Green patina and maybe corrosion hidden in Afghanistan coin

Hi guys, good night and hope you are well. I want ask you what do you think about this coin, with a green dark patina. I don’t know if the coin has corrosion hidden and lack of details, however the green patina looks good for me but I don’t know if this can damage the coin. I’m not sure because I’m not used to threat with more than 1000 years old coins (in the case if is original). Waiting for your opinions. Thank you and have a good rest of the day.