CREATE TABLE entities (
    entity_id serial PRIMARY KEY,
    jid text NOT NULL UNIQUE
);

CREATE TABLE nodes (
    node_id serial PRIMARY KEY,
    node text NOT NULL UNIQUE,
    node_type text NOT NULL DEFAULT 'leaf'
        CHECK (node_type IN ('leaf', 'collection')),
    persist_items boolean,
    deliver_payloads boolean NOT NULL DEFAULT TRUE,
    send_last_published_item text NOT NULL DEFAULT 'on_sub'
        CHECK (send_last_published_item IN ('never', 'on_sub'))
);

INSERT INTO nodes (node, node_type) values ('', 'collection');

CREATE TABLE affiliations (
    affiliation_id serial PRIMARY KEY,
    entity_id integer NOT NULL REFERENCES entities ON DELETE CASCADE,
    node_id integer NOT NULL references nodes ON DELETE CASCADE,
    affiliation text NOT NULL
        CHECK (affiliation IN ('outcast', 'publisher', 'owner')),
    UNIQUE (entity_id, node_id)
);

CREATE TABLE subscriptions (
    subscription_id serial PRIMARY KEY,
    entity_id integer NOT NULL REFERENCES entities ON DELETE CASCADE,
    resource text,
    node_id integer NOT NULL REFERENCES nodes ON delete CASCADE,
    state text NOT NULL DEFAULT 'subscribed'
    	CHECK (state IN ('subscribed', 'pending', 'unconfigured')),
    subscription_type text
    	CHECK (subscription_type IN (NULL, 'items', 'nodes')),
    subscription_depth text
    	CHECK (subscription_depth IN (NULL, '1', 'all')),
    UNIQUE (entity_id, resource, node_id));

CREATE TABLE items (
    item_id serial PRIMARY KEY,
    node_id integer NOT NULL REFERENCES nodes ON DELETE CASCADE,
    item text NOT NULL,
    publisher text NOT NULL,
    data text,
    date timestamp with time zone NOT NULL DEFAULT now(),
    UNIQUE (node_id, item)
);