# This is the default Clever Golang Makefile.
# It is stored in the dev-handbook repo, github.com/Clever/dev-handbook
# Please do not alter this file directly.
GOLANG_MK_VERSION := 0.4.0

SHELL := /bin/bash
SYSTEM := $(shell uname -a | cut -d" " -f1 | tr '[:upper:]' '[:lower:]')
.PHONY: golang-test-deps bin/dep golang-ensure-curl-installed

# set timezone to UTC for golang to match circle and deploys
export TZ=UTC

# if the gopath includes several directories, use only the first
GOPATH=$(shell echo $$GOPATH | cut -d: -f1)

# This block checks and confirms that the proper Go toolchain version is installed.
# It uses ^ matching in the semver sense -- you can be ahead by a minor
# version, but not a major version (patch is ignored).
# arg1: golang version
define golang-version-check
_ := $(if  \
		$(shell  \
			expr >/dev/null  \
				`go version | cut -d" " -f3 | cut -c3- | cut -d. -f2 | sed -E 's/beta[0-9]+//'`  \
				\>= `echo $(1) | cut -d. -f2`  \
				\&  \
				`go version | cut -d" " -f3 | cut -c3- | cut -d. -f1`  \
				= `echo $(1) | cut -d. -f1`  \
			&& echo 1),  \
		@echo "",  \
		$(error must be running Go version ^$(1) - you are running $(shell go version | cut -d" " -f3 | cut -c3-)))
endef

# FGT is a utility that exits with 1 whenever any stderr/stdout output is recieved.
FGT := $(GOPATH)/bin/fgt
$(FGT):
	go get github.com/GeertJohan/fgt

golang-ensure-curl-installed:
	@command -v curl >/dev/null 2>&1 || { echo >&2 "curl not installed. Please install curl."; exit 1; }

DEP_VERSION = v0.4.1
DEP_INSTALLED := $(shell [[ -e "bin/dep" ]] && bin/dep version | grep version | grep -v go | cut -d: -f2 | tr -d '[:space:]')
# Dep is a tool used to manage Golang dependencies. It is the offical vendoring experiment, but
# not yet the official tool for Golang.
ifeq ($(DEP_VERSION),$(DEP_INSTALLED))
bin/dep: # nothing to do, dep is already up-to-date
else
CACHED_DEP = /tmp/dep-$(DEP_VERSION)
bin/dep: golang-ensure-curl-installed
	@echo "Updating dep..."
	@mkdir -p bin
	@if [ ! -f $(CACHED_DEP) ]; then curl -o $(CACHED_DEP) -sL https://github.com/golang/dep/releases/download/$(DEP_VERSION)/dep-$(SYSTEM)-amd64; fi;
	@cp $(CACHED_DEP) bin/dep
	@chmod +x bin/dep || true
endif

# figure out "github.com/<org>/<repo>"
# `go list` will fail if there are no .go files in the directory
# if this is the case, fall back to assuming github.com/Clever
REF = $(shell go list || echo github.com/Clever/$(notdir $(shell pwd)))
golang-verify-no-self-references:
	@if grep -q -i "$(REF)" Gopkg.lock; then echo "Error: Gopkg.lock includes a self-reference ($(REF)), which is not allowed. See: https://github.com/golang/dep/issues/1690" && exit 1; fi;
	@if grep -q -i "$(REF)" Gopkg.toml; then echo "Error: Gopkg.toml includes a self-reference ($(REF)), which is not allowed. See: https://github.com/golang/dep/issues/1690" && exit 1; fi;

golang-dep-vendor-deps: bin/dep golang-verify-no-self-references

# golang-godep-vendor is a target for saving dependencies with the dep tool
# to the vendor/ directory. All nested vendor/ directories are deleted via
# the prune command.
# In CI, -vendor-only is used to avoid updating the lock file.
ifndef CI
define golang-dep-vendor
bin/dep ensure -v
endef
else
define golang-dep-vendor
bin/dep ensure -v -vendor-only
endef
endif

# Golint is a tool for linting Golang code for common errors.
GOLINT := $(GOPATH)/bin/golint
$(GOLINT):
	go get golang.org/x/lint/golint

# golang-fmt-deps requires the FGT tool for checking output
golang-fmt-deps: $(FGT)

# golang-fmt checks that all golang files in the pkg are formatted correctly.
# arg1: pkg path
define golang-fmt
@echo "FORMATTING $(1)..."
@$(FGT) gofmt -l=true $(GOPATH)/src/$(1)/*.go
endef

# golang-lint-deps requires the golint tool for golang linting.
golang-lint-deps: $(GOLINT)

# golang-lint calls golint on all golang files in the pkg.
# arg1: pkg path
define golang-lint
@echo "LINTING $(1)..."
@find $(GOPATH)/src/$(1)/*.go -type f | grep -v gen_ | xargs $(GOLINT)
endef

# golang-lint-deps-strict requires the golint tool for golang linting.
golang-lint-deps-strict: $(GOLINT) $(FGT)

# golang-lint-strict calls golint on all golang files in the pkg and fails if any lint
# errors are found.
# arg1: pkg path
define golang-lint-strict
@echo "LINTING $(1)..."
@find $(GOPATH)/src/$(1)/*.go -type f | grep -v gen_ | xargs $(FGT) $(GOLINT)
endef

# golang-test-deps is here for consistency
golang-test-deps:

# golang-test uses the Go toolchain to run all tests in the pkg.
# arg1: pkg path
define golang-test
@echo "TESTING $(1)..."
@go test -v $(1)
endef

# golang-test-strict-deps is here for consistency
golang-test-strict-deps:

# golang-test-strict uses the Go toolchain to run all tests in the pkg with the race flag
# arg1: pkg path
define golang-test-strict
@echo "TESTING $(1)..."
@go test -v -race $(1)
endef

# golang-vet-deps is here for consistency
golang-vet-deps:

# golang-vet uses the Go toolchain to vet all the pkg for common mistakes.
# arg1: pkg path
define golang-vet
@echo "VETTING $(1)..."
@go vet $(GOPATH)/src/$(1)/*.go
endef

# golang-test-all-deps installs all dependencies needed for different test cases.
golang-test-all-deps: golang-fmt-deps golang-lint-deps golang-test-deps golang-vet-deps

# golang-test-all calls fmt, lint, vet and test on the specified pkg.
# arg1: pkg path
define golang-test-all
$(call golang-fmt,$(1))
$(call golang-lint,$(1))
$(call golang-vet,$(1))
$(call golang-test,$(1))
endef

# golang-test-all-strict-deps: installs all dependencies needed for different test cases.
golang-test-all-strict-deps: golang-fmt-deps golang-lint-deps-strict golang-test-strict-deps golang-vet-deps

# golang-test-all-strict calls fmt, lint, vet and test on the specified pkg with strict
# requirements that no errors are thrown while linting.
# arg1: pkg path
define golang-test-all-strict
$(call golang-fmt,$(1))
$(call golang-lint-strict,$(1))
$(call golang-vet,$(1))
$(call golang-test-strict,$(1))
endef

# golang-build: builds a golang binary. ensures CGO build is done during CI. This is needed to make a binary that works with a Docker alpine image.
# arg1: pkg path
# arg2: executable name
define golang-build
@echo "BUILDING..."
@if [ -z "$$CI" ]; then \
	go build -o bin/$(2) $(1); \
else \
	echo "-> Building CGO binary"; \
	CGO_ENABLED=0 go build -installsuffix cgo -o bin/$(2) $(1); \
fi;
endef

# golang-update-makefile downloads latest version of golang.mk
golang-update-makefile:
	@wget https://raw.githubusercontent.com/Clever/dev-handbook/master/make/golang.mk -O /tmp/golang.mk 2>/dev/null
	@if ! grep -q $(GOLANG_MK_VERSION) /tmp/golang.mk; then cp /tmp/golang.mk golang.mk && echo "golang.mk updated"; else echo "golang.mk is up-to-date"; fi