CREATE TABLE users (
  username TEXT PRIMARY KEY,
  password TEXT NOT NULL
);

CREATE TABLE plans (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  name TEXT NOT NULL,
  owner TEXT REFERENCES users(username) NOT NULL,
  description TEXT DEFAULT '',
  join_code TEXT NOT NULL
);

CREATE TABLE members (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  plan_id INTEGER REFERENCES plans(id) NOT NULL,
  name TEXT NOT NULL,
  user_id TEXT REFERENCES users(username)
);

CREATE TABLE polls (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  plan_id INTEGER REFERENCES plans(id) NOT NULL,
  options TEXT DEFAULT ''
);

CREATE TABLE votes (
  poll_id INTEGER REFERENCES polls(id),
  member_id INTEGER REFERENCES members(id),
  value text,
  PRIMARY KEY (poll_id,member_id)
);

CREATE TABLE expenses (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  plan_id INTEGER REFERENCES plans(id) NOT NULL,
  payer_id INTEGER REFERENCES members(id) NOT NULL,
  amount DECIMAL NOT NULL
);

CREATE TABLE debts (
  expense_id INTEGER REFERENCES expenses(id) NOT NULL,
  debtor_id INTEGER REFERENCES members(id) NOT NULL,
  amount DECIMAL NOT NULL,
  paid DECIMAL,
  PRIMARY KEY (expense_id,debtor_id)
);