GO_PACKAGE ?= git.kle.li/tools/go-import-redirector
BINARY_BASE_NAME ?= $(shell echo ${GO_PACKAGE} | rev | cut -d'/' -f1 | rev)

DIST := dist
DIST_BIN_DIR := $(DIST)/binaries
DIST_RELEASE_DIR := $(DIST)/release
DIST_DOCKER_DIR := $(DIST)/docker
DIST_DIRS := $(DIST_BIN_DIR) $(DIST_RELEASE_DIR) $(DIST_DOCKER_DIR)

# Tool packages
GOLANGCI_LINT_PACKAGE ?= github.com/golangci/golangci-lint/cmd/golangci-lint@latest
XGO_PACKAGE ?= src.techknowlogick.com/xgo@latest
GOVULNCHECK_PACKAGE ?= golang.org/x/vuln/cmd/govulncheck@latest
GXZ_PAGAGE ?= github.com/ulikunitz/xz/cmd/gxz@v0.5.11

# Allow overriding the go binary
GO ?= go

SHASUM ?= shasum -a 256

# Construct the version strings

# VERSION default to dev or in CI next for default branch, and branch name for everything else...
ifneq ($(CI),)
    # in CI
	ifeq ($(CI_REPO_DEFAULT_BRANCH),$(CI_COMMIT_BRANCH))
    	VERSION ?= next
	else
		VERSION ?= $(CI_COMMIT_BRANCH)
	endif
else
    # not in CI
    VERSION ?= dev
endif

# VERSION_NUMBER semver compliant without the v prefix
VERSION_NUMBER ?= 0.0.0

# Use CI_COMMIT_TAG from CI if set as version and version number
ifneq ($(CI_COMMIT_TAG),)
    ISTAG := "true"
	VERSION := $(CI_COMMIT_TAG:v%=%)
	VERSION_NUMBER := ${VERSION}
else
	ISTAG := "false"
endif

# Use CI provided SHA, else use git
ifneq ($(CI_COMMIT_SHA),)
    SOURCE_SHA := $(CI_COMMIT_SHA)
endif

SOURCE_SHA ?= $(shell git rev-parse HEAD)
SOURCE_SHA_SHORT := $(shell echo ${SOURCE_SHA} | head -c 8)

COMMITTIME = $(shell git log -1 --format=%ct | xargs -I{} date -u +%Y%m%d%H%M%S -d "@{}")

# VERSIONED_BINARY is the base output name for xgo
VERSIONED_BINARY := $(BINARY_BASE_NAME)-$(VERSION)

# https://docs.gitlab.com/ee/ci/variables/predefined_variables.html
# https://woodpecker-ci.org/docs/next/usage/environment
# gl GITLAB_CI CI CI_COMMIT_TAG CI_DEFAULT_BRANCH CI_COMMIT_SHA CI_COMMIT_SHORT_SHA CI_MERGE_REQUEST_IID CI_PIPELINE_SOURCE
# WP CI=woodpecker CI_COMMIT_TAG CI_REPO_DEFAULT_BRANCH CI_COMMIT_SHA CI_COMMIT_PULL_REQUEST

# Default LDFlags, stripping, dwarfing, statically linking and adding the version and commit to pkg/meta, extendable via LDFLAGS
LDFLAGS := $(LDFLAGS) -s -w
LDFLAGS := $(LDFLAGS) -X ${GO_PACKAGE}/pkg/meta.version=${VERSION}
LDFLAGS := $(LDFLAGS) -X ${GO_PACKAGE}/pkg/meta.commit=${SOURCE_SHA}
LDFLAGS := $(LDFLAGS) -X ${GO_PACKAGE}/pkg/meta.commitTime=${COMMITTIME}
LDFLAGS := $(LDFLAGS) -X ${GO_PACKAGE}/pkg/meta.isTag=${ISTAG}
LDFLAGS := $(LDFLAGS) -X ${GO_PACKAGE}/pkg/meta.branch=${CI_COMMIT_BRANCH}
LDFLAGS := $(LDFLAGS) -X ${GO_PACKAGE}/pkg/meta.defaultBranch=${CI_REPO_DEFAULT_BRANCH}
# Disable cgo, but overridable
CGO_ENABLED ?= 0

HAS_GO = $(shell hash go > /dev/null 2>&1 && echo "GO" || echo "NOGO" )
ifeq ($(HAS_GO),GO)
	GOPATH ?= $(shell $(GO) env GOPATH)
	export PATH := $(GOPATH)/bin:$(PATH)
	CGO_CFLAGS ?= $(shell $(GO) env CGO_CFLAGS) $(CGO_EXTRA_CFLAGS)
endif

GOFLAGS := -v -trimpath
EXECUTABLE ?= $(BINARY_BASE_NAME)

# Release packagin stuffs...
STORED_VERSION_FILE := VERSION
TAR_EXCLUDES := .git $(EXECUTABLE) $(DIST)

# just print the help instead of running any builds...
all: help

##@ Prerequisites

.PHONY: go-check
go-check: ## Check Go version >= go.mod version
	$(eval MIN_GO_VERSION_STR := $(shell grep -Eo '^go\s+[0-9]+\.[0-9]+' go.mod | cut -d' ' -f2))
	$(eval MIN_GO_VERSION := $(shell printf "%03d%03d" $(shell echo '$(MIN_GO_VERSION_STR)' | tr '.' ' ')))
	$(eval GO_VERSION := $(shell printf "%03d%03d" $(shell $(GO) version | grep -Eo '[0-9]+\.[0-9]+' | tr '.' ' ');))
	@if [ "$(GO_VERSION)" -lt "$(MIN_GO_VERSION)" ]; then \
		echo "This project requires Go $(MIN_GO_VERSION_STR) or greater to build. You can get it at https://go.dev/dl/"; \
		exit 1; \
	fi

##@ Convention Checking

.PHONY: checks ## Run all checks
checks: tidy-check security-check

.PHONY: tidy-check
tidy-check: tidy ## Check that mods have been cleaned up before checking in
	@diff=$$(git diff --color=always go.mod go.sum); \
	if [ -n "$$diff" ]; then \
		echo "Please run 'make tidy' and commit the result:"; \
		echo "$${diff}"; \
		exit 1; \
	fi

.PHONY: security-check
security-check:
	go run $(GOVULNCHECK_PACKAGE) ./...

##@ Linting

.PHONY: lint
lint: ## Lint code
	@echo "Running golangci-lint"
	go run $(GOLANGCI_LINT_PACKAGE) run --timeout 10m

##@ Others

# Help prints all targets (identified by ##) and categories (identified by ##@)
.PHONY: help
help: ## Display this help.
	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n"} /^[a-zA-Z_0-9-]+:.*?##/ { printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)

.PHONY: clean
clean: ## Cleanup
	$(GO) clean -i ./...
	rm -rf $(EXECUTABLE) $(DIST) vendor

.PHONY: tidy
tidy: ## Tidy mods
	$(eval MIN_GO_VERSION := $(shell grep -Eo '^go\s+[0-9]+\.[0-9.]+' go.mod | cut -d' ' -f2))
	$(GO) mod tidy -compat=$(MIN_GO_VERSION)

vendor: go.mod go.sum ## Download mods to vendor
	$(GO) mod vendor
	@touch vendor

.PHONY: build
build: go-check build-linux ## Build the binary matching the local system

$(DIST_DIRS):
	mkdir -p $(DIST_DIRS)

.PHONY: build-linux
build-linux: | $(DIST_DIRS)
	CGO_ENABLED="$(CGO_ENABLED)" CGO_CFLAGS="$(CGO_CFLAGS)" $(GO) build $(GOFLAGS) -tags 'netgo osusergo tzdata $(TAGS)' -ldflags '$(LDFLAGS)' -o $(DIST_BIN_DIR)/$(VERSIONED_BINARY)

.PHONY: release-copy
release-copy: | $(DIST_DIRS)
	cd $(DIST); for file in `find . -type f -name "*"`; do cp $${file} ./release/; done;

.PHONY: release-check
release-check: | $(DIST_DIRS)
	cd $(DIST)/release/; for file in `find . -type f -name "*"`; do echo "checksumming $${file}" && $(SHASUM) `echo $${file} | sed 's/^..//'` > $${file}.sha256; done;

.PHONY: release-compress
release-compress: | $(DIST_DIRS)
	cd $(DIST)/release/; for file in `find . -type f -name "*"`; do echo "compressing $${file}" && $(GO) run $(GXZ_PAGAGE) -k -9 $${file}; done;

.PHONY: release-sources
release-sources: | $(DIST_DIRS)
	echo $(VERSION) > $(STORED_VERSION_FILE)
# bsdtar needs a ^ to prevent matching subdirectories
	$(eval EXCL := --exclude=$(shell tar --help | grep -q bsdtar && echo "^")./)
# use transform to a add a release-folder prefix; in bsdtar the transform parameter equivalent is -s
	$(eval TRANSFORM := $(shell tar --help | grep -q bsdtar && echo "-s '/^./$(BINARY_BASE_NAME)-src-$(VERSION)/'" || echo "--transform 's|^./|$(BINARY_BASE_NAME)-src-$(VERSION)/|'"))
	tar $(addprefix $(EXCL),$(TAR_EXCLUDES)) $(TRANSFORM) -czf $(DIST)/release/$(BINARY_BASE_NAME)-src-$(VERSION).tar.gz .
	rm -f $(STORED_VERSION_FILE)

.PHONY: release ## Prepare a full release
release: build-linux # release-copy release-compress vendor release-sources release-check

.PHONY: dockerize
dockerize: | $(DIST_DIRS)
	cp -R docker/fscopy/* $(DIST_DOCKER_DIR)/
	cp $(DIST_BIN_DIR)/$(VERSIONED_BINARY) $(DIST_DOCKER_DIR)/bin/$(BINARY_BASE_NAME)
	docker/make_dockerfile.sh > $(DIST_DOCKER_DIR)/Dockerfile