#!/usr/bin/env bash

set -e
if [ "$XTRACE" = 1 ]; then
   set -x
fi

if [ -z "$O3" ]; then
    echo O3 var must point to ovpn3 tree
    exit 1
fi

enum_build_extras()
{
    ls -d $(echo $O3/*/scripts/build-extras/*) | sort
}

if [ -z "$1" ]; then
    echo "usage: ./build target"
    echo "options:"
    echo " PROF=<platform> -- source vars/vars-<platform> before running"
    echo " DPROF=1 -- when PROF is specified, use the debugging variant"
    echo " CLANG=1 -- use clang instead of gcc"
    echo " DEBUG=1 -- enable debug symbols"
    echo " CO=1 -- compile only"
    echo " OBJC=1 -- top-level source file is Obj-C"
    echo ' ECHO=1 -- show commands'
    echo ' OUTBIN=name -- write binary to name'
    echo " STRIP=1 -- strip binary"
    echo " STRICT=1 -- more warnings"
    echo " GPROF=1 -- build for gprof profiling"
    echo " PGEN=1 -- generate data for profile-guided optimization"
    echo " PUSE=1 -- use data from previous run of PGEN=1 build"
    echo " ASIO=1 -- build with ASIO"
    echo " ASIO_DIR=<dir> -- specify ASIO tree"
    echo " MTLS=1 -- include mbedTLS"
    echo " MTLS_SYS=1 -- use system mbedTLS"
    echo " MTLS_PATH=path -- use user specified mbedTLS source folder"
    echo " MTLS_LIBS=ldflags -- user specific mbedTLS LDFLAGS"
    echo " MTLS_DIST=path -- use user-specified mbedTLS distribution"
    echo " MA_HYBRID=1 -- use mbedTLS/AppleCrypto hybrid"
    echo " OPENSSL_DIST=<dir> -- specify custom OpenSSL build"
    echo " NOSSL=1 -- don't include OpenSSL"
    echo " OPENSSL_SYS=1 -- include system OpenSSL"
    echo " MINI=1 -- link with OpenSSL mini crypto lib"
    echo " OSSL=1 -- include OpenSSL"
    echo " SSL_BOTH=1 -- include OpenSSL and Apple SSL on Mac"
    echo " NOTHREADS=1 -- disable threads"
    echo ' GCC_EXTRA="-DITER=5" -- add build flags'
    echo " LZO=1 -- build with LZO compression library"
    echo " LZ4=1 -- build with LZ4 compression library"
    echo " LZ4_SYS=1 -- build with system LZ4 compression library"
    echo " SNAP=1 -- build with Snappy compression library"
    echo " CITY=1 -- build with Cityhash hash library"
    echo " XXHASH=1 -- build with XXHash hash library"
    echo " CAP=1 -- build with libcap"
    echo " JAVA=1 -- build with JVM"
    echo ' EXTRA_CPP="foo1.cpp foo2.cpp" -- add extra .cpp files into single compilation unit'
    echo ' EXTRA_CPP_OBJS="bar1.cpp foo2.cpp" -- add extra .cpp as separate compilation units'
    echo " GTEST_DIR=<dir> -- specify googletest tree, required for building unit tests"
    echo " VAL=1 -- (optional) build with valgrind run-time extensions"
    echo " ASAN=1 -- (optional) enable ASAN run-time checks"
    echo " PCRE=1 -- build with PCRE library"
    echo " SYSD=1 -- build with systemd library"
    echo " SQLITE=1 -- build with sqlite3 library"
    for s in $(enum_build_extras) ; do
	. $s args
    done
    exit 1
fi

# determine platform if PROF is set to "auto"
if [ "$PROF" = "auto" ]; then
    if [ "$(uname)" == "Darwin" ]; then
	export PROF=osx64
    elif [ "$(uname)" == "Linux" ]; then
	export PROF=linux
    else
	echo "PROF=auto : cannot determine platform"
	exit 1
    fi
fi

# source vars file
if [ "$PROF" ]; then
    suffix=""
    [ "$DPROF" = "1" ] && suffix="-dbg"
    pfn="$O3/core/vars/vars-$PROF$suffix"
    if ! [ -f "$pfn" ]; then
	pfn="$PROF"
    fi
    . $pfn || exit 1
fi

# remove previous build
[ -z "$OUTBIN" ] && OUTBIN="$(basename $1)"
rm -f $OUTBIN

# build options
CPPFLAGS=""
LIBS=""
LIBDIRS=""
EXTRA_SRC_OBJ=""

# MbedTLS/AppleCrypto hybrid
if [ "$MA_HYBRID" = "1" ]; then
    MTLS=1
fi

# building on Mac OS X for osx or ios?
if [ "$APPLE_FAMILY" = "1" ]; then
    [ -z "$CLANG" ] && CLANG=1
fi

# clang support
if [ "$CLANG" = "1" ]; then
    [ -z "$GPP_CMD" ] && GPP_CMD=clang++
fi

# building on Linux, use system OpenSSL
if [ "$PLATFORM" = "linux" ] && [ "$OSSL" = "1" ] && [ "$NOSSL" != "1" ] && [ -z "$OPENSSL_SYS" ]; then
    OSSL=0
    OPENSSL_SYS=1
fi

# building on Linux, use system LZ4
if [ "$PLATFORM" = "linux" ] && [ "$LZ4" = "1" ] && [ -z "$LZ4_SYS" ]; then
    LZ4_SYS=1
fi

# default commands
[ -z "$STRIP_CMD" ] && STRIP_CMD=strip
[ -z "$GPP_CMD" ] && GPP_CMD=g++

# build flags
FLAGS="-Wall"
[ "$STRICT" = "1" ] && FLAGS="$FLAGS -Wextra"
[ "$CLANG" = "1" ] && FLAGS="$FLAGS -Wno-tautological-compare -Wno-unused-private-field -Wno-c++1y-extensions"
FLAGS="$FLAGS -Wno-sign-compare -Wno-unused-parameter"

# The Mac OS X tun/tap driver doesn't play with with kqueue.
# utun devices, however, work fine with kqueue.
#if [ "$PLATFORM" = "osx" ]; then
#    CPPFLAGS="$CPPFLAGS -DBOOST_ASIO_DISABLE_KQUEUE"
#fi

# MbedTLS
if [ -n "$MTLS_DIST" ]; then
    CPPFLAGS="$CPPFLAGS -DUSE_MBEDTLS -I$MTLS_DIST/include"
    LIBDIRS="$LIBDIRS -L$MTLS_DIST/library"
    LIBS="$LIBS -lmbedtls -lmbedx509 -lmbedcrypto"
    MTLS=1
elif [ "$MTLS_SYS" = "1" ]; then
    CPPFLAGS="$CPPFLAGS -DUSE_MBEDTLS"
    LIBS="$LIBS -lmbedtls -lmbedx509 -lmbedcrypto"
elif [ "$MTLS" = "1" ]; then
    LIBS="$LIBS -lmbedtls $MTLS_LIBS"
    if [ "$MA_HYBRID" = "1" ]; then
	CPPFLAGS="$CPPFLAGS -DUSE_MBEDTLS_APPLE_HYBRID"
    else
	CPPFLAGS="$CPPFLAGS -DUSE_MBEDTLS"
    fi
    if [ -n "$MTLS_PATH" ]; then
	CPPFLAGS="$CPPFLAGS -I$MTLS_PATH/include"
	LIBDIRS="$LIBDIRS -L$MTLS_PATH/library"
    else
	CPPFLAGS="$CPPFLAGS -I$DEP_DIR/mbedtls/mbedtls-$PLATFORM/include"
	LIBDIRS="$LIBDIRS -L$DEP_DIR/mbedtls/mbedtls-$PLATFORM/library"
    fi
    if [ "$MINI" = "1" ]; then
	LIBS="$LIBS -lminicrypto"
	LIBDIRS="$LIBDIRS -L$DEP_DIR/minicrypto/minicrypto-$PLATFORM"
	CPPFLAGS="$CPPFLAGS -DUSE_MINICRYPTO"
	NOSSL=1
    fi
fi

# OpenSSL
if [ "$OPENSSL_DIST" ]; then
    CPPFLAGS="$CPPFLAGS -DUSE_OPENSSL -I$OPENSSL_DIST/include"
    LIBDIRS="$LIBDIRS -L$OPENSSL_DIST/lib"
    LIBS="$LIBS -lssl -lcrypto"
elif [ "$APPLE_FAMILY" = "1" ]; then
    # On Mac, only link with OpenSSL if OSSL is defined.
    # On other platforms, usually link with OpenSSL.
    if [ "$OPENSSL_SYS" == "1" ]; then
	NO_DEPRECATE="-Wno-deprecated-declarations"
    else
	NO_DEPRECATE=""
    fi
    if [ "$OPENSSL_LINK" = "1" ]; then
	LIBS="$LIBS -lcrypto -lssl"
    elif [ "$OSSL" = "1" ]; then
	CPPFLAGS="$CPPFLAGS -DUSE_OPENSSL"
	LIBS="$LIBS -lcrypto -lssl"
	[ "$CLANG" = "1" ] && [ "$NO_DEPRECATE" ] && FLAGS="$FLAGS $NO_DEPRECATE"
    elif [ "$SSL_BOTH" = "1" ]; then
	CPPFLAGS="$CPPFLAGS -DUSE_APPLE_SSL -DUSE_OPENSSL"
	LIBS="$LIBS -lcrypto -lssl"
	[ "$CLANG" = "1" ] && [ "$NO_DEPRECATE" ] && FLAGS="$FLAGS $NO_DEPRECATE"
    elif [ "$MTLS" = "1" ]; then
	NOSSL=1
    else
	NOSSL=1
	CPPFLAGS="$CPPFLAGS -DUSE_APPLE_SSL"
    fi
    LIBS="$LIBS -framework Security"
else
    if [ "$OPENSSL_LINK" = "1" ]; then
	LIBS="$LIBS -lcrypto -lssl"
    elif [ "$NOSSL" != "1" ]; then
	CPPFLAGS="$CPPFLAGS -DUSE_OPENSSL"
	LIBS="$LIBS -lssl -lcrypto -ldl"
    fi
fi
if [ "$OPENSSL_SYS" != "1" ] && [ "$OPENSSL_LINK" != "1" ] && [ "$NOSSL" != "1" ] && [ -z "$OPENSSL_DIST" ]; then
    CPPFLAGS="$CPPFLAGS -I$DEP_DIR/openssl/openssl-$PLATFORM/include"
    LIBDIRS="$LIBDIRS -L$DEP_DIR/openssl/openssl-$PLATFORM/lib"
fi

# Apple libs
if [ "$APPLE_FAMILY" = "1" ]; then
    LIBS="$LIBS -framework CoreFoundation -framework SystemConfiguration -framework IOKit -framework ApplicationServices"
fi

# boost
#CPPFLAGS="$CPPFLAGS -I$DEP_DIR/boost"
#LIBS="$LIBS -lboost_system"
#LIBDIRS="$LIBDIRS -L$DEP_DIR/boost/stage-$PLATFORM/lib"
#if [ "$NOTHREADS" = "1" ]; then
#    CPPFLAGS="$CPPFLAGS -DBOOST_DISABLE_THREADS"
#else
#    #LIBS="$LIBS -lboost_thread" # no longer needed because we use std::thread now
#    [ "$PLATFORM" != "android" ] && FLAGS="$FLAGS -pthread"
#fi

# asio
if [ "$ASIO" = "1" ] || [ "$ASIO_DIR" ]; then
    [ -z "$ASIO_DIR" ] && ASIO_DIR="$DEP_DIR/asio"
    CPPFLAGS="$CPPFLAGS -DUSE_ASIO -DASIO_STANDALONE -DASIO_NO_DEPRECATED -I$ASIO_DIR/asio/include"
fi

# gtest
if [ "$GTEST_DIR" ]; then
    CPPFLAGS="$CPPFLAGS -I$GTEST_DIR/googletest/include"
    LIBDIRS="$LIBDIRS -L$GTEST_DIR/lib"
    LIBS="$LIBS -lgtest"
fi

# LZO compression
if [ "$LZO" = "1" ]; then
    LIBDIRS="$LIBDIRS -L$DEP_DIR/lzo/lzo-$PLATFORM/lib"
    CPPFLAGS="$CPPFLAGS -I$DEP_DIR/lzo/lzo-$PLATFORM/include"
    LIBS="$LIBS -llzo2"
    CPPFLAGS="$CPPFLAGS -DHAVE_LZO"
fi

# LZ4 compression
if [ "$LZ4_SYS" = "1" ]; then
    CPPFLAGS="$CPPFLAGS -DHAVE_LZ4"
    LIBS="$LIBS -llz4"
elif [ "$LZ4" = "1" ]; then
    EXTRA_SRC_OBJ="$EXTRA_SRC_OBJ $DEP_DIR/lz4/lz4-$PLATFORM/lib/liblz4.a"
    CPPFLAGS="$CPPFLAGS -I$DEP_DIR/lz4/lz4-$PLATFORM/include -DHAVE_LZ4"
fi

# Snappy compression
if [ "$SNAP" = "1" ]; then
    LIBDIRS="$LIBDIRS -L$DEP_DIR/snappy/snappy-$PLATFORM/lib"
    CPPFLAGS="$CPPFLAGS -I$DEP_DIR/snappy/snappy-$PLATFORM/include"
    LIBS="$LIBS -lsnappy"
    CPPFLAGS="$CPPFLAGS -DHAVE_SNAPPY"
fi

# Cityhash
if [ "$CITY" = "1" ]; then
    if [ -d "$DEP_DIR/cityhash/cityhash-$PLATFORM/lib" ]; then
	LIBDIRS="$LIBDIRS -L$DEP_DIR/cityhash/cityhash-$PLATFORM/lib"
    fi
    if [ -d "$DEP_DIR/cityhash/cityhash-$PLATFORM/include" ]; then
	CPPFLAGS="$CPPFLAGS -I$DEP_DIR/cityhash/cityhash-$PLATFORM/include"
    fi
    LIBS="$LIBS -lcityhash"
    CPPFLAGS="$CPPFLAGS -DHAVE_CITYHASH"
fi

# XXHash
if [ "$XXHASH" = "1" ] || [ "$XXHASH_DIR" ]; then
    [ -z "$XXHASH_DIR" ] && XXHASH_DIR="$DEP_DIR/xxHash"
    CPPFLAGS="$CPPFLAGS -DHAVE_XXHASH -I$XXHASH_DIR"
fi

# libcap
if [ "$CAP" = "1" ]; then
    LIBS="$LIBS -lcap"
    CPPFLAGS="$CPPFLAGS -DHAVE_LIBCAP"
fi

# libsystemd
if [ "$SYSD" = "1" ]; then
    LIBS="$LIBS -lsystemd"
    CPPFLAGS="$CPPFLAGS -DHAVE_LIBSYSTEMD"
fi

# libsqlite3
if [ "$SQLITE" = "1" ]; then
    LIBS="$LIBS -lsqlite3"
    CPPFLAGS="$CPPFLAGS -DHAVE_SQLITE"
fi

# PCRE
if [ "$PCRE" = "1" ]; then
    LIBS="$LIBS -lpcre"
fi

# ASAN requested -- ensure higher-fidelity stacks
if [ "$ASAN" = "1" ]; then
    FLAGS+=" -ggdb3 -fno-omit-frame-pointer -fsanitize=address"
    CPPFLAGS="$CPPFLAGS -DINSTRUMENTATION_SLOWDOWN"
else
    ASAN=
fi

# Valgrind -- but only if ASAN is not enabled
if [ "$ASAN" = "" -a "$VAL" ]; then
    CPPFLAGS="$CPPFLAGS -DHAVE_VALGRIND -DINSTRUMENTATION_SLOWDOWN"
fi

# JVM
if [ "$JAVA" = "1" ]; then
    if [ -z "$JAVA_HOME" ]; then
	echo JAVA_HOME not defined
	exit 1
    fi
    LIBDIRS="$LIBDIRS -L$JAVA_HOME/jre/lib/amd64/server"
    CPPFLAGS="$CPPFLAGS -I$JAVA_HOME/include -I$JAVA_HOME/include/linux"
    LIBS="$LIBS -ljvm"
fi

# other environments
for s in $(enum_build_extras) ; do
    . $s deps
done

# Android NDK
if [ "$PLATFORM" = "android" ]; then
    CPPFLAGS="$CPPFLAGS -D__GLIBC__"
    CPPFLAGS="$CPPFLAGS -D_GLIBCXX_HAVE_FENV_H=1"
#   CPPFLAGS="$CPPFLAGS -DBOOST_NO_INTRINSIC_WCHAR_T"
fi

# Special platform flags
if [ "$PLATFORM_FLAGS" ]; then
    FLAGS="$FLAGS $PLATFORM_FLAGS"
fi

# C++ compiler flags
if [ "$CXX_COMPILER_FLAGS" ]; then
    FLAGS="$FLAGS $CXX_COMPILER_FLAGS"
fi

# Other compiler flags
if [ "$OTHER_COMPILER_FLAGS" ]; then
    FLAGS="$FLAGS $OTHER_COMPILER_FLAGS"
fi

# ovpn3
CPPFLAGS="$CPPFLAGS -I$O3/core"

# profile-guided optimization
if [ "$PGEN" = "1" ]; then
    FLAGS="$FLAGS -fprofile-generate"
elif [ "$PUSE" = "1" ]; then
    FLAGS="$FLAGS -fprofile-use"
fi

# compiler flags
FLAGS="$LIB_OPT_LEVEL $FLAGS"

# whole-program
if [ "$CLANG" != "1" ] && [ "$DEBUG_BUILD" != "1" ] && [ -z "$EXTRA_CPP" ] && [ "$CO" != "1" ]; then
    FLAGS="-fwhole-program $FLAGS"
fi

# compile only
if [ "$CO" == "1" ]; then
    OUTPUT="-c"
    LIBDIRS=""
    LIBS=""
    EXTRA_SRC_OBJ=""
else
    OUTPUT="-o $OUTBIN"
fi

# main source file
MAIN_CPP="$1.cpp"
if ! [ -e "$MAIN_CPP" ] && [ "$EXTRA_CPP" ]; then
    MAIN_CPP=""
fi

# release/debug builds
if [ "$DEBUG" = "1" ]; then
    # build with debug symbols
    if [ "$PLATFORM" = "linux" ]; then
	FLAGS="-ggdb $FLAGS"
    else
	FLAGS="-g $FLAGS"
    fi
else
    # release build
    [ "$CLANG" != "1" ] && FLAGS="$FLAGS -flto=4 -Wl,--no-as-needed"
    [ "$GPROF" = "1" ] && FLAGS="$FLAGS -pg"
fi


if [ ! -z "${EXTRA_CPP_OBJS}" ]; then
  for CPP_OBJ in $EXTRA_CPP_OBJS $MAIN_CPP; do
      [ "$ECHO" = "1" ] && echo "compiling $CPP_OBJ"
      CMD="$GPP_CMD $FLAGS $GCC_EXTRA $CPPFLAGS $LIBDIRS $CPP_OBJ -c -o $CPP_OBJ.o"
      [ "$ECHO" = "1" ] && echo $CMD
      $CMD
      EXTRA_SRC_OBJ="${EXTRA_SRC_OBJ} $CPP_OBJ.o"
  done
  MAIN_CPP=""
fi

# Construct command
if [ "$OBJC" == "1" ]; then
    FLAGS="$FLAGS -fobjc-arc"
    LIBS="-framework Foundation $LIBS"
    SRC="$1.mm"
    CMD="$GPP_CMD $FLAGS $GCC_EXTRA $CPPFLAGS $LIBDIRS $SRC $EXTRA_CPP $EXTRA_SRC_OBJ $OUTPUT $LIBS"
else
    CMD="$GPP_CMD $FLAGS $GCC_EXTRA $CPPFLAGS $LIBDIRS $MAIN_CPP $EXTRA_CPP $EXTRA_SRC_OBJ $OUTPUT $LIBS"
fi

# execute CMD
[ "$ECHO" = "1" ] && echo $CMD
$CMD

# maybe strip
[ "$STRIP" = "1" ] && $STRIP_CMD $OUTBIN
exit 0