更新现有文件中的一些json项

i'm trying to do a simple script to manipulate some json, so i decode the json file , create a foreach to make some ifs looking for information with live games, live.json file:

{
Match: [
{
Id: "348324",
Date: "2015-07-19T21:30:00+00:00",
League: "Brasileirao",
Round: "14",
HomeTeam: "Joinville",
HomeTeam_Id: "1208",
HomeGoals: "1",
AwayTeam: "Ponte Preta",
AwayTeam_Id: "745",
AwayGoals: "1",
Time: "67",
Location: "Arena Joinville",
HomeTeamYellowCardDetails: { },
AwayTeamYellowCardDetails: { },
HomeTeamRedCardDetails: { },
AwayTeamRedCardDetails: { }
},
{
Id: "348319",
Date: "2015-07-19T21:30:00+00:00",
League: "Brasileirao",
Round: "14",
HomeTeam: "Cruzeiro",
HomeTeam_Id: "749",
HomeGoals: "1",
AwayTeam: "Avai FC",
AwayTeam_Id: "1203",
AwayGoals: "1",
Time: "Finished",
Location: "Mineirão",
HomeTeamYellowCardDetails: { },
AwayTeamYellowCardDetails: { },
HomeTeamRedCardDetails: { },
AwayTeamRedCardDetails: { }
}

Check the comments in the code i specify what i want in each part.

      <?php

    $json_url = "http://domain.com/live.json"; // the file comes with live games 
        $json = file_get_contents($json_url);
        $links = json_decode($json, TRUE);

    foreach($links["Match"] as $key=>$val) {
        if($val['Id'] == "live games id") // i want to live.json games ids match with the games with the same id in file.json


            // i only want to update the items below, and 
            {
            $links["Match"][$key]['Time'] = ['Time']; // in the end i just want to get the item Time to update file.json in item time for the game with the same id
            $links["Match"][$key]['HomeGoals'] = ['HomeGoals']; // similar to what i want with Time
            $links["Match"][$key]['AwayGoals'] = ['AwayGoals'];
            }
    }



$fp = fopen( "file.json","w+"); // this file have the list of all games including the ones that came from live.json, the structure are exactly the same.
    fwrite($fp,json_encode($links));
    fclose($fp);


?>

The content of new file.json

{
Match: [
{
Id: "348324",
Date: "2015-07-19T21:30:00+00:00",
League: "Brasileirao",
Round: "14",
HomeTeam: "Joinville",
HomeTeam_Id: "1208",
HomeGoals: "1",
AwayTeam: "Ponte Preta",
AwayTeam_Id: "745",
AwayGoals: "1",
Time: "69",
Location: "Arena Joinville",
HomeTeamYellowCardDetails: { },
AwayTeamYellowCardDetails: { },
HomeTeamRedCardDetails: { },
AwayTeamRedCardDetails: { }
},
{
Id: "348319",
Date: "2015-07-19T21:30:00+00:00",
League: "Brasileirao",
Round: "14",
HomeTeam: "Cruzeiro",
HomeTeam_Id: "749",
HomeGoals: "1",
AwayTeam: "Avai FC",
AwayTeam_Id: "1203",
AwayGoals: "1",
Time: "Finished",
Location: "Mineirão",
HomeTeamYellowCardDetails: { },
AwayTeamYellowCardDetails: { },
HomeTeamRedCardDetails: { },
AwayTeamRedCardDetails: { }
}

Somebody can help ? What is the best approach to do this ?