Split one file into 2 and renaming the file name

For example of one file:

348657856**56985897568976
N1*PR*Jasmine sdgugu
gughyug
35647856834756
REF*2U*7248
gfhgfdugs
ghdugyuigy4576
4867586
N1*PR*John ~
eghufgguigr
4975876346
REF*2U*SMIL
tfgugrt47587
CAS495787656
5687564

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I want to spilt N1*PR*Jasmine to be:

348657856**56985897568976
N1*PR*Jasmine sdgugu
gughyug
35647856834756
REF*2U*7248
gfhgfdugs
ghdugyuigy4576
4867586
CAS495787656
5687564

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And
N1*PR*John ~:

348657856**56985897568976
N1*PR*John ~
eghufgguigr
4975876346
REF*2U*SMIL
tfgugrt47587
CAS495787656
5687564

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However, some files just contain one name, I want them to just leave those files alone?

And for each file that had two, I want the filename like for example if the filename was for the one above :

98475789456.5010.4676897.edi
after splitting them, I want it to show as

98475789456.5010.4676897.edi
98475789456.5010.4676897_copy.edi

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$files = './';
$dh  = opendir($files);



$i = 5010;
while(! feof($files)) {
	$contents = stream_get_line($dh,1000,"REF*2U*");
	file_put_contents('new_file.'.$i. $contents);
	
}

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I have the code above, but it doesn't seem to work with me.