#!/bin/sh

# Defaults

APP_NAME="Prosody"
APP_DIRNAME="prosody"
PREFIX="/usr/local"
SYSCONFDIR="$PREFIX/etc/$APP_DIRNAME"
LIBDIR="$PREFIX/lib"
DATADIR="$PREFIX/var/lib/$APP_DIRNAME"
LUA_SUFFIX=""
LUA_DIR="/usr"
LUA_BINDIR="/usr/bin"
LUA_INCDIR="/usr/include"
LUA_LIBDIR="/usr/lib"
IDN_LIB="idn"
ICU_FLAGS="-licui18n -licudata -licuuc"
OPENSSL_LIB="crypto"
CC="gcc"
LD="gcc"
RUNWITH="lua"
EXCERTS="yes"
PRNG=
PRNGLIBS=

CFLAGS="-fPIC -Wall -pedantic -std=c99"
LDFLAGS="-shared"

IDN_LIBRARY="idn"
# Help

show_help() {
cat <<EOF
Configure $APP_NAME prior to building.

--help                      This help.
--ostype=OS                 Use one of the OS presets. May be one of:
                            debian, macosx, linux, freebsd, openbsd, netbsd
--prefix=DIR                Prefix where $APP_NAME should be installed.
                            Default is $PREFIX
--sysconfdir=DIR            Location where the config file should be installed.
                            Default is \$PREFIX/etc/$APP_DIRNAME
--libdir=DIR                Location where the server files should be stored.
                            Default is \$PREFIX/lib
--datadir=DIR               Location where the server data should be stored.
                            Default is \$PREFIX/var/lib/$APP_DIRNAME
--lua-version=VERSION       Use specific Lua version: 5.1, 5.2, or 5.3
                            Default is auto-detected.
--lua-suffix=SUFFIX         Versioning suffix to use in Lua filenames.
                            Default is "$LUA_SUFFIX" (lua$LUA_SUFFIX...)
--with-lua=PREFIX           Use Lua from given prefix.
                            Default is auto-detected (the parent directory of \$LUA_BINDIR).
--with-lua-bin=DIR          You can also specify Lua's bin dir.
                            Default is the directory of the auto-detected Lua interpreter,
                            or \$LUA_DIR/bin if --with-lua is used.
--runwith=BINARY            What Lua binary to set as runtime environment.
                            Default is $RUNWITH
--with-lua-include=DIR      You can also specify Lua's includes dir.
                            Default is \$LUA_DIR/include
--with-lua-lib=DIR          You can also specify Lua's libraries dir.
                            Default is \$LUA_DIR/lib
--with-idn=LIB              The name of the IDN library to link with.
                            Default is $IDN_LIB
--idn-library=(idn|icu)     Select library to use for IDNA functionality.
                            idn: use GNU libidn (default)
                            icu: use ICU from IBM
--with-ssl=LIB              The name of the SSL to link with.
                            Default is $OPENSSL_LIB
--with-random=METHOD        CSPRNG backend to use. One of
                            getrandom: Linux kernel
                            arc4random: OpenBSD kernel
                            openssl: OpenSSL RAND method
                            Default is to use /dev/urandom
--cflags=FLAGS              Flags to pass to the compiler
                            Default is $CFLAGS
--add-cflags=FLAGS          Adds additional CFLAGS, preserving defaults.
                            Can be repeated.
--ldflags=FLAGS             Flags to pass to the linker
                            Default is $LDFLAGS
--add-ldflags=FLAGS         Adds additional linker flags, preserving defaults.
                            Can be repeated.
--c-compiler=CC             The C compiler to use when building modules.
                            Default is $CC
--compiler-wrapper=WRAPPER  Adds a prefix to compiler and linker calls,
                            usable for eg distcc or ccache.
--linker=CC                 The linker to use when building modules.
                            Default is $LD
--no-example-certs          Disables generation of example certificates.
EOF
}

# Helper functions

find_program() {
   prog=$(command -v "$1" 2>/dev/null)
   if [ -n "$prog" ]
   then
      dirname "$prog"
   fi
}

die() {
   echo "$*"
   echo
   echo "configure failed."
   echo
   exit 1
}

# shellcheck disable=SC2039
case $(echo -n x) in
-n*) echo_n_flag='';;
*)   echo_n_flag='-n';;
esac

echo_n() {
   echo $echo_n_flag "$*"
}

# ----------------------------------------------------------------------------
# MAIN PROGRAM
# ----------------------------------------------------------------------------

# Parse options

while [ -n "$1" ]
do
   value=$(echo "$1" | sed 's/[^=]*.\(.*\)/\1/')
   key=$(echo "$1" | sed 's/=.*//')
   # shellcheck disable=SC2088
   if echo "$value" | grep "~" >/dev/null 2>/dev/null
   then
      echo
      echo '*WARNING*: the "~" sign is not expanded in flags.'
      # shellcheck disable=SC2016
      echo 'If you mean the home directory, use $HOME instead.'
      echo
   fi
   case "$key" in
   --help)
      show_help
      exit 0
      ;;
   --prefix)
      [ -n "$value" ] || die "Missing value in flag $key."
      PREFIX="$value"
      PREFIX_SET=yes
      ;;
   --sysconfdir)
      [ -n "$value" ] || die "Missing value in flag $key."
      SYSCONFDIR="$value"
      SYSCONFDIR_SET=yes
      ;;
   --ostype)
	# TODO make this a switch?
      OSPRESET="$value"
      if [ "$OSPRESET" = "debian" ]; then
         if [ "$LUA_SUFFIX_SET" != "yes" ]; then
            LUA_SUFFIX="5.1";
            LUA_SUFFIX_SET=yes
         fi
         if [ "$RUNWITH_SET" != "yes" ]; then
            RUNWITH="lua$LUA_SUFFIX";
            RUNWITH_SET=yes
         fi
         LUA_INCDIR="/usr/include/lua$LUA_SUFFIX"
         LUA_INCDIR_SET=yes
         CFLAGS="$CFLAGS -ggdb"
      fi
      if [ "$OSPRESET" = "macosx" ]; then
         LUA_INCDIR=/usr/local/include;
         LUA_INCDIR_SET=yes
         LUA_LIBDIR=/usr/local/lib
         LUA_LIBDIR_SET=yes
         CFLAGS="$CFLAGS -mmacosx-version-min=10.3"
         LDFLAGS="-bundle -undefined dynamic_lookup"
      fi
      if [ "$OSPRESET" = "linux" ]; then
         LUA_INCDIR=/usr/local/include;
         LUA_INCDIR_SET=yes
         LUA_LIBDIR=/usr/local/lib
         LUA_LIBDIR_SET=yes
         CFLAGS="$CFLAGS -ggdb"
      fi
      if [ "$OSPRESET" = "freebsd" ] || [ "$OSPRESET" = "openbsd" ]; then
         LUA_INCDIR="/usr/local/include/lua51"
         LUA_INCDIR_SET=yes
         CFLAGS="-Wall -fPIC -I/usr/local/include"
         LDFLAGS="-I/usr/local/include -L/usr/local/lib -shared"
         LUA_SUFFIX="51"
         LUA_SUFFIX_SET=yes
         LUA_DIR=/usr/local
         LUA_DIR_SET=yes
         CC=cc
         LD=ld
      fi
      if [ "$OSPRESET" = "openbsd" ]; then
         LUA_INCDIR="/usr/local/include";
         LUA_INCDIR_SET="yes"
      fi
      if [ "$OSPRESET" = "netbsd" ]; then
         LUA_INCDIR="/usr/pkg/include/lua-5.1"
         LUA_INCDIR_SET=yes
         LUA_LIBDIR="/usr/pkg/lib/lua/5.1"
         LUA_LIBDIR_SET=yes
         CFLAGS="-Wall -fPIC -I/usr/pkg/include"
         LDFLAGS="-L/usr/pkg/lib -Wl,-rpath,/usr/pkg/lib -shared"
      fi
      if [ "$OSPRESET" = "pkg-config" ]; then
         if [ "$LUA_SUFFIX_SET" != "yes" ]; then
            LUA_SUFFIX="5.1";
            LUA_SUFFIX_SET=yes
         fi
         LUA_CF="$(pkg-config --cflags-only-I lua$LUA_SUFFIX)"
         LUA_CF="${LUA_CF#*-I}"
         LUA_CF="${LUA_CF%% *}"
         if [ "$LUA_CF" != "" ]; then
            LUA_INCDIR="$LUA_CF"
            LUA_INCDIR_SET=yes
         fi
         CFLAGS="$CFLAGS"
      fi
      ;;
   --libdir)
      LIBDIR="$value"
      LIBDIR_SET=yes
      ;;
   --datadir)
      DATADIR="$value"
      DATADIR_SET=yes
      ;;
   --lua-suffix)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_SUFFIX="$value"
      LUA_SUFFIX_SET=yes
      ;;
   --lua-version|--with-lua-version)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_VERSION="$value"
      [ "$LUA_VERSION" = "5.1" ] || [ "$LUA_VERSION" = "5.2" ] || [ "$LUA_VERSION" = "5.3" ] || [ "$LUA_VERSION" = "5.4" ] || die "Invalid Lua version in flag $key."
      LUA_VERSION_SET=yes
      ;;
   --with-lua)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_DIR="$value"
      LUA_DIR_SET=yes
      ;;
   --with-lua-bin)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_BINDIR="$value"
      LUA_BINDIR_SET=yes
      ;;
   --with-lua-include)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_INCDIR="$value"
      LUA_INCDIR_SET=yes
      ;;
   --with-lua-lib)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_LIBDIR="$value"
      LUA_LIBDIR_SET=yes
      ;;
   --with-idn)
      IDN_LIB="$value"
      ;;
   --idn-library)
      IDN_LIBRARY="$value"
      ;;
   --with-ssl)
      OPENSSL_LIB="$value"
      ;;
   --with-random)
      case "$value" in
         getrandom)
            PRNG=GETRANDOM
            ;;
         openssl)
            PRNG=OPENSSL
            ;;
         arc4random)
            PRNG=ARC4RANDOM
            ;;
      esac
      ;;
   --cflags)
      CFLAGS="$value"
      ;;
   --add-cflags)
      CFLAGS="$CFLAGS $value"
      ;;
   --ldflags)
      LDFLAGS="$value"
      ;;
   --add-ldflags)
      LDFLAGS="$LDFLAGS $value"
      ;;
   --c-compiler)
      CC="$value"
      ;;
   --linker)
      LD="$value"
      ;;
   --runwith)
      RUNWITH="$value"
      RUNWITH_SET=yes
      ;;
    --no-example-certs)
      EXCERTS=
      ;;
   --compiler-wrapper)
      CC="$value $CC"
      LD="$value $LD"
      ;;
   *)
      die "Error: Unknown flag: $1"
      ;;
   esac
   shift
done

if [ "$PREFIX_SET" = "yes" ] && [ ! "$SYSCONFDIR_SET" = "yes" ]
then
   if [ "$PREFIX" = "/usr" ]
   then SYSCONFDIR=/etc/$APP_DIRNAME
   else SYSCONFDIR=$PREFIX/etc/$APP_DIRNAME
   fi
fi

if [ "$PREFIX_SET" = "yes" ] && [ ! "$DATADIR_SET" = "yes" ]
then
   if [ "$PREFIX" = "/usr" ]
   then DATADIR=/var/lib/$APP_DIRNAME
   else DATADIR=$PREFIX/var/lib/$APP_DIRNAME
   fi
fi

if [ "$PREFIX_SET" = "yes" ] && [ ! "$LIBDIR_SET" = "yes" ]
then
   LIBDIR=$PREFIX/lib
fi

detect_lua_version() {
   detected_lua=$("$1" -e 'print(_VERSION:match(" (5%.[1234])$"))' 2> /dev/null)
   if [ "$detected_lua" != "nil" ]
   then
      if [ "$LUA_VERSION_SET" != "yes" ]
      then
         echo "Lua version detected: $detected_lua"
         LUA_VERSION=$detected_lua
         return 0
      elif [ "$LUA_VERSION" = "$detected_lua" ]
      then
         return 0
      fi
   fi
   return 1
}

search_interpreter() {
   suffix="$1"
   if [ "$LUA_BINDIR_SET" = "yes" ]
      then
      find_lua="$LUA_BINDIR"
   elif [ "$LUA_DIR_SET" = "yes" ]
   then
      LUA_BINDIR="$LUA_DIR/bin"
      if [ -f "$LUA_BINDIR/lua$suffix" ]
      then
         find_lua="$LUA_BINDIR"
      fi
   else
      find_lua=$(find_program lua"$suffix")
   fi
   if [ -n "$find_lua" ] && [ -x "$find_lua/lua$suffix" ]
   then
      if detect_lua_version "$find_lua/lua$suffix"
      then
         echo "Lua interpreter found: $find_lua/lua$suffix..."
         if [ "$LUA_BINDIR_SET" != "yes" ]
         then
            LUA_BINDIR="$find_lua"
         fi
         if [ "$LUA_DIR_SET" != "yes" ]
         then
            LUA_DIR=$(dirname "$find_lua")
         fi
         LUA_SUFFIX="$suffix"
         return 0
      fi
   fi
   return 1
}

lua_interp_found=no
if [ "$LUA_SUFFIX_SET" != "yes" ]
then
   if [ "$LUA_VERSION_SET" = "yes" ] && [ "$LUA_VERSION" = "5.1" ]
   then
      suffixes="5.1 51 -5.1 -51"
   elif [ "$LUA_VERSION_SET" = "yes" ] && [ "$LUA_VERSION" = "5.2" ]
   then
      suffixes="5.2 52 -5.2 -52"
   elif [ "$LUA_VERSION_SET" = "yes" ] && [ "$LUA_VERSION" = "5.3" ]
   then
      suffixes="5.3 53 -5.3 -53"
   elif [ "$LUA_VERSION_SET" = "yes" ] && [ "$LUA_VERSION" = "5.4" ]
   then
      suffixes="5.4 54 -5.4 -54"
   else
      suffixes="5.1 51 -5.1 -51"
      suffixes="$suffixes 5.2 52 -5.2 -52"
      suffixes="$suffixes 5.3 53 -5.3 -53"
      suffixes="$suffixes 5.4 54 -5.4 -54"
   fi
   for suffix in "" $suffixes
   do
      search_interpreter "$suffix" && {
      lua_interp_found=yes
      break
   }
done
else
   search_interpreter "$LUA_SUFFIX" && {
   lua_interp_found=yes
}
fi

if [ "$lua_interp_found" != "yes" ] && [ "$RUNWITH_SET" != "yes" ]
then
   if [ "$LUA_VERSION_SET" ]; then
      interp="Lua $LUA_VERSION";
   else
      interp="Lua";
   fi
   if [ "$LUA_DIR_SET" ] || [ "$LUA_BINDIR_SET" ]; then
      where="$LUA_BINDIR";
   else
      where="\$PATH";
   fi
   echo "$interp interpreter not found in $where"
   die "You may want to use the flags --with-lua, --with-lua-bin and/or --lua-suffix. See --help."
fi

if [ "$LUA_VERSION_SET" = "yes" ] && [ "$RUNWITH_SET" != "yes" ]
then
   echo_n "Checking if $LUA_BINDIR/lua$LUA_SUFFIX is Lua version $LUA_VERSION... "
   if detect_lua_version "$LUA_BINDIR/lua$LUA_SUFFIX"
   then
      echo "yes"
   else
      echo "no"
      die "You may want to use the flags --with-lua, --with-lua-bin and/or --lua-suffix. See --help."
   fi
fi

if [ "$LUA_INCDIR_SET" != "yes" ]
then
   LUA_INCDIR="$LUA_DIR/include"
fi

if [ "$LUA_LIBDIR_SET" != "yes" ]
then
   LUA_LIBDIR="$LUA_DIR/lib"
fi

echo_n "Checking Lua includes... "
lua_h="$LUA_INCDIR/lua.h"
if [ -f "$lua_h" ]
then
   echo "lua.h found in $lua_h"
else
  for postfix in "$LUA_VERSION" "$LUA_SUFFIX"; do
    if ! [ "$postfix" = "" ]; then
      v_dir="$LUA_INCDIR/lua/$postfix";
    else
      v_dir="$LUA_INCDIR/lua";
    fi
    lua_h="$v_dir/lua.h"
    if [ -f "$lua_h" ]
    then
      echo "lua.h found in $lua_h"
      LUA_INCDIR="$v_dir"
      break;
    else
      d_dir="$LUA_INCDIR/lua$postfix"
      lua_h="$d_dir/lua.h"
      if [ -f "$lua_h" ]
      then
        echo "lua.h found in $lua_h"
        LUA_INCDIR="$d_dir"
        break;
      else
        lua_h_search="$lua_h_search\n  $v_dir/lua.h\n  $d_dir/lua.h"
      fi
    fi
  done
  if [ ! -f "$lua_h" ]; then
    echo "lua.h not found. Looked for:"
    echo "$lua_h_search" | uniq
    echo
    die "You may want to use the flag --with-lua or --with-lua-include. See --help."
  fi
fi

if [ "$lua_interp_found" = "yes" ]
then
   echo_n "Checking if Lua header version matches that of the interpreter... "
   header_version=$(sed -n 's/.*LUA_VERSION_NUM.*5.\(.\).*/5.\1/p' "$lua_h")
   if [ "$header_version" = "$LUA_VERSION" ]
   then
      echo "yes"
   else
      echo "no"
      echo "lua.h version mismatch (interpreter: $LUA_VERSION; lua.h: $header_version)."
      die "You may want to use the flag --with-lua or --with-lua-include. See --help."
   fi
fi

if [ "$IDN_LIBRARY" = "icu" ]
then
   IDNA_LIBS="$ICU_FLAGS"
   CFLAGS="$CFLAGS -DUSE_STRINGPREP_ICU"
fi
if [ "$IDN_LIBRARY" = "idn" ]
then
   IDNA_LIBS="-l$IDN_LIB"
fi

if [ -f config.unix ]; then
   rm -f config.unix
fi

if [ "$RUNWITH_SET" != yes ]; then
   RUNWITH="lua$LUA_SUFFIX"
fi

OPENSSL_LIBS="-l$OPENSSL_LIB"

if [ "$PRNG" = "OPENSSL" ]; then
   PRNGLIBS=$OPENSSL_LIBS
elif [ "$PRNG" = "ARC4RANDOM" ] && [ "$(uname)" = "Linux" ]; then
   PRNGLIBS="-lbsd"
fi

# Write config

echo "Writing configuration..."
echo

rm -f built
cat <<EOF > config.unix
# This file was automatically generated by the configure script.
# Run "./configure --help" for details.

LUA_VERSION=$LUA_VERSION
PREFIX=$PREFIX
SYSCONFDIR=$SYSCONFDIR
LIBDIR=$LIBDIR
DATADIR=$DATADIR
LUA_SUFFIX=$LUA_SUFFIX
LUA_DIR=$LUA_DIR
LUA_DIR_SET=$LUA_DIR_SET
LUA_INCDIR=$LUA_INCDIR
LUA_LIBDIR=$LUA_LIBDIR
LUA_BINDIR=$LUA_BINDIR
IDN_LIB=$IDN_LIB
IDNA_LIBS=$IDNA_LIBS
OPENSSL_LIBS=$OPENSSL_LIBS
CFLAGS=$CFLAGS
LDFLAGS=$LDFLAGS
CC=$CC
LD=$LD
RUNWITH=$RUNWITH
EXCERTS=$EXCERTS
RANDOM=$PRNG
RANDOM_LIBS=$PRNGLIBS


EOF

echo "Installation prefix: $PREFIX"
echo "$APP_NAME configuration directory: $SYSCONFDIR"
echo "Using Lua from: $LUA_DIR"

make clean > /dev/null 2> /dev/null

echo
echo "Done. You can now run 'make' to build."
echo