};
+
+/// An error intended for the public interface.
+#[derive(Display, Error, Debug)]
+pub enum ServerError {
+    NotFound,
+    Unauthorized,
+    Forbidden,
+    Internal,
+}
+
+impl error::ResponseError for ServerError {
+    fn error_response(&self) -> HttpResponse {
+        HttpResponseBuilder::new(self.status_code()).finish()
+    }
+
+    fn status_code(&self) -> StatusCode {
+        match self {
+            ServerError::NotFound => StatusCode::NOT_FOUND,
+            ServerError::Unauthorized => StatusCode::UNAUTHORIZED,
+            ServerError::Forbidden => StatusCode::FORBIDDEN,
+            ServerError::Internal => StatusCode::INTERNAL_SERVER_ERROR,
+        }
+    }
+}
+
+impl From<r2d2::Error> for ServerError {
+    fn from(error: r2d2::Error) -> Self {
+        ServerError::Internal
+    }
+}
+
+impl From<anyhow::Error> for ServerError {
+    fn from(error: anyhow::Error) -> Self {
+        ServerError::Internal
+    }
+}
+
+impl From<error::BlockingError<ServerError>> for ServerError {
+    fn from(error: error::BlockingError<ServerError>) -> Self {
+        match error {
+            error::BlockingError::Error(error) => error,
+            error::BlockingError::Canceled => ServerError::Internal,
+        }
+    }
+}

musicus_server/src/routes/mod.rs

@@ -0,0 +1,20 @@
+pub mod auth;
+pub use auth::*;
+
+pub mod ensembles;
+pub use ensembles::*;
+
+pub mod error;
+pub use error::*;
+
+pub mod instruments;
+pub use instruments::*;
+
+pub mod persons;
+pub use persons::*;
+
+pub mod recordings;
+pub use recordings::*;
+
+pub mod works;
+pub use works::*;

musicus_server/src/routes/persons.rs

@@ -0,0 +1,103 @@
+use super::{authenticate, ServerError};
+use crate::database;
+use crate::database::{DbPool, PersonInsertion};
+use actix_web::{delete, get, post, put, web, HttpResponse};
+use actix_web_httpauth::extractors::bearer::BearerAuth;
+
+/// Get an existing person.
+#[get("/persons/{id}")]
+pub async fn get_person(
+    db: web::Data<DbPool>,
+    id: web::Path<u32>,
+) -> Result<HttpResponse, ServerError> {
+    let person = web::block(move || {
+        let conn = db.into_inner().get()?;
+        database::get_person(&conn, id.into_inner())?.ok_or(ServerError::NotFound)
+    })
+    .await?;
+
+    Ok(HttpResponse::Ok().json(person))
+}
+
+/// Add a new person. The user must be authorized to do that.
+#[post("/persons")]
+pub async fn post_person(
+    auth: BearerAuth,
+    db: web::Data<DbPool>,
+    data: web::Json<PersonInsertion>,
+) -> Result<HttpResponse, ServerError> {
+    let id = rand::random();
+
+    web::block(move || {
+        let conn = db.into_inner().get()?;
+        let user = authenticate(&conn, auth.token()).or(Err(ServerError::Unauthorized))?;
+
+        database::insert_person(&conn, id, &data.into_inner(), &user.username)?;
+
+        Ok(())
+    })
+    .await?;
+
+    Ok(HttpResponse::Ok().body(id.to_string()))
+}
+
+#[put("/persons/{id}")]
+pub async fn put_person(
+    auth: BearerAuth,
+    db: web::Data<DbPool>,
+    id: web::Path<u32>,
+    data: web::Json<PersonInsertion>,
+) -> Result<HttpResponse, ServerError> {
+    web::block(move || {
+        let conn = db.into_inner().get()?;
+
+        let user = authenticate(&conn, auth.token()).or(Err(ServerError::Unauthorized))?;
+
+        let id = id.into_inner();
+        let old_person = database::get_person(&conn, id)?.ok_or(ServerError::NotFound)?;
+
+        if user.username != old_person.created_by {
+            Err(ServerError::Forbidden)?;
+        }
+
+        database::update_person(&conn, id, &data.into_inner())?;
+
+        Ok(())
+    })
+    .await?;
+
+    Ok(HttpResponse::Ok().finish())
+}
+
+#[get("/persons")]
+pub async fn get_persons(db: web::Data<DbPool>) -> Result<HttpResponse, ServerError> {
+    let persons = web::block(move || {
+        let conn = db.into_inner().get()?;
+        Ok(database::get_persons(&conn)?)
+    })
+    .await?;
+
+    Ok(HttpResponse::Ok().json(persons))
+}
+
+#[delete("/persons/{id}")]
+pub async fn delete_person(
+    auth: BearerAuth,
+    db: web::Data<DbPool>,
+    id: web::Path<u32>,
+) -> Result<HttpResponse, ServerError> {
+    web::block(move || {
+        let conn = db.into_inner().get()?;
+        let user = authenticate(&conn, auth.token()).or(Err(ServerError::Unauthorized))?;
+
+        if user.is_editor {
+            database::delete_person(&conn, id.into_inner())?;
+            Ok(())
+        } else {
+            Err(ServerError::Forbidden)
+        }
+    })
+    .await?;
+
+    Ok(HttpResponse::Ok().finish())
+}