property debug : 0 -- 1 is on, every other integer is off
property loc : "dummy" --dummy value to pass when debug is off

--first, check to make sure the plist file exists; construct the path first
set plistFile to ((path to preferences folder from user domain) as string) & "com.yahoo.groups.tech.wordperfectmac.openwpfiles.plist"
tell application "System Events"
	exists file plistFile
	if the result is false then
		if debug = 1 then
			set loc to "The plist file does not exist."
		end if
		my setDataFolder(loc) -- no plist, so figure out the UNIX folder
	else -- there's a plist, so check for the value of the UNIXFolderPath
		set anError to false -- set up a reminder to prevent us from re-entering later
		try
			set UNIXFolderPath to value of property list item "UNIXFolderPath" of property list file plistFile
			
		on error --if there's an error getting the value, just figure out the UNIX folder again (this is probably the first run and the value hasn't yet been set initially)
			if debug = 1 then
				set loc to "The UNIXFolderPath plist key does not exist."
			end if
			set anError to true
			--we don't want to figure out the UNIX folder path and then re-enter here, so we call setDataFolder later, inside another if-statement
		end try
		
		if anError is false then -- only check to see if UNIXFolderPath is a valid folder if we actually retrieved something from the plist
			exists folder UNIXFolderPath
			if the result is false then
				if debug = 1 then
					set loc to "The UNIXFolderPath is not a valid folder."
				end if
				my setDataFolder(loc) -- The supposed UNIX folder doesn't exist
			else
				-- we have a live UNIX folder; let's open files
				if debug = 1 then
					display dialog "Success! There's a valid UNIX folder ready for use. Let's go sheep-shaving!"
				end if
			end if
		else -- (anError = true) we didn't retrieve a value for UNIXFolderPath from the plist
			my setDataFolder(loc)
		end if
		
	end if
end tell

on setDataFolder(loc)
	if debug = 1 then
		display dialog loc & " We need a UNIX folder before we can go sheep-shaving!"
	end if
	-- do all the stuff to determine the UNIX folder from the .sheepshaver_prefs file
	-- and store the path as, e.g., myNewUNIXFolderPath
	
	-- finally, write the UNIX folder to the prefs so we'll have it from here on out
	do shell script "defaults write com.yahoo.groups.tech.wordperfectmac.openwpfiles UNIXFolderPath -string " & myNewUNIXFolderPath
end setDataFolder