#!/bin/bash
# Helper to change the numerical prefixes across the repo, say if you want to
# create room between 023 and 024, and so on.
#
# Assumes there's only ever one file with any numeric prefix. If you move
# 003trace.test.cc you might need to do some manual patch-up.

set -e

if [[ $# -eq 0 && `git diff HEAD |wc -l` -gt 0 ]]
then
  echo "Uncommitted changes"
  exit
fi

if [[ $# -gt 0 ]] # dry run
then
  git() {
    echo $*
  }
fi

#

index=0
ls [0-9]* |grep -v "trace.test" |sort -n |
  while read file
  do
    while [[ $file != `printf "%03d" $index`* ]]
    do
      echo
      index=$(($index+1))
    done
    echo $file
    index=$(($index+1))
  done > .layout

vim -c "set nu" .layout

#

root() {
  echo $1 |sed 's/^[0-9]*//'
}

index=0
cat .layout |
  while read file
  do
    if [ ! -z $file ]
    then
      newfile=`printf "%03d" $index``root $file`
      if [[ $newfile != $file ]]
      then
        echo git mv $file $newfile
        git mv $file $newfile
      fi
    fi
    index=$(($index+1))
  done

rm .layout

# Scenarios considered:
#   Don't redo the layout if Vim exits with error.