1998 Hyundai Accent idles rough and no power

Engine Mechanical problem
1998 Hyundai Accent 4 cyl Front Wheel Drive Automatic

The problem I have with the car is at the beginning it would run fine and after awhile it would bog out no power, I would shut the key off for a second and turn back on would would great for a little whil longer. Took it for a 2 hour drive and now it is running rough all the tiime like a dead plug or something and engine light flashs now do you have any ideas befor I spend alot of money on this
Thanks