CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

CREATE TYPE "QuantityUnit" AS ENUM (
    'g',
    'dkg',
    'kg',
    'piece'
);

CREATE TABLE photos (
    id serial NOT NULL PRIMARY KEY,
    local_path character varying NOT NULL,
    file_name character varying NOT NULL,
    unique_name text DEFAULT (gen_random_uuid())::text NOT NULL
);

CREATE TABLE products (
    id serial NOT NULL PRIMARY KEY,
    "name" character varying NOT NULL,
    category character varying,
    deliver_days_flag integer DEFAULT 127 NOT NULL
);

CREATE TABLE product_variants (
    id serial NOT NULL PRIMARY KEY,
    product_id integer REFERENCES products (id) NOT NULL,
    "name" character varying NOT NULL,
    short_description character varying NOT NULL,
    long_description character varying NOT NULL,
    price integer NOT NULL,
    CONSTRAINT non_negative CHECK ((price >= 0))
);

CREATE TABLE stocks (
    id serial NOT NULL PRIMARY KEY,
    product_variant_id integer REFERENCES product_variants(id) NOT NULL,
    quantity integer DEFAULT 0 NOT NULL,
    quantity_unit "QuantityUnit" NOT NULL,
    CONSTRAINT positive_quantity CHECK ((quantity >= 0))
);

CREATE TABLE product_photos (
    id serial NOT NULL PRIMARY KEY,
    product_variant_id integer REFERENCES product_variants(id) NOT NULL,
    photo_id integer REFERENCES photos(id) NOT NULL
);