-- Creating the DB structure
-- Version 2.0 (2021-10-10)

CREATE TABLE IF NOT EXISTS Art (
    ID INTEGER PRIMARY KEY generated always as identity,
    md5_hash CHAR(32) NOT NULL UNIQUE,
    path VARCHAR NOT NULL UNIQUE,
    title VARCHAR,
    link VARCHAR,
    description VARCHAR
);

CREATE TABLE IF NOT EXISTS Artist (
    ID INTEGER PRIMARY KEY generated always as identity,
    name VARCHAR  -- used as artists name
);

CREATE TABLE IF NOT EXISTS Topic (  -- as of yet unimplemented, see Art_Topic
    ID INTEGER PRIMARY KEY generated always as identity,
    name CHAR(20) UNIQUE NOT NULL,
    description VARCHAR
);

CREATE TABLE IF NOT EXISTS Presence (
    name CHAR(30) NOT NULL,
    domain CHAR(20) NOT NULL,
    link VARCHAR,
    artist_ID INTEGER NOT NULL,
    PRIMARY KEY (name, domain),
    FOREIGN KEY (artist_ID) REFERENCES Artist(ID) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS Art_Collection (  -- for ordered lists of art
    ID INTEGER PRIMARY KEY generated always as identity,
    name VARCHAR NOT NULL UNIQUE,
    description VARCHAR
);

CREATE TABLE IF NOT EXISTS Art_to_Art_Collection (
    collection_ID INTEGER NOT NULL,
    art_ID INTEGER NOT NULL,
    ranking VARCHAR,  -- order in the collection by string value, allows easy insert see https://stackoverflow.com/questions/9536262/best-representation-of-an-ordered-list-in-a-database; same rank or empty rank means unordered
    PRIMARY KEY (collection_ID, art_ID),
    FOREIGN KEY (collection_ID) REFERENCES Art_Collection(ID) ON DELETE CASCADE,
    FOREIGN KEY (art_ID) REFERENCES Art(ID)
);

CREATE TABLE IF NOT EXISTS Art_to_Presence (
    presence_name CHAR(20) NOT NULL,
    presence_domain CHAR(20) NOT NULL,
    art_ID INTEGER NOT NULL,
    PRIMARY KEY (presence_name, presence_domain, art_ID),
    FOREIGN KEY (presence_name, presence_domain) REFERENCES Presence(name, domain) ON UPDATE CASCADE ON DELETE CASCADE,
    FOREIGN KEY (art_ID) REFERENCES Art(ID) ON UPDATE CASCADE ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS Artist_to_Topic (  -- TODO implement, meant to indicate an artists main topics
    artist_ID INTEGER NOT NULL,
    topic_ID INTEGER NOT NULL,
    PRIMARY KEY (artist_ID, topic_ID),
    FOREIGN KEY (artist_ID) REFERENCES Artist(ID) ON UPDATE CASCADE ON DELETE CASCADE,
    FOREIGN KEY (topic_ID) REFERENCES Topic(ID) ON UPDATE CASCADE ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS  Tag_Category (
    category_id INTEGER PRIMARY KEY generated always as identity,
    name CHAR(20) NOT NULL
);

CREATE TABLE IF NOT EXISTS Tag (
    tag_ID INTEGER PRIMARY KEY generated always as identity,
    name CHAR(50) UNIQUE,
    description VARCHAR,
    category_id SERIAL,
    FOREIGN KEY (category_id) REFERENCES tag_category(category_id)
);

CREATE TABLE IF NOT EXISTS Art_to_Tag (
    art_ID INTEGER,
    tag_ID INTEGER,
    PRIMARY KEY (art_ID, tag_ID),
    FOREIGN KEY(art_ID) REFERENCES Art(ID) ON DELETE CASCADE,
    FOREIGN KEY (tag_ID) REFERENCES tag(tag_ID) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS Tag_Alias (
    tag1 INTEGER,
    tag2 INTEGER,
    PRIMARY KEY (tag1, tag2),
    FOREIGN KEY (tag1) REFERENCES tag(tag_ID) ON DELETE CASCADE,
    FOREIGN KEY (tag2) REFERENCES tag(tag_ID) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS Tag_Implication (
    root_tag INTEGER,
    implicate INTEGER,
    PRIMARY KEY (root_tag, implicate),
    FOREIGN KEY (root_tag) REFERENCES tag(tag_ID) ON DELETE CASCADE,
    FOREIGN KEY (implicate) REFERENCES tag(tag_ID) ON DELETE CASCADE
);

-- Granting appropriate permissions for the user artnet_editor (editing, deleting, reading, inserting)
GRANT CONNECT ON
    DATABASE artnet
    TO artnet_editor;
GRANT SELECT, INSERT, UPDATE, DELETE ON
    TABLE art, art_to_presence, tag_category, art_to_tag, artist_to_topic, artist, presence, tag, tag_alias, tag_implication, topic, art_collection, art_to_art_collection
    TO artnet_editor;

GRANT USAGE ON
    SEQUENCE art_id_seq, artist_id_seq, tag_tag_id_seq
    TO artnet_editor;