install

#!/bin/bash

set -e

# Defaults
FORCE=false
ATTEMPT_NIX_INSTALL=false

TMP=`getopt --name=$0 -a --longoptions=checkout-version:,cv:,force,playground:,for-development,attempt-nix-install -o p: -- $@`
eval set -- $TMP

until [ $1 == -- ]; do
    case $1 in
	--force)
	   FORCE=true;;
	--attempt-nix-install)
	    ATTEMPT_NIX_INSTALL=true;;
	# The remaining options are 'to be implemented'
        # --cv|--checkout-version)
        #    CHECKOUT_VERSION="$2"
        #    shift;; # Remove option value.
	# We leave this one active to allow early testing.
	-p|--playground)
	    CONVEYOR_PLAYGROUND="$2"
	    shift;; # Remove option value.
    esac
    shift # Remove just-processed option.
done
shift # Remove the '--', now $1 positioned at first argument if any.

# /**
#  * </div><!-- #Default-Values.section -->
#  *
#  * <div id="Prerequisite-Checks" class="section">
#  * <div class="section-header"><span>Prerequisites Check</span></div>
#  */
PREREQUISITES_GOOD='true'
# /**
#  * Unless <code>--force</code>d, the OS+distro is explicitly 
#  * supported.
#  */
if [[ $FORCE != 'true' ]]; then
    DISTRO_SUPPORT_STATEMENT="Conveyor 0.1 supports openSuSE 13.1."
    if [ ! -f /etc/SuSE-release ]; then
       echo $DISTRO_SUPPORT_STATEMENT >&2
       PREREQUISITES_GOOD='false'
    else
       # Wish the SuSE-release file was bash compatible...
       VERSION=`grep 'VERSION' /etc/SuSE-release | awk '{print $3}'`
       case "$VERSION" in
           13.1)
               ;; # that's fine
           *) # anything else though...
               echo $DISTRO_SUPPORT_STATEMENT >&2
	       PREREQUISITES_GOOD='false'
               ;;
       esac
    fi
fi
# /**
#  * Now we check absolute, un-forceable prerequisites.
#  */
# Check if 'nix' is installed / available.
if [[ ! $(type -P nix-env) ]]; then
    if [[ "$ATTEMPT_NIX_INSTALL" != "true" ]]; then
	read -r -p "Nix installation not found, install? (y/N) " ANSWER
    fi
    if [[ "$ATTEMPT_NIX_INSTALL" == "true" ]] \
	|| [[ "$ANSWER" =~ ^([yY]|[yY][eE][sS])$ ]]; then
	# TODO: Implement MD5 check, target specific version. 
	bash <(curl https://nixos.org/nix/install)
	source $HOME/.nix-profile/etc/profile.d/nix.sh
    fi
fi
# If nix still not installed at this point, then we're out of luck.
if [[ ! $(type -P nix-env) ]]; then
    echo "Could not find or install nix. After manually install nix," >&2
    echo "  try the installation again." >&2
    exit 2
fi

# Setup DogFoodSoftware.com distro.
for DIR in "$HOME/.conveyor" \
           "$HOME/.conveyor/subscriptions"; do
    # We do the check and create because the '-p' can mask problems. Since
    # we build from the bottom up, the 'create parents' effect is not
    # necessary.
    if [ ! -d "$DIR" ]; then
	mkdir "$DIR"
    fi
done

# Use local playground distro if present.
if [ -d "$HOME/playground/dogfoodsoftware.com/distro" ]; then
    if [ -h "$HOME/.conveyor/subscriptions/dogfoodsoftware.com/distro" ]; then
	if [[ `readlink "$HOME/.conveyor/subscriptions/dogfoodsoftware.com/distro"` == "$HOME/playground/dogfoodsoftware.com/distro" ]]; then
	    echo "Local DogFoodSoftware.com distro checkout already linked as subscription. Continuing..."
	else
	    echo "Local DogFoodSoftware.com distro found, but subscription links to:" >&2
	    echo "  `readlink '$HOME/.conveyor/subscriptions/dogfoodsoftware.com/distro'`" >&2
	    echo "bailing out. >&2"
	    exit 2
	fi
    elif [ -d "$HOME/.conveyor/subscriptions/dogfoodsoftware.com/distro" ]; then	
	echo "Found local dogfoodsoftware.com/distro checkout, but also" >&2
	echo "'$HOME/.conveyor/subscriptions/dogfoodsoftware.com/distro' to use checkout, execute:" >&2
	echo >&2
	echo "  rm -rf '$HOME/.conveyor/subscriptions/dogfoodsoftware.com/distro'"
	echo >&2
	echo "and re-run the install script."
	exit 2
    else # Then we have a local checkout, but no distro link; create it.
	mkdir -p "$HOME/playground/dogfoodsoftware.com"
	ln -s "$HOME/playground/dogfoodsoftware.com/distro" "$HOME/.conveyor/subscriptions/dogfoodsoftware.com/distro"
    fi
else # No local checkout found, checkout from github.
    mkdir -p "$HOME/.conveyor/subscriptions/dogfoodsoftware.com"
    cd "$HOME/.conveyor/subscriptions/dogfoodsoftware.com"
    git clone --depth 1 https://github.com/DogFoodSoftware/distro
fi