#!/usr/bin/env bash
#

set -e

## This script is initiated by either xcodebuild or Xcode.app.
##
## We must guarantee no jobserver is passed through since file-descriptors are
## clobbered by Xcode. If this is not done then make allows unlimited jobs.
##
MAKEFLAGS=
MFLAGS=

## validate environment
case "$EXTERNAL_DRIVER" in
bootstrap) ;; ## bootstrapping from terminal
terminal)  ;; ## building from terminal
xcode)     ;; ## building from Xcode.app
*)
    echo "ERROR: unexpected value for EXTERNAL_DRIVER: $EXTERNAL_DRIVER"
    exit 1
    ;;
esac

## validate environment
for name in EXTERNAL_BUILD EXTERNAL_JOBS EXTERNAL_SRC; do
    eval v="\$$name"
    if [ -z "$v" ]; then
        echo "ERROR: missing value for $name"
        exit 1
    fi
done

## validate environment
archcount=`echo $ARCHS | awk '{ print NF }'`
if [ "$archcount" -ne 1 ]; then
    echo "*********************************************************************"
    echo "***"
    echo "*** ERROR: multiple architectures: $ARCHS"
    echo "***"
    echo "*** This build system does not support more than one (1)"
    echo "*** simultaneous architecture setting."
    echo "***"
    echo "*********************************************************************"
    exit 1
fi

exit_post_log=0

## compute goals; these correlate with TARGET_NAME and ACTION from Xcode
spec="$TARGET_NAME:$ACTION"
echo "target specification: $spec"
case "$spec" in
    external:clean)
        if [ "$EXTERNAL_DRIVER" == "xcode" ]; then
            ## driving build from Xcode.app do pristine clean
            if [ -z "$EXTERNAL_BUILD" ]; then
                echo "ERROR: unsafe rm -fr would result because EXTERNAL_BUILD is not defined"
                exit 1
            fi
            if [ -d "$EXTERNAL_BUILD" ]; then
                cmd="/bin/rm -fr $EXTERNAL_BUILD/*"
                echo "$cmd"
                $cmd
                [ $? -ne 0 ] && exit 1
                exit_post_log=1
            else
                echo "already clean"
            fi
        else
            ## driving build from xcodebuild do xclean, preserving configuration
            goals=xclean
        fi
        ;;
    external:*)
        if [ -z "$EXTERNAL_GOALS" ]; then
            goals=build
        else
            goals="$EXTERNAL_GOALS"
        fi
        ;;
    *)
        echo "ERROR: unexpected env specification: $spec"
        exit 1
        ;;
esac

## compute if re/configure necessary
if [ ! -f "$EXTERNAL_BUILD/GNUmakefile" ]; then
    reconfigure="no configuration present"
elif [ "$EXTERNAL_SRC/make/configure.py" -nt "$EXTERNAL_BUILD/GNUmakefile" ]; then
    reconfigure="configure script was updated"
elif [ "$EXTERNAL_DRIVER" == "bootstrap" ]; then
    reconfigure="driver bootstrap"
elif [[ "${PATH}" == "${DEVELOPER_BIN_DIR%/bin}"* ]] ||
     [[ "${PATH}" == "${DT_TOOLCHAIN_DIR%/bin}"* ]]  ||
     [[ "${PATH}" == "${PLATFORM_DIR%/bin}"* ]]      ||
     [[ "${PATH}" == "${PLATFORM_DEVELOPER_BIN_DIR%/bin}"* ]] ||
     [[ "${PATH}" == "${SYSTEM_DEVELOPER_BIN_DIR%/bin}"*   ]]; then
    reconfigure="unclobber PATH"
else
    reconfigure=
fi

## perform re/configure
if [ -n "$reconfigure" ]; then
    echo "reconfiguring ($reconfigure)"

    ## respect PATH priority
    OIFS="${IFS}"
    IFS=':'
    read -r -a PATH_ITEMS <<< "${PATH}"
    IFS="${OIFS}"
    PATH=""
    APPLE_PATH=""
    for ITEM in "${PATH_ITEMS[@]}"; do
        if [[ "${ITEM}" == "${DEVELOPER_BIN_DIR%/bin}"* ]] ||
           [[ "${ITEM}" == "${DT_TOOLCHAIN_DIR%/bin}"* ]]  ||
           [[ "${ITEM}" == "${PLATFORM_DIR%/bin}"* ]]      ||
           [[ "${ITEM}" == "${PLATFORM_DEVELOPER_BIN_DIR%/bin}"* ]] ||
           [[ "${ITEM}" == "${SYSTEM_DEVELOPER_BIN_DIR%/bin}"*   ]]; then
            APPLE_PATH="${APPLE_PATH}:${ITEM}"
        else
            PATH="${PATH}:${ITEM}"
        fi
    done
    PATH="${PATH}${APPLE_PATH}"
    export PATH="${PATH:1}"
    echo "Unclobbering PATH:"
    echo "    export PATH=\"${PATH}\""

    if [ "$EXTERNAL_DRIVER" == "bootstrap" ]; then
        driver="--xcode-driver=terminal"
    else
        driver="--xcode-driver=$EXTERNAL_DRIVER"
    fi

    ## determine which compiler to use based on Xcode environment (project).
    case "$GCC_VERSION" in
    com.apple.compilers.llvmgcc42)
        gcc="--gcc=`$DEVELOPER_BIN_DIR/xcodebuild -find-executable llvm-gcc-4.2`"
        ;;
    com.apple.compilers.llvm.clang.1_0)
        gcc="--gcc=`$DEVELOPER_BIN_DIR/xcodebuild -find-executable clang`"
        ;;
    *)
        echo "*********************************************************************"
        echo "***"
        echo "*** ERROR: unexpected value for GCC_VERSION: $GCC_VERSION"
        echo "***"
        echo "*********************************************************************"
        exit 1
        ;;
    esac

    if [ -n "$ARCHS" ]; then
        arch="--arch=$ARCHS"
    else
        arch=
    fi

    case "$CONFIGURATION" in
    debug*)
        debug="--debug=std --optimize=none"
        ;;
    release*|*)
        debug=
        ;;
    esac

    if [ -n "$SDKROOT" ]; then
        sysroot="--sysroot=$SDKROOT"
    else
        sysroot=
    fi

    if [ -n "$MACOSX_DEPLOYMENT_TARGET" ]; then
        minver="--minver=$MACOSX_DEPLOYMENT_TARGET"
    else
        minver=
    fi

    ## pickup user setting from Xcode IDE and avoid recursion
    if [ -n "$EXTERNAL_CONFIGURE" ]; then
        extconf="$EXTERNAL_CONFIGURE"
    else
        extconf=
    fi
    EXTERNAL_CONFIGURE=

    ## invoke configure with (hidden) option which indicates conf performed by xcode
    (set -ex; "$EXTERNAL_SRC/configure" --force \
        $EXTERNAL_CONF_ARGS \
        --build="$EXTERNAL_BUILD" \
        $driver \
        --xcode-symroot="$SYMROOT" \
        --xcode-config="$EXTERNAL_XCCONFIG" \
        $gcc $arch $debug $sysroot $minver $extconf)
    [ $? -ne 0 ] && exit 1
fi

## log environment as provided by Xcode
logdir="$EXTERNAL_BUILD/log"
if [ ! -d "$logdir" ]; then
    mkdir -p "$logdir"
fi
env | sort > "$logdir/xcodemake.env.txt"

[ $exit_post_log -ne 0 ] && exit 0

## safeguard against passing blank value which would result in unlimited jobs
if [ -z "$EXTERNAL_JOBS" ]; then
    jobs=
elif [ "$EXTERNAL_JOBS" == "auto" ]; then
    jobs=--jobs=`sysctl -n hw.activecpu`
else
    jobs=--jobs=$EXTERNAL_JOBS
fi

## when driving from terminal; ensure $SYMROOT/external/ exists relative to SYMROOT
if [ "$EXTERNAL_DRIVER" == "terminal" -a ! -e "$SYMROOT/external" ]; then
    ln -s "$EXTERNAL_BUILD" "$SYMROOT/external"
fi

## pull the trigger
## must set XCODE.driver to prevent inifinite recursion
set -x
exec make -C "$EXTERNAL_BUILD" XCODE.driver=xcodemake $jobs $goals $EXTERNAL_VARS