-- 0004_media.sql
CREATE TABLE IF NOT EXISTS media (
    id           BIGSERIAL PRIMARY KEY,
    uploader_id  BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    filename     TEXT NOT NULL,
    content_type TEXT NOT NULL,
    size         BIGINT NOT NULL,
    storage_key  TEXT NOT NULL UNIQUE,
    thumb_key    TEXT,
    created_at   TIMESTAMPTZ NOT NULL DEFAULT now()
);
CREATE INDEX IF NOT EXISTS idx_media_uploader ON media(uploader_id);

ALTER TABLE messages ADD COLUMN IF NOT EXISTS media_id BIGINT REFERENCES media(id) ON DELETE SET NULL;