#! /bin/sh

OS=`uname -s`
DEBUG=0
PREFIX=/usr/local

config_h_append_generic_endian() {
    cat <<EOF >> "$1"

/*
 * Generic compatibility
 */
#include <endian.h>
EOF
}

config_h_append_darwin_endian() {
    cat <<EOF >> "$1"

/*
 * Darwin compatibility
 */
#include <libkern/OSByteOrder.h>

#define htobe16(n) OSSwapHostToBigInt16(n)
#define htole16(n) OSSwapHostToLittleInt16(n)
#define be16toh(n) OSSwapBigToHostInt16(n)
#define le16toh(n) OSSwapLittleToHostInt16(n)

#define htobe32(n) OSSwapHostToBigInt32(n)
#define htole32(n) OSSwapHostToLittleInt32(n)
#define be32toh(n) OSSwapBigToHostInt32(n)
#define le32toh(n) OSSwapLittleToHostInt32(n)

#define htobe64(n) OSSwapHostToBigInt64(n)
#define htole64(n) OSSwapHostToLittleInt64(n)
#define be64toh(n) OSSwapBigToHostInt64(n)
#define le64toh(n) OSSwapLittleToHostInt64(n)
EOF
}

config_h_append_bsd_pty() {
    cat <<EOF >> "$1"

/*
 * BSD openpty(3) compatibility
 */
#include <util.h>
EOF
}

config_h_append_linux_pty() {
    cat <<EOF >> "$1"

/*
 * Linux openpty(3) compatibility
 */
#include <pty.h>
EOF
}

config_h_create() {
    cat <<EOF > "$1"
#ifndef _CONFIG_H
#define _CONFIG_H
EOF

    if [ "$OS" = "Darwin" ]; then
        config_h_append_darwin_endian "$1"
    else
        config_h_append_generic_endian "$1"
    fi

    if [ "$OS" = "Linux" ]; then
        config_h_append_linux_pty "$1"
    else
        config_h_append_bsd_pty "$1"
    fi

    cat <<EOF >> "$1"

#endif /* _CONFIG_H */
EOF
}

build_mk_append_generic() {
    cat <<'EOF' >> "$1"
LDFLAGS_SO	= -shared -Wl,-soname=$(SONAME)

STATIC		= lib$(LIBNAME).a

SONAME_SHORT	= lib$(LIBNAME).so
SONAME		= $(SONAME_SHORT).$(VERSION_MAJOR)
SONAME_FULL	= $(SONAME_SHORT).$(VERSION)

EOF

    cat <<EOF >> "$1"
PREFIX		= $PREFIX
EOF
}

build_mk_append_man_generic() {
    cat <<'EOF' >> "$1"
MANDIR		= $(PREFIX)/share/man
EOF
}

build_mk_append_man_bsd() {
    if [ "$PREFIX" = "/usr" ]; then
        local mandir='$(PREFIX)/share/man'
    else
        local mandir='$(PREFIX)/man'
    fi

    cat <<EOF >> "$1"
MANDIR		= $mandir
EOF
}

build_mk_append_darwin() {
    cat <<'EOF' >> "$1"
LDFLAGS_SO	= -dynamiclib -current_version $(VERSION)

STATIC      = lib$(LIBNAME).a

SONAME_SHORT	= lib$(LIBNAME).dylib
SONAME		= lib$(LIBNAME).$(VERSION_MAJOR).dylib
SONAME_FULL	= lib$(LIBNAME).$(VERSION).dylib

EOF

    cat <<EOF >> "$1"
PREFIX      = $PREFIX
EOF
}

build_mk_create() {
    if [ "$DEBUG" = 1 ]; then
        cat <<'EOF' > "$1"
CFLAGS_DEBUG	= -g -fno-inline
EOF
    else
        cat <<'EOF' > "$1"
CFLAGS_DEBUG	=
EOF
    fi

    if [ "$OS" = "Darwin" ]; then
        build_mk_append_darwin "$1"
    else
        build_mk_append_generic "$1"
    fi

    case $OS in
        FreeBSD|NetBSD|OpenBSD)
            build_mk_append_man_bsd "$1"
        ;;

        *)
            build_mk_append_man_generic "$1"
        ;;
    esac

    cat <<'EOF' >> "$1"
CFLAGS_WARN	= -Wall
CFLAGS_OPT	= -O2
CFLAGS_GEN	= -fPIC
CFLAGS		= $(CFLAGS_DEBUG) $(CFLAGS_WARN) $(CFLAGS_OPT) $(CFLAGS_GEN)

AR		= $(CROSS)ar
RANLIB		= $(CROSS)ranlib

RM		= /bin/rm
LN		= /bin/ln
RMDIR		= /bin/rmdir
INSTALL		= /usr/bin/install
EOF
}

parse_opt() {
    local _IFS="$IFS"

    IFS="="

    set -- $1

    echo $2

    IFS="$_IFS"
}

for arg in $@; do
    case $arg in
        --enable-debug)
            DEBUG=1
        ;;

        --prefix=*)
            PREFIX="`parse_opt "$arg"`"
        ;;
    esac
done

if [ ! -d "mk" ]; then
    mkdir -m 0755 mk
fi

config_h_create "src/config.h"
build_mk_create "mk/build.mk"