#!/bin/bash
# -*- coding: UTF-8 -*-
# gitstatus.sh -- produce the current git repo status on STDOUT
# Functionally equivalent to 'gitstatus.py', but written in bash (not python).
#
# Alan K. Stebbens <aks@stebbens.org> [http://github.com/aks]

# helper functions
count_lines() { echo "$1" | egrep -c "^$2" ; }
all_lines() { echo "$1" | grep -v "^$" | wc -l ; }

if [ -z "${__GIT_PROMPT_DIR}" ]; then
  SOURCE="${BASH_SOURCE[0]}"
  while [ -h "${SOURCE}" ]; do
    DIR="$( cd -P "$( dirname "${SOURCE}" )" && pwd )"
    SOURCE="$(readlink "${SOURCE}")"
    [[ $SOURCE != /* ]] && SOURCE="${DIR}/${SOURCE}"
  done
  __GIT_PROMPT_DIR="$( cd -P "$( dirname "${SOURCE}" )" && pwd )"
fi

branch=$( git rev-parse --abbrev-ref HEAD )

#If error code we are not in a repo - exit
if [[ $? != 0 ]]; then exit 0; fi

#If we are detached, branch name will be HEAD
if [[ "$branch" == "HEAD" ]]; then
  unset branch
fi

gitstatus=$( git diff --name-status 2>&1 )

# if the diff is fatal, exit now
if [[ $? != 0 ]]; then exit 0; fi

staged_files=$( git diff --staged --name-status )

num_changed=$(( `all_lines "$gitstatus"` - `count_lines "$gitstatus" U` ))
num_conflicts=`count_lines "$staged_files" U`
num_staged=$(( `all_lines "$staged_files"` - num_conflicts ))
num_untracked=$( git ls-files --others --exclude-standard $(git rev-parse --show-cdup) | wc -l )

num_stashed=0
if [[ "$__GIT_PROMPT_IGNORE_STASH" != "1" ]]; then
  stash_file="$( git rev-parse --git-dir )/logs/refs/stash"
  if [[ -e "${stash_file}" ]]; then
    while IFS='' read -r wcline || [[ -n "$wcline" ]]; do
      ((num_stashed++))
    done < ${stash_file}
  fi
fi

clean=0
if (( num_changed == 0 && num_staged == 0 && num_U == 0 && num_untracked == 0 && num_stashed == 0 )) ; then
  clean=1
fi

remote=
upstream=

if [[ -z "$branch" ]]; then
  tag=$( git describe --exact-match 2>/dev/null)
  if [[ -n "$tag" ]]; then
    branch="$tag"
  else
    branch="_PREHASH_$( git rev-parse --short HEAD )"
  fi
else
  remote_name=$( git config branch.${branch}.remote )

  if [[ -n "$remote_name" ]]; then
    merge_name=$( git config branch.${branch}.merge )
  else
    remote_name='origin'
    merge_name="refs/heads/${branch}"
  fi

  if [[ "$remote_name" == '.' ]]; then
    remote_ref="$merge_name"
  else
    remote_ref="refs/remotes/$remote_name/${merge_name##refs/heads/}"
  fi

  # detect if the local branch have a remote tracking branch
  upstream=$( git rev-parse --abbrev-ref ${branch}@{upstream} 2>&1 )

  if [[ $? == 0 ]]; then
    has_remote_tracking=1
  else
    has_remote_tracking=0
    unset upstream
  fi

  # get the revision list, and count the leading "<" and ">"
  revgit=$( git rev-list --left-right ${remote_ref}...HEAD 2>/dev/null )
  if [[ $? == 0 ]]; then
    num_revs=$( all_lines "$revgit" )
    num_ahead=$( count_lines "$revgit" "^>" )
    num_behind=$(( num_revs - num_ahead ))
    if (( num_behind > 0 )) ; then
      remote="${remote}_BEHIND_${num_behind}"
    fi
    if (( num_ahead > 0 )) ; then
      remote="${remote}_AHEAD_${num_ahead}"
    fi
  fi
fi

if [[ -z "$remote" ]] ; then
  remote='.'
fi

if [[ "$has_remote_tracking" == "0" ]] ; then
  remote='_NO_REMOTE_TRACKING_'
fi

if [[ -z "$upstream" ]] ; then
  upstream='^'
fi

printf "%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n" \
  "$branch" \
  "$remote" \
  "$upstream" \
  $num_staged \
  $num_conflicts \
  $num_changed \
  $num_untracked \
  $num_stashed \
  $clean

exit