As far as long period stay is concerned I opine that you should clearly communicate them as far as you are satisfied with the work environment, your pay package etc., you will continue but at the same time you should assure a minimum period like 1 / 2 yrs and to be strict to that.
Thanks and regards
Have those reasons been addressed?
What is the offer you have got from same company now?
Any reason to call you back?
AS per you record was good but you left, then at that stage why company did not hold you back or try to change your mind?
How much time has passed since you left/
How are things with your current employer-career wise, learning wise.
Take a holistic view in long term
Planning to leave after one year or so does not make sense