-- 002: Wallets table (user-service)
CREATE TABLE IF NOT EXISTS wallets (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    user_id UUID NOT NULL UNIQUE REFERENCES users(id) ON DELETE CASCADE,
    balance NUMERIC(15,2) NOT NULL DEFAULT 0 CHECK (balance >= 0),
    frozen NUMERIC(15,2) NOT NULL DEFAULT 0 CHECK (frozen >= 0),
    currency VARCHAR(10) NOT NULL DEFAULT 'USD',
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    CONSTRAINT chk_frozen_le_balance CHECK (frozen <= balance)
);

CREATE INDEX idx_wallets_user_id ON wallets(user_id);