#!/bin/sh
set -e

# Environment variables that are used if not empty:
#   SERVER_NAMES
#   LOCATION
#   AUTH_TYPE
#   REALM
#   USERNAME
#   PASSWORD
#   ANONYMOUS_METHODS
#   SSL_CERT

# Just in case this environment variable has gone missing.
HTTPD_PREFIX="${HTTPD_PREFIX:-/usr/local/apache2}"

# Configure vhosts.
if [ "x$SERVER_NAMES" != "x" ]; then
    # Use first domain as Apache ServerName.
    SERVER_NAME="${SERVER_NAMES%%,*}"
    sed -e "s|ServerName .*|ServerName $SERVER_NAME|" \
        -i "$HTTPD_PREFIX"/conf/sites-available/default*.conf

    # Replace commas with spaces and set as Apache ServerAlias.
    SERVER_ALIAS="`printf '%s\n' "$SERVER_NAMES" | tr ',' ' '`"
    sed -e "/ServerName/a\ \ ServerAlias $SERVER_ALIAS" \
        -i "$HTTPD_PREFIX"/conf/sites-available/default*.conf
fi

# Configure dav.conf
if [ "x$LOCATION" != "x" ]; then
    sed -e "s|Alias .*|Alias $LOCATION /var/lib/dav/data/|" \
        -i "$HTTPD_PREFIX/conf/conf-available/dav.conf"
fi
if [ "x$REALM" != "x" ]; then
    sed -e "s|AuthName .*|AuthName \"$REALM\"|" \
        -i "$HTTPD_PREFIX/conf/conf-available/dav.conf"
else
    REALM="WebDAV"
fi
if [ "x$AUTH_TYPE" != "x" ]; then
    # Only support "Basic" and "Digest".
    if [ "$AUTH_TYPE" != "Basic" ] && [ "$AUTH_TYPE" != "Digest" ]; then
        printf '%s\n' "$AUTH_TYPE: Unknown AuthType" 1>&2
        exit 1
    fi
    sed -e "s|AuthType .*|AuthType $AUTH_TYPE|" \
        -i "$HTTPD_PREFIX/conf/conf-available/dav.conf"
fi

# Add password hash, unless "user.passwd" already exists (ie, bind mounted).
if [ ! -e "/user.passwd" ]; then
    touch "/user.passwd"
    # Only generate a password hash if both username and password given.
    if [ "x$USERNAME" != "x" ] && [ "x$PASSWORD" != "x" ]; then
        if [ "$AUTH_TYPE" = "Digest" ]; then
            # Can't run `htdigest` non-interactively, so use other tools.
            HASH="`printf '%s' "$USERNAME:$REALM:$PASSWORD" | md5sum | awk '{print $1}'`"
            printf '%s\n' "$USERNAME:$REALM:$HASH" > /user.passwd
        else
            htpasswd -B -b -c "/user.passwd" $USERNAME $PASSWORD
        fi
    fi
fi

# If specified, allow anonymous access to specified methods.
if [ "x$ANONYMOUS_METHODS" != "x" ]; then
    if [ "$ANONYMOUS_METHODS" = "ALL" ]; then
        sed -e "s/Require valid-user/Require all granted/" \
            -i "$HTTPD_PREFIX/conf/conf-available/dav.conf"
    else
        ANONYMOUS_METHODS="`printf '%s\n' "$ANONYMOUS_METHODS" | tr ',' ' '`"
        sed -e "/Require valid-user/a\ \ \ \ Require method $ANONYMOUS_METHODS" \
            -i "$HTTPD_PREFIX/conf/conf-available/dav.conf"
    fi
fi

# If specified, generate a selfsigned certificate.
if [ "${SSL_CERT:-none}" = "selfsigned" ]; then
    # Generate self-signed SSL certificate.
    # If SERVER_NAMES is given, use the first domain as the Common Name.
    if [ ! -e /privkey.pem ] || [ ! -e /cert.pem ]; then
        openssl req -x509 -newkey rsa:2048 -days 1000 -nodes \
            -keyout /privkey.pem -out /cert.pem -subj "/CN=${SERVER_NAME:-selfsigned}"
    fi
fi

# This will either be the self-signed certificate generated above or one that
# has been bind mounted in by the user.
if [ -e /privkey.pem ] && [ -e /cert.pem ]; then
    # Enable SSL Apache modules.
    for i in http2 ssl; do
        sed -e "/^#LoadModule ${i}_module.*/s/^#//" \
            -i "$HTTPD_PREFIX/conf/httpd.conf"
    done
    # Enable SSL vhost.
    ln -sf ../sites-available/default-ssl.conf \
        "$HTTPD_PREFIX/conf/sites-enabled"
fi

# Create directories for Dav data and lock database.
[ ! -d "/var/lib/dav/data" ] && mkdir -p "/var/lib/dav/data"
[ ! -e "/var/lib/dav/DavLock" ] && touch "/var/lib/dav/DavLock"
chown -R www-data:www-data "/var/lib/dav"

exec "$@"