#!/usr/bin/env bash
#
# Copyright (c) 2016-2018 The Brenwill Workshop Ltd.
#
# fetchDependencies - Retrieves the correct versions of all dependencies
#
# macOS usage: ./fetchDependencies [--v-lvl-root path] [--glslang-root path]
#
#	--v-lvl-root path
#		"path" specifies a directory path to a
#		KhronosGroup/Vulkan-LoaderAndValidationLayers repository.
#		This repository does not have to be built.
#	--glslang-root path
#		"path" specifies a directory path to a KhronosGroup/glslang 
#		repository.  This repository does need to be built and the
#		build directory must be in the specified directory.
#		It should be built the same way this script builds it.


# ----------------- Functions -------------------

# Update a repository. If it exists, fetch it, if not clone it.
# $1 repo name
# $2 repo url
# $3 repo revision (commit SHA)
update_repo() {
	echo "$1 repo: $2"
	echo "$1 revision: $3"

	if [ -d $1 -a -d $1/.git ]; then
		cd $1
		git fetch --all
		git checkout --force $3
		cd -
	else
		rm -rf $1
		git clone $2 $1
		cd $1
		git checkout $3
		cd -
	fi
}

# Build a repository
# $1 repo name
build_repo() {
	echo "Building $1"

	mkdir -p $1/build
	cd $1/build
	if type ninja >/dev/null 2>&1 ; then
		cmake .. -G Ninja
		ninja
	else
		cmake ..
		make
	fi
	cd -
}


# ----------------- Main -------------------

EXT_DIR=External
EXT_REV_DIR=ExternalRevisions
V_LVL_NAME=Vulkan-LoaderAndValidationLayers
GLSLANG_NAME=glslang
V_LVL_ROOT=""
GLSLANG_ROOT=""

while (( "$#" )); do
  case "$1" in
	--v-lvl-root)
	  V_LVL_ROOT=$2
	  shift 2
	  ;;
	--glslang-root)
	  GLSLANG_ROOT=$2
	  shift 2
	  ;;
	-*|--*=)
	  echo "Error: Unsupported flag $1" >&2
	  exit 1
	  ;;
  esac
done

echo
echo Retrieving MoltenVK dependencies into ${EXT_DIR}.
echo

mkdir -p ${EXT_DIR}
cd ${EXT_DIR}

# ----------------- Cereal -------------------

REPO_NAME=cereal
REPO_URL="https://github.com/USCiLab/${REPO_NAME}.git"
REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")

update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}


# ----------------- SPIRV-Cross -------------------

REPO_NAME=SPIRV-Cross
REPO_URL="https://github.com/KhronosGroup/${REPO_NAME}.git"
REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")

update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}


# ----------------- VulkanSamples -------------------

REPO_NAME=VulkanSamples
REPO_URL="https://github.com/LunarG/${REPO_NAME}.git"
REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")

update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}


# ----------------- Vulkan-LoaderAndValidationLayers -------------------

# When MoltenVK is built by something that already has a copy of the
# Vulkan-LoaderAndValidationLayers repo, use it by creating a symlink.
if [ ! "$V_LVL_ROOT" = "" ]; then

	REPO_NAME=${V_LVL_NAME}
	rm -rf ${REPO_NAME}
	ln -sfn ${V_LVL_ROOT} ${REPO_NAME}

else

	REPO_NAME=${V_LVL_NAME}
	REPO_URL="https://github.com/KhronosGroup/${REPO_NAME}.git"
	REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")

	update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}

	cd ${REPO_NAME}
	./update_external_sources.sh -g
	cd -

fi

cd ..