#!/bin/sh

# Defaults

prefix="/usr/local"
sysconfdir="$prefix/etc"
rocks_tree="$prefix"

# ----------------------------------------------------------------------------
# FUNCTION DEFINITIONS
# ----------------------------------------------------------------------------

# Utility functions
# -----------------

# Resolves a full path
# - alternative to "readlink -f", which is not available on solaris
# based on https://stackoverflow.com/a/6554854/1793220
canonicalpath() {
   oldpwd="$PWD"
   if [ -d "$1" ]
   then
      if cd "$1" >/dev/null 2>&1
      then
         echo "$PWD"
      else
         echo "$1"
      fi
   else
      if cd "$(dirname "$1")" >/dev/null 2>&1
      then
         echo "$PWD/$(basename "$1")"
      else
         echo "$1"
      fi
   fi
   cd "$oldpwd" >/dev/null 2>&1 || return
}

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

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

echo_n() {
   printf "%s" "$*"
}

bold='\033[1m'
red='\033[1;31m'
green='\033[1;32m'
blue='\033[1;36m'
reset='\033[0m'

BOLD() {
   printf "$bold%s$reset" "$*"
}

RED() {
   printf "$red%s$reset" "$*"
}

GREEN() {
   printf "$green%s$reset" "$*"
}

BLUE() {
   printf "$blue%s$reset" "$*"
}

# Help
# ----

show_help() {
cat <<EOF
Usage: ./configure [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.

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

Installation directories:
  --prefix=PREFIX              Directory where LuaRocks should be installed
                               [/usr/local]

By default, \`make install' will install all the files in \`/usr/local',
\`/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.

Fine tuning of the installation directories:
  --sysconfdir=SYSCONFDIR      Directory for single-machine config [PREFIX/etc]

Where to install files provided by rocks:
  --rocks-tree=DIR             Root of the local tree of installed rocks.
                               To make files installed in this location
                               accessible to Lua and your \$PATH, see
                               "luarocks path --help" after installation.
                               Avoid using paths controlled by your
                               system's package manager, such as /usr.
                               - Default is [PREFIX]

Where is your Lua interpreter:
  --lua-version=VERSION        Use specific Lua version: 5.1, 5.2, 5.3, or 5.4
                               - Default is auto-detected.
  --with-lua-bin=LUA_BINDIR    Location of your Lua binar(y/ies).
                               - Default is the directory of the
                               auto-detected Lua interpreter,
                               (or DIR/bin if --with-lua is used)
  --with-lua=LUA_DIR           Use Lua from given directory. [LUA_BINDIR/..]
  --with-lua-include=DIR       Lua's includes dir. [LUA_DIR/include]
  --with-lua-lib=DIR           Lua's libraries dir. [LUA_DIR/lib]
  --with-lua-interpreter=NAME  Lua interpreter name.
                               - Default is to auto-detected

For specialized uses of LuaRocks:
  --force-config               Force using a single config location.
                               Do not honor the \$LUAROCKS_CONFIG_5_x
                               or \$LUAROCKS_CONFIG environment
                               variable or the user's local config.
                               Useful to avoid conflicts when LuaRocks
                               is embedded within an application.
  --disable-incdir-check       If you do not wish to use "luarocks build",
                               (e.g. when only deploying binary packages)
                               you do not need lua.h installed. This flag
                               skips the check for lua.h in "configure".

EOF
}

# Lua detection
# -------------

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: $(GREEN "$detected_lua")"
         LUA_VERSION=$detected_lua
         return 0
      elif [ "$LUA_VERSION" = "$detected_lua" ]
      then
         return 0
      fi
   fi
   return 1
}

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

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

# Parse options

while [ -n "$1" ]
do
   value="$(echo "$1" | sed 's/[^=]*.\(.*\)/\1/')"
   key="$(echo "$1" | sed 's/=.*//')"
   if echo "$value" | grep "~" >/dev/null 2>/dev/null
   then
      echo
      echo "$(RED WARNING:) the '~' sign is not expanded in flags."
      echo "If you mean the home directory, use \$HOME instead."
      echo
   fi
   case "$key" in

   # Help
   # ----
   -h|--help)
      show_help
      exit 0
      ;;

   # Where to install LuaRocks:
   # --------------------------
   --prefix)
      [ -n "$value" ] || die "Missing value in flag $key."
      prefix="$(canonicalpath "$value")"
      prefix_SET=yes
      ;;
   --sysconfdir)
      [ -n "$value" ] || die "Missing value in flag $key."
      sysconfdir="$(canonicalpath "$value")"
      sysconfdir_SET=yes
      ;;


   # Where to install files provided by rocks:
   # -----------------------------------------
   --rocks-tree)
      [ -n "$value" ] || die "Missing value in flag $key."
      rocks_tree="$(canonicalpath "$value")"
      rocks_tree_SET=yes
      ;;

   # Where is your Lua interpreter:
   # ------------------------------
   --lua-version|--with-lua-version)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_VERSION="$value"
      case "$LUA_VERSION" in
      5.1|5.2|5.3|5.4) ;;
      *) die "Invalid Lua version in flag $key."
      esac
      LUA_VERSION_SET=yes
      ;;
   --with-lua)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_DIR="$(canonicalpath "$value")"
      [ -d "$LUA_DIR" ] || die "Bad value for --with-lua: $LUA_DIR is not a valid directory."
      LUA_DIR_SET=yes
      ;;
   --with-lua-bin)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_BINDIR="$(canonicalpath "$value")"
      [ -d "$LUA_BINDIR" ] || die "Bad value for --with-lua-bin: $LUA_BINDIR is not a valid directory."
      LUA_BINDIR_SET=yes
      ;;
   --with-lua-include)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_INCDIR="$(canonicalpath "$value")"
      [ -d "$LUA_INCDIR" ] || die "Bad value for --with-lua-include: $LUA_INCDIR is not a valid directory."
      LUA_INCDIR_SET=yes
      ;;
   --with-lua-lib)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_LIBDIR="$(canonicalpath "$value")"
      [ -d "$LUA_LIBDIR" ] || die "Bad value for --with-lua-lib: $LUA_LIBDIR is not a valid directory."
      LUA_LIBDIR_SET=yes
      ;;
   --with-lua-interpreter)
      [ -n "$value" ] || die "Missing value in flag $key."
      LUA_INTERPRETER="$value"
      LUA_INTERPRETER_SET=yes
      ;;

   # For specialized uses of LuaRocks:
   # ---------------------------------
   --force-config)
      FORCE_CONFIG=yes
      ;;
   --disable-incdir-check)
      DISABLE_INCDIR_CHECK=yes
      ;;

   # Old options that no longer apply
   # --------------------------------
   --versioned-rocks-dir)
      echo "--versioned-rocks-dir is no longer necessary."
      echo "The rocks tree in LuaRocks 3.0 is always versioned."
      ;;
   --lua-suffix)
      echo "--lua-suffix is no longer necessary."
      echo "The suffix is automatically detected."
      ;;

   *)
      die "Error: Unknown flag: $1"
      ;;
   esac
   shift
done

echo
BLUE "Configuring LuaRocks version dev..."
echo
echo

# ----------------------------------------
# Derive options from the ones given
# ----------------------------------------

if [ "$prefix_SET" = "yes" ] && [ ! "$sysconfdir_SET" = "yes" ]
then
   if [ "$prefix" = "/usr" ]
   then sysconfdir=/etc
   else sysconfdir=$prefix/etc
   fi
   sysconfdir_SET=yes
fi

if [ "$prefix_SET" = "yes" ] && [ ! "$rocks_tree_SET" = "yes" ]
then
   rocks_tree=$prefix
fi

# ----------------------------------------
# Search for Lua
# ----------------------------------------

lua_interp_found=no

case "$LUA_VERSION" in
5.1)
   names="lua5.1 lua51 lua-5.1 lua-51 luajit lua"
   ;;
5.2)
   names="lua5.2 lua52 lua-5.2 lua-52 lua"
   ;;
5.3)
   names="lua5.3 lua53 lua-5.3 lua-53 lua"
   ;;
5.4)
   names="lua5.4 lua54 lua-5.4 lua-54 lua"
   ;;
*)
   names="lua5.4 lua54 lua-5.4 lua-54 lua5.3 lua53 lua-5.3 lua-53 lua5.2 lua52 lua-5.2 lua-52 lua5.1 lua51 lua-5.1 lua-51 luajit lua"
   ;;
esac

if [ "$LUA_INTERPRETER_SET" = "yes" ]
then
   names="$LUA_INTERPRETER"
fi

for name in $names
do
   search_interpreter "$name" && {
      lua_interp_found=yes
      break
   }
done

if [ "$lua_interp_found" != "yes" ]
then
   if [ "$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 "$(RED $interp interpreter not found) in $where"
   echo "You may want to use the flags $(BOLD --with-lua), $(BOLD --with-lua-bin) and/or $(BOLD --lua-version)"
   die "Run $(BOLD ./configure --help) for details."
fi

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

# ----------------------------------------
# Additional checks
# ----------------------------------------

check_incdir() {
   if [ "$LUA_INCDIR_SET" = "yes" ]
   then
      incdir="$LUA_INCDIR"
   else
      incdir="$LUA_DIR/include"
   fi

   tried=""
   # Verification of the Lua include path happens at LuaRocks runtime,
   # but we also perform it here just so that the user gets an early failure
   # if they try to install LuaRocks with the Lua interpreter package
   # but not the "development files" that many Linux distros ship separately.
   for lua_h in \
      "$incdir/lua/$LUA_VERSION/lua.h" \
      "$incdir/lua$LUA_VERSION/lua.h" \
      "$incdir/lua$(echo "$LUA_VERSION" | tr -d .)/lua.h" \
      "$incdir/lua.h" \
      $("$LUA_BINDIR/$LUA_INTERPRETER" -e 'print(jit and [['"$incdir"'/luajit-]]..jit.version:match("(%d+%.%d+)")..[[/lua.h]] or "")')
   do
      [ -f "$lua_h" ] && return
      tried="$tried $lua_h"
   done

   echo "$(RED "lua.h not found") (tried$tried)"
   echo
   echo "If the development files for Lua (headers and libraries)"
   echo "are installed in your system, you may need to use the"
   echo "$(BOLD --with-lua) or $(BOLD --with-include) flags to specify their location."
   echo
   echo "If those files are not yet installed, you need to install"
   echo "them using the appropriate method for your operating system."
   echo
   die "Run $(BOLD ./configure --help) for details on flags."
}

if [ "$DISABLE_INCDIR_CHECK" != "yes" ]
then
   check_incdir
   echo "lua.h found: $(GREEN "$lua_h")"
fi

unzip_found=$(find_program "unzip")
if [ -n "$unzip_found" ]
then
   echo "unzip found in PATH: $(GREEN "$unzip_found")"
else
   RED "Could not find 'unzip'."
   echo
   die "Make sure it is installed and available in your PATH."
fi

# ----------------------------------------
# Write config
# ----------------------------------------

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

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

prefix=$prefix
sysconfdir=$sysconfdir
rocks_tree=$rocks_tree
LUA_VERSION=$LUA_VERSION
LUA_INTERPRETER=$LUA_INTERPRETER
LUA_DIR=$LUA_DIR
LUA_BINDIR=$LUA_BINDIR
LUA_INCDIR=$LUA_INCDIR
LUA_LIBDIR=$LUA_LIBDIR
FORCE_CONFIG=$FORCE_CONFIG
EOF

echo
BLUE "Done configuring."
echo
echo
echo "LuaRocks will be installed at......: $(GREEN "$prefix")"
echo "LuaRocks will install rocks at.....: $(GREEN "$rocks_tree")"
echo "LuaRocks configuration directory...: $(GREEN "$sysconfdir/luarocks")"
echo "Using Lua from.....................: $(GREEN "$LUA_DIR")"
if [ "$LUA_BINDIR_SET" = "yes" ]; then echo "Lua bin directory..................: $(GREEN "$LUA_BINDIR")" ; fi
if [ "$LUA_INCDIR_SET" = "yes" ]; then echo "Lua include directory..............: $(GREEN "$LUA_INCDIR")" ; fi
if [ "$LUA_LIBDIR_SET" = "yes" ]; then echo "Lua lib directory..................: $(GREEN "$LUA_LIBDIR")" ; fi
echo
echo "* Type $(BOLD make) and $(BOLD make install):"
echo "  to install to $prefix as usual."
echo "* Type $(BOLD make bootstrap):"
echo "  to install LuaRocks into $rocks_tree as a rock."
echo