#!/bin/sh

set -e

# augment path to help it find cmake installed in /usr/local/bin,
# e.g. via brew. Xcode's Run Script phase doesn't seem to honor
# ~/.MacOSX/environment.plist
if [[ `uname -m` == 'arm64' ]]; then
  echo "** Running on a Apple Silicon M1"
  PATH="/opt/homebrew/bin:$PATH"
else
  echo "** Running on a Apple x86"
  PATH="/usr/local/bin:$PATH"
fi

SCRIPT_DIR=$(dirname "$0")
source "${SCRIPT_DIR}/xcode_functions.sh"

function setup_build_environment ()
{
    pushd "$SCRIPT_DIR/.." > /dev/null
    ROOT_PATH="$PWD"
    popd > /dev/null

    CLANG="/usr/bin/xcrun clang"
    CC="${CLANG}"
    CPP="${CLANG} -E"

    # We need to clear this so that cmake doesn't have a conniption
    MACOSX_DEPLOYMENT_TARGET=""

    XCODE_MAJOR_VERSION=$(xcode_major_version)
    XCODE_MINOR_VERSION=$(xcode_minor_version)

    CAN_BUILD_ARM="0"

    # Determine if we can be building for ARM Macs
    if [ "${XCODE_MAJOR_VERSION}" -ge "13" ]
    then
        CAN_BUILD_ARM="1"
    elif  [ "${XCODE_MAJOR_VERSION}" -eq "12" ] && [ "${XCODE_MINOR_VERSION}" -ge "2" ]
    then
        CAN_BUILD_ARM="1"
    fi

    ARCHS="x86_64"
    if [ "${CAN_BUILD_ARM}" -eq "1" ]
    then
        ARCHS="${ARCHS} arm64 arm64e"
    fi
}

function build_all_archs ()
{
    setup_build_environment

    local setup=$1
    local build_arch=$2
    local finish_build=$3

    # run the prepare function
    eval $setup

    echo "Building for ${ARCHS}"

    for ARCH in ${ARCHS}
    do
        PLATFORM="macosx"
        SDKVERSION=$(macos_sdk_version)

        SDKNAME="${PLATFORM}${SDKVERSION}"
        SDKROOT="$(sdk_path ${SDKNAME})"

        echo "Building ${LIBRARY_NAME} for ${SDKNAME} ${ARCH}"
        echo "Please stand by..."

        # run the per arch build command
        eval $build_arch
    done

    # finish the build (usually lipo)
    eval $finish_build
}

function setup ()
{
    if [ "${ROOT_PATH}/External/libgit2-mac/libgit2-mac.a" -nt "${ROOT_PATH}/External/libgit2" ]
    then
        echo "No update needed."
        exit 0
    fi

    LIBRARY_NAME="libgit2"
    LIB_PATH="${ROOT_PATH}/External/libgit2-mac"
    rm -rf "${LIB_PATH}"

    pushd "${ROOT_PATH}/External/libgit2" > /dev/null
}

function build_libgit2 ()
{
    rm -rf "build"
    mkdir "build"

    pushd "build" > /dev/null

    # install the each built arch somewhere sane
    INSTALL_PREFIX="${LIB_PATH}/${SDKNAME}-${ARCH}.sdk"

    mkdir -p "${INSTALL_PREFIX}"

    LOG="${INSTALL_PREFIX}/build-libgit2.log"
    echo "$LOG"

    MACOSX_DEPLOYMENT_TARGET="10.9" cmake \
        -DBUILD_SHARED_LIBS:BOOL=OFF \
        -DCMAKE_PREFIX_PATH:PATH="${ROOT_PATH}/External/libssh2-mac/bin/${SDKNAME}-${ARCH}.sdk" \
        -DCMAKE_INSTALL_PREFIX:PATH="${INSTALL_PREFIX}/" \
        -DBUILD_CLAR:BOOL=OFF \
        -DTHREADSAFE:BOOL=ON \
        -DCMAKE_OSX_ARCHITECTURES:STRING="${ARCH}" \
        .. >> "${LOG}" 2>&1
    cmake --build . --target install >> "${LOG}" 2>&1

    # push the built library into the list
    BUILT_LIB_PATHS+=("${INSTALL_PREFIX}/lib/libgit2.a")
    popd > /dev/null
}

function fat_binary ()
{
    echo "Building fat binary..."

    lipo -create "${BUILT_LIB_PATHS[@]}" -output "${ROOT_PATH}/External/libgit2-mac/libgit2-mac.a"

    echo "Building done."

    popd > /dev/null
}

build_all_archs setup build_libgit2 fat_binary

echo "libgit2 has been updated."