.PHONY: generate build test vet cover release docs docs-clean clean format lint
.DEFAULT_GOAL := build

ARTIFACTDIR := artifacts

ifdef ZREPL_VERSION
    _ZREPL_VERSION := $(ZREPL_VERSION)
endif
ifndef _ZREPL_VERSION
    _ZREPL_VERSION := $(shell git describe --always --dirty 2>/dev/null || echo "ZREPL_BUILD_INVALID_VERSION" )
    ifeq ($(_ZREPL_VERSION),ZREPL_BUILD_INVALID_VERSION) # can't use .SHELLSTATUS because Debian Stretch is still on gmake 4.1
        $(error cannot infer variable ZREPL_VERSION using git and variable is not overriden by make invocation)
    endif
endif
GO := go
GO_LDFLAGS := "-X github.com/zrepl/zrepl/version.zreplVersion=$(_ZREPL_VERSION)"
GO_MOD_READONLY := -mod=readonly
GO_BUILDFLAGS := $(GO_MOD_READONLY)
GO_BUILD := GO111MODULE=on $(GO) build $(GO_BUILDFLAGS) -v -ldflags $(GO_LDFLAGS)

# keep in sync with vet target
RELEASE_BINS := $(ARTIFACTDIR)/zrepl-freebsd-amd64
RELEASE_BINS += $(ARTIFACTDIR)/zrepl-linux-amd64
RELEASE_BINS += $(ARTIFACTDIR)/zrepl-linux-arm64
RELEASE_BINS += $(ARTIFACTDIR)/zrepl-darwin-amd64

RELEASE_NOARCH := $(ARTIFACTDIR)/zrepl-noarch.tar
THIS_PLATFORM_RELEASE_BIN := $(shell bash -c 'source <($(GO) env) && echo "zrepl-$${GOOS}-$${GOARCH}"' )

generate: #not part of the build, must do that manually
	protoc -I=replication/logic/pdu --go_out=plugins=grpc:replication/logic/pdu replication/logic/pdu/pdu.proto
	$(GO) generate $(GO_BUILDFLAGS) -x ./...

format:
	goimports -srcdir . -local 'github.com/zrepl/zrepl' -w $(shell find . -type f -name '*.go' -not -path "./vendor/*" -not -name '*.pb.go' -not -name '*_enumer.go')

lint:
	golangci-lint run ./...

build:
	$(GO_BUILD) -o "$(ARTIFACTDIR)/zrepl"

test:
	$(GO) test $(GO_BUILDFLAGS) ./...
	# TODO compile the tests for each supported platform
	# but `go test -c ./...` is not supported

vet:
	$(GO) vet $(GO_BUILDFLAGS) ./...
	# for each supported platform to cover conditional compilation
	# (keep in sync with RELEASE_BINS)
	GOOS=freebsd	GOARCH=amd64 	$(GO) vet $(GO_BUILDFLAGS) ./...
	GOOS=linux		GOARCH=amd64 	$(GO) vet $(GO_BUILDFLAGS) ./...
	GOOS=linux		GOARCH=arm64 	$(GO) vet $(GO_BUILDFLAGS) ./...
	GOOS=darwin		GOARCH=amd64 	$(GO) vet $(GO_BUILDFLAGS) ./...

$(ARTIFACTDIR):
	mkdir -p "$@"

$(ARTIFACTDIR)/docs: $(ARTIFACTDIR)
	mkdir -p "$@"

$(ARTIFACTDIR)/bash_completion: $(RELEASE_BINS)
	artifacts/$(THIS_PLATFORM_RELEASE_BIN) bashcomp "$@"

.PHONY: $(ARTIFACTDIR)/go_version.txt
$(ARTIFACTDIR)/go_version.txt:
	$(GO) version > $@

docs: $(ARTIFACTDIR)/docs
	make -C docs \
		html \
		BUILDDIR=../artifacts/docs \

docs-clean:
	make -C docs \
		clean \
		BUILDDIR=../artifacts/docs

.PHONY: $(RELEASE_BINS)
# TODO: two wildcards possible
$(RELEASE_BINS): $(ARTIFACTDIR)/zrepl-%: generate $(ARTIFACTDIR) vet test lint
	STEM=$*; GOOS="$${STEM%%-*}"; GOARCH="$${STEM##*-}"; export GOOS GOARCH; \
		$(GO_BUILD) -o "$(ARTIFACTDIR)/zrepl-$$GOOS-$$GOARCH"

$(RELEASE_NOARCH): docs $(ARTIFACTDIR)/bash_completion $(ARTIFACTDIR)/go_version.txt
	tar --mtime='1970-01-01' --sort=name \
		--transform 's/$(ARTIFACTDIR)/zrepl-$(_ZREPL_VERSION)-noarch/' \
		-acf $@ \
		$(ARTIFACTDIR)/docs/html \
		$(ARTIFACTDIR)/bash_completion \
		$(ARTIFACTDIR)/go_version.txt

release: $(RELEASE_BINS) $(RELEASE_NOARCH)
	rm -rf "$(ARTIFACTDIR)/release"
	mkdir -p "$(ARTIFACTDIR)/release"
	cp $^ "$(ARTIFACTDIR)/release"
	cd "$(ARTIFACTDIR)/release" && sha512sum $$(ls | sort) > sha512sum.txt
	@# note that we use ZREPL_VERSION and not _ZREPL_VERSION because we want to detect the override
	@if git describe --always --dirty 2>/dev/null | grep dirty >/dev/null; then \
        echo '[INFO] either git reports checkout is dirty or git is not installed or this is not a git checkout'; \
		if [ "$(ZREPL_VERSION)" = "" ]; then \
			echo '[WARN] git checkout is dirty and make variable ZREPL_VERSION was not used to override'; \
			git status; \
			echo "git diff:";  \
			git diff | cat; \
			exit 1; \
		fi; \
	fi;

clean: docs-clean
	rm -rf "$(ARTIFACTDIR)"