#!/bin/bash
# Show actions needed for a list of git directories
#
# Usage: gitcheck [-v] [DIR [DIR]]
#

set -e; set -u

# Helper functions
PROG=`basename "$0" | tr -d '\n'`

function info()  { echo `date +%c` ${PROG}\: info: "$@" 1>&2; }
function warn()  { echo `date +%c` ${PROG}\: warning: "$@" 1>&2; }
function error() { echo `date +%c` ${PROG}\: error: "$@" 1>&2; }
function debug() { [[ -v DEBUG ]] && echo `date +%c` ${PROG}\: debug: "$@" 1>&2 || true ; }
function die()   { echo `date +%c` ${PROG}\: fatal: "$@" 1>&2 && exit 1; }

# Global Variables
declare csv_row
csv_row="" # build up a one line output for each repo

function isGitPushOrPullNeeded() {
    # Show if git push or pull is needed to upstream
    #
    # Source: http://stackoverflow.com/questions/3258243/git-check-if-pull-needed
    #
    # TO DOs:
    #   TODO collect all info in a CSV by default, put put one summary line per repo
    #   TODO add number of modified, untracked, etc files from "git ls-files [--optione]"
    #
    #   Here are the "git branch --format" options
    #
    #     $ git branch --format "refname %(refname) objecttype %(objecttype) objectsize %(objectsize) objectname %(objectname) deltabase %(deltabase) upstream %(upstream) push %(push) HEAD %(HEAD) symref %(symref) worktreepath %(worktreepath) contents:subject %(contents:subject) contents:body %(contents:body) contents:signature %(contents:signature)"
    #
    #   They are likely useful for getting info

    # Fetch so we can compare local state with upstream without pull
    git fetch --all

    LOCAL=$(git rev-parse @)
    REMOTE=$(git rev-parse @{u})
    BASE=$(git merge-base @ @{u})

    push_or_pull_needed=":"
    
    if [ $LOCAL = $REMOTE ]; then
        push_or_pull_needed="UP-TO-DATE"
    elif [ $LOCAL = $BASE ]; then
        push_or_pull_needed="pull"
    elif [ $REMOTE = $BASE ]; then
        push_or_pull_needed="push"
    else
        push_or_pull_needed="DIVERGED"
    fi

    info "push_or_pull_needed: $push_or_pull_needed"
    csv_row="${csv_row}:${push_or_pull_needed}"
}

function gitChecks() {
    # Perform various checks of status of git in currenct directory
    # Show any actions needed
    
    DIR=${1:-`pwd`} # get directory name

    if [ ! -d "$DIR/.git" ]; then
        warn "$DIR is not a git repo.  Skipping."
        echo
        return
    fi
    
    pushd ${DIR} > /dev/null # go there
    info "Checking ${DIR}"

    csv_row="${DIR}:"
    
    isGitPushOrPullNeeded
    echo
    
    info git status for $DIR
    git status .
    echo
    
    popd > /dev/null # back to original directory
}



ARGC=$#  # Number of args, not counting $0

if [ "$ARGC" == "0" ]; then
    set -- `pwd` "$@" # add pwd if no args
fi

i=1  # Used as argument index
while true; do

    DIR=${1:-""}
    
    if [ "$DIR" ]; then
        gitChecks "$DIR"
  	shift
     else
   	break # Stop loop when no more args.
     fi
     i=$((i+1))
done

echo
info "Done."