CREATE TABLE links (
    id SERIAL PRIMARY KEY,
    original_url TEXT NOT NULL,
    short_code VARCHAR(8) NOT NULL UNIQUE,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    clicks BIGINT NOT NULL DEFAULT 0
);

CREATE INDEX idx_short_code ON links(short_code);

CREATE TABLE clicks (
    id SERIAL PRIMARY KEY,
    link_id INTEGER REFERENCES links(id),
    source TEXT,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX idx_link_id ON clicks(link_id);