#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU Affero General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU Affero General Public License
#   along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
#   Copyright 2020 Emilis Dambauskas <emilis@emilis.net>

### Instructions ---------------------------------------------------------------
#
#   Example directory structure to get you started:
#   .
#   ├── Makefile
#   ├── _posts
#   │   └── 2020
#   │       └── 11
#   │           └── 16-first-post.gmi
#   └── _src
#     ├── index-footer.gmi
#     ├── index-header.gmi
#     ├── post-footer.gmi
#     ├── post-header.gmi
#     ├── rss-footer.txt
#     └── rss-header.txt
#
#   Run `make`.
#
#   It will add these files:
#
#   .
#   ├── 2020
#   │   └── 11
#   │       └── 16-first-post.gmi
#   ├── atom.xml
#   ├── feed.gmi
#   ├── index.gmi
#
#   If you are going to use Git to version your files. You can add this to a
#   .gitignore:
#
#   /2020/
#   atom.xml
#   index.gmi
#   feed.gmi

### Variables: -----------------------------------------------------------------

AUTHOR=				~emilis
BASE_URL=			gemini://tilde.team/~emilis
CURRENT_YEAR=		$(shell date +%Y)
FIND_POSTS=			find _posts -type f -name \*gmi -printf '%P\0'
SERVER_PATH=		tilde.team:public_gemini


### Tasks ----------------------------------------------------------------------

.PHONY: default
default: build

.PHONY: build
build: \
	atom.xml \
	index.gmi \
	feed.gmi \
	feed.xml \
	${CURRENT_YEAR}


.PHONY: deploy
deploy:
	rsync -rv \
		--exclude=.git \
		--exclude=.gitignore \
		--exclude=_posts \
		--exclude=_src \
		./ "${SERVER_PATH}/"


### Targets --------------------------------------------------------------------

${CURRENT_YEAR}: Makefile _src _posts
	rm -rf ${CURRENT_YEAR}/*
	${FIND_POSTS} | xargs -0 dirname | sort | uniq | xargs mkdir -p
	${FIND_POSTS} | xargs -0 -n 1 -I {} \
		bash -c 'cat _src/post-header.gmi _posts/{} _src/post-footer.gmi > {}'


index.gmi: Makefile _src ${CURRENT_YEAR}
	cat "_src/index-header.gmi" > "$@"
	find 20* -type f -name \*.gmi \
		| sort -r \
		| head -10 \
		| xargs grep -H -m 1 -E '^# ' \
		| sed -E -e 's/^([0-9]{4})\/([0-9]{2})\/([0-9]{2})([^#]+).gmi:# /=> \1\/\2\/\3\4.gmi \1-\2-\3 /g' \
		>> "$@"
	cat _src/index-footer.gmi >> "$@"


feed.gmi: Makefile ${CURRENT_YEAR}
	echo "# ${AUTHOR}" > "$@"
	find 20* -type f -name \*.gmi \
		| sort -r \
		| head -20 \
		| xargs grep -H -m 1 -E '^# ' \
		| sed -E -e 's/^([0-9]{4})\/([0-9]{2})\/([0-9]{2})([^#]+).gmi:# /=> \1\/\2\/\3\4.gmi \1-\2-\3 /g' \
		>> "$@"

feed.xml: atom.xml
	cp atom.xml feed.xml

atom.xml: Makefile _src ${CURRENT_YEAR}
	cat "_src/atom-header.txt" > "$@"
	echo -n "<updated>" >> $@
	date --iso-8601=seconds | tr -d '\n' >> "$@"
	echo "</updated>" >> "$@"
	find 20* -type f -name \*.gmi \
		| sort -r \
		| head -20 \
		| xargs grep -H -m 1 -E '^# ' \
		| xargs -d '\n' -n 1 -I {} \
			bash -c ' \
				FILE_NAME=`echo "{}" | sed -E -e "s/.gmi:#.*$$/.gmi/"`; \
				TITLE=`echo "{}" | sed -E -e "s/^.*.gmi:# //"`; \
				echo "<entry>" >> "$@"; \
				echo -n "<updated>" >> "$@"; \
				date --iso-8601=seconds -r "_posts/$$FILE_NAME" | tr -d "\n" >> "$@"; \
				echo "</updated>" >> "$@"; \
				echo "<title>$$TITLE</title>" >> "$@"; \
				echo "<link href=\"${BASE_URL}/$$FILE_NAME\"/>" >> "$@"; \
				echo "<id>${BASE_URL}/$$FILE_NAME</id>" >> "$@"; \
				echo "<summary />" >> "$@"; \
				echo "</entry>" >> "$@"; \
				'
	cat "_src/atom-footer.txt" >> "$@"