-- Accounts, so a person can sign up, be approved, and then issue their own keys
-- without an operator running a command for each one.
CREATE TABLE users (
  id            TEXT PRIMARY KEY,
  -- Lowercased at the boundary. Two accounts differing only in case would be
  -- two accounts to the database and one to every human who looks at them.
  email         TEXT NOT NULL UNIQUE,
  name          TEXT NOT NULL,
  -- argon2id, encoded with its own parameters so the cost can be raised later
  -- without invalidating existing hashes. Slow hashing is right here and wrong
  -- for API keys: this input is chosen by a human and has a dictionary.
  password_hash TEXT NOT NULL,
  -- 'pending' until an operator approves, then 'active'. 'suspended' keeps the
  -- account and stops it working.
  state         TEXT NOT NULL,
  -- Assigned at approval: which project this person's keys belong to, and
  -- therefore which limits they inherit.
  project_id    TEXT REFERENCES projects(id),
  created_at    INTEGER NOT NULL,
  approved_at   INTEGER,
  approved_by   TEXT,
  last_login_at INTEGER
);
CREATE INDEX users_by_state ON users(state);

-- Server-side sessions rather than signed cookies, so signing out and
-- suspending an account take effect immediately instead of whenever a token
-- happens to expire.
CREATE TABLE sessions (
  token_hash BLOB PRIMARY KEY,
  user_id    TEXT NOT NULL REFERENCES users(id),
  -- Per session, submitted with every form. A cookie alone authenticates the
  -- browser, not the page that asked, which is what makes a cross-site POST
  -- work.
  csrf_hash  BLOB NOT NULL,
  created_at INTEGER NOT NULL,
  expires_at INTEGER NOT NULL,
  last_seen  INTEGER NOT NULL
);
CREATE INDEX sessions_by_user ON sessions(user_id);
CREATE INDEX sessions_by_expiry ON sessions(expires_at);

-- A key issued through the profile page belongs to the person who made it, so
-- they can see and revoke their own and nobody else's. NULL means a key an
-- operator issued directly.
ALTER TABLE api_keys ADD COLUMN user_id TEXT REFERENCES users(id);
CREATE INDEX api_keys_by_user ON api_keys(user_id);