#!/usr/bin/env lua

--[[
Copyright (c) 2017 Vadim "mva" Misbakh-Soloviov
This file is distributed under terms of MIT license (just as most Lua Programs).
--]]

local expert
local libexec="/usr/libexec/srlua"

if os.getenv("IKNOWWHATIAMDOING") then
	expert=true
end

local function p(...)
	io.stderr:write(...)
	io.stderr:write("\n")
end

local function getabis(abi)
	local ret={}
	local abistr
	local abi=abi or "*" -- luacheck: ignore
	local arch

	if abi=="default" then
		arch=io.popen("uname -m"):read()
		if jit then
			--and jit.version then
			--local jit_v=jit.version:match("LuaJIT (%d.%d)")
			--abi="luajit"..(jit_v and "-"..jit_v.."*" or "")..(arch and "."..arch or "")
			abi="luajit"..(arch and "."..arch or "")
		else
			abi="lua"..(_VERSION:match("Lua (%S+)$") or "")..(arch or "")
		end
	end

	abistr=(io.popen(("echo %s/%s/srlua*"):format(libexec,abi)):read() or "")

	if abistr:match("%*") then abistr="" end -- failed matching -> nothing found

	if #abistr>8 then
		for abi in abistr:gmatch(libexec.."/(%S*)/srlua") do -- luacheck: ignore
			table.insert(ret,abi)
		end
	end

	return ret
end

local function help(err,msg)
	if err then
		p("Invalid command syntax"..((msg and (#msg>0)) and (": "..msg) or "!").."\n")
		p""
	end
	p"Description:"
	p"This is a wrapper on original `srglue` program from `srlua` package"
	p"The only difference is that you should pass 'ABI' string instead of path to `srlua`"
	p""
	p"Usage:"
	p("\t"..arg[0].." [<ABI>] <prorgam.lua> [<out_program_name>]")
	p""
	p"\tWhere <ABI> is <lua_interpreter>.<multilib_abi>."
	p"\tIf you see 'default' value in the list below, then <ABI> can be an optional argument. Otherwise it is mandatory."
	p"\tAlso, if you see '<none>' value, it means this installation is broken and this program will not work at all."
	p""
	p"List of ABIs supported on tis system:"
	local abilist=getabis()
	if #abilist>0 then
		for _,abi in ipairs(abilist) do
			p("\t"..abi)
		end
		local defabi=getabis("default")
		if #defabi==1 then
			p("\tdefault (will be expanded to '"..defabi[1].."')")
		end
	else
		p"\t<none>"
	end
	os.exit(err and 1 or 0)
end

local function argparse(argv)
	local srlua=argv[1]
	local script=argv[2]
	local out=argv[3] or "a.out"

	if srlua:match(".*%.lua") and (not expert) then
		out=script or out
		script=srlua
		srlua="default"
	end

	local abi=getabis(srlua)
	if #abi==0 then
		help(true,"There is no such ABI that you specified.")
	elseif #abi>1 then
		help(true,("Multiple ABIs (%d) matched your ABI selection. Please, be more specific."):format(#abi))
		--local interpreter, multilib = k:match("(%S*)%.(%w-)$")
	else
		abi=abi[1]
	end

	if not script:match(".*%.lua") and not expert then
		help(true,
			"Invalid Lua Program name. Only '*.lua' files are allowed (to prevent unexpected results)."
			.."\n"
			.."If you're sure you want to continue anyway, set IKNOWWHATIAMDOING environment variable."
		)
	end

	local chmod, chmod_mod
	chmod="chmod" -- TODO: setfacl support
	chmod_mod="755"

	local abidir=libexec.."/"..abi

	os.exit(os.execute(("%s/glue %s/srlua %s %s && %s %s %s"):format(abidir,abidir,script,out,chmod,chmod_mod,out)))
end

if #arg>3 or #arg==0 then
	-- TODO: maybe add support to squish
	help(#arg~=0,
		"wrong paramaters count (maximum: 3)"
		.."\n"
		.."If you need to glue more then one Lua Program, then squish them in single file first."
	)
else
	argparse(arg)
end