term.lt

-- determine forward or back slash
var slash = package.config.sub(@, 1, 1)

-- ansi colors
var color = {
	reset     = "\27[0m"
	, red     = "\27[91;1m"
	, green   = "\27[92;1m"
	, yellow  = "\27[93;1m"
	, blue    = "\27[94;1m"
	, magenta = "\27[95;1m"
	, cyan    = "\27[96;1m"
	, white   = "\27[97;1m"
}


-- we dont want ending newline in print()
-- but io.write() doesn't implicitly call tostring()
var write = \... ->
	var n = select("#", ...)
	for i = 1, n, 1
		io.stdout.write(@, tostring(select(i, ...)))
		-- separate each item with tab
		--if i ~= n
		--	io.stdout.write(@, "\t")


-- show usage and exit
var usage = \... ->
	write(...)
	os.exit(1)


-- parses command line
-- yields switch and its matching parameter if any
var scan = \args ->
	-- const
	var yield = coroutine.yield
	var null = ""

	return coroutine.wrap(->
		var switch = null
		var k = 1
		while args[k]
			var a = args[k]
			if "-" == string.sub(a, 1, 1)
				-- previous loop had a switch
				if switch ~= null
					yield(switch)
				switch = string.sub(a, 2)
			else
				yield(switch, a)
				switch = null
			k = k + 1

		if switch ~= null
			yield(switch)

	)


var localize = \path ->
	if slash == '\\'
		return string.gsub(path, '/', slash)
	return string.gsub(path, '\\', slash)


--``
https://github.com/keplerproject/lua-compat-5.3/wiki/os.execute

os.execute in Lua 5.2 and 5.3 returns three values: a boolean indicating sucessful/unsuccessful execution, a string ("exit" or "signal"), and the actual exit status or signal number.
But in 5.1 only 1 one value returned
--``
var exec = \cmd ->
	--write(cmd)
	var ok, exit_or_signal, code = os.execute(cmd)
	if code
		return code
	-- Lua 5.1, ok is code
	return ok


var mkdir = \path ->
	var cmd
	if slash == '\\'
		cmd = "md " .. path
	else
		cmd = "mkdir -p " .. path
	var code = exec(cmd)
	-- success is always 0, see man page for command
	if code == 0
		return true
	return false, cmd .. " failed, exit code: " .. tostring(code)


-- pushd and popd exists on linux, unix and DOS
var exist_dir = \path ->
	var p = string.gsub(path, "/*$", "")
	-- if Path Not Found, dont show on stderr
	var code = exec("pushd " .. p .. " 2> nul")
	if code == 0
		exec("popd")
	return code == 0


var list_files = \path ->
	var cmd
	if slash == '\\'
		cmd = 'dir /b/a:-D "' .. path .. '"'
	else
		cmd = '/bin/ls -p "' .. path .. '" | grep -v /'
	return io.popen(cmd)



-- Window to support ANSI color, may not work on all Windows version
if slash == '\\'
	var bit = require("bit")
	var ffi = require("ffi")
	var kernel32 = ffi.load("kernel32")

	ffi.cdef(``
		typedef long BOOL;
		typedef void* HANDLE;
		typedef uint32_t DWORD;
		typedef DWORD* LPDWORD;
		static const int STD_OUTPUT_HANDLE                  = ((DWORD)-11);
		static const int ENABLE_VIRTUAL_TERMINAL_PROCESSING = ((DWORD)4);
		HANDLE GetStdHandle(DWORD nStdHandle);
		BOOL GetConsoleMode(HANDLE hConsoleHandle, LPDWORD lpMode);
		BOOL SetConsoleMode(HANDLE hConsoleHandle, DWORD dwMode);
		DWORD GetLastError(void);
	``)

	var enable_VT = ->
		var handle = kernel32.GetStdHandle(kernel32.STD_OUTPUT_HANDLE)
		var lpMode = ffi.new("DWORD[1]")
		var res = kernel32.GetConsoleMode(handle, lpMode)
		if res ~= 0
			var mode = bit.bor(lpMode[0], kernel32.ENABLE_VIRTUAL_TERMINAL_PROCESSING)
			res = kernel32.SetConsoleMode(handle, mode)
			if res ~= 0
				return true

		return false

	if not enable_VT()
		-- write('No ANSI colors support, error ' .. kernel32.GetLastError())
		color = setmetatable({}, {__index = -> return ""})



return {
	slash = slash
	, color = color
	, write = write
	, usage = usage
	, scan = scan
	, localize = localize
	, mkdir = mkdir
	, exist_dir = exist_dir
	, list_files = list_files
}