/*
 Mentorenwahl: A fullstack application for assigning mentors to students based on their whishes.
 Copyright (C) 2022  Dominic Grimm
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
 
 This program 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 General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
-- +micrate Up
-- SQL in section ' Up ' is executed when this migration is applied
CREATE TYPE user_roles AS ENUM ('student', 'teacher');

CREATE TABLE users(
  id serial PRIMARY KEY,
  username text UNIQUE NOT NULL,
  password_hash text NOT NULL,
  first_name text NOT NULL,
  last_name text NOT NULL,
  role user_roles NOT NULL,
  admin boolean NOT NULL
);

CREATE TABLE tokens(
  id uuid PRIMARY KEY,
  iat timestamp NOT NULL,
  exp timestamp NOT NULL,
  active boolean NOT NULL,
  user_id int NOT NULL REFERENCES users(id)
);

CREATE TABLE teachers(
  id serial PRIMARY KEY,
  user_id int NOT NULL UNIQUE REFERENCES users(id),
  max_students int NOT NULL
);

CREATE TABLE classes(id serial PRIMARY KEY, name text UNIQUE NOT NULL);

CREATE TABLE students(
  id serial PRIMARY KEY,
  user_id int NOT NULL UNIQUE REFERENCES users(id),
  class_id int NOT NULL REFERENCES classes(id)
);

CREATE TABLE votes(
  id serial PRIMARY KEY,
  student_id int NOT NULL UNIQUE REFERENCES students(id)
);

CREATE TABLE teacher_votes(
  id serial PRIMARY KEY,
  vote_id int NOT NULL REFERENCES votes(id),
  teacher_id int NOT NULL REFERENCES teachers(id),
  priority int NOT NULL,
  UNIQUE (vote_id, teacher_id, priority)
);

CREATE TABLE assignments(
  id serial PRIMARY KEY,
  student_id int NOT NULL REFERENCES students(id) UNIQUE,
  teacher_id int NOT NULL REFERENCES teachers(id)
);

-- +micrate Down
-- SQL section ' Down ' is executed when this migration is rolled back
DROP TABLE assignments;

DROP TABLE teacher_votes;

DROP TABLE votes;

DROP TABLE admins;

DROP TABLE teachers;

DROP TABLE students;

DROP TABLE classes;

DROP TABLE tokens;

DROP TABLE users;

DROP TYPE user_roles;