#!/bin/sh
# Build mgsh for the usual platforms into ./bin, auto-incrementing the patch
# version by 0.0.1 on every build.
#
# version.txt holds the currently built version. Each run increments the patch
# component, then builds every platform with that one version injected via
# -ldflags, and writes it back. So version.txt always reflects the version of
# the binaries just built, and all of them carry the same one.
#
# Override the platform list to build just one:
#   PLATFORMS="linux/amd64" ./build.sh
#
# Windows is deliberately absent: mgsh shells out to stty and /bin/sh, so it
# would compile there and then not work.
set -e
cd "$(dirname "$0")"

PLATFORMS=${PLATFORMS:-"darwin/arm64 darwin/amd64 linux/amd64 linux/arm64"}

V=$(cat version.txt 2>/dev/null || echo 4.0.0)

# split MAJOR.MINOR.PATCH and increment PATCH (no carry: 4.0.9 -> 4.0.10)
MAJOR=${V%%.*}
REST=${V#*.}
MINOR=${REST%%.*}
PATCH=${REST#*.}
PATCH=$((PATCH + 1))
NV="$MAJOR.$MINOR.$PATCH"

# earlier versions built ./mgsh in the repo root; drop it so nothing keeps
# running a stale binary from a path that is no longer written
if [ -f mgsh ]; then
	rm -f mgsh
	echo "removed stale ./mgsh (the build now writes ./bin)"
fi

mkdir -p bin
HOST="$(go env GOOS)/$(go env GOARCH)"

for p in $PLATFORMS; do
	os=${p%/*}
	arch=${p#*/}
	out="bin/mgsh-$os-$arch"

	# CGO_ENABLED=0 throughout: it makes the cross builds work without a
	# toolchain per target and the binaries static, and os/user still resolves
	# the current user without cgo on both darwin and linux.
	CGO_ENABLED=0 GOOS="$os" GOARCH="$arch" \
		go build -ldflags "-X main.VERSION=$NV" -o "$out" .

	if [ "$p" = "$HOST" ]; then
		ln -sf "mgsh-$os-$arch" bin/mgsh # the one for this machine
		echo "  $out  ->  bin/mgsh"
	else
		echo "  $out"
	fi
done

echo "$NV" > version.txt
echo "built mgsh v$NV"