#!/bin/sh

# On a clean Debian squeeze or Ubuntu precise installation you should
# be able to install FixMyStreet with:
#
#     curl https://raw.github.com/mysociety/fixmystreet/master/bin/pre-install-as-root | \
#         sh -s fms whatever.compute.amazonaws.com
#
# ... where the first argument is the Unix user who will own the code
# and the application will run as, and the second argument is the
# public hostname for the server, which will be used for creating the
# named virtualhost.

set -e
set -x

SITE=fixmystreet

DEFAULT_SERVER=false
if [ x"$1" = x"--default" ]
then
    DEFAULT_SERVER=true
    shift
fi

# Install some packages that we will definitely need:
apt-get install -y git-core lockfile-progs rubygems curl dnsutils lsb-release

# If we're not running on an EC2 instance, an empty body is returned
# by this request:
EC2_HOSTNAME=`curl -s http://169.254.169.254/latest/meta-data/public-hostname || true`

usage_and_exit() {
    cat >&2 <<EOUSAGE
Usage: $0 [--default] <UNIX-USER> [HOST]
HOST is only optional if you are running this on an EC2 instance.
--default means to install as the default site for this server,
rather than a virtualhost for HOST.
EOUSAGE
    exit 1
}

if [ $# = 1 ]
then
    if [ x = x$EC2_HOSTNAME ]
    then
        usage_and_exit
    else
        HOST="$EC2_HOSTNAME"
    fi
elif [ $# = 2 ]
then
    HOST="$2"
else
    usage_and_exit
fi

UNIX_USER="$1"

if [ $DEFAULT_SERVER = true ]
then
    DIRECTORY="/var/www/$SITE"
else
    DIRECTORY="/var/www/$HOST"
fi
REPOSITORY="$DIRECTORY/$SITE"

REPOSITORY_URL=git://github.com/mysociety/$SITE.git
BRANCH=master

DISTRIBUTION="$(lsb_release -i -s  | tr A-Z a-z)"
VERSION="$(lsb_release -c -s)"

IP_ADDRESS_FOR_HOST="$(dig +short $HOST)"

if [ x = x"$IP_ADDRESS_FOR_HOST" ]
then
    echo "The hostname $HOST didn't resolve to an IP address"
    exit 1
fi

generate_locales() {
    # If language-pack-en is present, install that:
    apt-get install -y language-pack-en || true

    # We get lots of locale errors if the en_GB.UTF-8 locale isn't
    # present.  (This is from Kagee's script.)
    if [ "$(locale -a | egrep -i '^en_GB.utf-?8$' | wc -l)" = "1" ]
    then
        echo "en_GB.utf8 activated and generated"
    else
        echo "en_GB.utf8 not generated"
        if [ x"$(grep -c '^en_GB.UTF-8 UTF-8' /etc/locale.gen)" = x1 ]
        then
            echo "'en_GB.UTF-8 UTF-8' already in /etc/locale.gen we will only generate"
        else
            echo "Appending 'en_GB.UTF-8 UTF-8' and 'cy_GB.UTF-8 UTF-8'"
            echo "to /etc/locale.gen for generation"
            echo "\nen_GB.UTF-8 UTF-8\ncy_GB.UTF-8 UTF-8" >> /etc/locale.gen
        fi
        echo "Generating new locales"
        locale-gen
    fi
}

set_locale() {
    echo 'LANG="en_GB.UTF-8"' > /etc/default/locale
    export LANG="en_GB.UTF-8"
}

add_unix_user() {
    # Create the required user if it doesn't already exist:
    if id "$1" 2> /dev/null > /dev/null
    then
        echo "The user $1 already exists."
    else
        adduser --disabled-password --gecos 'The FixMyStreet User' "$1"
    fi
}

add_postgresql_user() {
    su -l -c "createuser --createdb --no-createrole --no-superuser '$UNIX_USER'" postgres || true
}

update_apt_sources() {
    if [ x"$DISTRIBUTION" = x"ubuntu" ] && [ x"$VERSION" = x"precise" ]
    then
        cat > /etc/apt/sources.list.d/mysociety-extra.list <<EOF
deb http://eu-west-1.ec2.archive.ubuntu.com/ubuntu/ precise multiverse
deb-src http://eu-west-1.ec2.archive.ubuntu.com/ubuntu/ precise multiverse
deb http://eu-west-1.ec2.archive.ubuntu.com/ubuntu/ precise-updates multiverse
deb-src http://eu-west-1.ec2.archive.ubuntu.com/ubuntu/ precise-updates multiverse
EOF
    elif [ x"$DISTRIBUTION" = x"debian" ] && [ x"$VERSION" = x"squeeze" ]
    then
        # Install the basic packages we require:
        cat > /etc/apt/sources.list.d/mysociety-extra.list <<EOF
# Debian mirror to use, including contrib and non-free:
deb http://the.earth.li/debian/ squeeze main contrib non-free
deb-src http://the.earth.li/debian/ squeeze main contrib non-free

# Security Updates:
deb http://security.debian.org/ squeeze/updates main non-free
deb-src http://security.debian.org/ squeeze/updates main non-free

# Debian Backports
deb http://backports.debian.org/debian-backports squeeze-backports main contrib non-free
deb-src http://backports.debian.org/debian-backports squeeze-backports main contrib non-free
EOF
    else
        echo Unsupport distribution and version combination $DISTRIBUTION $VERSION
        exit 1
    fi
    apt-get update
}

clone_or_update_repository() {
    # Clone the repository into place if the directory isn't already
    # present:
    if [ -d $REPOSITORY ]
    then
        echo the directory $REPOSITORY already exists
        cd $REPOSITORY
        git remote set-url origin "$REPOSITORY_URL"
        git fetch origin
        # Check that there are no uncommitted changes before doing a
        # git reset --hard:
        git diff --quiet || { echo "There were changes in the working tree in $REPOSITORY; exiting."; exit 1; }
        git diff --cached --quiet || { echo "There were staged but uncommitted changes in $REPOSITORY; exiting."; exit 1; }
        # If that was fine, carry on:
        git reset --hard origin/"$BRANCH"
        git submodule sync
        git submodule update --recursive
    else
        PARENT="$(dirname $REPOSITORY)"
        echo creating $PARENT
        mkdir -p $PARENT
        git clone --recursive --branch "$BRANCH" "$REPOSITORY_URL" "$REPOSITORY"
    fi
}

install_nginx() {
    apt-get install -y nginx libfcgi-procmanager-perl
}

add_website_to_nginx() {
    UNIX_USER="$1"
    HOST="$2"
    REPOSITORY="$3"
    NGINX_SITE="$HOST"
    if [ $DEFAULT_SERVER = true ]
    then
        NGINX_SITE=default
    fi
    SITE_FILENAME=/etc/nginx/sites-available/"$NGINX_SITE"
    SITE_LINK=/etc/nginx/sites-enabled/"$NGINX_SITE"
    cp $REPOSITORY/conf/nginx.conf.example $SITE_FILENAME
    sed -i "s,/var/www/$SITE,$DIRECTORY," $SITE_FILENAME
    if [ $DEFAULT_SERVER = false ]
    then
        sed -i "/listen 80/a\
\    server_name $HOST;
" $SITE_FILENAME
    fi
    ln -nsf "$SITE_FILENAME" "$SITE_LINK"
    LOG_DIRECTORY="$(readlink -f $REPOSITORY/../logs)"
    mkdir -p "$LOG_DIRECTORY"
    chown -R "$UNIX_USER"."$UNIX_USER" "$LOG_DIRECTORY"
    /etc/init.d/nginx restart
}

install_sysvinit_script() {
    SYSVINIT_FILENAME=/etc/init.d/$SITE
    cp $REPOSITORY/conf/sysvinit.example $SYSVINIT_FILENAME
    sed -i "s,/var/www/$SITE,$DIRECTORY,g" $SYSVINIT_FILENAME
    sed -i "s/^ *USER=.*/USER=$UNIX_USER/" $SYSVINIT_FILENAME
    chmod a+rx $SYSVINIT_FILENAME
    update-rc.d $SITE start 20 2 3 4 5 . stop 20 0 1 6 .
    /etc/init.d/$SITE restart
}

install_website_packages() {
    EXACT_PACKAGES="$1/conf/packages.$DISTRIBUTION-$VERSION"
    PRECISE_PACKAGES="$1/conf/packages.ubuntu-precise"
    SQUEEZE_PACKAGES="$1/conf/packages.debian-squeeze"
    GENERIC_PACKAGES="$1/conf/packages"
    # If there's an exact match for the distribution and release, use that:
    if [ -e "$EXACT_PACKAGES" ]
    then
        PACKAGES_FILE="$EXACT_PACKAGES"
    # Otherwise, if this is Ubuntu, and there's a version specifically
    # for precise, use that:
    elif [ x"$DISTRIBUTION" = x"ubuntu" ] && [ -e "$PRECISE_PACKAGES" ]
    then
        PACKAGES_FILE="$PRECISE_PACKAGES"
    # Otherwise, if this is Debian, and there's a version specifically
    # for squeeze, use that:
    elif [ x"$DISTRIBUTION" = x"debian" ] && [ -e "$SQUEEZE_PACKAGES" ]
    then
        PACKAGES_FILE="$SQUEEZE_PACKAGES"
    else
        PACKAGES_FILE="$GENERIC_PACKAGES"
    fi
    xargs -a "$PACKAGES_FILE" apt-get -y install
}

overwrite_rc_local() {
    cat > /etc/rc.local <<EOF
#!/bin/sh -e

su -l -c $REPOSITORY/bin/ec2-rewrite-conf $UNIX_USER
/etc/init.d/$SITE restart

exit 0

EOF
    chmod a+rx /etc/rc.local
}

generate_locales
set_locale

add_unix_user "$UNIX_USER"

update_apt_sources

# And remove one crippling package, if it's installed:
apt-get remove -y --purge apt-xapian-index || true

clone_or_update_repository $REPOSITORY

chown -R "$UNIX_USER"."$UNIX_USER" "$DIRECTORY"

install_nginx

install_website_packages "$REPOSITORY"

su -l -c "touch '$DIRECTORY/admin-htpasswd'" "$UNIX_USER"

add_website_to_nginx "$UNIX_USER" "$HOST" "$REPOSITORY"

add_postgresql_user "$UNIX_USER"

DEFAULT_PARAMETER=''
if [ $DEFAULT_SERVER = true ]
then
    DEFAULT_PARAMETER='--default'
fi

su -l -c "$REPOSITORY/bin/install-as-user $DEFAULT_PARAMETER '$UNIX_USER' '$HOST'" "$UNIX_USER"

install_sysvinit_script

if [ $DEFAULT_SERVER = true ] && [ x != x$EC2_HOSTNAME ]
then
    # If we're setting up as the default on an EC2 instance,
    # make sure the ec2-rewrite-conf script is called from
    # /etc/rc.local
    overwrite_rc_local
fi

# Tell the user what to do next:

echo Installation complete - you should now be able to view the site at:
echo   http://$HOST/
echo Or you can run the tests by switching to the "'$UNIX_USER'" user and
echo running: $REPOSITORY/bin/cron-wrapper prove -r t