#!/bin/sh

#This script changes the header of .ml* files

if [ ! $# = 2 ]; then
  echo Usage: change-header old-header-file new-header-file
  exit 1
fi

oldheader=$1
newheader=$2

if [ ! -f $oldheader ]; then echo Cannot read file $oldheader; exit 1; fi
if [ ! -f $newheader ]; then echo Cannot read file $newheader; exit 1; fi

n=`wc -l $oldheader | sed -e "s/ *\([0-9]*\).*/\1/g"`
nsucc=`expr $n + 1`

linea='(* -*- coding:utf-8 -*- *)'
lineb='(* -*- compile-command: "make -C ../.. bin/coqdoc" -*- *)'

modified=0
kept=0

for i in `find . -name \*.mli -o -name \*.ml -o -name \*.ml4 -o -name \*.mll -o -name \*.mly -o -name \*.mlp -o -name \*.v`; do
  headline=`head -n 1 $i`
  if `echo $headline | grep "(\* -\*- .* \*)" > /dev/null`; then
      # Has emacs header
      head -n +$nsucc $i | tail -n $n > $i.head.tmp$$
      hasheadline=1
      nnext=`expr $nsucc + 1`
  else
      head -n +$n $i > $i.head.tmp$$
      hasheadline=0
      nnext=$nsucc
  fi
  if diff -a -q $oldheader $i.head.tmp$$ > /dev/null; then
    echo "$i: header changed"
    if [ $hasheadline = 1 ]; then
        echo $headline > $i.tmp$$
    else
        touch $i.tmp$$
    fi
    cat $newheader >> $i.tmp$$
    tail -n +$nnext $i >> $i.tmp$$
    mv $i.tmp$$ $i
    modified=`expr $modified + 1`
  else
    kept=`expr $kept + 1`
  fi
  rm $i.head.tmp$$
done

echo $modified files updated 
echo $kept files unchanged