SHELL := /bin/bash

TARGETS  := $(patsubst %.md,%.html,$(wildcard *.md))
CSSINC   := assets/css.inc

# our main html5 template, mostly taken from :
# https://github.com/jgm/pandoc-templates/blob/master/default.html5
TEMPLATE := assets/pandoc-template.html5

# CSS to be included as stylesheets and alternate stylesheets
CSS      := assets/ghost.css
ALTCSS   := assets/ghost-dark.css assets/ghost-caca.css

OPTS     := --standalone --include-in-header=$(CSSINC) --template=$(TEMPLATE) \
            --metadata=title:"$(call TIT,$<)" --from=gfm --to=html5

# To provide a title to pandoc. We take the first line starting with '#',
# and remove initial '#' and spaces
TITLE = $(shell sed -n '0,/^#/ s/^[# ]*//p' $1)

define ADD_LINE
printf '<link rel="%s" href="%s">\n' "$(2)" "$(1)" >> $(3);
endef

.PHONY: all html clean $(CSSINC)

all: $(CSSINC) html

html: $(TARGETS)

clean:
	@echo cleaning $(TARGETS) $(CSSINC)
	@rm -f $(TARGETS) $(CSSINC)

$(CSSINC): $(_CSS) $(_ALTCSS)
	@echo generating $@
	@rm -f $@
	@$(foreach css,$(_CSS),$(call ADD_LINE,$(css),stylesheet,$@))
	@$(foreach css,$(_ALTCSS),$(call ADD_LINE,$(css),alternate stylesheet,$@))

%.html: %.md $(_CSS)
	@echo generating $@
	@pandoc $(PANDOCOPTS) -o $@ $<