MKT_GIT_CHGLOG_VERSION ?= 0.15.4
MKT_GIT_CHGLOG_DOWNLOAD_URL ?= https://github.com/git-chglog/git-chglog/releases/download/v$(MKT_GIT_CHGLOG_VERSION)/git-chglog_$(MKT_GIT_CHGLOG_VERSION)_linux_amd64.tar.gz
MKT_GIT_CHGLOG_ARGS ?= --output CHANGELOG.md
MKT_GIT_CHGLOG_PROJECT_ORG ?= 
export MKT_GIT_CHGLOG_PROJECT_ORG
MKT_GIT_CHGLOG_PROJECT_NAME ?= 
export MKT_GIT_CHGLOG_PROJECT_NAME

define _MKT_GIT_CHGLOG_CONFIG_SCRIPT =
mkdir -p .chglog
cat > .chglog/config.yml << EOF
style: github
template: CHANGELOG.tpl.md
info:
  title: CHANGELOG
  repository_url: https://forge.cadoles.com/${MKT_GIT_CHGLOG_PROJECT_ORG}/${MKT_GIT_CHGLOG_PROJECT_NAME}
options:
  commits:
    filters:
      Type:
        - feat
        - fix
        - perf
        - refactor
        - docs
  commit_groups:
    title_maps:
      feat: Features
      fix: Bug Fixes
      perf: Performance Improvements
      refactor: Code Refactoring
      docs: Documentation
  header:
    pattern: "^(\\\\w*)(?:\\\\(([\\\\w\\\\$\\\\.\\\\-\\\\*\\\\s]*)\\\\))?\\\\:\\\\s(.*)$"
    pattern_maps:
      - Type
      - Scope
      - Subject
  notes:
    keywords:
      - BREAKING CHANGE
  issues:
    prefix:
      - '#'
EOF
endef
export MKT_GIT_CHGLOG_CONFIG_SCRIPT = $(value _MKT_GIT_CHGLOG_CONFIG_SCRIPT)

define _MKT_GIT_CHGLOG_TEMPLATE_SCRIPT =
mkdir -p .chglog
cat > .chglog/CHANGELOG.tpl.md << EOF
{{ if .Versions -}}
{{ if .Unreleased.CommitGroups -}}
<a name="unreleased"></a>
## [Unreleased]

{{ range .Unreleased.CommitGroups -}}
### {{ .Title }}
{{ range .Commits -}}
- {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
{{ end }}
{{ end -}}
{{ end -}}
{{ end -}}

{{ range .Versions }}
<a name="{{ .Tag.Name }}"></a>
## {{ if .Tag.Previous }}[{{ .Tag.Name }}]{{ else }}{{ .Tag.Name }}{{ end }} - {{ datetime "2006-01-02" .Tag.Date }}
{{ range .CommitGroups -}}
### {{ .Title }}
{{ range .Commits -}}
- {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
{{ end }}
{{ else }}
_Nothing functionally significant._
{{ end -}}

{{- if .NoteGroups -}}
{{ range .NoteGroups -}}
### {{ .Title }}
{{ range .Notes }}
{{ .Body }}
{{ end }}
{{ end -}}
{{ end -}}
{{ end -}}

{{- if .Versions }}
[Unreleased]: {{ .Info.RepositoryURL }}/compare/{{ \$latest := index .Versions 0 }}{{ \$latest.Tag.Name }}...HEAD
{{ range .Versions -}}
{{ if .Tag.Previous -}}
[{{ .Tag.Name }}]: {{ $.Info.RepositoryURL }}/compare/{{ .Tag.Previous.Name }}...{{ .Tag.Name }}
{{ end -}}
{{ end -}}
{{ end -}}
EOF
endef
export MKT_GIT_CHGLOG_TEMPLATE_SCRIPT = $(value _MKT_GIT_CHGLOG_TEMPLATE_SCRIPT)

mkt-changelog: tools/git-chglog/bin/git-chglog .chglog/config.yml .chglog/CHANGELOG.tpl.md
	tools/git-chglog/bin/git-chglog $(MKT_GIT_CHGLOG_ARGS)

.chglog/config.yml:
	@eval "$$MKT_GIT_CHGLOG_CONFIG_SCRIPT"

.chglog/CHANGELOG.tpl.md:
	@eval "$$MKT_GIT_CHGLOG_TEMPLATE_SCRIPT"

tools/git-chglog/bin/git-chglog:
	mkdir -p tools/git-chglog/bin
	grep -qF -- "tools/" ".gitignore" 2>/dev/null || echo "tools/" >> ".gitignore"
	( cd tools/git-chglog/bin && curl -sL "$(MKT_GIT_CHGLOG_DOWNLOAD_URL)" | tar -xz git-chglog )