Watching past games on the league of legends website?

What if you could watch your friend's past games with their permission? As of right now the only way you could watch one of their past games is to log into their account which is not allowed. Also what if you could watch past games on the league of legends website instead of having to log into the client. You could save a match you really liked from the client to your account on the website. And perhaps with permission you could watch the past matches of other players.