TOP_DIR = ../..
OUT_DIR = $(TOP_DIR)/public
TEXT_FILES = md org

dirname = $(patsubst %/,%,$(dir $(1)))
dirnames = $(sort $(call dirname,$(1)))

text_patterns = $(foreach ext,$(TEXT_FILES),'$(TOP_DIR)/**.$(ext)')
text_folders = $(call dirnames,$(shell git ls-files $(text_patterns)))
top_readme = $(shell git ls-files $(addprefix $(TOP_DIR)/README.,$(TEXT_FILES)))

all: site

cache = .cache
# Site title, parsed from the top-level README.
title = $(cache)/title
# Maps folders to their contents (files and subfolders).
site_tree = $(cache)/site-tree.json
# Defines $(pages) and $(indices).
dependencies = $(cache)/deps.mk

$(title): $(top_readme) | $(cache)
	pandoc --lua-filter print-title.lua $< > $@

$(site_tree): $(text_folders) | $(cache)
	./generate-tree.py -o $@ $(TEXT_FILES)

$(dependencies): $(site_tree) | $(cache)
	./generate-deps.py $< $@ $(OUT_DIR)

include $(dependencies)

site: $(pages) $(indices)

# List of output folders.  Compute this from the full list of HTML
# pages, since $(text_folders) may be missing some intermediate
# directories (e.g. folders that only contain subfolders).
html_folders = $(call dirnames,$(pages) $(indices))

$(html_folders) $(cache):
	mkdir -p $@

$(pages) $(indices): $(title)

$(pages): $(OUT_DIR)/%.html:
	pandoc -s $< -o $@ -T "$$(cat $(title))" -M title="$*"

# ⚠ When tweaking this rule, check whether it still works for the
#   top-level index.html.
$(indices): $(OUT_DIR)/%index.html:
	./generate-index.py $(site_tree) "$$(cat $(title))" "$(patsubst %/,%,$*)" $@

clean:
	-rm $(dependencies)
	-rm -r $(OUT_DIR)