#!/usr/bin/env lua

require "alt_getopt"
require "moonscript"

local util = require "moonscript.util"
local errors = require "moonscript.errors"

-- moonloader and repl
local opts, ind = alt_getopt.get_opts(arg, "cvhd", { version = "v", help = "h" })

local help = [=[Usage: %s [options] [script [args]]

    -h          Print this message
    -d          Disable stack trace rewriting
    -v          Print version
]=]

local function print_err(...)
	local msg = table.concat({...}, "\t")
	io.stderr:write(msg .. "\n")
end

local function print_help(err)
	if err then print("Error: "..err) end
	print(help:format(arg[0]))
	os.exit()
end

if opts.h then print_help() end

if opts.v then
	local v = require "moonscript.version"
	v.print_version()
	os.exit()
end

local script_fname = arg[ind]
if not script_fname then
	print_help("repl not yet supported")
	return
end

local new_arg = {
	[-1] = arg[0],
	[0] = arg[ind],
	select(ind + 1, unpack(arg))
}

local moonscript_chunk, lua_parse_error
local passed, err = pcall(function()
	moonscript_chunk, lua_parse_error = moonscript.loadfile(script_fname, { implicitly_return_root = false })
end)

if not passed then
	print_err(err)
	os.exit(1)
end

if not moonscript_chunk then
	if lua_parse_error then
		print_err(lua_parse_error)
	else
		print_err("Can't find file: " .. script_fname)
	end
	os.exit(1)
end

getfenv(moonscript_chunk).arg = new_arg

if not opts.d then
	local err, trace

	xpcall(function() moonscript_chunk(unpack(new_arg)) end, function(_err)
		err = _err
		trace = debug.traceback("", 2)
	end)

	if err then
		local truncated = errors.truncate_traceback(util.trim(trace))
		local rewritten = errors.rewrite_traceback(truncated, err)

		if rewritten then
			print_err(rewritten)
		else
			-- faield to rewrite, show original
			print_err(table.concat({
				err,
				util.trim(trace)
			}, "\n"))
		end
	end
else
	moonscript_chunk(unpack(new_arg))
end