#!/bin/bash
GVM_VERSION="@GVM_VERSION@"
PLATFORM=$(uname)

#
# function definitions
#

function help {
	CANDIDATES=$(curl -s "$GVM_SERVICE/candidates")
	echo ""
	echo "Usage: gvm <command> <candidate> [version]"
	echo ""
	echo "   command    :  install, uninstall, list, use, current, version, selfupdate, broadcast or help"
	echo "   candidate  :  $CANDIDATES"
	echo "   version    :  optional, defaults to latest stable if not provided"
	echo ""
	echo "eg: gvm install groovy"
}

function check_candidate_present {
	if [ -z "$1" ]; then
		echo -e "\nNo candidate provided."
		help
		exit 0
	fi
}

function check_version_present {
	if [ -z "$1" ]; then
		echo -e "\nNo candidate version provided."
		help
		exit 0
	fi
}

function determine_version {
	if [ -z "$1" ]; then
		VERSION=$(curl -s "$GVM_SERVICE/candidates/$CANDIDATE/default")
	else
		VERSION_VALID=$(curl -s "$GVM_SERVICE/candidates/$CANDIDATE/$1")
		if [ $VERSION_VALID == 'valid' ]; then
			VERSION="$1"
		else
			echo ""
			echo "Stop! $1 is not a valid $CANDIDATE version."
			exit 0
		fi
	fi
}

function build_version_csv {
	CANDIDATE="$1"
	CSV=""
	for version in $(ls -1 "$GVM_DIR/$CANDIDATE"); do
		if [ $version != 'current' ]; then
			CSV="$version,$CSV"
		fi
	done
	CSV=${CSV%?}
}

function determine_current_version {
	CANDIDATE="$1"
	CURRENT=$(readlink "$GVM_DIR/$CANDIDATE/current" | sed -e "s_$GVM_DIR/$CANDIDATE/__g")
}

function download {
	CANDIDATE="$1"
	VERSION="$2"
	mkdir -p "$GVM_DIR/archives"
	if [ ! -f "$GVM_DIR/archives/$CANDIDATE-$VERSION.zip" ]; then
		echo ""
		echo "Downloading: $CANDIDATE $VERSION" 
		echo ""
		DOWNLOAD_URL="$GVM_SERVICE/download/$CANDIDATE/$VERSION?platform=$PLATFORM"
		ZIP_ARCHIVE="$GVM_DIR/archives/$CANDIDATE-$VERSION.zip"
		curl -L "$DOWNLOAD_URL" > "$ZIP_ARCHIVE"
		validate_zip "$ZIP_ARCHIVE"
	else
		echo ""
		echo "Found a previously downloaded $CANDIDATE $VERSION archive. Not downloading it again..."
		validate_zip "$GVM_DIR/archives/$CANDIDATE-$VERSION.zip"
	fi
	echo ""
}

function validate_zip {
	ZIP_ARCHIVE="$1"
	ZIP_OK=$(zip -T "$ZIP_ARCHIVE" | grep 'OK')
	if [ -z "$ZIP_OK" ]; then
		rm "$ZIP_ARCHIVE"
		echo ""
		echo "Stop! The archive was corrupt and has been removed! Please try installing again."
		exit 0
	fi
}

function no_connection {
	echo "                                                         "
	echo "---------------------------------------------------------"
	echo "                                                         "
	echo "The GVM service is down or the internet is not reachable!"
	echo "     If the problem persists please notify: @gvmtool     "
	echo "                                                         "
	echo "---------------------------------------------------------"
	exit 0
}

function default_environment_variables {
	if [ ! "$GVM_SERVICE" ]; then
		GVM_SERVICE="http://localhost:8080"
	fi

	if [ ! "$GVM_DIR" ]; then
		GVM_DIR="$HOME/.gvm"
	fi
}

function server_broadcast {
	BROADCAST_LIVE=$(curl -s "$GVM_SERVICE/broadcast/$GVM_VERSION")
	if [ ! "$BROADCAST_LIVE" ]; then
		no_connection
		exit 0
	fi
}

function check_upgrade_available {
	UPGRADE_AVAILABLE=""
	UPGRADE_NOTICE=$(echo "$BROADCAST_LIVE" | grep 'Your version of GVM is out of date!')
	if [[ "$UPGRADE_NOTICE" && "$COMMAND" != 'selfupdate' ]]; then
		UPGRADE_AVAILABLE="true"
	fi
}

function display_broadcast {
	COMMAND="$1"
	BROADCAST_FILE="$GVM_DIR/var/broadcast"
	if [ -f "$BROADCAST_FILE" ]; then
		BROADCAST_HIST=$(cat "$BROADCAST_FILE")
	fi

	if [[ "$BROADCAST_LIVE" != "$BROADCAST_HIST" && "$COMMAND" != 'broadcast' ]]; then
		mkdir -p "$GVM_DIR/var"
		echo "$BROADCAST_LIVE" > "$BROADCAST_FILE"
		echo "$BROADCAST_LIVE"
	fi

	if [ "$1" == "help" -o -z "$1" ]; then
		help
		exit 0
	fi
}

function link_candidate_version {
	CANDIDATE="$1"
	VERSION="$2"
	if [ -L "$GVM_DIR/$CANDIDATE/current" ]; then
		unlink "$GVM_DIR/$CANDIDATE/current"
	fi
	ln -s "$GVM_DIR/$CANDIDATE/$VERSION" "$GVM_DIR/$CANDIDATE/current"
	echo ""
	echo Using "$CANDIDATE" version "$VERSION"
}

function install_candidate_version {
	CANDIDATE="$1"
	VERSION="$2"
	download "$CANDIDATE" "$VERSION"
	echo "Installing: $CANDIDATE $VERSION"

	mkdir -p "$GVM_DIR/$CANDIDATE"

	unzip -oq "$GVM_DIR/archives/$CANDIDATE-$VERSION.zip" -d "/tmp/"
	mv "/tmp/$CANDIDATE-$VERSION" "$GVM_DIR/$CANDIDATE/$VERSION"
	echo "Done installing!"
	echo ""
}

#
# Various sanity checks and default settings
#

default_environment_variables
mkdir -p "$GVM_DIR"

server_broadcast
check_upgrade_available
if [[ "$UPGRADE_AVAILABLE" && "$1" != "broadcast" ]]; then
	echo "$BROADCAST_LIVE"
	echo ""
else
	display_broadcast "$1"
fi

#
# Command functions
#

function gvm-install {
	CANDIDATE="$1"
	check_candidate_present "$CANDIDATE"
	determine_version "$2"

	if [ -d "$GVM_DIR/$CANDIDATE/$VERSION" ]; then
		echo ""
		echo "Stop! $CANDIDATE $VERSION is already installed."
		exit 0
	fi

	install_candidate_version "$CANDIDATE" "$VERSION"

	echo -n "Do you want to use $CANDIDATE $VERSION now? (Y/n): "
	read USE
	if [[ -z "$USE" || "$USE" == "y" || "$USE" == "Y" ]]; then
		link_candidate_version "$CANDIDATE" "$VERSION"
	fi
}

function gvm-use {
	CANDIDATE="$1"
	check_candidate_present "$CANDIDATE"
	determine_version "$2"

	if [ ! -d "$GVM_DIR/$CANDIDATE/$VERSION" ]; then
		echo ""
		echo "Stop! $CANDIDATE $VERSION is not installed."
		echo -n "Do you want to install it now? (Y/n): "
		read INSTALL 
		if [[ -z "$INSTALL" || "$INSTALL" == "y" || "$INSTALL" == "Y" ]]; then
			install_candidate_version "$CANDIDATE" "$VERSION"
		else
			exit 0
		fi
	fi

	link_candidate_version "$CANDIDATE" "$VERSION"
}

function gvm-current {
	CANDIDATE="$1"
	check_candidate_present "$CANDIDATE"
	determine_current_version "$CANDIDATE"
	if [ -n "$CURRENT" ]; then
		echo Using "$CANDIDATE" version "$CURRENT"
	else
		echo Not using any version of "$CANDIDATE"
	fi
}

function gvm-list {
	CANDIDATE="$1"
	check_candidate_present "$CANDIDATE"
	build_version_csv "$CANDIDATE"
	determine_current_version "$CANDIDATE"
	FRAGMENT=$(curl -s "$GVM_SERVICE/candidates/$CANDIDATE/list?platform=$PLATFORM&current=$CURRENT&installed=$CSV")
	echo "$FRAGMENT"
}

function gvm-uninstall {
	CANDIDATE="$1"
	VERSION="$2"
	check_candidate_present "$CANDIDATE"
	check_version_present "$VERSION"
	CURRENT=$(readlink "$GVM_DIR/$CANDIDATE/current" | sed -e "s_$GVM_DIR/$CANDIDATE/__g")
	if [ -h "$GVM_DIR/$CANDIDATE/current" -a "$VERSION" == "$CURRENT" ]; then
		echo ""
		echo "Unselecting $CANDIDATE $VERSION..."
		unlink "$GVM_DIR/$CANDIDATE/current"
	fi
	echo ""
	if [ -d "$GVM_DIR/$CANDIDATE/$VERSION" ]; then
		echo "Uninstalling $CANDIDATE $VERSION..."
		rm -rf "$GVM_DIR/$CANDIDATE/$VERSION"
	else
		echo "$CANDIDATE $VERSION is not installed."
	fi
}

function gvm-version {
	echo "Groovy enVironment Manager $GVM_VERSION"
}

function gvm-broadcast {
	if [ "$BROADCAST_HIST" ]; then
		echo "$BROADCAST_HIST"
	else
		echo "$BROADCAST_LIVE"
	fi
}

function gvm-selfupdate {
	curl -s "$GVM_SERVICE/selfupdate" | bash
}

# INSERT NEW COMMANDS BEFORE HERE

# Check whether the command exists

CMD_TYPE=`type -t gvm-"$1"`

if [ -z $CMD_TYPE ]; then
	echo -e "\nInvalid command: $1"
	help
	exit 0
fi

# Check whether the candidate exists

CANDIDATE_VALID=$(curl -s "$GVM_SERVICE/candidates/$2")
if [ "$CANDIDATE_VALID" == 'invalid' ]; then
	echo -e "\nStop! $2 is not a valid candidate."
	exit 0
fi

# Main command

gvm-"$1" "$2" "$3"