Ask HN: Tax implications of becoming a full time remote employee

I've been freelance consulting for the past few months and everything was pretty clear from a tax return perspective (ie. independent income/expenses - I do my own return and the company do theirs).

Now they wish to hire me full time (and I'm on board). Trouble is - the company is in Ireland and I live in Canada.

Does the company in question have to register here? Do I pay income tax in Ireland or Canada? What are the obligations for both the employer and employee?

Any help is much appreciated!