#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# TURN server functions
#
# License
# =======
#
# Copyright (C) 2016 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/>.

TURN_PORT=3478
TURN_HTTP_PORT=3407
TURN_ONION_PORT=8110

function generate_turn_key {
    local turnkey="${1}"
    local filepath="${2}"

    echo "lt-cred-mech" > "${filepath}"
    echo "use-auth-secret" >> "${filepath}"
    echo "static-auth-secret=${turnkey}" >> "${filepath}"
    echo "realm=turn.${DEFAULT_DOMAIN_NAME}" >> "${filepath}"
    if [[ $ONION_ONLY == 'no' ]]; then
        echo "cert=$MATRIX_DATA_DIR/${DEFAULT_DOMAIN_NAME}.tls.crt" >> "${filepath}"
        echo "pkey=$MATRIX_DATA_DIR/${DEFAULT_DOMAIN_NAME}.tls.key" >> "${filepath}"
    fi
}

function remove_turn {
    firewall_remove ${TURN_HTTP_PORT}
    firewall_remove ${TURN_PORT}
    systemctl stop turn
    systemctl disable turn
    if [ -f /etc/systemd/system/turn.service ]; then
        rm /etc/systemd/system/turn.service
    fi
    systemctl daemon-reload

    apt-get -y remove coturn
    rm -rf /var/lib/turn
    sed -i "/# TURN Server/,/# End of TURN Server/d" /etc/nginx/sites-available/${DEFAULT_DOMAIN_NAME}
    remove_onion_service turn ${TURN_ONION_PORT}
    rm /etc/avahi/services/turn.service
    systemctl restart nginx
}

function install_turn {
    create_default_web_site

    # append the matrix server to the web site config
    turn_nginx_site=/etc/nginx/sites-available/$DEFAULT_DOMAIN_NAME
    if ! grep -q '# End of TURN Server' $turn_nginx_site; then
        if [[ $ONION_ONLY == "no" ]]; then
            echo '# TURN Server' >> $turn_nginx_site
            echo 'server {' >> $turn_nginx_site
            echo "  listen ${TURN_HTTP_PORT} ssl;" >> $turn_nginx_site
            echo "  listen [::]:${TURN_HTTP_PORT} ssl;" >> $turn_nginx_site
            echo "  server_name ${DEFAULT_DOMAIN_NAME};" >> $turn_nginx_site
            echo '' >> $turn_nginx_site
            echo '  # Security' >> $turn_nginx_site
            function_check nginx_ssl
            nginx_ssl ${DEFAULT_DOMAIN_NAME}

            function_check nginx_disable_sniffing
            nginx_disable_sniffing ${DEFAULT_DOMAIN_NAME}

            echo '  add_header Strict-Transport-Security max-age=15768000;' >> $turn_nginx_site
            echo '' >> $turn_nginx_site
            echo '  # Logs' >> $turn_nginx_site
            echo '  access_log /dev/null;' >> $turn_nginx_site
            echo '  error_log /dev/null;' >> $turn_nginx_site
            echo '' >> $turn_nginx_site
            echo '  # Index' >> $turn_nginx_site
            echo '  index index.html;' >> $turn_nginx_site
            echo '' >> $turn_nginx_site
            echo '  # Location' >> $turn_nginx_site
            echo '  location / {' >> $turn_nginx_site
            function_check nginx_limits
            nginx_limits ${DEFAULT_DOMAIN_NAME} '15m'
            echo "      proxy_pass http://localhost:${TURN_PORT};" >> $turn_nginx_site
            echo '      proxy_set_header X-Forwarded-For $remote_addr;' >> $turn_nginx_site
            echo '  }' >> $turn_nginx_site
            echo '}' >> $turn_nginx_site
            echo '' >> $turn_nginx_site
        else
            echo '# TURN Server' >> $turn_nginx_site
        fi
        echo 'server {' >> $turn_nginx_site
        echo "    listen 127.0.0.1:$TURN_ONION_PORT default_server;" >> $turn_nginx_site
        echo "    server_name $DEFAULT_DOMAIN_NAME;" >> $turn_nginx_site
        echo '' >> $turn_nginx_site
        function_check nginx_disable_sniffing
        nginx_disable_sniffing $DEFAULT_DOMAIN_NAME
        echo '' >> $turn_nginx_site
        echo '  # Logs' >> $turn_nginx_site
        echo '  access_log /dev/null;' >> $turn_nginx_site
        echo '  error_log /dev/null;' >> $turn_nginx_site
        echo '' >> $turn_nginx_site
        echo '  # Location' >> $turn_nginx_site
        echo '  location / {' >> $turn_nginx_site
        function_check nginx_limits
        nginx_limits $DEFAULT_DOMAIN_NAME '15m'
        echo "      proxy_pass http://localhost:${TURN_PORT};" >> $turn_nginx_site
        echo '      proxy_set_header X-Forwarded-For $remote_addr;' >> $turn_nginx_site
        echo '  }' >> $turn_nginx_site
        echo '}' >> $turn_nginx_site
        echo '# End of TURN Server' >> $turn_nginx_site
    fi

    export DEBIAN_FRONTEND=noninteractive
    apt-get -yq install coreutils coturn \
            curl file gcc git libevent-2.0-5 \
            libevent-dev libffi-dev libffi6 \
            libgnutls28-dev libjpeg62-turbo \
            libjpeg62-turbo-dev libldap-2.4-2 \
            libldap2-dev libsasl2-dev \
            libsqlite3-dev libssl-dev \
            libssl1.1 libtool libxml2 \
            libxml2-dev libxslt1-dev libxslt1.1 \
            make python python-dev \
            python-pip python-psycopg2 \
            python-virtualenv sqlite unzip \
            zlib1g zlib1g-dev

    pip install --upgrade pip
    pip install --upgrade python-ldap
    pip install --upgrade lxml

    if [ ! -d /var/lib/turn ]; then
        mkdir /var/lib/turn
    fi

    turnkey="$(create_password 30)"
    generate_turn_key $turnkey /var/lib/turn/turnserver.conf

    chmod -R 700 /var/lib/turn/turnserver.conf
    chown -R matrix:matrix /var/lib/turn

    echo '[Unit]' > /etc/systemd/system/turn.service
    echo 'Description=TURN server' >> /etc/systemd/system/turn.service
    echo 'After=network.target nginx.target' >> /etc/systemd/system/turn.service
    echo '' >> /etc/systemd/system/turn.service
    echo '[Service]' >> /etc/systemd/system/turn.service
    echo 'Type=simple' >> /etc/systemd/system/turn.service
    echo 'User=matrix' >> /etc/systemd/system/turn.service
    echo "WorkingDirectory=/var/lib/turn" >> /etc/systemd/system/turn.service
    echo "ExecStart=/usr/bin/turnserver -c /var/lib/turn/turnserver.conf --pidfile /var/lib/matrix/homeserver.pid" >> /etc/systemd/system/turn.service
    echo "Environment=REPORT_STATS=\"no\"" >> /etc/systemd/system/turn.service
    echo 'Restart=always' >> /etc/systemd/system/turn.service
    echo 'RestartSec=10' >> /etc/systemd/system/turn.service
    echo '' >> /etc/systemd/system/turn.service
    echo '[Install]' >> /etc/systemd/system/turn.service
    echo 'WantedBy=multi-user.target' >> /etc/systemd/system/turn.service
    systemctl enable turn
    systemctl daemon-reload
    systemctl start turn

    firewall_add turn ${TURN_PORT}
    firewall_add turn-http ${TURN_HTTP_PORT}

    TURN_ONION_HOSTNAME=$(add_onion_service turn ${TURN_PORT} ${TURN_ONION_PORT})

    echo '<?xml version="1.0" standalone="no"?><!--*-nxml-*-->' > /etc/avahi/services/turn.service
    echo '<!DOCTYPE service-group SYSTEM "avahi-service.dtd">' >> /etc/avahi/services/turn.service
    echo '<service-group>' >> /etc/avahi/services/turn.service
    echo '  <name replace-wildcards="yes">%h TURN</name>' >> /etc/avahi/services/turn.service
    echo '  <service>' >> /etc/avahi/services/turn.service
    echo '    <type>_turn._tcp</type>' >> /etc/avahi/services/turn.service
    echo "    <port>$TURN_PORT</port>" >> /etc/avahi/services/turn.service
    echo '  </service>' >> /etc/avahi/services/turn.service
    echo '  <service>' >> /etc/avahi/services/turn.service
    echo '    <type>_turn._udp</type>' >> /etc/avahi/services/turn.service
    echo "    <port>$TURN_PORT</port>" >> /etc/avahi/services/turn.service
    echo '  </service>' >> /etc/avahi/services/turn.service
    echo '</service-group>' >> /etc/avahi/services/turn.service

    systemctl restart avahi-daemon
    systemctl restart nginx
}

# NOTE: deliberately no exit 0
