#!/bin/bash
#################################################################################################
# title         :git-myshellconfig-checkout                                                     #
# description   :checkout git detached HEAD                                                     #
# author        :Jakobus Schürz                                                                 #
# changes by    :Jakobus Schürz                                                                 #
# created       :17.01.2019                                                                     #
# updated       :28.10.2020                                                                     #
# version       :2.0                                                                            #
# usage         :git myshellconfig-checkout [-h]                                                #
# notes         :                                                                               #
#################################################################################################

[ -z "${SGIT+x}" ] && SGIT=git
    [ -z "${MYSHELLCONFIG_LOGDIR+x}" ]                  && export MYSHELLCONFIG_LOGDIR="${HOME}/logs"
    [ -z "${MYSHELLCONFIG_LOGFILE+x}" ]                 && export MYSHELLCONFIG_LOGFILE="${MYSHELLCONFIG_LOGDIR}/myshellconfig.log"
#MYSHELLCONFIG_LOGDIR="./logs"
#MYSHELLCONFIG_LOGFILE="${MYSHELLCONFIG_LOGDIR}/git.log"
[ -d "${MYSHELLCONFIG_LOGDIR}" ] || mkdir -p "${MYSHELLCONFIG_LOGDIR}"
[ -z "${MYSHELLCONFIG_GIT_REMOTE_NAME+x}" ] && export MYSHELLCONFIG_GIT_REMOTE_NAME=origin
[ -z "${MYSHELLCONFIG_GIT_BRANCH+x}" ] && export MYSHELLCONFIG_GIT_BRANCH=master

ENTRY
cat << EOF >> "${MYSHELLCONFIG_LOGFILE}"
+-----BEGINN git update repo $(date) -------------------------------+
EOF

case $1 in
    -h)
        # Headless repo local
        PRE="${MYSHELLCONFIG_GIT_REMOTE_NAME}"
        ;;
    -s)
        GIT_FETCH_OPTIONS="--recurse-submodules"
        ;;
    *)
        PRE=""
        ;;
esac
# If TAG is set, checkout is always headless. 
[ -z "${MYSHELLCONFIG_GIT_TAG:+x}" ] || { export MYSHELLCONFIG_GIT_BRANCH=${MYSHELLCONFIG_GIT_TAG}; export PRE=""; }

# Output
#echo -n " remote: ${MYSHELLCONFIG_GIT_REMOTE_NAME}, branch: ${MYSHELLCONFIG_GIT_BRANCH}: "

# Check for updates in submodules only if last check was INTERVALL hours in the past
updated=$(cat ${MYSHELLCONFIG_BASE%/}${MYSHELLCONFIG_BASE:+/}.last_udate_submodules 2>/dev/null || echo 0 )
if [ $updated -lt $(date --date="${MYSHELLCONFIG_GIT_SUBMODULES_UPDATE_INTERVALL} hours ago" "+%s") ]; then
    GIT_FETCH_OPTIONS="--recurse-submodules"
fi
    
#echo $SGIT fetch ${MYSHELLCONFIG_GIT_REMOTE_NAME} -p 1>&2 
$SGIT fetch ${GIT_FETCH_OPTIONS} ${MYSHELLCONFIG_GIT_REMOTE_NAME} -p  2>>"${MYSHELLCONFIG_LOGFILE}"|| { logwarn fetch failed; exit 1; }

echo "Check for local changes:" >> "${MYSHELLCONFIG_LOGFILE}"
if $SGIT diff-index --ignore-submodules --exit-code HEAD -- >> "${MYSHELLCONFIG_LOGFILE}" ; then
    cat << EOF >> "${MYSHELLCONFIG_LOGFILE}"
    no changes in local repo
    $SGIT checkout repo ${PRE}${PRE:+/}${MYSHELLCONFIG_GIT_BRANCH}
EOF
    $SGIT checkout ${PRE}${PRE:+/}${MYSHELLCONFIG_GIT_BRANCH} 1>>"${MYSHELLCONFIG_LOGFILE}" 2>>"${MYSHELLCONFIG_LOGFILE}"|| exit 2
    $SGIT merge FETCH_HEAD 1>>"${MYSHELLCONFIG_LOGFILE}" 2>>"${MYSHELLCONFIG_LOGFILE}"|| exit 3
else
    logwarn -n "    Lokale Änderungen festgestellt:"
    echo "    Siehe Logfile ${MYSHELLCONFIG_LOGFILE}" >&2
    cat << EOF >> "${MYSHELLCONFIG_LOGFILE}"
    um die Änderung zurückzusetzen bitte

      $SGIT checkout \$FILENAME

    oder um alle lokalen Änderungen auf einmal zurückzusetzen:

      $SGIT checkout .

    ausführen

    Die Änderungen sind:
    $($SGIT diff-index HEAD --|awk '{print $5, $6}')
    $($SGIT diff-index -p HEAD --)
EOF

cat << EOF >> "${MYSHELLCONFIG_LOGFILE}"

+-----ENDE git update repo $(date) ---------------------------------+
 
EOF
    exit 4

fi

loginfo -n "repo synced"

if ${MYSHELLCONFIG_GIT_SUBMODULES_UPDATE-${MYSHELLCONFIG_GIT_SUBMODULES_UPDATE_DEFAULT-true}}; then
#    updated=$(cat ${MYSHELLCONFIG_BASE%/}${MYSHELLCONFIG_BASE:+/}.last_udate_submodules 2>/dev/null || echo 0 )
#    if [ $updated -lt $(date --date="${MYSHELLCONFIG_GIT_SUBMODULES_UPDATE_INTERVALL} hours ago" "+%s") ]; then
        logdebug "update submodules"
        rc=0
    #    srv="${MYSHELLCONFIG_GIT_SUBMODULES_SERVER-${MYSHELLCONFIG_GIT_SUBMODULES_SERVER_DEFAULT}}" 
    #    logwarn "srv $srv"
    #    $SGIT config --file=.gitmodules -l | \
    #        grep url= | \
    #        awk -F "=" -v srv="${srv%/}${srv:+/}" \
    #        '{gsub(/^.*github.com\//,srv,$2); print $1" "$2}' | \
    #        while read a b; do
    #            logdebug "$SGIT config --file=.gitmodules ${a} ${b}"
    #            $SGIT config --file=.gitmodules "${a}" "${b}"
    #        done

        # Submodules always have origin and master as repo and branch to track
        #$SGIT submodule init 1>>"${MYSHELLCONFIG_LOGFILE}" 2>&1|| { logwarn "update submodules failed on ini"; rc=5; }
        #$SGIT submodule foreach "git checkout master"  1>>"${MYSHELLCONFIG_LOGFILE}" 2>&1               || { logwarn "checkout master submodules failed on set upstream"; rc=7;  }
        #$SGIT submodule foreach "git branch -u origin/master master"  1>>"${MYSHELLCONFIG_LOGFILE}" 2>&1|| { logwarn "set-upstream submodules failed on set upstream"; rc=8;  }
        #$SGIT submodule update --init --recursive --remote --merge 1>>"${MYSHELLCONFIG_LOGFILE}" 2>&1          || { logwarn " update submodules failed on update"; rc=9;  }
        
        # run git submodule sync only ich local repo should use submodule urls from main-project
        # so don't use it here
        # logdebug "$($SGIT submodule sync)" || { logwarn "sync submodules failed on sync"; rc=6;  }
        logdebug "$($SGIT submodule update --remote)"
        #logdebug "$($SGIT submodule update --init --recursive)"
        logdebug "$($SGIT commit .gitmodules -m 'update submodules')"
        #$SGIT submodule update --init --remote --merge 1>>"${MYSHELLCONFIG_LOGFILE}" 2>&1          || { logwarn " update submodules failed on update"; rc=9;  }
        #$SGIT checkout .gitmodules
        logdebug "submodules updated successfully"
        loginfo -n ", submodules synced"
        date "+%s" > ${MYSHELLCONFIG_BASE%/}${MYSHELLCONFIG_BASE:+/}.last_udate_submodules
    else
        logdebug "submodules not updated. last update is less then ${MYSHELLCONFIG_GIT_SUBMODULE_UPDATE_INTERVALL} hours ago"
    fi

#else
#    loginfo -n ", submodules not synced"
#    logdebug "Do not update submodules. It's denied by environment MYSHELLCONFIG_GIT_UPDATE_SUBMODULES: ${MYSHELLCONFIG_GIT_SUBMODULES_UPDATE-${MYSHELLCONFIG_GIT_SUBMODULES_UPDATE_DEFAULT-true}}"
#fi
loginfo -n ": "

EXIT
exit $rc