#!/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) 2016-2018 Bob Mottram <bob@freedombone.net>
#
# 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"

UTILS_FILES="/usr/share/${PROJECT_NAME}/utils/${PROJECT_NAME}-utils-*"
for f in $UTILS_FILES
do
    source "$f"
done

# 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

SYNCTHING_SHORT_DESCRIPTION=$'File Synchronization'
SYNCTHING_DESCRIPTION=$'File Synchronization'
SYNCTHING_MOBILE_APP_URL='https://f-droid.org/packages/com.nutomic.syncthingandroid'

function remove_user_syncthing {
    remove_username="$1"

    sed -i "/<folder id=\"${remove_username}\" /,/</folder>/d" $SYNCTHING_CONFIG_FILE
    systemctl restart syncthing
}

function new_syncthing_id {
    for i in {1..8}
    do
        v=""
        # shellcheck disable=SC2034
        for j in {1..2}
        do
            v2=$(echo "obase=16;$RANDOM" | bc)
            v=$v$v2
        done
        v=$(echo "$v" | cut -c1-7)
        if [ "${i}" -lt 8 ]; then
            v=$v"-"
        fi
        echo -n "$v"
    done
    echo "$v"
}

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

    set_completion_param "syncthing ID" "$SYNCTHING_ID"

    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 [[ $(is_valid_user "$USERNAME") == "1" ]]; 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
                    line2=$(echo -e "${line}" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')
                    if [[ $line2 != *"#"* && $line2 != *"*"* && $line2 != *'/'*  && $line2 == *"-"* ]]; then
                        if [ ${#line2} -gt 10 ]; then
                            if ! grep -q "$line2" $TEMP_IDS_FILE; then
                                echo "        <device id=\"$line2\"></device>" >> $SYNCTHING_CONFIG_FILE
                                echo "$line2" >> $TEMP_IDS_FILE
                            fi
                        fi
                    fi
                done < "/home/$USERNAME/$SYNCTHING_USER_IDS_FILE"
                rm $TEMP_IDS_FILE
            fi
            { echo "        <device id=\"$SYNCTHING_ID\"></device>";
              echo '        <minDiskFreePct>1</minDiskFreePct>';
              echo '        <versioning></versioning>';
              echo '        <copiers>0</copiers>';
              echo '        <pullers>0</pullers>';
              echo '        <hashers>0</hashers>';
              echo '        <order>random</order>';
              echo '        <ignoreDelete>false</ignoreDelete>';
              echo '        <scanProgressIntervalS>0</scanProgressIntervalS>';
              echo '        <pullerSleepS>0</pullerSleepS>';
              echo '        <pullerPauseS>0</pullerPauseS>';
              echo '        <maxConflicts>10</maxConflicts>';
              echo '        <disableSparseFiles>false</disableSparseFiles>';
              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 [[ $(is_valid_user "$USERNAME") == "1" ]]; then
            if [ -f "/home/$USERNAME/$SYNCTHING_USER_IDS_FILE" ]; then
                while read -r line || [[ -n "$line" ]]; do
                    line2=$(echo -e "${line}" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')
                    if [[ $line2 != *"#"* && $line2 != *"*"* && $line2 != *'/'*  && $line2 == *"-"* ]]; then
                        if [ ${#line2} -gt 10 ]; then
                            if ! grep -q "$line2" $TEMP_IDS_FILE; then
                                echo "        <device id=\"$line2\"></device>" >> $SYNCTHING_CONFIG_FILE
                                echo "$line2" >> $TEMP_IDS_FILE
                            fi
                        fi
                    fi
                done < "/home/$USERNAME/$SYNCTHING_USER_IDS_FILE"
            fi
        fi
    done
    rm $TEMP_IDS_FILE
    { echo "        <device id=\"$SYNCTHING_ID\"></device>";
      echo '        <minDiskFreePct>1</minDiskFreePct>';
      echo '        <versioning></versioning>';
      echo '        <copiers>0</copiers>';
      echo '        <pullers>0</pullers>';
      echo '        <hashers>0</hashers>';
      echo '        <order>random</order>';
      echo '        <ignoreDelete>false</ignoreDelete>';
      echo '        <scanProgressIntervalS>0</scanProgressIntervalS>';
      echo '        <pullerSleepS>0</pullerSleepS>';
      echo '        <pullerPauseS>0</pullerPauseS>';
      echo '        <maxConflicts>10</maxConflicts>';
      echo '        <disableSparseFiles>false</disableSparseFiles>';
      echo '    </folder>';

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

    echo "" > $TEMP_IDS_FILE
    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $(is_valid_user "$USERNAME") == "1" ]]; then
            if [ -f "/home/$USERNAME/$SYNCTHING_USER_IDS_FILE" ]; then
                while read -r line || [[ -n "$line" ]]; do
                    line2=$(echo -e "${line}" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')
                    if [[ $line2 != *"#"* && $line2 != *"*"* && $line2 != *'/'*  && $line2 == *"-"* ]]; then
                        if [ ${#line2} -gt 10 ]; then
                            if ! grep -q "$line2" $TEMP_IDS_FILE; then
                                echo "    <device id=\"$line2\" name=\"${USERNAME}\" compression=\"metadata\" introducer=\"false\">" >> "$SYNCTHING_CONFIG_FILE"
                                echo '        <address>dynamic</address>' >> $SYNCTHING_CONFIG_FILE
                                echo '    </device>' >> $SYNCTHING_CONFIG_FILE
                                echo "$line2" >> $TEMP_IDS_FILE
                            fi
                        fi
                    fi
                done < "/home/$USERNAME/$SYNCTHING_USER_IDS_FILE"
            fi
        fi
    done
    rm $TEMP_IDS_FILE

    { echo '    <options>';
      echo "        <listenAddress>tcp://0.0.0.0:$SYNCTHING_PORT</listenAddress>";
      echo '        <globalAnnounceServer>default</globalAnnounceServer>';
      echo '        <globalAnnounceEnabled>true</globalAnnounceEnabled>';
      echo '        <localAnnounceEnabled>true</localAnnounceEnabled>';
      echo '        <localAnnouncePort>21027</localAnnouncePort>';
      echo '        <localAnnounceMCAddr>[ff12::8384]:21027</localAnnounceMCAddr>';
      echo "        <relayServer>dynamic+$SYNCTHING_RELAY_SERVER</relayServer>";
      echo '        <maxSendKbps>0</maxSendKbps>';
      echo '        <maxRecvKbps>0</maxRecvKbps>';
      echo '        <reconnectionIntervalS>60</reconnectionIntervalS>';
      echo '        <relaysEnabled>true</relaysEnabled>';
      echo '        <relayReconnectIntervalM>10</relayReconnectIntervalM>';
      echo '        <startBrowser>true</startBrowser>';
      echo '        <upnpEnabled>true</upnpEnabled>';
      echo '        <upnpLeaseMinutes>60</upnpLeaseMinutes>';
      echo '        <upnpRenewalMinutes>30</upnpRenewalMinutes>';
      echo '        <upnpTimeoutSeconds>10</upnpTimeoutSeconds>';
      echo '        <urAccepted>-1</urAccepted>';
      echo '        <urUniqueID></urUniqueID>';
      echo '        <urURL>https://data.syncthing.net/newdata</urURL>';
      echo '        <urPostInsecurely>false</urPostInsecurely>';
      echo '        <urInitialDelayS>1800</urInitialDelayS>';
      echo '        <restartOnWakeup>true</restartOnWakeup>';
      echo '        <autoUpgradeIntervalH>12</autoUpgradeIntervalH>';
      echo '        <keepTemporariesH>24</keepTemporariesH>';
      echo '        <cacheIgnoredFiles>true</cacheIgnoredFiles>';
      echo '        <progressUpdateIntervalS>5</progressUpdateIntervalS>';
      echo '        <symlinksEnabled>true</symlinksEnabled>';
      echo '        <limitBandwidthInLan>false</limitBandwidthInLan>';
      echo '        <minHomeDiskFreePct>1</minHomeDiskFreePct>';
      echo "        <releasesURL>$SYNCTHING_RELEASES</releasesURL>";
      echo '    </options>';
      echo '</configuration>'; } >> "$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 [[ $(is_valid_user "$USERNAME") == "1" ]]; 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 $3}')
        if [ ! -f "/home/$USERNAME/.syncthing-server-id" ]; then
            CHANGED=1
            return
        fi
    done

    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $(is_valid_user "$USERNAME") == "1" ]]; 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

            # Permissions on user Sync directories
            if [ -d "/home/$USERNAME/Sync" ]; then
                chown "$USERNAME":"$USERNAME" "/home/$USERNAME" "/home/$USERNAME/Sync"
            fi
            if [ -d "/home/$USERNAME/SyncShared" ]; then
                chown "$USERNAME":"$USERNAME" "/home/$USERNAME" "/home/$USERNAME/SyncShared"
            fi
        fi
    done
}

function syncthing_set_permissions {
    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [ -d "/home/$USERNAME/Sync" ]; then
            chown "$USERNAME":"$USERNAME" "/home/$USERNAME" "/home/$USERNAME/Sync"
        fi
        if [ -d "/home/$USERNAME/SyncShared" ]; then
            chown "$USERNAME":"$USERNAME" "/home/$USERNAME" "/home/$USERNAME/SyncShared"
        fi
    done
}

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

exit 0