#!/bin/bash

# runner will replace key words in the template and generate a batch script to run.
# Keywords: 
#  PROCESSID = pid
#  RUNNERPROCESSNAME = Runner.Listener[.exe]
#  ROOTFOLDER = ./
#  EXISTRUNNERVERSION = 2.100.0
#  DOWNLOADRUNNERVERSION = 2.101.0 
#  UPDATELOG = _diag/SelfUpdate-UTC.log
#  RESTARTINTERACTIVERUNNER = 0/1

runnerpid=_PROCESS_ID_
runnerprocessname=_RUNNER_PROCESS_NAME_
rootfolder="_ROOT_FOLDER_"
existrunnerversion=_EXIST_RUNNER_VERSION_
downloadrunnerversion=_DOWNLOAD_RUNNER_VERSION_
logfile="_UPDATE_LOG_"
restartinteractiverunner=_RESTART_INTERACTIVE_RUNNER_

# log user who run the script
date "+[%F %T-%4N] --------whoami--------" >> "$logfile" 2>&1
whoami >> "$logfile" 2>&1
date "+[%F %T-%4N] --------whoami--------" >> "$logfile" 2>&1

# wait for runner process to exit.
date "+[%F %T-%4N] Waiting for $runnerprocessname ($runnerpid) to complete" >> "$logfile" 2>&1
while [ -e /proc/$runnerpid ]
do
    date "+[%F %T-%4N] Process $runnerpid still running" >> "$logfile" 2>&1
    ping -c 2 127.0.0.1 >nul
done
date "+[%F %T-%4N] Process $runnerpid finished running" >> "$logfile" 2>&1

# start re-organize folders
date "+[%F %T-%4N] Sleep 1 more second to make sure process exited" >> "$logfile" 2>&1
ping -c 2 127.0.0.1 >nul

# the folder structure under runner root will be
# ./bin -> bin.2.100.0 (junction folder)
# ./externals -> externals.2.100.0 (junction folder)
# ./bin.2.100.0
# ./externals.2.100.0
# ./bin.2.99.0
# ./externals.2.99.0
# by using the juction folder we can avoid file in use problem.

# if the bin/externals junction point already exist, we just need to delete the juction point then re-create to point to new bin/externals folder.
# if the bin/externals still are real folders, we need to rename the existing folder to bin.version format then create junction point to new bin/externals folder.

# check bin folder
if [[ -L "$rootfolder/bin" && -d "$rootfolder/bin" ]]
then
    # return code 0 means it find a bin folder that is a junction folder
    # we just need to delete the junction point.
    date "+[%F %T-%4N] Delete existing junction bin folder" >> "$logfile"
    rm "$rootfolder/bin" >> "$logfile"
    if [ $? -ne 0 ]
    then
        date "+[%F %T-%4N] Can't delete existing junction bin folder" >> "$logfile"
        mv -fv "$logfile" "$logfile.failed"
        exit 1
    fi
else
   # otherwise, we need to move the current bin folder to bin.2.99.0 folder.
    date "+[%F %T-%4N] move $rootfolder/bin $rootfolder/bin.$existrunnerversion" >> "$logfile" 2>&1
    mv -fv "$rootfolder/bin" "$rootfolder/bin.$existrunnerversion" >> "$logfile" 2>&1
    if [ $? -ne 0 ]
    then
        date "+[%F %T-%4N] Can't move $rootfolder/bin to $rootfolder/bin.$existrunnerversion" >> "$logfile" 2>&1
        mv -fv "$logfile" "$logfile.failed"
        exit 1
    fi
fi

# check externals folder
if [[ -L "$rootfolder/externals" && -d "$rootfolder/externals" ]]
then
    # the externals folder is already a junction folder
    # we just need to delete the junction point.
    date "+[%F %T-%4N] Delete existing junction externals folder" >> "$logfile"
    rm "$rootfolder/externals" >> "$logfile"
    if [ $? -ne 0 ]
    then
        date "+[%F %T-%4N] Can't delete existing junction externals folder" >> "$logfile"
        mv -fv "$logfile" "$logfile.failed"
        exit 1
    fi
else
    # otherwise, we need to move the current externals folder to externals.2.99.0 folder.
    date "+[%F %T-%4N] move $rootfolder/externals $rootfolder/externals.$existrunnerversion" >> "$logfile" 2>&1
    mv -fv "$rootfolder/externals" "$rootfolder/externals.$existrunnerversion" >> "$logfile" 2>&1
    if [ $? -ne 0 ]
    then
        date "+[%F %T-%4N] Can't move $rootfolder/externals to $rootfolder/externals.$existrunnerversion" >> "$logfile" 2>&1
        mv -fv "$logfile" "$logfile.failed"
        exit 1
    fi
fi

# create junction bin folder
date "+[%F %T-%4N] Create junction bin folder" >> "$logfile" 2>&1
ln -s "$rootfolder/bin.$downloadrunnerversion" "$rootfolder/bin" >> "$logfile" 2>&1
if [ $? -ne 0 ]
then
    date "+[%F %T-%4N] Can't create junction bin folder" >> "$logfile" 2>&1
    mv -fv "$logfile" "$logfile.failed"
    exit 1
fi

# create junction externals folder
date "+[%F %T-%4N] Create junction externals folder" >> "$logfile" 2>&1
ln -s "$rootfolder/externals.$downloadrunnerversion" "$rootfolder/externals" >> "$logfile" 2>&1
if [ $? -ne 0 ]
then
    date "+[%F %T-%4N] Can't create junction externals folder" >> "$logfile" 2>&1
    mv -fv "$logfile" "$logfile.failed"
    exit 1
fi

date "+[%F %T-%4N] Update succeed" >> "$logfile"

# rename the update log file with %logfile%.succeed/.failed/succeedneedrestart
# runner service host can base on the log file name determin the result of the runner update
date "+[%F %T-%4N] Rename $logfile to be $logfile.succeed" >> "$logfile" 2>&1
mv -fv "$logfile" "$logfile.succeed" >> "$logfile" 2>&1

# restart interactive runner if needed
if [ $restartinteractiverunner -ne 0 ]
then
    date "+[%F %T-%4N] Restarting interactive runner"  >> "$logfile.succeed" 2>&1
    "$rootfolder/run.sh" &
fi