#!/bin/bash

HOST_ARCH="x86_64"
BUILD_ARCH=`uname -m | cut -d. -f1`
MINIMAL_OSX_VERSION="10.11"

get_actual_arch() {
    if [ "$1" = "aarch64" ]; then
        echo "arm64"
    else
        echo "$1"
    fi
}

get_buildsystem_arch() {
    if [ "$1" = "arm64" ]; then
        echo "aarch64"
    else
        echo "$1"
    fi
}

ACTUAL_HOST_ARCH="$(get_actual_arch "${HOST_ARCH}")"

vlcGetOSXKernelVersion() {
    local OSX_KERNELVERSION=$(uname -r | cut -d. -f1)
    if [ ! -z "$VLC_FORCE_KERNELVERSION" ]; then
        OSX_KERNELVERSION="$VLC_FORCE_KERNELVERSION"
    fi

    echo "$OSX_KERNELVERSION"
}

vlcGetBuildTriplet() {
    echo "$BUILD_ARCH-apple-darwin$(vlcGetOSXKernelVersion)"
}

vlcGetHostTriplet() {
    echo "$HOST_ARCH-apple-darwin$(vlcGetOSXKernelVersion)"
}

# Gets VLCs root dir based on location of this file, also follow symlinks
vlcGetRootDir() {
    local SOURCE="${BASH_SOURCE[0]}"
    while [ -h "$SOURCE" ]; do
        local DIR="$(cd -P "$( dirname "$SOURCE" )" && pwd)"
        SOURCE="$(readlink "$SOURCE")"
        [[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE" # Relative symlink needs dir prepended
    done
    echo "$(cd -P "$(dirname "$SOURCE")/../../../" && pwd)"
}

# If VLC_CCACHE_BINS_PATH is set, it is assumed it contains
# clang and clang++ symlinks to the ccache binary which will
# then act as a compiler wrapper
vlcSetBaseEnvironment() {
    local LOCAL_BUILD_TRIPLET="$BUILD_TRIPLET"
    if [ -z "$LOCAL_BUILD_TRIPLET" ]; then
        LOCAL_BUILD_TRIPLET="$(vlcGetBuildTriplet)"
    fi

    local VLC_ROOT_DIR="$(vlcGetRootDir)"

    echo "Setting base environment"
    echo "Using VLC root dir $VLC_ROOT_DIR, build triplet $LOCAL_BUILD_TRIPLET and host triplet $(vlcGetHostTriplet)"

    export AR="$(xcrun --find ar)"
    export CC="$(xcrun --find clang)"
    export CXX="$(xcrun --find clang++)"
    export NM="$(xcrun --find nm)"
    export OBJC="$(xcrun --find clang)"
    export OBJCXX="$(xcrun --find clang++)"
    export RANLIB="$(xcrun --find ranlib)"
    export STRIP="$(xcrun --find strip)"

    if [ -n "${VLC_CCACHE_BINS_PATH}" ]; then
        if [ -d "${VLC_CCACHE_BINS_PATH}" ]; then
            echo "Using ccache compiler wrappers in '${VLC_CCACHE_BINS_PATH}'"
            export CC="${VLC_CCACHE_BINS_PATH}/cc"
            export CXX="${VLC_CCACHE_BINS_PATH}/c++"
            export OBJC="${VLC_CCACHE_BINS_PATH}/cc"
            export OBJCXX="${VLC_CCACHE_BINS_PATH}/c++"
        else
            echo "Invalid VLC_CCACHE_BINS_PATH given, directory not found: '${VLC_CCACHE_BINS_PATH}'"
            echo "Proceeding without ccache wrappers"
        fi
    fi

    python3Path=$(echo /Library/Frameworks/Python.framework/Versions/3.*/bin | awk '{print $1;}')
    if [ ! -d "$python3Path" ]; then
        python3Path=""
    fi

    export PATH="${VLC_ROOT_DIR}/extras/tools/build/bin:${VLC_ROOT_DIR}/contrib/${LOCAL_BUILD_TRIPLET}/bin:$python3Path:${VLC_PATH}:/bin:/sbin:/usr/bin:/usr/sbin"
}

vlcSetSymbolEnvironment() {
    # If the command is called without argument, default to exporting
    # all the ac_cv_* symbols to the environment. Else we'll pass the
    # symbol values to the command in the first argument, after the
    # command's arguments.
    #
    # It's typically made to work with cmd="configure" to write the
    # configuration into the config.status script or cmd="echo" to
    # write the variables into a config.mak file for the contribs.
    local cmd="${1:-export}"; [ "$#" -ge 1 ] && shift

    # The following symbols do not exist on the minimal macOS / iOS, so they are disabled
    # here. This allows compilation also with newer macOS SDKs.
    # List assumes macOS 10.10 / iOS 8 at minimum.

    # - Added symbols in macOS 10.12 / iOS 10 / watchOS 3
    # - Added symbols in macOS 10.13 / iOS 11 / watchOS 4 / tvOS 11
    # - Added symbol in macOS 10.14 / iOS 12 / tvOS 9
    # - Added symbols in macOS 10.15 / iOS 13 / tvOS 13
    "${cmd}" "$@" \
    \
    ac_cv_func_basename_r=no \
    ac_cv_func_clock_getres=no \
    ac_cv_func_clock_gettime=no \
    ac_cv_func_clock_settime=no \
    ac_cv_func_dirname_r=no \
    ac_cv_func_getentropy=no \
    ac_cv_func_mkostemp=no \
    ac_cv_func_mkostemps=no \
    ac_cv_func_timingsafe_bcmp=no \
    \
    ac_cv_func_open_wmemstream=no \
    ac_cv_func_fmemopen=no \
    ac_cv_func_open_memstream=no \
    ac_cv_func_futimens=no \
    ac_cv_func_utimensat=no \
    \
    ac_cv_func_thread_get_register_pointer_values=no \
    \
    ac_cv_func_aligned_alloc=no \
    ac_cv_func_timespec_get=no
}

vlcSetContribEnvironment() {
    if [ -z "$1" ]; then
        return 1
    fi
    local MINIMAL_OSX_VERSION="$1"

    if [ -z "$SDKROOT" ]; then
        export SDKROOT="$(xcrun --sdk macosx --show-sdk-path)"
    fi

    echo "Setting contrib environment with minimum macOS version $MINIMAL_OSX_VERSION and SDK $SDKROOT"

    # Usually, VLCs contrib libraries do not support partial availability at runtime.
    # Forcing those errors has two reasons:
    # - Some custom configure scripts include the right header for testing availability.
    #   Those configure checks fail (correctly) with those errors, and replacements are
    #   enabled. (e.g. ffmpeg)
    # - This will fail the build if a partially available symbol is added later on
    #   in contribs and not mentioned in the list of symbols above.
    export CFLAGS="-Werror=partial-availability"
    export CXXFLAGS="-Werror=partial-availability"
    export OBJCFLAGS="-Werror=partial-availability"

    export EXTRA_CFLAGS="-isysroot $SDKROOT -mmacosx-version-min=$MINIMAL_OSX_VERSION -DMACOSX_DEPLOYMENT_TARGET=$MINIMAL_OSX_VERSION -arch $ACTUAL_HOST_ARCH"
    export EXTRA_LDFLAGS="-isysroot $SDKROOT -mmacosx-version-min=$MINIMAL_OSX_VERSION -DMACOSX_DEPLOYMENT_TARGET=$MINIMAL_OSX_VERSION -arch $ACTUAL_HOST_ARCH"
    export XCODE_FLAGS="MACOSX_DEPLOYMENT_TARGET=$MINIMAL_OSX_VERSION -sdk $SDKROOT WARNING_CFLAGS=-Werror=partial-availability"
}

vlcUnsetContribEnvironment() {
    echo "Unsetting contrib flags"

    unset CFLAGS
    unset CXXFLAGS
    unset OBJCFLAGS

    unset EXTRA_CFLAGS
    unset EXTRA_LDFLAGS
    unset XCODE_FLAGS
}

vlcSetLibVLCEnvironment() {
    echo "Setting libVLC flags"

    # Enable debug symbols by default
    export CFLAGS="-g -arch $ACTUAL_HOST_ARCH"
    export CXXFLAGS="-g -arch $ACTUAL_HOST_ARCH"
    export OBJCFLAGS="-g -arch $ACTUAL_HOST_ARCH"
    export LDFLAGS="-arch $ACTUAL_HOST_ARCH"
}

vlcUnsetLibVLCEnvironment() {
    echo "Unsetting libVLC flags"

    unset CFLAGS
    unset CXXFLAGS
    unset OBJCFLAGS
    unset LDFLAGS
}

# Parameter handling


# First parameter: mode to use this script:
# vlc (default): auto-setup environment suitable for building vlc itself
# contrib: auto-setup environment suitable for building vlc contribs
# none: do not perform any auto-setup (used for scripts)
VLC_ENV_MODE="vlc"
if [ "$1" = "contrib" ]; then
    VLC_ENV_MODE="contrib"
fi
if [ "$1" = "none" ]; then
    VLC_ENV_MODE="none"
fi

if [ "$VLC_ENV_MODE" = "contrib" ]; then
    vlcSetBaseEnvironment
    vlcSetSymbolEnvironment
    vlcUnsetLibVLCEnvironment
    vlcSetContribEnvironment "$MINIMAL_OSX_VERSION"
elif [ "$VLC_ENV_MODE" = "vlc" ]; then
    vlcSetBaseEnvironment
    vlcSetSymbolEnvironment
    vlcUnsetContribEnvironment
    vlcSetLibVLCEnvironment
fi
