#!/bin/sh

if [ "x$DEBUG" = "x" ]; then
    :
else
    set -x
fi

if [ "x$BUILDTYPE" = "xdebug" ]; then
    CGO_CFLAGS="$CGO_CFLAGS -DWITH_DEBUG=1 -Og -ggdb "
    CGO_LDFLAGS="$CGO_LDFLAGS -Og -ggdb "
    GO_FLAGS=' -gcflags "all=-N -l"'

    export CGO_CFLAGS CGO_LDFLAGS GO_FLAGS
fi

fix_env() {
    local _n _x _cmd _v

    _n="$1"
    shift
    _cmd="sed "
    for _x in $*; do
        _v=$(eval $(echo "echo \$$_x") | sed -s 's@"@@g')
        _cmd="$_cmd -e s|@$_x@|$_v|g "
    done
    _v=$(eval $(echo "echo \$$_n"))
    _cmd="$_n=\"$(echo $_v | $_cmd)\"; export $_n"
    eval "$_cmd"
}

# fix value of environment variable by realpath
# of it
fix_input_envs() {
    local _n _v _cmd

    for _n in CURRENT_SOURCE_DIR BUILD_ROOT; do
        _v=$(eval $(echo "echo \$$_n") | sed -e 's@"@@g')
        _v=$(realpath $_v)
        _cmd="$_n=$_v; export $_n"
        eval "$_cmd"
    done
}

# fix dependencies, by:
#  for math just add -lmath
#  for thread by add -pthread
#  otherwise using
#     pkg-config --cflags/ pkg-config --libs
fix_dependencies() {
    local _x _cflags _ldflags

    for _x in $DEPENDENCIES; do
        case "$_x" in
            math)
                _cflags=""
                _ldflags="-lm"
                ;;
            thread)
                _cflags="-pthread"
                _ldflags="-pthread"
                ;;
            *)
                _cflags=$(pkg-config --cflags "$_x")
                _ldflags=$(pkg-config --libs "$_x")
                ;;
        esac
        
        CGO_CFLAGS="$CGO_CFLAGS $_cflags"
        CGO_LDFLAGS="$CGO_LDFLAGS $_ldflags"
    done

    export CGO_CFLAGS CGO_LDFLAGS
}

if [ "$#" -ne 2 ]; then
    echo go_build sfile dest
    exit 1
fi

_sfile=$(realpath "$1")
_sdir=$(dirname "$_sfile")
_dfile=$(realpath "$2")

fix_input_envs
fix_dependencies

if [ -z "$HOME" -o ! -w "$HOME" ]; then
    HOME=$TMPDIR
    export HOME
fi

export GOCACHE=$TMPDIR/go-cache
export GOPATH="$TMPDIR/go"

for _n in $FIX_ENVARS; do
    fix_env $_n $ENVARS;
done

export GOPROXY=https://goproxy.cn

(cd $_sdir; go build -gcflags "all=-N -l" -o "$_dfile" "$_sfile")