#!/bin/sh

PREFIX="from now"
MESSAGE="[${PREFIX}] `date +\"%Y/%m/%d %T\"`"

if [ $# -eq 0 ]
then
  git add -u
  printf "${MESSAGE}\n\n%s" "`git diff --cached`" | git commit -F -
elif [ $1 != "--rebase" ]
then
  if [ $1 != "--all" ]
  then
    git add $@
  else
    git add -u
    git add .
  fi
  printf "${MESSAGE}\n\n%s" "`git diff --cached`" | git commit -F -
else
  if [ $# -eq 1 ]
  then
    FIRST_NOW_COMMIT=`git log --pretty=oneline --grep="${PREFIX}" | tail -n 1 | cut -d " " -f 1`
    INITIAL_COMMIT=`git log --pretty=oneline | tail -n 1 | cut -d " " -f 1`

    if [ ${FIRST_NOW_COMMIT} != ${INITIAL_COMMIT} ]
    then
      git rebase -i ${FIRST_NOW_COMMIT}^
    else
      WORKING_BRANCH=`git branch -l | grep "*" | cut -d " " -f 2`

      git checkout ${FIRST_NOW_COMMIT}
      git commit --amend
      git rebase --onto HEAD ${FIRST_NOW_COMMIT} ${WORKING_BRANCH}
    fi
  else
    BASE_BRANCH=$2
    WORKING_BRANCH=`git branch -l | grep "*" | cut -d " " -f 2`
    COMMON_ANCESTOR_COMMIT=`git merge-base ${BASE_BRANCH} ${WORKING_BRANCH}`
    FIRST_NOW_COMMIT=`git log ${COMMON_ANCESTOR_COMMIT}.. --pretty=oneline --grep="${PREFIX}" | tail -n 1 | cut -d " " -f 1`
    INITIAL_COMMIT=`git log --pretty=oneline | tail -n 1 | cut -d " " -f 1`

    if [ ${FIRST_NOW_COMMIT} != ${INITIAL_COMMIT} ]
    then
      git rebase -i ${FIRST_NOW_COMMIT}^
    else
      git checkout ${FIRST_NOW_COMMIT}
      git commit --amend
      git rebase --onto HEAD ${FIRST_NOW_COMMIT} ${WORKING_BRANCH}
    fi
  fi
fi