-- Store learner audio answer submissions for AUDIO-type questions
CREATE TABLE IF NOT EXISTS user_audio_responses (
    id BIGSERIAL PRIMARY KEY,
    user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    question_id BIGINT NOT NULL REFERENCES questions(id) ON DELETE CASCADE,
    question_set_id BIGINT NOT NULL REFERENCES question_sets(id) ON DELETE CASCADE,
    audio_object_key TEXT NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP
);

CREATE INDEX IF NOT EXISTS idx_user_audio_responses_user_question
    ON user_audio_responses(user_id, question_id, question_set_id);