CREATE TABLE IF NOT EXISTS post_reactions (
    user_id UUID NOT NULL REFERENCES profiles(id) ON DELETE CASCADE,
    post_id UUID NOT NULL REFERENCES posts(id) ON DELETE CASCADE,
    emoji TEXT NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    PRIMARY KEY (user_id, post_id, emoji)
);

CREATE INDEX IF NOT EXISTS idx_post_reactions_post_id ON post_reactions(post_id);