--[[
VT100 ANSI escape sequences.
Ported from the Lantern Build Engine, which si written in Bash.
Other versions:
 - Bash, in the Lantern Build Engine: https://gitlab.com/sbrl/lantern-build-engine/-/blob/master/lantern.sh
 - Javascript: massCode/Ansi.mjs
 - C♯: massCode/Ansi.cs

Changelog:
	6th September 2020:
		Initial release - port complete!
]]--


local ansi
if os.getenv("NO_COLOR") ~= nil then
	ansi = {
		RS		= "",
		HC		= "",
		UL		= "",
		INV		= "",
		LC		= "",
		FBLK	= "",
		FRED	= "",
		FGRN	= "",
		FYEL	= "",
		FBLE	= "",
		FMAG	= "",
		FCYN	= "",
		FWHT	= "",
		BBLK	= "",
		BRED	= "",
		BGRN	= "",
		BYEL	= "",
		BBLE	= "",
		BMAG	= "",
		BCYN	= "",
		BWHT	= "",
	}
else
	ansi = {
		RS		= "\27[0m",		-- reset
		HC		= "\27[1m",		-- hicolor
		UL		= "\27[4m",		-- underline
		INV		= "\27[7m",		-- inverse background and foreground
		LC		= "\27[2m",		-- locolor / dim
		FBLK	= "\27[30m",	-- foreground black
		FRED	= "\27[31m",	-- foreground red
		FGRN	= "\27[32m",	-- foreground green
		FYEL	= "\27[33m",	-- foreground yellow
		FBLE	= "\27[34m",	-- foreground blue
		FMAG	= "\27[35m",	-- foreground magenta
		FCYN	= "\27[36m",	-- foreground cyan
		FWHT	= "\27[37m",	-- foreground white
		BBLK	= "\27[40m",	-- background black
		BRED	= "\27[41m",	-- background red
		BGRN	= "\27[42m",	-- background green
		BYEL	= "\27[43m",	-- background yellow
		BBLE	= "\27[44m",	-- background blue
		BMAG	= "\27[45m",	-- background magenta
		BCYN	= "\27[46m",	-- background cyan
		BWHT	= "\27[47m",	-- background white
		
		
		-- Invalid escape sequence, apparently - we'll need to look into how to do it properly
		-- Perhaps knowing the hex code for the character we want would be helpful
		-- URL_START			= '\e]8;;',
		-- URL_DISPLAY_TEXT	= '\e\\',
		-- URL_END				= '\e]8;;\e\\'
	}
end

function ansi.wrap(str, start)
	return start..str..ansi.RS
end
function ansi.hicol(str) return ansi.wrap(str, ansi.HC) end
function ansi.locol(str) return ansi.wrap(str, ansi.LC) end
function ansi.uline(str) return ansi.wrap(str, ansi.UL) end
function ansi.invert(str) return ansi.wrap(str, ansi.INV) end
function ansi.fblack(str) return ansi.wrap(str, ansi.FBLK) end
function ansi.fred(str) return ansi.wrap(str, ansi.FRED) end
function ansi.fgreen(str) return ansi.wrap(str, ansi.FGRN) end
function ansi.fyellow(str) return ansi.wrap(str, ansi.FYEL) end
function ansi.fblue(str) return ansi.wrap(str, ansi.FBLE) end
function ansi.fmagenta(str) return ansi.wrap(str, ansi.FMAG) end
function ansi.fcyan(str) return ansi.wrap(str, ansi.FCYN) end
function ansi.fwhite(str) return ansi.wrap(str, ansi.FWHT) end
function ansi.bblack(str) return ansi.wrap(str, ansi.FBLK) end
function ansi.bred(str) return ansi.wrap(str, ansi.BRED) end
function ansi.bgreen(str) return ansi.wrap(str, ansi.BGRN) end
function ansi.byellow(str) return ansi.wrap(str, ansi.BYEL) end
function ansi.bblue(str) return ansi.wrap(str, ansi.BBLE) end
function ansi.bmagenta(str) return ansi.wrap(str, ansi.BMAG) end
function ansi.bcyan(str) return ansi.wrap(str, ansi.BCYN) end
function ansi.bwhite(str) return ansi.wrap(str, ansi.BWHT) end

return ansi