#!/usr/bin/env ruby
require 'getoptlong'
require 'mkmf'

target="bdb2"

$distcleanfiles=["bdb_aux._c"]


def usage
  $stderr.puts "

Options:

 --va build an alternate output bdb2a, use this to avoid overwriting a
      previous bdb2 library, since R0.3 the interfaces are not
      compatible due to the addition of transaction parameters to many
      calls. Note the impact on indicating the include, below.
      If you have not used bdb2 before, you need not use this argument.

 -h,--help this

 --dbh {dir for db.h}
      If we cannot find the right db.h automatically, use this to
      indicate where to look. Do not use --with... because we need
      to find the file itself to extract all the DB defines.

"
end

opts = GetoptLong.new(
                      [ "--va", GetoptLong::NO_ARGUMENT],
                      [ "-h","--help",GetoptLong::NO_ARGUMENT],
                      [ "--dbh", GetoptLong::REQUIRED_ARGUMENT]
                      )
opts.each do |opt,arg|
  case opt
  when '--va'
    target="bdb2a"
  when '-h','--help'
    usage
    exit
  when '--dbh'
    $dbh_location=arg
  end
end

message "Target is #{target}\n"

if CONFIG['INSTALL'] =~ %r{./install-sh}
  CONFIG.delete("INSTALL")
end

mj,mi,rv=RUBY_VERSION.split('.').collect {|s| s.to_i}
ri=(((mj*1000)+mi)*1000)+rv
if ri < 1008004
  $stderr.puts("Version 1.8.4 minimum required")
  exit(3)
end

inc_dir,lib_dir = dir_config(target,$dbh_location)

$stderr.puts("lib_dir=#{lib_dir} inc_dir=#{inc_dir}")


#case Config::CONFIG["arch"]
#when /solaris2/
#  $DLDFLAGS ||= ""
#  $DLDFLAGS += " -R#{lib_dir}"
#end

$libs << " -lpthread"
case Config::CONFIG["arch"]
when /solaris2/
$libs << " -lnsl"
end

versions=%w(db-4.4 db-4.3 db-4.2)
locations=%w(/usr/local/lib /opt/local/lib /usr/local/BerkeleyDB.4.3/lib /usr/local/BerkeleyDB.4.2/lib /opt/csw/bdb44/lib)
until versions.empty?
  (lib_ok=find_library(this_version=versions.shift,'db_create',*locations)) && break
end

$maj,$min=0,0
if try_link0(<<SRC)
#include <db.h>
#include <stdio.h>
main() {
int maj,min;
db_version(&maj,&min,NULL);
printf("%d %d",maj,min);
}
SRC
  xpopen("./conftest") do |f|
  $maj,$min=f.gets.chomp.split.collect {|v| v.to_i}
  end
  rm_f("conftest*")
else
  message("unable to compile against found DB library\n")
  exit
end

message("Found DB version #{$maj}.#{$min}\n")

def check_header dir
  opt=if dir; "-I#{dir}".quote; else nil; end
  hmaj=hmin=nil
  if try_cpp(cpp_include("db.h"),opt)
    if (hmaj=try_constant("DB_VERSION_MAJOR","db.h",opt)) and
        (hmin=try_constant("DB_VERSION_MINOR","db.h",opt)) and
        hmaj.to_i == $maj and hmin.to_i == $min
      message("Found matching db.h with #{opt}\n")
      $INCFLAGS << " " << opt
      $db_inc=dir
      return true
    else
      if hmaj
        message("found a db.h, but wrong version (lib) #{$maj}.#{$min} != (db.h) #{hmaj}.#{hmin}\n")
      end
    end
  end
  false
end

# All systems seem to have a default db.h, so this is more selective
h_test_locations=%w(
 /usr/local/include
 /opt/local/include
 /usr/local
 /opt/csw/bdb44/include
)
h_test_locations.unshift($dbh_location) if $dbh_location
message("Header test locations are #{h_test_locations.inspect}\n")
found=false
$db_inc=nil

# Find possible headers first:
require 'find'
Find.find(*h_test_locations) do |p1|
  if FileTest.directory?(p1)
    Find.prune if File.basename(p1)[0] == ?.
  else
    if File.basename(p1) == 'db.h'
      break if found=check_header(File.dirname(p1))
    end
  end
end

unless found
  usage
  message("\nUnable to find db.h to match library (#{maj}.#{min})\n")
  exit 4
end

# This is an alternate way of find headers, by makedepend
# support of gcc. It is not as necessary as we could just use
# the above result, but it is another check.
# Find db.h, not sure this will work everywhere, gcc is ok
src=create_tmpsrc("#include <db.h>")
cmd=cpp_command("-M")
r=`#{cmd}`
header_loc=r.split.collect {|k| k if k =~ %r{^/.*db.h} }.compact[0]
message("header is #{header_loc}\n")

inc="#include <db.h>"
n=0
message("Writing bdb_aux._c (defines), this takes a while\n")
defines=[]
File.open(File.join($db_inc,"db.h")) {|fd|
  File.open("bdb_aux._c","w") {|hd|
    hd.puts("/* This file automatically generated by extconf.rb */\n")
    fd.each_line {|l|
      if l =~ %r{^#define\s+(DBC?_\w*)\s+(\"?)} and macro_defined?($1,inc)
        if $2 == '\"'
          hd.print(%Q{    cs(mBdb,%s);\n}%[$1])
        else
          hd.print(%Q{    ci(mBdb,%s);\n}%[$1])
        end
        message(".")
        n+=1
      end
    }
  }
  message("\nwrote #{n} defines\n")
} unless File.exist?("bdb_aux._c")

$defs << $INCFLAGS

if lib_ok
  create_header
  create_makefile(target)
else
  $stderr.puts("cannot create Makefile")
end