# -*- coding: utf-8; mode: makefile-gmake -*-

export DOCS_FOLDER DOCS_BUILD DOCS_DIST BOOKS_FOLDER BOOKS_DIST

# You can set these variables from the command line.
SPHINXOPTS  ?=
SPHINXBUILD ?= $(PY_ENV_BIN)/sphinx-build
SPHINX_CONF ?= conf.py

DOCS_FOLDER = docs$(LXC_ENV_FOLDER)
DOCS_BUILD  = build/docs$(LXC_ENV_FOLDER)
DOCS_DIST   = dist/docs$(LXC_ENV_FOLDER)
GH_PAGES    ?= gh-pages

BOOKS_FOLDER = docs$(LXC_ENV_FOLDER)
BOOKS_DIST   = dist/books$(LXC_ENV_FOLDER)

ifeq ($(KBUILD_VERBOSE),1)
  SPHINX_VERBOSE = "-v"
else
  SPHINX_VERBOSE =
endif

## SPHINXVERS variable
## ===================
##
## .. _requirement-specifiers: https://pip.pypa.io/en/stable/reference/pip_install/#requirement-specifiers
##
## Sphinx version to use, when building documentation.  Set this when calling
## build target.  The default value is empty (install latest), to select a
## specific version use a requirement-specifiers_.  E.g. to build your target
## 'doc' with a select sphinx-doc_ version 1.7.9::
##
##     make SPHINXVERS='==1.7.9' docs
##
## To build with latest 1.7::
##
##     make SPHINXVERS='>=1.7,<1.8' docs
##
SPHINXVERS  ?=

docs-help:
	@echo  'makefile.sphinx:'
	@echo  '  docs-clean	- clean intermediate doc objects'
	@echo  '  $(GH_PAGES)	- create & upload github pages'
	@echo  '  sphinx-pdf    - run sphinx latex & pdf targets'
	echo   ''
	@echo  '  books/{name}.html : build only the HTML of document {name}'
	@echo  '  valid values for books/{name}.html are:'
	@echo  '    $(BOOKS_HTML)' | $(FMT)
	@echo  '  books/{name}.pdf : build only the PDF of document {name}'
	@echo  '  valid values for books/{name}.pdf are:'
	@echo  '    $(BOOKS_PDF) ' | $(FMT)

# ------------------------------------------------------------------------------
# requirements
# ------------------------------------------------------------------------------

sphinx-doc: $(PY_ENV)
	@echo "PYENV     installing Sphinx$(SPHINXVERS)"
	$(Q)$(PY_ENV_BIN)/pip install $(PIP_VERBOSE) 'Sphinx$(SPHINXVERS)'

sphinx-live: $(PY_ENV)
	@echo "PYENV     installing Sphinx$(SPHINXVERS)"
	$(Q)$(PY_ENV_BIN)/pip install $(PIP_VERBOSE) 'Sphinx$(SPHINXVERS)' sphinx-autobuild


PHONY += msg-texlive texlive

ifeq ($(shell which xelatex >/dev/null 2>&1; echo $$?), 1)
texlive: msg-TeXLive
	$(error The 'xelatex' command was not found)
else
texlive:
	@:
endif

msg-texlive:
	$(Q)echo "\n\
The TeX/PDF output and the *math* extension require TexLive and latexmk:\n\n\
  Make sure you have a updated TeXLive with XeTeX engine installed, grab it\n\
  it from https://www.tug.org/texlive or install it from your package manager.\n\n\
  Install latexmk from your package manager or visit https://ctan.org/pkg/latexmk\n\n\
  Sphinx-doc produce (Xe)LaTeX files which might use additional TeX-packages\n\
  and fonts. To process these LaTeX files, a TexLive installation with the\n\
  additional packages is required. On debian based OS these requirements\n\
  are installed by::\n\n\
    sudo -H apt-get install\n\
         latexmk\n\
         texlive-base texlive-xetex texlive-latex-recommended\n\
         texlive-extra-utils dvipng ttf-dejavu\n"

# ------------------------------------------------------------------------------
# commands
# ------------------------------------------------------------------------------

# $2 sphinx builder e.g. "html"
# $3 path where configuration file (conf.py) is located
# $4 sourcedir
# $5 dest subfolder e.g. "man" for man pages at $(DOCS_DIST)/man

quiet_cmd_sphinx = SPHINX    $@ --> file://$(abspath $(DOCS_DIST)/$5)
      cmd_sphinx = SPHINX_CONF=$(abspath $4/$(SPHINX_CONF))\
	$(SPHINXBUILD) $(SPHINX_VERBOSE) $(SPHINXOPTS)\
	-b $2 -c $3 -d $(DOCS_BUILD)/.doctrees $4 $(DOCS_DIST)/$5

quiet_cmd_sphinx_autobuild = SPHINX    $@ --> file://$(abspath $(DOCS_DIST)/$5)
      cmd_sphinx_autobuild = PATH="$(PY_ENV_BIN):$(PATH)" $(PY_ENV_BIN)/sphinx-autobuild  $(SPHINX_VERBOSE) --poll -B --host 0.0.0.0 --port 8080 $(SPHINXOPTS)\
	-b $2 -c $3 -d $(DOCS_BUILD)/.doctrees $4 $(DOCS_DIST)/$5

quiet_cmd_sphinx_clean = CLEAN     $@
      cmd_sphinx_clean = rm -rf $(DOCS_BUILD) $(DOCS_DIST) $(GH_PAGES)/* $(GH_PAGES)/.buildinfo

# ------------------------------------------------------------------------------
# targets
# ------------------------------------------------------------------------------

# build PDF of whole documentation in: $(DOCS_DIST)/pdf 

PHONY += sphinx-pdf
sphinx-pdf: sphinx-latex
	$(Q)cd $(DOCS_BUILD)/latex/; make all-pdf
	$(Q)mkdir -p $(DOCS_DIST)/pdf
	$(Q)cp $(DOCS_BUILD)/latex/*.pdf $(DOCS_DIST)/pdf
	@echo "SPHINX    *.pdf --> file://$(abspath $(DOCS_DIST)/pdf)"

PHONY += sphinx-latex
sphinx-latex: texlive sphinx-doc
	$(SPHINXBUILD) $(SPHINX_VERBOSE) $(SPHINXOPTS)\
	  -b latex \
	  -c $(DOCS_FOLDER) \
	  -d $(DOCS_BUILD)/.doctrees \
	  $(DOCS_FOLDER) \
	  $(DOCS_BUILD)/latex

# Sphinx projects, we call them *books* (what is more common).  Books are
# folders under $(BOOKS_FOLDER) containing a conf.py file. The HTML output goes
# to folder $(BOOKS_DIST)/<name> while PDF is placed (BOOKS_DIST)/<name>/pdf

BOOKS=$(patsubst $(BOOKS_FOLDER)/%/conf.py,books/%,$(wildcard $(BOOKS_FOLDER)/*/conf.py))

# fine grained targets
BOOKS_HTML  = $(patsubst %,%.html,$(BOOKS))
BOOKS_CLEAN = $(patsubst %,%.clean,$(BOOKS))
BOOKS_LATEX = $(patsubst %,%.latex,$(BOOKS))
BOOKS_PDF   = $(patsubst %,%.pdf,$(BOOKS))
BOOKS_LIVE  = $(patsubst %,%.live,$(BOOKS))

$(BOOKS_DIST):
	mkdir -p $(BOOKS_DIST)

PHONY += $(BOOKS_HTML)
$(BOOKS_HTML): sphinx-doc | $(BOOKS_DIST)
	SPHINX_CONF=$(patsubst books/%.html,%,$@)/conf.py \
	$(SPHINXBUILD) $(SPHINX_VERBOSE) $(SPHINXOPTS)\
	  -b html \
	  -c $(DOCS_FOLDER) \
	  -d $(DOCS_BUILD)/books/$(patsubst books/%.html,%,$@)/.doctrees \
	  $(BOOKS_FOLDER)/$(patsubst books/%.html,%,$@) \
	  $(BOOKS_DIST)/$(patsubst books/%.html,%,$@)
	@echo "SPHINX    $@ --> file://$(abspath $(BOOKS_DIST)/$(patsubst books/%.html,%,$@))"

PHONY += $(BOOKS_HTML)
$(BOOKS_LIVE): sphinx-live | $(BOOKS_DIST)
	PATH="$(PY_ENV_BIN):$(PATH)" \
	SPHINX_CONF=$(patsubst books/%.live,%,$@)/conf.py \
	$(PY_ENV_BIN)/sphinx-autobuild --poll -B --host 0.0.0.0 --port 8080 $(SPHINX_VERBOSE) $(SPHINXOPTS)\
	  -b html \
	  -c $(DOCS_FOLDER) \
	  -d $(DOCS_BUILD)/books/$(patsubst books/%.live,%,$@)/.doctrees \
	  $(BOOKS_FOLDER)/$(patsubst books/%.live,%,$@) \
	  $(BOOKS_DIST)/$(patsubst books/%.live,%,$@)

$(BOOKS_PDF): %.pdf : %.latex
	$(Q)cd $(DOCS_BUILD)/latex/$(patsubst books/%.pdf,%,$@); make all-pdf
	$(Q)mkdir -p $(BOOKS_DIST)/$(patsubst books/%.pdf,%,$@)/pdf
	$(Q)cp -v $(DOCS_BUILD)/latex/$(patsubst books/%.pdf,%,$@)/*.pdf $(BOOKS_DIST)/$(patsubst books/%.pdf,%,$@)/pdf
	@echo "SPHINX    $@ --> file://$(abspath $(BOOKS_DIST)/$(patsubst books/%.pdf,%,$@))/pdf"

PHONY += $(BOOKS_LATEX)
$(BOOKS_LATEX): sphinx-doc | $(BOOKS_DIST)
	SPHINX_CONF=$(patsubst books/%.latex,%,$@)/conf.py \
	$(SPHINXBUILD) $(SPHINX_VERBOSE) $(SPHINXOPTS)\
	  -b latex \
	  -c $(DOCS_FOLDER) \
	  -d $(DOCS_BUILD)/books/$(patsubst books/%.latex,%,$@)/.doctrees \
	  $(BOOKS_FOLDER)/$(patsubst books/%.latex,%,$@) \
	  $(DOCS_BUILD)/latex/$(patsubst books/%.latex,%,$@)
	@echo "SPHINX    $@ --> file://$(abspath $(DOCS_BUILD)/latex/$(patsubst books/%.latex,%,$@))"

$(BOOKS_CLEAN):
	$(Q)rm -rf $(BOOKS_DIST)/$(patsubst books/%.clean,%,$@) \
	       $(DOCS_BUILD)/books/$(patsubst books/%.clean,%,$@) \
	       $(DOCS_BUILD)/latex/$(patsubst books/%.clean,%,$@)

# github pages

PHONY += $(GH_PAGES)
$(GH_PAGES)::
	$(MAKE) docs
	[ -d "gh-pages/.git" ] || git clone $(GIT_URL) gh-pages
	-cd $(GH_PAGES); git checkout gh-pages >/dev/null
	-cd $(GH_PAGES); git pull
	-cd $(GH_PAGES); ls -A | grep -v '.git$$' | xargs rm -rf
	cp -r $(DOCS_DIST)/* $(GH_PAGES)/
	touch $(GH_PAGES)/.nojekyll
	echo "<html><head><META http-equiv='refresh' content='0;URL=index.html'></head></html>" > $(GH_PAGES)/404.html
	cd $(GH_PAGES);\
		git add --all . ;\
		git commit -m "gh-pages: updated" ;\
		git push origin gh-pages


PHONY += docs-clean
docs-clean: $(BOOKS_CLEAN)
	$(call cmd,sphinx_clean)

.PHONY: $(PHONY)