A 54-year-old woman complains of a fogged vision in her right eye, rainbow circles in her vision field, headache, and nausea. Within the last month she twice experienced a similar condition, but back then all the signs eventually disappeared and her sight was restored. Currently, all the signs have been persisting for over 2 days. Objectively, the patient has eyelid edema, congestive injection of the eyeball, corneal opacity, shallow anterior chamber of the eye, and dilated pupil that is unresponsive to the light. Her intraocular pressure is 48 mm Hg. What is the most likely diagnosis in this case?