#! /bin/bash

help() {
  echo "Update all file extensions in a directory using `color 3 git mv`."
  echo ""
  echo "`color 2 Example:` git-mv-ext .png .final.png"
  echo ""
}

# no args
if [[ "$#" < 2 ]]; then help; exit 0; fi

FROM="$1"
TO="$2"

FROM_LEN=${#FROM}

for ENTRY in *
do
  if [[ "$ENTRY" == *"$FROM" ]]; then
    LEN=${#ENTRY}
    ENDINDEX=$(expr $LEN - $FROM_LEN)
    BASE=${ENTRY:0:$ENDINDEX}
    NEWNAME="$BASE$TO"
    echo "git mv `color 1 $ENTRY` `color 2 $NEWNAME`"
    git mv "$ENTRY" "$NEWNAME"
  fi
done
