#!/bin/sh

set -e

usage() {
	cat <<USAGE
There is an error in your command.
More information: ./configure --help
USAGE
	exit
}

help() {
	cat <<HELP
This script tries to be similar to autotools' \`configure', but is different.

Usage: ./configure [OPTION]...

Defaults for the options are specified in brackets.

Configuration:
  -h, --help              Display this help and exit

Installation directories:
  --prefix PREFIX         install architecture-independent files in PREFIX
                          [/usr/local]
  --exec-prefix EPREFIX   install architecture-dependent files in EPREFIX
                          [PREFIX]

By default, \`make install' will install all the files in
\`/usr/local/bin', \`/usr/local/lib' etc. You can specify
an installation prefix other than \`/usr/local' using \`--prefix',
for instance \`--prefix \$HOME'.

For better control, use the options below.

File tuning of the installation directories:
  --bindir DIR            user executables [EPREFIX/bin]
  --datarootdir DIR       read-only arch.-independent data root [PREFIX/share]
  --mandir DIR            man documentation [DATAROOTDIR/man]

Optional Features:
  --disable-xinerama      disable Xinerama

Optional Packages:
  --with-PACKAGE[ ARG]    use PACKAGE [ARG=yes]
  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE no)
  --with-terminal [alacritty|gnome|st|xterm]
                          use ARG as terminal [alacritty]
  --without-terminal      do not use terminal at all
HELP
	exit
}

prefix='/usr/local'
eprefix=''
bindir=''
datarootdir=''
mandir=''
enable_xinerama=''
with_terminal=''

while [ $# -gt 0 ]; do
	do_shift='yes'

	case "$1" in
		-h | -? | --help | -help | help)
			help
			;;
		--prefix)
			shift
			prefix="$1"
			;;
		--exec-prefix)
			shift
			eprefix="$1"
			;;
		--bindir)
			shift
			bindir="$1"
			;;
		--datarootdir)
			shift
			datarootdir="$1"
			;;
		--mandir)
			shift
			mandir="$1"
			;;
		--disable-xinerama)
			enable_xinerama='no'
			;;
		--without-terminal)
			if [ "$with_terminal" = '' ]; then
				with_terminal='no'
			elif [ "$with_terminal" != 'no' ]; then
				usage
			fi
			;;
		--with-terminal)
			shift

			case "$1" in
				yes)
					if [ "$with_terminal" = '' ]; then
						with_terminal='yes'
					elif [ "$with_terminal" != 'yes' ]; then
						usage
					fi
					;;
				no)
					if [ "$with_terminal" = '' ]; then
						with_terminal='no'
					elif [ "$with_terminal" != 'no' ]; then
						usage
					fi
					;;
				alacritty)
					if [ "$with_terminal" = '' ]; then
						with_terminal='alacritty'
					elif [ "$with_terminal" != 'alacritty' ]; then
						usage
					fi
					;;
				gnome)
					if [ "$with_terminal" = '' ]; then
						with_terminal='gnome'
					elif [ "$with_terminal" != 'gnome' ]; then
						usage
					fi
					;;
				st)
					if [ "$with_terminal" = '' ]; then
						with_terminal='st'
					elif [ "$with_terminal" != 'st' ]; then
						usage
					fi
					;;
				xterm)
					if [ "$with_terminal" = '' ]; then
						with_terminal='xterm'
					elif [ "$with_terminal" != 'xterm' ]; then
						usage
					fi
					;;
				*)
					do_shift='no'
					;;
			esac
			;;
		*)
			usage
			;;
	esac

	if [ "$do_shift" = 'yes' ]; then shift; fi
done

if [ "$eprefix" = '' ]; then
	eprefix="$prefix"
fi

if [ "$bindir" = '' ]; then
	bindir="$eprefix/bin"
fi

if [ "$datarootdir" = '' ]; then
	datarootdir="$prefix/share"
fi

if [ "$mandir" = '' ]; then
	mandir="$datarootdir/man"
fi

if [ "$enable_xinerama" = '' ]; then
	enable_xinerama='yes'
fi

if [ "$with_terminal" = '' -o "$with_terminal" = 'yes' ]; then
	with_terminal='alacritty'
fi

echo "PREFIX          = $prefix"
echo "EPREFIX         = $eprefix"
echo "BINDIR          = $bindir"
echo "DATAROOTDIR     = $datarootdir"
echo "MANDIR          = $mandir"
echo "ENABLE_XINERAMA = $enable_xinerama"
echo "WITH_TERMINAL   = $with_terminal"

cat > 'config/1-generated.mk' << MAKE
PREFIX          = $prefix
EPREFIX         = $eprefix
BINDIR          = $bindir
DATAROOTDIR     = $datarootdir
MANDIR          = $mandir
ENABLE_XINERAMA = $enable_xinerama
WITH_TERMINAL   = $with_terminal
MAKE

make_help_result="$(make --help 2>&1 || true)"
if [ "$(echo "$make_help_result" | grep 'gnu.org')" = '' ]; then
	ln -sf '2-conditionals-bsd.mk' 'config/2-conditionals.mk'
else
	ln -sf '2-conditionals-gnu.mk' 'config/2-conditionals.mk'
fi