CREATE TABLE IF NOT EXISTS user_blocks (
    blocker_user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    blocked_user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (blocker_user_id, blocked_user_id),
    CONSTRAINT user_blocks_no_self_block CHECK (blocker_user_id <> blocked_user_id)
);

CREATE INDEX IF NOT EXISTS idx_user_blocks_blocker_created
    ON user_blocks(blocker_user_id, created_at DESC, blocked_user_id DESC);

CREATE INDEX IF NOT EXISTS idx_user_blocks_blocked
    ON user_blocks(blocked_user_id, blocker_user_id);