# SPDX-FileCopyrightText: 2024, 2025 Lady <https://www.ladys.computer/about/#lady>
# SPDX-License-Identifier: MPL-2.0

SHELL = /bin/sh

# ━ § BASIC INFORMATION ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
override define makefileinfo
 ╭──────────────────────────────╮
╔╡ ⁌ 🪾📰 Caudex ∷ GNUmakefile ╞═══════════════════════════════╗
║╰──────────────────────────────╯                              ║
╟┬ ¶ Prerequisites ───────────────────────────────────────────┬╢
║│                                                            │║
║│ Requires G·N·U Make, at least version 3.81. Otherwise,     │║
║│ only programs specified by Posix are required. The full    │║
║│ list of program requirements is as follows :—             │║
║│                                                            │║
║│ • awk                                                      │║
║│ • mkdir                                                    │║
║│ • od                                                       │║
║│ • printf                                                   │║
║│ • sed                                                      │║
║│ • test                                                     │║
║│ • tr                                                       │║
║│ • xargs                                                    │║
║│                                                            │║
║│ In all cases, you can supply your own version of any       │║
║│ program `program´ by overriding the corresponding variable │║
║│ `PROGRAM´ when calling Make.                               │║
║╰────────────────────────────────────────────────────────────╯║
╟┬ ¶ Usage ───────────────────────────────────────────────────┬╢
║│                                                            │║
║│ • `make help (default)´: Print this message.               │║
║│                                                            │║
║│ • `make wrmg´: Output a random unused identifier.          │║
║│                                                            │║
║│ • `make +⟨CATEGORY⟩´: Create a new entry in ⟨CATEGORY⟩ and │║
║│   output its path.                                         │║
║│                                                            │║
║│ Set `VERBOSE=1´ to see the text of commands as they are    │║
║│ executed.                                                  │║
║│                                                            │║
║│ See `README.markdown´ for a more involved description of   │║
║│ the capabilities and configuration of this program.        │║
║╰────────────────────────────────────────────────────────────╯║
╟┬ ¶ Copyright & License ─────────────────────────────────────┬╢
║│                                                            │║
║│ Copyright © 2024–2025 Lady [@ Ladys Computer].             │║
║│                                                            │║
║│ This Source Code Form is subject to the terms of the       │║
║│ Mozilla Public License, v 2.0. If a copy of the M·P·L was  │║
║│ not distributed with this file, You can obtain one at      │║
║│ <http://mozilla.org/MPL/2.0/>.                             │║
║╰────────────────────────────────────────────────────────────╯║
╚══════════════════════════════════════════════════════════════╝
endef

# ━ § MAKE·FILE SETUP ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

# Programs needed to run this make·file.
#
# If these are not installed on your computer, or you need to use a different implementation, you can override the appropriate variable.
AWK := awk
MKDIR := mkdir
OD := od
PRINTF := printf
SED := sed
TEST := test
TR := tr
XARGS := xargs

# The directory which contains the codex entries and related metadata.
SRCDIR := data/codex

# The default language for new entries.
DOCLANG := en

# Set to a non·empty value to print all commands as they run.
VERBOSE :=

# The default target for this makefile.
.DEFAULT_GOAL := help

# ━ § BEGIN MAKE·FILE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

# ─ ¶ Non‐Recipe Variable Definitions ─────────────────────────────────

# A variable which contains a newline, to allow the generation of multiline strings in function calls.
override define newline


endef

# (callable) Quote the given string for use within shell calls.
override quote = '$(subst ','"'"',$1)'

# Outputs an `@´ to silence rules, unless `VERBOSE´ is nonempty.
override silent := $(if $(VERBOSE),,@)

# A random W·R·M·G(·like) base⹀32 identifier.
#
# This variable returns a different value each time it is referenced.
# Use `foreach´ to save the value for repeated usage.
#
# This variable recursively calls itself to ensure there is no existing entry with the resulting identifier.
#
# The checksum digits differ from W·R·M·G to get around limitations in Make and to enable usage with·in a U·R·N.
override wrmg = $(foreach attempt,$(shell $(OD) -t u4 -N 4 /dev/random | $(SED) 's/^[0-9]* *//' | $(TR) -d ' \n' | $(AWK) 'BEGIN{chars="0123456789ABCDEFGHJKMNPQRSTVWXYZ+!@=U"}{d=32^5;r=$$0%(32^6);printf("%s",substr(chars,r%37,1));while(d>0){printf("%s", substr(chars,int(r/d),1));if(d==32^4)printf("%s", "-");r%=d;d=int(d/32)}}'),$(if $(wildcard $(SRCDIR)/*/$(attempt)*),$(call wrmg),$(attempt)))

# ─ ¶ Recipe Variable Definitions ─────────────────────────────────────

# (callable) Check to see if the given directory exists and create it if not.
override ensuredirectory = if $(TEST) ! -d $(call quote,$1); then $(MKDIR) -p $(call quote,$1); fi

# ─ ¶ Phony Targets ───────────────────────────────────────────────────

# Provide help.
help :
	@$(PRINTF) '%b' $(call quote,$(subst $(newline),\n,$(makefileinfo)))

# Output a random unused identifier.
wrmg :
	@$(PRINTF) '%s\n' $(wrmg)

# Create a new entry in the provided category and output its path.
+% : $(SRCDIR)/~ FORCE
	$(silent)$(call ensuredirectory,$(SRCDIR)/$*)
	$(if $(wildcard $(SRCDIR)/$*/~),,$(silent)$(PRINTF) '%b@%s$$ profile=urn:fdc:ladys.computer:20240204:Caudex:pf:category\n%s\n' '\0043!lesml' '$(DOCLANG)' '%%' >|$(call quote,$(SRCDIR)/$*/~))
	$(foreach identifier,$(wrmg),$(silent)$(PRINTF) '%b@%s$$ profile=urn:fdc:ladys.computer:20240204:Caudex:pf:entry\n%s\n' '\0043!lesml' '$(DOCLANG)' '%%' >|$(call quote,$(SRCDIR)/$*/$(identifier))$(newline)$(silent)$(PRINTF) '%s\n' $(call quote,$(SRCDIR)/$*/$(identifier)))

# ─ ¶ Special Targets ─────────────────────────────────────────────────

# Don’t use any implicit rules.
.SUFFIXES : ;

# Treat targets with this as a prerequisite as though they were phony.
#
# Mainly useful in pattern rules.
FORCE : ;

# Phony rules; always consider these out·of·date.
.PHONY : FORCE help wrmg ;

# ─ ¶ Build Targets ───────────────────────────────────────────────────

# Create an empty codex metadata file if none exists.
$(SRCDIR)/~ :
	$(silent)$(PRINTF) '%b@%s$$ profile=urn:fdc:ladys.computer:20240204:Caudex:pf:codex\n%s\n' '\0043!lesml' '$(DOCLANG)' '%%' >|$(call quote,$@)