-- Notification receivers table (links a notification to a specific user)
CREATE TABLE notification_receivers (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    notification_id UUID NOT NULL REFERENCES notifications(id) ON DELETE CASCADE,
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    is_read BOOLEAN NOT NULL DEFAULT FALSE,
    read_at TIMESTAMP WITH TIME ZONE,
    is_deleted BOOLEAN NOT NULL DEFAULT FALSE,
    deleted_at TIMESTAMP WITH TIME ZONE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- Indexes
CREATE INDEX idx_notification_receivers_notification_id ON notification_receivers(notification_id);
CREATE INDEX idx_notification_receivers_user_id ON notification_receivers(user_id);
CREATE INDEX idx_notification_receivers_user_unread ON notification_receivers(user_id, is_read) WHERE is_deleted = FALSE;
CREATE UNIQUE INDEX idx_notification_receivers_unique ON notification_receivers(notification_id, user_id);