CREATE TABLE users (
    discord_id BIGINT PRIMARY KEY,
    discord_username TEXT NOT NULL,
    discord_avatar_hash TEXT,
    is_admin BOOLEAN NOT NULL DEFAULT false,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE TABLE user_sessions (
    id TEXT PRIMARY KEY,
    user_id BIGINT NOT NULL REFERENCES users(discord_id) ON DELETE CASCADE,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    expires_at TIMESTAMPTZ NOT NULL,
    last_active_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX idx_user_sessions_user_id ON user_sessions(user_id);
CREATE INDEX idx_user_sessions_expires_at ON user_sessions(expires_at);