A judge is considering whether doctors should continue treating a retired steelworker aged is his 80s who has been left in a minimally conscious state after a heart attack.
Medical experts say the pensioner suffered "catastrophic" brain damage after collapsing in a street in June last year and has a life expectancy measured in months.
Doctors say he is showing no signs of awareness. They think he is experiencing no pleasure and fear that treatment is causing him pain.
But his daughter says he is improving, would want to carry on living and treatment is not overly burdensome. She says her father is a Christian and says ''sanctity of life'' is important to him. She says God, not doctors, should decide when he dies.
Mr Justice Hayden has analysed evidence over several days at a hearing in the specialist Court of Protection, where judges consider issues relating to people who lack the mental capacity to make decisions, in London.
He heard closing legal arguments from lawyers representing everyone involved late on Friday and said he would publish a ruling soon.
The judge says the pensioner cannot be identified.
He has heard that the man used to work in the steel industry and was a keen Swansea City supporter.
Bosses at Abertawe Bro Morgannwg University Health Board, which is based in Port Talbot and has responsibility for the man's care, have asked the judge to make decisions about treatment.
Mr Justice Hayden was last year asked by health board bosses to rule that life-support treatment should stop. Members of the man's family asked for videos to be taken and suggested that footage revealed hopeful signs. The judge agreed to more assessments being carried out.
In late 2015, Mr Justice Hayden made a ruling, which experts said was a landmark, when he decided that medics could stop providing nutrition to a woman in a minimally conscious state. Lawyers said it was the first time a judge had decided that life-sustaining treatment could be withdrawn from someone in a minimally conscious state.