#!/bin/sh -eu
#
# DFM configure script.
#
# Copyright (c) 2026 Dylan Araps - MIT License
#
# The configure script takes three forms of arguments.
#
# 1) Long-opts:           --prefix=/usr --help
# 2) Variables:           CC=/bin/cc CFLAGS="-O3" CONFIG_TINY=1
# 3) C macro definitions: -DMACRO -DMACRO=VALUE -UMACRO
#
# Everything below, as well as in the Makefile.in and config.h.in files can be
# configured via this script. Alternatively, you can edit the files directly,
# refer to them for more information.
#

#
# Program configuration.
#
export CFG_NAME=dfm
export CFG_VERSION=1.0.1
export c_version=c99

#
# DPP configuration.
#
export CFG_DPP_INCLUDE=./configure
CFG_DPP_CMD="$(command -v dpp 2>/dev/null || echo bin/dpp)"
export CFG_DPP_CMD
export PATH="$PWD/bin:$PATH"

#
# Make configuration.
#
export CFG_MAKE_FILE=Makefile
export CFG_MAKE_CONFIG=Makefile.in
export CFG_MANUAL=README.txt
export CFG_BUILD=config.h.in
export CFG_BUILD_GEN=config.h
export CFG_INPUT=config_key.h.in
export CFG_INPUT_GEN=config_key.h
export CFG_COMMAND_GEN=config_cmd.h
export CFG_COMMAND=config_cmd.h.in
export CFG_MACRO_GEN=.config_macro.h
export CFG_MAKE_DEP="*/*.[ch] *.[ch] $CFG_MAKE_FILE $CFG_MAKE_CONFIG $CFG_DPP_INCLUDE"
export CFG_IGNORE=.gitignore

#
# Installation
#
export prefix=/usr/local

#
# Build commands.
#
export RM="${RM:-rm}"
export MKDIR="${MKDIR:-mkdir}"
export CP="${CP:-cp}"
export CC="${CC:-cc}"
export STRIP="${STRIP:-strip}"

#
# Compiler flags.
#
export cc_flags="-std=$c_version -O2 -pipe"
export cc_flags="$cc_flags -Wall -Wextra -pedantic -Wshadow"

#///////////////////////////////////////////////////////////////////////////////
#
# NOTE: Do not edit below this line.
#
case ${DPP_LEVEL:-} in '')
  #
  # Handle command-line arguments.
  #
  # '--prefix=/usr' -> 'export prefix=/usr'
  # 'prefix=/usr'   -> 'export prefix=/usr'
  # '-DWORD'        -> 'export WORD' '#undef WORD\n#define WORD'
  # '-DWORD=val'    -> 'export WORD' '#undef WORD\n#define WORD val'
  # '-UWORD'        -> 'unset WORD'  'CFLAGS+=-UWORD'
  #
  for a do case $a in
    --help) cat "$0"; exit 0 ;;
       -D*) mo="${mo:-}$a
" _a=${a#-D}; export "${_a%%=*}=1"  ;;
       -U*) cc_flags="$cc_flags $a"; unset  "${a#-U}" ;;
     *?=?*) export "${a#--}" ;;
  esac done

  #
  # Build configurations.
  #
  case ${CONFIG_SMALL:=${CONFIG_TINY:=0}} in 1)
    cc_flags="$cc_flags -Os -DNDEBUG"
    cc_flags="$cc_flags -fno-asynchronous-unwind-tables -fno-unwind-tables"
    cc_flags="$cc_flags -Wl,-z,norelro"
    cc_flags="$cc_flags -no-pie"
    cc_flags="$cc_flags -fno-plt"
    strip_flags="${strip_flags:-} -s -R .comment -R .note"
    strip_flags="$strip_flags --remove-section=.eh_frame"
    strip_flags="$strip_flags --remove-section=.eh_frame_hdr"
    export strip_flags

    case ${CONFIG_TINY:=0} in 1)
      cc_flags="$cc_flags -Oz"
    esac
  esac

  #
  # Generate macro overrides.
  #
  while IFS== read -r k v; do
    echo "${k:+#undef ${k#-D}
#define ${k#-D} $v}"
  done <<EOF > "$CFG_MACRO_GEN"
${mo:-}
EOF

  #
  # Generate .gitignore.
  #
  cat <<EOF > "$CFG_IGNORE"
$CFG_IGNORE
$CFG_NAME
$CFG_MACRO_GEN
$CFG_BUILD_GEN
$CFG_COMMAND_GEN
$CFG_INPUT_GEN
$CFG_MAKE_FILE
EOF

  #
  # Generate Makefile
  #
  "$CFG_DPP_CMD" < "$CFG_MAKE_CONFIG" > "$CFG_MAKE_FILE"
esac