theme.park.app/qbittorrent/root/etc/cont-init.d/98-themepark

#!/usr/bin/with-contenv bash

echo '------------------------------'
echo '| qBittorrent theme.park Mod |'
echo '------------------------------'

if ! [[ -x "$(command -v svn)" ]]; then
echo '--------------------------'
echo '| Installing svn package |'
echo '--------------------------'
 apt-get update && \
 apt-get install -y subversion
fi

# Display variables for troubleshooting
echo -e "Variables set:\\n\
'TP_DOMAIN'=${TP_DOMAIN}\\n\
'TP_THEME'=${TP_THEME}\\n"

# Set default
if [[ -z ${TP_DOMAIN} ]]; then
    echo 'No domain set, defaulting to gilbn.github.io'
    TP_DOMAIN='gilbn.github.io'
fi

if [[ -z ${TP_THEME} ]]; then
    echo 'No theme set, defaulting to organizr-dark'
    TP_THEME='organizr-dark'
fi

# Downloading fresh webui files from source.
if [[ ! -d /themepark ]]; then
    echo '---------------------------------------'
    echo '| Downloading WebUI files from github |'
    echo '---------------------------------------'
    printf '\nDownloading qBittorrent webui to "/themepark"..please wait\n'
    svn export --quiet https://github.com/qbittorrent/qBittorrent/trunk/src/webui/www /themepark
    printf '\nDownload finished\n\n'
    printf '\nDownloading qBittorrent webui icons to "/themepark/xxx"..please wait\n'
    svn export --force --quiet https://github.com/qbittorrent/qBittorrent/trunk/src/icons /temp
    cp -a /temp/. /themepark/public/icons
    cp -a /temp/. /themepark/private/icons
    rm -rf /temp
    printf '\nDownload finished\n\n'
fi

# Adding stylesheets
if ! grep -q "${TP_DOMAIN}" /themepark/public/index.html; then
    echo '---------------------------------------------------------'
    echo '| Adding the stylesheet to /themepark/public/index.html |'
    echo '---------------------------------------------------------'
    sed -i "s/<\/head>/<link rel='stylesheet' href='https:\/\/${TP_DOMAIN}\/theme.park\/CSS\/themes\/qbittorrent\/${TP_THEME}.css'><\/head> /g" /themepark/public/index.html
    printf 'Stylesheet set to %s on public index.html\n' "${TP_THEME}"
fi

if ! grep -q "${TP_DOMAIN}" /themepark/private/index.html; then
    echo '----------------------------------------------------------'
    echo '| Adding the stylesheet to /themepark/private/index.html |'
    echo '----------------------------------------------------------'
    sed -i "s/<\/head>/<link rel='stylesheet' href='https:\/\/${TP_DOMAIN}\/theme.park\/CSS\/themes\/qbittorrent\/${TP_THEME}.css'><\/head> /g" /themepark/private/index.html
    printf 'Stylesheet set to %s on private index.html\n\n' "${TP_THEME}"
fi

if ! grep -q "WebUI\\\RootFolder" /config/qBittorrent/qBittorrent.conf; then
    echo '--------------------------------------'
    echo '| Adding WebUI\RootFolder=/themepark |'
    echo '--------------------------------------'
    sed -i -e '$aWebUI\\RootFolder=/themepark' /config/qBittorrent/qBittorrent.conf;
fi

if ! grep -q "WebUI\\\AlternativeUIEnabled" /config/qBittorrent/qBittorrent.conf; then
    echo '------------------------------------------'
    echo '| Adding WebUI\AlternativeUIEnabled=true |'
    echo '------------------------------------------'
    sed -i -e '$aWebUI\\AlternativeUIEnabled=true' /config/qBittorrent/qBittorrent.conf;
fi

if  ! grep -q "WebUI\\\RootFolder=/themepark" /config/qBittorrent/qBittorrent.conf || ! grep -q "WebUI\\\AlternativeUIEnabled=true" /config/qBittorrent/qBittorrent.conf; then
    echo '-------------------------------------------------------'
    echo '| Updating RootFolder and AlternativeUIEnabled values |'
    echo '-------------------------------------------------------'
    sed -i "s/WebUI\\\AlternativeUIEnabled=.*$/WebUI\\\AlternativeUIEnabled=true/g" /config/qBittorrent/qBittorrent.conf;
    sed -i "s/WebUI\\\RootFolder=.*$/WebUI\\\RootFolder=\/themepark/g" /config/qBittorrent/qBittorrent.conf;
fi