#!/usr/bin/env ruby
ESSENTIALS = [
  "boost/detail/{limits,endian}.hpp",
  "boost/config/*",
  "boost/detail/sp_counted_*",
  "boost/detail/atomic_count*",
  "libs/thread/src/*"
]
PROGRAM_SOURCE = %q{
  #include <boost/shared_ptr.hpp>
  #include <boost/thread.hpp>
  #include <boost/function.hpp>
  #include <boost/bind.hpp>
  #include <boost/date_time/posix_time/posix_time.hpp>
}
BOOST_DIR = ARGV[0]
Dir.chdir(File.dirname(__FILE__) + "/../ext")
 
# Run the given command, and abort on error.
def sh(*command)
  puts command.join(" ")
  if !system(*command)
    puts "*** ERROR"
    exit 1
  end
end
 
def install(source_filename, target_filename)
  command = ["install", "-D", "--mode=u+rw,g+r,o+r", source_filename, target_filename]
  sh(*command)
end
 
def copy_boost_files(*patterns)
  patterns.each do |pattern|
    Dir["#{BOOST_DIR}/#{pattern}"].each do |source|
      if File.directory?(source)
        source.slice!(0 .. BOOST_DIR.size)
        copy_boost_files("#{source}/*")
      else
        target = source.slice(BOOST_DIR.size + 1 .. source.size - 1)
        target.sub!(%r{^libs/thread/}, 'boost/')
        if !File.exist?(target)
          install(source, target)
        end
      end
    end
  end
end
 
def copy_essential_files
  copy_boost_files(*ESSENTIALS)
end
 
def prepare
  File.open("test.cpp", "w") do |f|
    f.write(PROGRAM_SOURCE)
  end
end
 
def cleanup
  File.unlink("test.cpp") rescue nil
end
 
# Compile PROGRAM_SOURCE and copy whatever missing header files the compiler needs.
def copy_dependencies
  done = false
  while !done
    missing_headers = `g++ test.cpp -c -I. 2>&1`.
      split("\n").
      grep(/error: .*: No such file/).
      map do |line|
      file = line.sub(/.*error: (.*): .*/, '\1')
      if file =~ /^boost\//
        file
      else
        line =~ /(.*?):/
        source = $1
        File.dirname(source) + "/" + file
      end
    end
    missing_headers.each do |header|
      install("#{BOOST_DIR}/#{header}", header)
    end
    done = missing_headers.empty?
  end
end
 
def start
  if BOOST_DIR.nil? || BOOST_DIR.empty?
    puts "Usage: copy_boost_headers.rb <boost source directory>"
    exit 1
  end
  begin
    prepare
    copy_essential_files
    copy_dependencies
  ensure
    cleanup
  end
end
 
start