# Copyright (c) 2023, Sebastian Rust <harlequix@gmail.com>
# All rights reserved.
#
# This file is part of 'quic-message'.


#----------------------------------#
# Variables                        #
#----------------------------------#

# Tools
LATEX              := latex
LUALATEX           := lualatex
BIBTEX             := biber

# Latexdiff config
LATEXDIFF_IGNORE   := picture tikzpicture tikzcd DIFnomarkup
LATEXDIFF_PACKAGES := amsmath hyperref

# Execution flags
LATEX_FLAGS        := --shell-escape --halt-on-error --interaction=nonstopmode
LATEXDIFF_FLAGS    := --packages=$(subst ' ',',',$(LATEXDIFF_PACKAGES)) \
                      --config "PICTUREENV=(?:$(subst ' ',|,$(LATEXDIFF_IGNORE)))[\w\d*@]*"

#----------------------------------#
# Directories                      #
#----------------------------------#

BLDDIR     := ./build
FIGDIR     := ./fig
LIBDIR     := ./lib
REFDIR     := ./ref
FLATDIR    := ./build/flat
DIFFDIR    := ./build/diff


#----------------------------------#
# Source Files                     #
#----------------------------------#

METADATA   := metadata.bib
DOCID      := $(shell perl -ne '/\@article[a-zA-Z{]*:(.*),/ && print "$$1\n"' $(METADATA))
DOCTYPE    := $(shell perl -ne '/entrysubtype\s*=\s*{\s*(.*)\s*}/ && print "$$1\n"' $(METADATA))

MKPREAMBLE := make/mkpreamble.py
PREAMBLE   := preamble.tex
GITREF     := gitref

FIGFILES   := $(sort $(wildcard $(FIGDIR)/*.png) $(wildcard $(FIGDIR)/*.pdf))
LIBFILES   := $(sort $(wildcard *.sty) $(wildcard $(LIBDIR)/*))
BIBFILES   := $(sort $(filter-out $(METADATA),$(wildcard *.bib)))
TEXFILES   := $(sort $(wildcard *.tex) $(PREAMBLE))
AUXFILES   := $(patsubst %.tex,$(notdir %.aux),$(TEXFILES))
TOCFILES   := $(DOCID).toc

BLDFILES   := Makefile .gitignore README.md $(METADATA) $(MKPREAMBLE)
BLDFILES   := $(foreach f,$(BLDFILES),$(wildcard $(f)))


#----------------------------------#
# Configurable variables           #
#----------------------------------#

## Git reference to compute diff against
REF        := HEAD


#----------------------------------#
# Functions                        #
#----------------------------------#

# setup environment for some commands
latex-environment  = TEXINPUTS="$1:$(LIBDIR):$(FIGDIR):" LUAINPUTS="$1:$(LIBDIR):"
lua-environment    = LUA_PATH="$(LIBDIR)/?.lua"

# extract tex file dependencies
latex-dependencies = $1.tex $(foreach p,\
	$(shell perl -ne '/^\s*\\(input|include)\{(.*?)(.tex)?\}/ && print "$$2.tex "' $1.tex),\
	$(dir $1)$(p)\
)

# bibliography files
doc-pdf-dependencies = $(call latex-dependencies,$1)       \
                       $(if $(BIBFILES),$(BLDDIR)/$1.bbl)  \
                       $(PREAMBLE) $(LIBFILES) $(FIGFILES)

doc-src-dependencies = $(call doc-pdf-dependencies,$1)

doc-html-dependencies = $(call latex-dependencies,$1)           \
                        $(if $(BIBFILES),$(BLDDIR)/html/$1.bbl) \
                        $(PREAMBLE) $(LIBFILES) $(FIGFILES)

# write string $2 to file $1 only if it is different from its contents.
write-if-changed-cmd = if [ ! -f "$2" ] || [ ! "$1" = "`cat $2 2> /dev/null`" ]; then echo "$1" > "$2"; fi


#----------------------------------#
# Abstract rules                   #
#----------------------------------#

# shell settings
SHELL       := /usr/bin/bash
.SHELLFLAGS := -e -u -c

# Use a single shell
.ONESHELL:

# So we can use $$(variable) on the prerequisites, that expand at matching time
.SECONDEXPANSION:

# never handle as intermediate targets but never delete them
.SECONDARY:

# always trigger rebuilds on those
.PHONY: pdf epub 2in1 src flat flatsrc diff figs clean

all: pdf

## Build PDF
pdf: $(DOCID).pdf $(DOCID).synctex.gz

## Build epub
epub: $(DOCID).epub

## Build PDF 2-in-1
2in1: $(DOCID).2in1.pdf

## Build source packages
src: $(DOCID).tar.gz

## Build flattened PDF
flat: $(FLATDIR)/$(DOCID).pdf

## Build flattened sources
flatsrc: $(FLATDIR)/$(DOCID).tar.gz

## Build PDF with differences highlighted
diff: $(DIFFDIR)/$(DOCID).pdf

## Produce figures
figs: $(FIGFILES)

## Remove build files
clean:
	rm -Rf $(BLDDIR) $(FLATDIR) $(DIFFDIR)
	rm -Rf *.pdf *.tar.gz *.synctex.gz


#----------------------------------#
# Generic file rules               #
#----------------------------------#

# add dependency to force always rebuild but still checking the file timestamps.
FORCE:

# create file with a hash, used to track modifications to the original file
$(BLDDIR)/%.sha: $(BLDDIR)/%
	@mkdir -p $(dir $@)
	SHA="`sha256sum '$<'`"; $(call write-if-changed-cmd,$$SHA,$@)

# convert pdf to ps
$(BLDDIR)/%.ps: $(BLDDIR)/%.pdf
	pdftops -paper A4 $< $@

# make a 2in1 ps
$(BLDDIR)/%.ps.imposed: $(BLDDIR)/%.ps
	cd $(dir $<); impose $(notdir $<)

# make a 2in1 pdf
%.2in1.pdf: $(BLDDIR)/%.ps.imposed
	ps2pdf -sPAPERSIZE=a4 $< $@

# copy files from the build directory
%.pdf: $(BLDDIR)/%.pdf
	cp $< $@

%.epub: $(BLDDIR)/%.epub
	cp $< $@

%.synctex.gz: $(BLDDIR)/%.pdf
	cp "$(BLDDIR)/$*.synctex.gz" "$@"

%.tar.gz: $(BLDDIR)/%.tar.gz
	cp $< $@


#----------------------------------#
# Git rules                        #
#----------------------------------#

$(BLDDIR)/$(GITREF): FORCE
	@mkdir -p $(dir $@)
	$(call write-if-changed-cmd,$(shell git describe --always --tags --dirty=+),$@)

$(DIFFDIR)/$(GITREF): FORCE
	@mkdir -p $(dir $@)
	$(call write-if-changed-cmd,$(shell git describe --always --tags $(REF)),$@)

$(DIFFDIR)/old/%.tex: $(DIFFDIR)/$(GITREF)
	@mkdir -p $(dir $@)
	git show $(shell cat $<):$*.tex > $@


#----------------------------------#
# Preamble and bibliography        #
#----------------------------------#

# create a preamble tex file
$(PREAMBLE): $(MKPREAMBLE) $(METADATA)
	@python $^ > $@

# precompile headers
$(BLDDIR)/preamble.fmt: $(PREAMBLE)
	@mkdir -p $(dir $@)
	$(call latex-environment,$(dir $<)) $(LUALATEX) $(LATEX_FLAGS) -ini \
		-job-name="preamble" "&lualatex $<\dump" --output-directory=$(dir $@) $<

# compile document to produce the bcf file. we do not want to rebuild on every tex file change.
$(BLDDIR)/%.bcf: | $$(call latex-dependencies,%)
	@mkdir -p $(dir $@)
	$(call latex-environment,$(dir $<)) $(LUALATEX) $(LATEX_FLAGS) \
		--output-directory=$(dir $@) $*.tex

# prepare bibliography when bibliography file changes. Do not rebuild when bcf file changes.
$(BLDDIR)/%.bbl: $(BIBFILES) | $(BLDDIR)/%.bcf
	@mkdir -p $(dir $@)
	$(BIBTEX) --input-directory=$(dir $@) --output-directory=$(dir $@) $*.bcf


#----------------------------------#
# pdf document                     #
#----------------------------------#

# compile pdf with up to date bibliography
$(BLDDIR)/%.pdf: %.tex $$(call doc-pdf-dependencies,%) | $(BLDDIR)/$(GITREF)
	@mkdir -p $(dir $@)
	$(call latex-environment,$(dir $<)) $(LUALATEX) $(LATEX_FLAGS) \
		--synctex=1 --output-directory=$(dir $@) $<

# compile one chapter alone
$(BLDDIR)/chapter-%.pdf: chapter-%.tex $(PREAMBLE) $(FIGFILES) | $(BLDDIR)/$(GITREF)
	@mkdir -p $(dir $@)
	$(call latex-environment,$(dir $<)) $(LUALATEX) $(LATEX_FLAGS) \
		--synctex=1 --output-directory=$(dir $@) \
		-jobname=chapter-$* "\\includeonly{$<}\\input{$(DOCID).tex}"

# make a tar.gz package of the sources
$(BLDDIR)/%.tar.gz: %.tex $$(call doc-src-dependencies) $(BIBFILES) $(BLDFILES)
	@mkdir -p $(dir $@)
	tar -cz -f $@ $(patsubst ./%,%,$^)

# make a tikz figure
$(FIGDIR)/%.pdf: $(FIGDIR)/%.tex
	@( cd $(FIGDIR); $(LUALATEX) --jobname=$* --output-directory=$(BLDDIR) $(notdir $<) )
	cp $(BLDDIR)/$*.pdf $@


#----------------------------------#
# epub document                    #
#----------------------------------#

$(BLDDIR)/html/%.bbl: $(BLDDIR)/%.bbl
	@mkdir -p $(dir $@)
	cp $< $@

# This obscure code comes from /usr/bin/htlatex
$(BLDDIR)/html/%.dvi: %.tex $$(call doc-html-dependencies,%) | $(BLDDIR)/$(GITREF)
	@mkdir -p $(dir $@)
	$(call latex-environment,$(dir $<)) $(LATEX) $(LATEX_FLAGS) --output-directory=$(dir $@) '\makeatletter\def\HCode{\futurelet\HCode\HChar}\def\HChar{\ifx"\HCode\def\HCode"##1"{\Link##1}\expandafter\HCode\else\expandafter\Link\fi}\def\Link#1.a.b.c.{\g@addto@macro\@documentclasshook{\RequirePackage[#1,html]{tex4ht}}\let\HCode\documentstyle\def\documentstyle{\let\documentstyle\HCode\expandafter\def\csname tex4ht\endcsname{#1,html}\def\HCode####1{\documentstyle[tex4ht,}\@ifnextchar[{\HCode}{\documentstyle[tex4ht]}}}\makeatother\HCode html.a.b.c.\input ' $<

$(BLDDIR)/html/%.html: $(BLDDIR)/html/%.dvi
	@mkdir -p $(dir $@)
	(
		cd $(dir $@)
		tex4ht -f/$(notdir $<)   # -i~/tex4ht.dir/texmf/tex4ht/ht-fonts/$3
		t4ht -f/$(notdir $<)
	)

$(BLDDIR)/%.epub: $(BLDDIR)/html/%.html
	@mkdir -p $(dir $@)
	ebook-convert $< $@ --no-default-epub-cover


#----------------------------------#
# Make diff and flat               #
#----------------------------------#

# flatten sources
$(FLATDIR)/%.tex: %.tex
	@mkdir -p $(dir $@)
	latexpand -o $@ $<

$(DIFFDIR)/%.tex: $(DIFFDIR)/old/%.tex %.tex
	@mkdir -p $(dir $@)
	latexdiff $(LATEXDIFF_FLAGS) $^ > $@


#----------------------------------#
# Miscelania rules                 #
#----------------------------------#

.PHONY: ref-tree auto-bib

## Prepare a tree of symlinks to the bibliography
ref-tree:
	rm -Rf $(REFDIR)
	cali lktree --classifier=flat "tag:paper:$(DOCID)" $(REFDIR)

## Autogenerate bibliography from citation keys
auto-bib:
	cali find --fmt=bib "tag:paper:$(DOCID)" > $(DOCID).auto.bib


.PHONY: view-pdf view-epub view slideshow

## Open PDF document
view-pdf: $(DOCID).pdf
	xdg-open $< &

## Open epub document
view-epub: $(DOCID).epub
	xdg-open $< &

## Open PDF document
view: view-pdf

## Start a slideshow
slideshow: $(DOCID).pdf
	pdfpc $< &


# ---------------------------------#
# Source maintenance               #
# ---------------------------------#

.PHONY: update-template update-copyright

## Update cookiecutter template branch
update-template:
	@python make/cookiecutter-update.py ".cookiecutter.json" template

## Update copyright from file headers
update-copyright:
	@year=$$(date '+%Y')
	git ls-files | while read f; do
		sed -i "1,10{s/Copyright (c) \([0-9]\+\)\(-[0-9]\+\)\?,/Copyright (c) \1-$$year,/}" "$$f"
		sed -i "1,10{s/Copyright (c) $$year-$$year,/Copyright (c) $$year,/}" "$$f"
	done


.PHONY: help

## Print Makefile documentation
help:
	@perl -0 -nle 'printf("%-25s - %s\n", "$$2", "$$1") while m/^##\s*([^\r\n]+)\n^([\w-]+):[^=]/gm' \
		$(MAKEFILE_LIST) | sort
	printf "\n"
	perl -0 -nle 'printf("%-25s - %s\n", "$$2=", "$$1") while m/^##\s*([^\r\n]+)\n^([\w-]+)\s*:=/gm' \
		$(MAKEFILE_LIST) | sort