DATA MODELS
===========

This document describes the key top-level entities this application will be working with and the attributes of each. This is a work-in-progress.

Other top-level entities will be introduced to the application as necessary.

Representations in this document are in application context; for database structure, see SCHEMA.md in this directory.

# Person

A Person represents a person! Specifically, a Person is a person who is using/has used the web application. Many applications call this entity a "User". We call them a Person.

``` rust
struct PersonId {
    id: String,
}
struct Person {
    id: PersonId,
    remote_id: String,
    name: String,
    handle: Option<String>,
    email: Option<Vec<String>>,
    is_active: bool,
    created_at: chrono::DateTime,
    modified_at: chrono::DateTime,
    modified_by: PersonId,
    deleted_at: Option<chrono::DateTime>,
    deleted_by: Option<PersonId>,
    last_seen: chrono::DateTime,
}
```

# Tag

A Tag is a classification label that a Person wants to associate to a Label, an Artist, an Album, a Track, or a Playlist, used as a way of grouping entities together via some commonality the context of which is not programmatically relevant.

``` rust
struct TagId {
    host: String,
    id: String,
}
struct Tag {
    id: TagId,
    name: String,
}
```

# Label

A Label represents a record label (a group of people who handle promotion and/or distribution for one or more Artists).

``` rust
struct LabelId {
    id: String,
}
struct Label {
    id: LabelId,
    name: String,
    description: String,
    website: String,
    artists: HashMap<Artist>,
    tags: Option<Vec<Tag>>,
    comments: Option<Vec<Comment>>,
}
```

# Artist

An Artist represents a musical artist.

``` rust
struct ArtistId {
    id: String,
}
struct Artist {
    id: ArtistId,
    name: String,
    bio: String,
    website: String,
    tags: Option<Vec<Tag>>,
    comments: Option<Vec<Comment>>,
}
```

# Track

A Track represents a single piece of work by an Artist that is contained in an audio file.

``` rust
struct TrackId {
    id: String,
}
struct Track {
    id: TrackId,
    title: String,
    description: String,
    duration: chrono::Duration,
    artists: HashMap<Artist>,
    is_public: bool,
    preview_source: Option<String>,
    source: String,
    price: Option<rusty_money::Money>,
    created_by: PersonId,
    created_at: chrono::DateTime,
    modified_by: PersonId,
    modified_at: chrono::DateTime,
    deleted_by: Option<PersonId>,
    deleted_at: Option<chrono::DateTime>,
    tags: Option<Vec<Tag>>,
    comments: Option<Vec<Comment>>,
    lyrics: Option<String>,
    cover: Option<String>,
    images: Option<Vec<String>>,
}
```

# Album

An Album represents a work by an Artist that contains one or more Tracks.

``` rust
struct AlbumId {
    id: String,
}
struct Album {
    id: AlbumId,
    title: String,
    description: String,
    artists: HashMap<Artist>,
    tracks: HashMap<Track>,
    is_public: bool,
    preview_source: Option<String>,
    source: String,
    price: Option<rusty_money::Money>,
    created_by: PersonId,
    created_at: chrono::DateTime,
    modified_by: PersonId,
    modified_at: chrono::DateTime,
    deleted_by: Option<PersonId>,
    deleted_at: Option<chrono::DateTime>,
    tags: Option<Vec<Tag>>,
    comments: Option<Vec<Comment>>,
    cover: Option<String>,
    images: Option<Vec<String>>,
}
```

# Playlist

A Playlist represents an ordered collection of Tracks assembled by a Person.

``` rust
struct PlaylistId {
    id: String,
}
struct Playlist {
    id: PlaylistId,
    title: String,
    description: String,
    created_by: String,
    created_at: chrono::DateTime,
    modified_at: chrono::DateTime,
    deleted_at: Option<chrono::DateTime>
    is_public: bool,
    cover: Option<String>,
    tracks: Vec<Track>,
    tags: Option<Vec<Tag>>,
    comments: Option<Vec<Comment>>,
}
```

# Article

An Article represents a "blog post" style article written by a Person.

``` rust
struct ArticleId {
    id: String,
}
struct Article {
    id: ArticleId,
    title: String,
    body: String,
    description: Option<String>,
    created_by: PersonId,
    created_at: chrono::DateTime,
    modified_at: chrono::DateTime,
    deleted_at: Option<chrono::DateTime>
    is_public: bool,
    cover: Option<String>,
    images: Option<Vec<String>>,
    tracks: Option<Vec<Track>>,
    tags: Option<Vec<Tag>>,
    comments: Option<Vec<Comment>>,
}
```

# Comment

A Comment represents a textual comment that a Person wants to attach contextually to an Artist, an Album, a Track, or a Playlist.

``` rust
enum CommentTargetType {
    Label,
    Artist,
    Album,
    Track,
    Playlist,
    Comment,
}
struct CommentTargetId {
    label_id: Option<LabelId>,
    artist_id: Option<ArtistId>,
    album_id: Option<AlbumId>,
    track_id: Option<TrackId>,
    playlist_id: Option<PlaylistId>,
    comment_id: Option<CommentId>,
}
struct CommentId {
    id: String,
}
struct Comment {
    id: CommentId,
    body: String,
    target_type: CommentTargetType,
    target_id: CommentTargetId,
    created_by: PersonId,
    created_at: chrono::DateTime,
    modified_at: chrono::DateTime,
    deleted_at: Option<chrono::DateTime>
    is_public: bool,
}
```

# Purchase

A Purchase represents one or more Tracks or Albums that a Person purchases from an Artist or Label through the server.

``` rust
enum PurchaseItemType {
    Album,
    Track,
    Collection,
    OtherProduct,
}
struct PurchaseItemId {
    id: String,
}
struct SkuId {
    id: String,
}
struct Sku {
    id: SkuId,
    album_id: Option<AlbumId>,
    track_id: Option<TrackId>,
    collection_id: Option<CollectionId>,
    other_product_id: Option<OtherProductId>,
}
struct PurchaseItem {
    id: PurchaseItemId,
    type: PurchaseItemType,
    sku: SkuId,
    quantity: usize,
    discount_percentage: usize,
}
struct Purchase {
    id: String,

}
```