-- Admin users table
CREATE TABLE admin_users (
    id SERIAL PRIMARY KEY,
    username VARCHAR(255) UNIQUE NOT NULL,
    password_hash VARCHAR(255) NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Sessions table (ULID stored as text)
CREATE TABLE sessions (
    id TEXT PRIMARY KEY,
    user_id INTEGER NOT NULL REFERENCES admin_users(id) ON DELETE CASCADE,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    expires_at TIMESTAMPTZ NOT NULL,
    last_active_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Indexes for efficient queries
CREATE INDEX idx_sessions_expires_at ON sessions(expires_at);
CREATE INDEX idx_sessions_user_id ON sessions(user_id);