#!/bin/sh -e

die() {
    printf '%s: %s\n' "${0##*/}" "$*" >&2
    exit 1
}

out() { printf '%s\n' "$@" ;}

usage() {
    out "usage: $0 [options]" \
        "Options:" \
        "  --prefix=dir         Set prefix directory" \
        "  --bindir=dir         Set directory where executables will be installed" \
        "  --manprefix=dir      Set directory where manual pages will be installed" \
        "  --with-netcat=opt    Whether to build netcat [yes,no,auto](default: auto)" \
        "  --with-less-t=opt    Whether to build mandoc with 'less -T' tagfile support" \
        "                                                 [yes,no,auto](default: auto)" \
        "  --with-fts=opt       One of glibc, musl-fts, none, auto (default: auto)" \
        "  --with-system-zlib   Use system zlib"
    exit 1
}

prefix=/usr/local
# We don't want expansion
# shellcheck disable=2016
{
    bindir='$(PREFIX)/bin'
    manprefix='${PREFIX}/share/man'
}
fts=auto
netcat=auto
lesst=auto
host=

for arg; do
    case $arg in
        --help) usage ;;
        --prefix=*) prefix=${arg#*=} ;;
        --bindir=*) bindir=${arg#*=} ;;
        --manprefix=*) manprefix=${arg#*=} ;;
        --with-fts=*) fts=${arg#*=}  ;;
        --with-system-zlib) zlib=1   ;;
        --with-less-t) lesst=yes     ;;
        --without-less-t) lesst=no   ;;
        --with-less-t=*) lesst=${arg#*=} ;;
        --with-netcat) netcat=yes    ;;
        --without-netcat) netcat=no  ;;
        --with-netcat=*) netcat=${arg#*=} ;;
        -*) die "Unknown flag: '$arg'" ;;
        *=*) export "${arg:?}";;
        *) die "Unknown option: '$arg'"
    esac
done

trap 'rm -f config.mk' EXIT
trap 'rm -f config.mk; exit 1' INT

: "${CC:=cc}" "${PKG_CONFIG:=pkg-config}"

printf 'checking system type... '
[ "$host" ] || host=$($CC -dumpmachine 2>/dev/null) || die "Could not determine host"
out "$host"

case $host in
    *linux*) ;;
    *) die "Unsupported system: $host"
esac

cat <<EOF >config.mk
PREFIX    = $prefix
BINDIR    = $bindir
MANPREFIX = $manprefix

AR     = ${AR:-ar}
CC     = ${CC:-cc}
RANLIB = ${RANLIB:-ranlib}
RM     = rm -f
YACC   = ${YACC:-yacc}

EOF

case $netcat in
    auto|yes)
        printf 'checking for libtls... '
        if tlslib=$("$PKG_CONFIG" --static --libs libtls 2>/dev/null); then
            out "$tlslib"
            out "TLSLIB = $tlslib" "BIN += nc" >>config.mk
            out "MAN += usr.bin/nc/nc.1" >>config.mk
        else
            out "none"
            [ "$netcat" = yes ] && die "No tls library found"
        fi
esac

printf 'checking for zlib... '
if [ "$zlib" = 1 ]; then
    zlib=$($PKG_CONFIG --static --libs zlib)
    out "$zlib"
    out "ZLIB = $zlib" >> config.mk
else
    zlib=lib/libz/libz.a
    out "in source"
    out "ZLIB = $zlib" "MANDOCLIBS += $zlib" "GREPLIBS += $zlib" >>config.mk
fi

printf 'checking for fts... '
if [ "$fts" = auto ]; then
    if out "#include <fts.h>" | $CC -E - >/dev/null 2>&1; then
        fts=glibc
        $PKG_CONFIG --exists musl-fts && fts=musl-fts
    else
        fts=none
    fi
fi

out "$fts"

case $fts in
    glibc) out "CFLAGS += -DHAVE_FTS" ;;
    musl-fts) out "CFLAGS += -DHAVE_FTS" "LIBFTS = -lfts" ;;
    none) out "LIBOBJ += lib/libc/gen/fts.o"
esac >>config.mk

case $lesst in
    auto|yes)
        printf "Checking if less supports '-T'... "
        if echo | less -T test >/dev/null 2>&1; then
            out yes
            out "CFLAGS += -DHAVE_LESS_T" >>config.mk
        else
            out no
            [ "$lesst" = yes ] && die "less doesn't support '-T' flag"
        fi
esac

out "written config.mk" "Run 'make' to compile otools"
trap - EXIT INT