-- Track when the last WebSocket session ended (last tab closed).
ALTER TABLE heroes ADD COLUMN IF NOT EXISTS ws_disconnected_at TIMESTAMPTZ NULL;

-- Accumulated offline session stats (after grace period); cleared when player opens init.
CREATE TABLE IF NOT EXISTS hero_offline_digest (
    hero_id BIGINT PRIMARY KEY REFERENCES heroes(id) ON DELETE CASCADE,
    monsters_killed INT NOT NULL DEFAULT 0,
    xp_gained BIGINT NOT NULL DEFAULT 0,
    gold_gained BIGINT NOT NULL DEFAULT 0,
    levels_gained INT NOT NULL DEFAULT 0,
    deaths INT NOT NULL DEFAULT 0,
    revives INT NOT NULL DEFAULT 0,
    loot JSONB NOT NULL DEFAULT '[]'::jsonb,
    updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX IF NOT EXISTS idx_hero_offline_digest_updated ON hero_offline_digest (updated_at);