/*
 * Change the skin of a screen in env:mui/screens.txt
 * by Thomas Igracki
 *
 * The change will take effect immediatly, if you want it to be permanently (after reboot),
 * just remove the command around the last "Copy" command, then it will be copied
 * to envarc: too!
 *
 * Usage: rx ChangeSkin.rexx <screen name, f.e. Ambient> <new skin>
 *
 * Example: rx ChangeSkin.rexx Ambient Nox
 *
 * 31-Jan-2019: v1.0 
 */
 
OPTIONS RESULTS

PARSE ARG Screen" "newSkin

IF Screen = "" | newSkin = "" THEN
	Say "Usage: rx ChangeSkin.rexx <screen name, f.e. Ambient> <new skin>"
ELSE; DO
	IF ~EXISTS("MOSSYS:Prefs/Skins/"newSkin) & ~EXISTS("SYS:Prefs/Skins/"newSkin) THEN
		Say "The skin '"newSkin"' didn't exists!"
	ELSE; DO
		IF Open(fhIn, "env:mui/screens.txt", "R") THEN; DO
			IF Open(fhOut, "t:new_screens.txt", "W") THEN; DO
				found = 0
				DO UNTIL EOF(fhIn)
					line = ReadLn(fhIn);
					PARSE VAR line "N="scr" "dummy" S="skin" "dummy2
					IF scr = Screen THEN; DO
						found = 1
						line = "N="scr" "dummy" S="newSkin" "dummy2
						oldSkin = skin
					END
					WriteLn(fhOut, line)
				END
				Close(fhIn)
				Close(fhOut)
				IF found=0 THEN
					Say "Didn't found the screen '"Screen"'!"
				ELSE; DO
					Say "Found the screen '"Screen"'!"
					Say "Changed the skin from '"oldSkin"' to '"newSkin"'."
					SHELL COMMAND "Copy t:new_screens.txt env:mui/screens.txt"
					SHELL COMMAND "Delete >NIL t:new_screens.txt"
					/* remove these comment if you want to save the new screens!
					SHELL COMMAND "Copy env:mui/screens.txt envarc:mui/screens.txt"
					*/
				END
			END
		END
	END
END	

--[[

A script to change MorphOS skin prefs. Use at your own risk.

Usage: LuaX changeskin.lua <location> <screen> <skin>

- The "location" argument can be ENV, ENVARC, or BOTH. It defines where
  the "screens.txt" file is modified.
- If the "skin" argument is omitted, the default skin is used.
- The "make_backup" setting creates a "screens.txt.bak" file
  to the corresponding location.
- The "screen" argument is case sensitive!

Examples:
 LuaX changeskin.lua ENV Ambient Ater
 LuaX changeskin.lua BOTH Ambient Default

]]

require 'io'
require 'os'
require 'string'


-- CONFIG BEGINS (Use true or false values)

make_backup = true

-- CONFIG ENDS


function change_skin(loc)
	if make_backup then os.execute('Copy ' .. loc .. ':MUI/screens.txt ' .. loc .. ':MUI/screens.txt.bak CLONE') end
	local file = io.open(loc .. ':MUI/screens.txt','r')
	if file then
		local found
		local content = file:read('*a')
		io.close(file)
		content, found = string.gsub(content, '(N="?' .. screen .. '.-S="?)(%w+)', "%1" .. skin)
		if found > 0 then
			file = io.open(loc .. ':MUI/screens.txt','w+')
			if file then
				file:write(content)
				io.close(file)
			else
				io.write('Failed to write the file in ' .. loc .. '.n')
			end
		else
			io.write('Failed to change the skin.n')
		end
	else
		io.write('Failed to read the file in ' .. loc .. '.n')
	end
end


if #arg > 1 then
	location = string.upper(arg[1])
	screen = arg[2]
	if arg[3] then skin = arg[3] else skin = 'Default' end
	if location == 'BOTH' then
		change_skin('ENVARC')
		change_skin('ENV')
	elseif location == 'ENV' then
		change_skin('ENV')
	elseif location == 'ENVARC' then
		change_skin('ENVARC')
	else
		io.write('The first argument must be "ENV", "ENVARC", or "BOTH"!n')
	end
else
	io.write('At least two arguments (location and screen name) are required.n')
end