#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Checks for changed syncthing device IDs within user home directories
# and then recreates the syncthing configuration file accordingly
#
# License
# =======
#
# Copyright (C) 2016 Bob Mottram <bob@robotics.uk.to>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

NO_OF_ARGS=$#

PROJECT_NAME='freedombone'

export TEXTDOMAIN=$PROJECT_NAME-syncthing
export TEXTDOMAINDIR="/usr/share/locale"

# File which keeps track of what has already been installed
COMPLETION_FILE=$HOME/${PROJECT_NAME}-completed.txt

SYNCTHING_ID=
SYNCTHING_CONFIG_PATH=/root/.config/syncthing
SYNCTHING_CONFIG_FILE=$SYNCTHING_CONFIG_PATH/config.xml
SYNCTHING_RELAY_SERVER='https://relays.syncthing.net/endpoint'
SYNCTHING_RELEASES='https://api.github.com/repos/syncthing/syncthing/releases?per_page=30'
SYNCTHING_PORT=22000
SYNCTHING_SHARED_DATA=/var/lib/syncthing/SyncShared
SYNCTHING_USER_IDS_FILE='.syncthingids'
SYNCTHING_UPDATE_FILE='.syncthing-update'
CHANGED=
TEMP_IDS_FILE=/root/.synthingids

function new_syncthing_id {
    for i in {1..8}
    do
        v=""
        for j in {1..2}
        do
            v2=`echo "obase=16;$RANDOM" | bc`
            v=$v$v2
        done
        v=$(echo "$v" | cut -c1-7)
        if [[ ${i} < 8 ]]; then
            v=$v"-"
        fi
        echo -n "$v"
    done
    echo "$v"
}

function create_syncthing_config {
    if grep -q "Syncthing ID" $COMPLETION_FILE; then
        SYNCTHING_ID=$(cat $COMPLETION_FILE | grep "Syncthing ID" | awk -F ':' '{print $2}')
    else
        if [ -f $SYNCTHING_CONFIG_FILE ]; then
            SYNCTHING_ID=$(cat $SYNCTHING_CONFIG_FILE | grep "device id=" | head -n 1 | awk -F '"' '{print $2}')
        else
            SYNCTHING_ID=$(new_syncthing_id)            
        fi      
    fi

    if ! grep -q "Syncthing ID" $COMPLETION_FILE; then
        echo "Syncthing ID:$SYNCTHING_ID" >> $COMPLETION_FILE
    else
        sed -i "s|Syncthing ID.*|Syncthing ID:$SYNCTHING_ID|g" $COMPLETION_FILE
    fi

    if [ ! -d $SYNCTHING_CONFIG_PATH ]; then
        mkdir -p $SYNCTHING_CONFIG_PATH
    fi
    if [ ! -d $SYNCTHING_SHARED_DATA ]; then
        mkdir -p $SYNCTHING_SHARED_DATA
    fi

    echo '<configuration version="12">' > $SYNCTHING_CONFIG_FILE

    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $USERNAME != "git" && $USERNAME != "mirrors" && $USERNAME != "sync" ]]; then
            echo "    <folder id=\"$USERNAME\" path=\"/home/$USERNAME/Sync/\" ro=\"false\" rescanIntervalS=\"60\" ignorePerms=\"false\" autoNormalize=\"true\">" >> $SYNCTHING_CONFIG_FILE
            # include any specified device IDs for this user
            if [ -f /home/$USERNAME/$SYNCTHING_USER_IDS_FILE ]; then
                echo "" > $TEMP_IDS_FILE
                while read -r line || [[ -n "$line" ]]; do
                    if [[ $line != *"#"* && $line != *"*"* && $line != *'/'*  && $line == *"-"* ]]; then
                        if [ ${#line} -gt 10 ]; then
                            if ! grep -q "$line" $TEMP_IDS_FILE; then
                                echo "        <device id=\"$line\"></device>" >> $SYNCTHING_CONFIG_FILE
                                echo "$line" >> $TEMP_IDS_FILE
                            fi
                        fi
                    fi
                done < /home/$USERNAME/$SYNCTHING_USER_IDS_FILE
                rm $TEMP_IDS_FILE
            fi
            echo "        <device id=\"$SYNCTHING_ID\"></device>" >> $SYNCTHING_CONFIG_FILE
            echo '        <minDiskFreePct>1</minDiskFreePct>' >> $SYNCTHING_CONFIG_FILE
            echo '        <versioning></versioning>' >> $SYNCTHING_CONFIG_FILE
            echo '        <copiers>0</copiers>' >> $SYNCTHING_CONFIG_FILE
            echo '        <pullers>0</pullers>' >> $SYNCTHING_CONFIG_FILE
            echo '        <hashers>0</hashers>' >> $SYNCTHING_CONFIG_FILE
            echo '        <order>random</order>' >> $SYNCTHING_CONFIG_FILE
            echo '        <ignoreDelete>false</ignoreDelete>' >> $SYNCTHING_CONFIG_FILE
            echo '        <scanProgressIntervalS>0</scanProgressIntervalS>' >> $SYNCTHING_CONFIG_FILE
            echo '        <pullerSleepS>0</pullerSleepS>' >> $SYNCTHING_CONFIG_FILE
            echo '        <pullerPauseS>0</pullerPauseS>' >> $SYNCTHING_CONFIG_FILE
            echo '        <maxConflicts>10</maxConflicts>' >> $SYNCTHING_CONFIG_FILE
            echo '        <disableSparseFiles>false</disableSparseFiles>' >> $SYNCTHING_CONFIG_FILE
            echo '    </folder>' >> $SYNCTHING_CONFIG_FILE
        fi
    done

    echo "    <folder id=\"shared\" path=\"$SYNCTHING_SHARED_DATA/\" ro=\"false\" rescanIntervalS=\"60\" ignorePerms=\"false\" autoNormalize=\"true\">" >> $SYNCTHING_CONFIG_FILE
    # all user devices may access this shared directory
    echo "" > $TEMP_IDS_FILE
    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $USERNAME != "git" && $USERNAME != "mirrors" && $USERNAME != "sync" ]]; then
            if [ -f /home/$USERNAME/$SYNCTHING_USER_IDS_FILE ]; then
                while read -r line || [[ -n "$line" ]]; do
                    if [[ $line != *"#"* && $line != *"*"* && $line != *'/'*  && $line == *"-"* ]]; then
                        if [ ${#line} -gt 10 ]; then
                            if ! grep -q "$line" $TEMP_IDS_FILE; then
                                echo "        <device id=\"$line\"></device>" >> $SYNCTHING_CONFIG_FILE
                                echo "$line" >> $TEMP_IDS_FILE
                            fi
                        fi
                    fi
                done < /home/$USERNAME/$SYNCTHING_USER_IDS_FILE
            fi
        fi
    done
    rm $TEMP_IDS_FILE
    echo "        <device id=\"$SYNCTHING_ID\"></device>" >> $SYNCTHING_CONFIG_FILE
    echo '        <minDiskFreePct>1</minDiskFreePct>' >> $SYNCTHING_CONFIG_FILE
    echo '        <versioning></versioning>' >> $SYNCTHING_CONFIG_FILE
    echo '        <copiers>0</copiers>' >> $SYNCTHING_CONFIG_FILE
    echo '        <pullers>0</pullers>' >> $SYNCTHING_CONFIG_FILE
    echo '        <hashers>0</hashers>' >> $SYNCTHING_CONFIG_FILE
    echo '        <order>random</order>' >> $SYNCTHING_CONFIG_FILE
    echo '        <ignoreDelete>false</ignoreDelete>' >> $SYNCTHING_CONFIG_FILE
    echo '        <scanProgressIntervalS>0</scanProgressIntervalS>' >> $SYNCTHING_CONFIG_FILE
    echo '        <pullerSleepS>0</pullerSleepS>' >> $SYNCTHING_CONFIG_FILE
    echo '        <pullerPauseS>0</pullerPauseS>' >> $SYNCTHING_CONFIG_FILE
    echo '        <maxConflicts>10</maxConflicts>' >> $SYNCTHING_CONFIG_FILE
    echo '        <disableSparseFiles>false</disableSparseFiles>' >> $SYNCTHING_CONFIG_FILE
    echo '    </folder>' >> $SYNCTHING_CONFIG_FILE

    
    echo "    <device id=\"$SYNCTHING_ID\" name=\"${PROJECT_NAME}\" compression=\"metadata\" introducer=\"false\">" >> $SYNCTHING_CONFIG_FILE
    echo '        <address>dynamic</address>' >> $SYNCTHING_CONFIG_FILE
    echo '    </device>' >> $SYNCTHING_CONFIG_FILE

    echo "" > $TEMP_IDS_FILE
    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $USERNAME != "git" && $USERNAME != "mirrors" && $USERNAME != "sync" ]]; then
            if [ -f /home/$USERNAME/$SYNCTHING_USER_IDS_FILE ]; then
                while read -r line || [[ -n "$line" ]]; do
                    if [[ $line != *"#"* && $line != *"*"* && $line != *'/'*  && $line == *"-"* ]]; then
                        if [ ${#line} -gt 10 ]; then
                            if ! grep -q "$line" $TEMP_IDS_FILE; then
                                echo "    <device id=\"$line\" name=\"${USERNAME}\" compression=\"metadata\" introducer=\"false\">" >> $SYNCTHING_CONFIG_FILE
                                echo '        <address>dynamic</address>' >> $SYNCTHING_CONFIG_FILE
                                echo '    </device>' >> $SYNCTHING_CONFIG_FILE
                                echo "$line" >> $TEMP_IDS_FILE
                            fi
                        fi
                    fi
                done < /home/$USERNAME/$SYNCTHING_USER_IDS_FILE
            fi
        fi
    done
    rm $TEMP_IDS_FILE   

    echo '    <options>' >> $SYNCTHING_CONFIG_FILE
    echo "        <listenAddress>tcp://0.0.0.0:$SYNCTHING_PORT</listenAddress>" >> $SYNCTHING_CONFIG_FILE
    echo '        <globalAnnounceServer>default</globalAnnounceServer>' >> $SYNCTHING_CONFIG_FILE
    echo '        <globalAnnounceEnabled>true</globalAnnounceEnabled>' >> $SYNCTHING_CONFIG_FILE
    echo '        <localAnnounceEnabled>true</localAnnounceEnabled>' >> $SYNCTHING_CONFIG_FILE
    echo '        <localAnnouncePort>21027</localAnnouncePort>' >> $SYNCTHING_CONFIG_FILE
    echo '        <localAnnounceMCAddr>[ff12::8384]:21027</localAnnounceMCAddr>' >> $SYNCTHING_CONFIG_FILE
    echo "        <relayServer>dynamic+$SYNCTHING_RELAY_SERVER</relayServer>" >> $SYNCTHING_CONFIG_FILE
    echo '        <maxSendKbps>0</maxSendKbps>' >> $SYNCTHING_CONFIG_FILE
    echo '        <maxRecvKbps>0</maxRecvKbps>' >> $SYNCTHING_CONFIG_FILE
    echo '        <reconnectionIntervalS>60</reconnectionIntervalS>' >> $SYNCTHING_CONFIG_FILE
    echo '        <relaysEnabled>true</relaysEnabled>' >> $SYNCTHING_CONFIG_FILE
    echo '        <relayReconnectIntervalM>10</relayReconnectIntervalM>' >> $SYNCTHING_CONFIG_FILE
    echo '        <startBrowser>true</startBrowser>' >> $SYNCTHING_CONFIG_FILE
    echo '        <upnpEnabled>true</upnpEnabled>' >> $SYNCTHING_CONFIG_FILE
    echo '        <upnpLeaseMinutes>60</upnpLeaseMinutes>' >> $SYNCTHING_CONFIG_FILE
    echo '        <upnpRenewalMinutes>30</upnpRenewalMinutes>' >> $SYNCTHING_CONFIG_FILE
    echo '        <upnpTimeoutSeconds>10</upnpTimeoutSeconds>' >> $SYNCTHING_CONFIG_FILE
    echo '        <urAccepted>-1</urAccepted>' >> $SYNCTHING_CONFIG_FILE
    echo '        <urUniqueID></urUniqueID>' >> $SYNCTHING_CONFIG_FILE
    echo '        <urURL>https://data.syncthing.net/newdata</urURL>' >> $SYNCTHING_CONFIG_FILE
    echo '        <urPostInsecurely>false</urPostInsecurely>' >> $SYNCTHING_CONFIG_FILE
    echo '        <urInitialDelayS>1800</urInitialDelayS>' >> $SYNCTHING_CONFIG_FILE
    echo '        <restartOnWakeup>true</restartOnWakeup>' >> $SYNCTHING_CONFIG_FILE
    echo '        <autoUpgradeIntervalH>12</autoUpgradeIntervalH>' >> $SYNCTHING_CONFIG_FILE
    echo '        <keepTemporariesH>24</keepTemporariesH>' >> $SYNCTHING_CONFIG_FILE
    echo '        <cacheIgnoredFiles>true</cacheIgnoredFiles>' >> $SYNCTHING_CONFIG_FILE
    echo '        <progressUpdateIntervalS>5</progressUpdateIntervalS>' >> $SYNCTHING_CONFIG_FILE
    echo '        <symlinksEnabled>true</symlinksEnabled>' >> $SYNCTHING_CONFIG_FILE
    echo '        <limitBandwidthInLan>false</limitBandwidthInLan>' >> $SYNCTHING_CONFIG_FILE
    echo '        <minHomeDiskFreePct>1</minHomeDiskFreePct>' >> $SYNCTHING_CONFIG_FILE
    echo "        <releasesURL>$SYNCTHING_RELEASES</releasesURL>" >> $SYNCTHING_CONFIG_FILE
    echo '    </options>' >> $SYNCTHING_CONFIG_FILE
    echo '</configuration>' >> $SYNCTHING_CONFIG_FILE

    # give each user account a file containing the device id for this server
    # This allows it to appear within the user control panel
    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $USERNAME != "git" && $USERNAME != "mirrors" && $USERNAME != "sync" ]]; then
            echo "$SYNCTHING_ID" > /home/$USERNAME/.syncthing-server-id
            chown $USERNAME:$USERNAME /home/$USERNAME/.syncthing-server-id
        fi
    done
}

function user_devices_changed {
    CHANGED=
    if [ ! -f $SYNCTHING_CONFIG_FILE ]; then
        CHANGED=1
        return
    fi

    if ! grep -q "${PROJECT_NAME}" $SYNCTHING_CONFIG_FILE; then
        CHANGED=1
        return
    fi
    
    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $USERNAME != "git" && $USERNAME != "mirrors" && $USERNAME != "sync" ]]; then
            if [ -f /home/$USERNAME/$SYNCTHING_UPDATE_FILE ]; then
                CHANGED=1
            fi
            
            if [ -f /home/$USERNAME/$SYNCTHING_USER_IDS_FILE ]; then
                while read -r line || [[ -n "$line" ]]; do
                    if [[ $line != *"#"* && $line != *"*"* && $line != *'/'*  && $line == *"-"* ]]; then
                        if [ ${#line} -gt 10 ]; then
                            if ! grep -q "$line" $SYNCTHING_CONFIG_FILE; then
                                CHANGED=1
                            fi
                        fi
                    fi
                done < /home/$USERNAME/$SYNCTHING_USER_IDS_FILE
            fi
        fi
    done
}

user_devices_changed
if [ $CHANGED ]; then
    create_syncthing_config
    systemctl restart syncthing
fi

exit 0