gistfile1.applescript

--Fucntions
on add_leading_zeros(this_number, max_leading_zeros)
  set the threshold_number to (10 ^ max_leading_zeros) as integer
	if this_number is less than the threshold_number then
		set the leading_zeros to ""
		set the digit_count to the length of ((this_number div 1) as string)
		set the character_count to (max_leading_zeros + 1) - digit_count
		repeat character_count times
			set the leading_zeros to (the leading_zeros & "0") as string
		end repeat
		return (leading_zeros & (this_number as text)) as string
	else
		return this_number as text
	end if
end add_leading_zeros

--Build Year String
set y to year of (current date)
set d to my add_leading_zeros(day of (current date), 1)
set m to my add_leading_zeros(month of (current date) as integer, 1)
set myDate to y & m & d as string

--Get Selected Text
tell application "Finder"
	set fileAlias to selection as alias
	set filePath to fileAlias as text
	set TID to AppleScript's text item delimiters
	set AppleScript's text item delimiters to ":"
	set fileName to last text item of filePath
	set AppleScript's text item delimiters to "."
	set fileNamePart1 to text item 1 of fileName
	set fileNamePart2 to text item 2 of fileName
	set AppleScript's text item delimiters to TID
	set mySubject to fileNamePart1 as text
	
	
	
	set legalPrefixCharacters to {"1", "2", "3", "4", "5", "6", "7", "8", "9", "0"}
	set legalSuffixCharacters to {"-U", "-P", "-PS", "-PC", "-PD", "-R", "-S", "-TS", "9", "0"}
	
	--Get the prefix eg "20130101" and the suffix eg "-U".		
	if length of mySubject > 8 then
		set thePrefix to (characters 1 thru 8) of mySubject
		
		set hasMODPrefix to true
		
		--Check that the prefix is all numbers
		repeat with thisChr from 1 to (get count of characters in thePrefix)
			set theChr to character thisChr of thePrefix
			if theChr is not in legalPrefixCharacters then
				set hasMODPrefix to false
			end if
		end repeat
	else
		set hasMODPrefix to false
	end if
	--If the prefix is there, get the rest of the message and put the new prefix date in it.
	--Otherwise use the whole message and add the new prefix date.
	if hasMODPrefix is true then
		set newSubject to (myDate & "-" & (characters 10 thru -1) of mySubject as text)
	else
		set newSubject to myDate & "-" & mySubject
	end if
	
	set theSuffix to (characters -1 thru -2) of newSubject as text
	
	--If the suffix is not there, add it
	if theSuffix is not in legalSuffixCharacters then
		set newSubject to newSubject & "-AdjCTT-U"
	end if
	
	set fileName to newSubject & "." & fileNamePart2
	--set name of fileAlias to fileName
	set properties of fileAlias to {name:fileName}
end tell