# Creates fat libs of all .a files in `ARCH1_DIR` (1st param), combining .a with same name in `ARCH2_DIR` (2nd param), saving fat lib in `OUTPUT_DIR` (3rd param).

# Exit on errors
set -e

SCRIPT_DIR=$(dirname "$0")
ARCH1_DIR=$1
ARCH2_DIR=$2
OUTPUT_DIR=$3

# Get absolute paths
pushd "${SCRIPT_DIR}"
    SCRIPT_DIR=$(pwd)
popd
pushd "${ARCH1_DIR}"
    ARCH1_DIR=$(pwd)
popd
pushd "${ARCH2_DIR}"
    ARCH2_DIR=$(pwd)
popd
pushd "${OUTPUT_DIR}"
    OUTPUT_DIR=$(pwd)
popd

exitAndPrintHelp()
{
    echo "Must be called with ARCH1_DIR ARCH2_DIR OUTPUT_DIR, all absolute paths."
    exit 1
}

if [ "${ARCH1_DIR}" = "" ]; then
    exitAndPrintHelp
elif [ "${ARCH2_DIR}" = "" ]; then
    exitAndPrintHelp
elif [ "${OUTPUT_DIR}" = "" ]; then
    exitAndPrintHelp
fi

echo "##############################################"
echo "# building fat binaries from ${ARCH1_DIR}"
echo "##############################################"

pushd "${ARCH1_DIR}"
    if [ "$(ls 2>/dev/null || :)" = "" ]; then
        exit 0
    fi
    BIN_FILE_NAMES=$(ls 2>/dev/null)
popd

for BIN_FILE_NAME in ${BIN_FILE_NAMES}; do
    IN1="${ARCH1_DIR}/${BIN_FILE_NAME}"
    IN2="${ARCH2_DIR}/${BIN_FILE_NAME}"
    OUT="${OUTPUT_DIR}/${BIN_FILE_NAME}"
    mkdir -p "${OUTPUT_DIR}"
    lipo -create -output "${OUT}" "${IN1}" "${IN2}" || :
done