#! /bin/bash

# Go Compiler 
# Source: https://go.dev/dl/go1.17.8.src.tar.gz
#
# $BUILD = Directory to temporarily install
# $PKGS  = Directory to store built packages
#
# DEPS
# Required:     golang-bootstrap
# Recommended:  NONE
# Optional:     NONE

# Apply patches from Alpine Linux
patch -Np1 -i ../patches/go-alpine/allow-unshare-to-return-enosys.patch 
patch -Np1 -i ../patches/go-alpine/disable-flaky-gc-test.patch
patch -Np1 -i ../patches/go-alpine/disable-flaky-sync-test.patch 

# For AMD64/x86_64
export GOARCH="amd64"

# For i686
# export GOARCH=386
# For arch64
# export GOARCH=arm64
# For armv7
# export GOARCH="arm" GOARM=7
# For armhf
# export GOARCH="arm" GOARM=6

# compile go itself as a PIE on supported arches.
case $(uname -m) in
	x86_64|s390x|aarch64) export GO_LDFLAGS=-buildmode=pie ;;
esac

export GOOS="linux"
export GOPATH="/src"
export GOROOT="/src/go"
export GOBIN="$GOROOT"/bin
export GOROOT_FINAL=/usr/lib/go

for p in /usr/lib/go-bootstrap /usr/lib/go-linux-$GOARCH-bootstrap /usr/lib/go; do
	if [ -d "$p" ]; then
		export GOROOT_BOOTSTRAP="$p"
		break
	fi
done

# Build!
cd src && ./make.bash -v

# Install
cd .. && \
sudo -S mkdir -pv $BUILD/usr/bin $BUILD/usr/lib/go/bin $BUILD/usr/share/doc/go &&
for binary in go gofmt; do
	sudo -S install -Dm755 bin/"$binary" $BUILD/usr/lib/go/bin/"$binary"
	sudo -S ln -sv ../../usr/lib/go/bin/"$binary" $BUILD/usr/bin/
done

sudo -S cp -av  pkg lib  $BUILD/usr/lib/go       && \
sudo -S cp -rv  doc misc $BUILD/usr/share/doc/go && \
sudo -S rm -rfv $BUILD/usr/lib/go/pkg/obj        && \
sudo -S rm -rfv $BUILD/usr/lib/go/pkg/bootstrap  && \
sudo -S rm -fv  $BUILD/usr/lib/go/pkg/tool/*/api && \

sudo -S mkdir -pv $BUILD/usr/lib/go/ && \
sudo -S cp -a src $BUILD/usr/lib/go/ && \

# Per Alpine Linux
# Remove tests from /usr/lib/go/src to reduce package size,
# these should not be needed at run-time by any program.
find $BUILD/usr/lib/go/src \( -type f -a -name "*_test.go" \) \
	-exec sudo -S rm -rf \{\} \+
find $BUILD/usr/lib/go/src \( -type d -a -name "testdata" \) \
	-exec sudo -S rm -rf \{\} \+

# Per Alpine Linux
# Remove rc (plan 9) and bat scripts (windows) to reduce package
#
# See: https://gitlab.alpinelinux.org/alpine/aports/issues/11091
find $BUILD/usr/lib/go/src -type f -a \( -name "*.rc" -o -name "*.bat" \) \
	-exec sudo -S rm -rf \{\} \+

cd $BUILD && sudo -S mkdir -v ${BUILD}/install &&
cat > /tmp/slack-desc << "EOF"
# HOW TO EDIT THIS FILE:
# The "handy ruler" below makes it easier to edit a package description.  Line
# up the first '|' above the ':' following the base package name, and the '|'
# on the right side marks the last column you can put a character in.  You must
# make exactly 11 lines for the formatting to be correct.  It's also
# customary to leave one space after the ':' except on otherwise blank lines.

      |-----handy-ruler------------------------------------------------------|
golang: golang
golang:
golang: Go programming language compiler
golang:
golang: https://go.dev/
golang:
EOF
sudo -S mv -v /tmp/slack-desc install/ &&
sudo -S mkdir -pv /BMAN/install /BMAN/usr && \
sudo mv $BUILD/usr/share /BMAN/usr/ && \
sudo -S makepkg -l y -c n $PKGS/golang-1.17.8-$(uname -m)-mlfs.txz &&
cd /BMAN && \
cat > /tmp/slack-desc << "EOF"
golang-doc: Documentation for golang
golang-doc:
golang-doc: Go programming language compiler
golang-doc:
golang-doc: https://go.dev/
golang-doc:
EOF
sudo -S mv -v /tmp/slack-desc install/ && \
sudo -S makepkg -l y -c n $PKGS/golang-doc-1.17.8-noarch-mlfs.txz &&
sudo -S rm -rf ${BUILD}/*