#!/bin/bash

# Copyright (c) 2011 Patrick Joseph Donnelly
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

DIRECTORY=$(dirname "$0") # directory of executable

ARGUMENTS='--options i,h --long in-place,help --name lua-format'
IN_PLACE=0

NEW_ARGUMENTS=$(getopt $ARGUMENTS -- "$@")

function usage {
  echo "$0 [--in-place] file1 [file2 [...]]"
}

if [ $? -ne 0 ]; then
  usage
  exit 1
fi

eval set -- "$NEW_ARGUMENTS"

while [ $# -ge 0 ]; do
  case "$1" in
    -i|--in-place)
      IN_PLACE=1
      shift
      ;;
    -h|--help)
      usage
      exit
      ;;
    --)
      shift
      break
      ;;
  esac
done

set -e

# batrick@batbytes:~$ luac -l -p -
# foo = function () end
#
# main <stdin:0,0> (3 instructions, 12 bytes at 0x172c230)
# 0+ params, 2 slots, 0 upvalues, 0 locals, 1 constant, 1 function
#         1       [1]     CLOSURE         0 0     ; 0x172c410
#         2       [1]     SETGLOBAL       0 -1    ; foo
#         3       [1]     RETURN          0 1
#
# function <stdin:1,1> (1 instruction, 4 bytes at 0x172c410)
# 0 params, 2 slots, 0 upvalues, 0 locals, 0 constants, 0 functions
#        1       [1]     RETURN          0 1
#
# We filter out everything but the opcodes and the lines specifying the
# function statistics (# of parameters, upvalues, etc.). We also remove CLOSURE
# opcodes because they include a runtime pointer address which changes across
# luac invocations.

function filter {
  grep --invert-match -E "^function|main" | grep --invert-match "^[[:space:]]*$" | grep --invert-match CLOSURE | cut -f 2,4-
}

for file do
  out="${file}.out"
  echo Formatting "$file" >&2
  lua "$DIRECTORY/lua-format.lua" < "$file" > "$out"
  diff -Naur <(luac -l -p "$file" | filter) <(luac -l -p "$out" | filter) >&2
  if [ $IN_PLACE -eq 1 ]; then
    mv -f "$out" "$file"
  fi
done