#!/usr/bin/env ruby

DOCUMENTATION = <<DOCEND

Generates a `Makefile` for compiling a Smalltalk/X class library. 

DOCEND

#

# Generates a makefile for a Smalltalk/X package. Return status code

# (0 means success)

def stmkmf(cwd: '.', out: 'makefile', top: nil)   

  if not File.exist? cwd then

    STDERR.puts "error: no such directory: #{cwd}"

    return 1

  end

  if not File.directory? cwd then

    STDERR.puts "error: not a directory: #{cwd}"

    return 2

  end

  if not File.exist? File.join(cwd, 'Make.proto') then

    STDERR.puts "error: could not find Make.proto: #{File.join(cwd, 'Make.proto')}"    

    return 3

  end

  if top.nil? then 

    # Spuriously it happens the `Make.proto` is somehow corrupted and not properly

    # UTF8 encoded. This would result in error like

    #

    #    `match': invalid byte sequence in UTF-8 (ArgumentError)

    #

    # To prevent, replace all invalid character by $?. Not a safest

    # approach, though.

    make_proto_contents = File.read(File.join(cwd, 'Make.proto')).encode("UTF-8", :invalid=>:replace, :replace=>"?").encode('UTF-8')

    match = /^TOP=(.*)$/.match(make_proto_contents)

    if match.nil? then

      STDERR.puts "error: could not extract TOP from Make.proto (missing TOP=.. definition?)"    

      return 4

    end

    top = match[1].rstrip()

  end

  if not File.directory? File.join(cwd, top) then

    require 'pry'

    require 'pry-byebug'

    binding.pry

    STDERR.puts "error: TOP does not exist or not a directory: #{top}"    

    return 5

  end

  makelib = File.join(cwd, top, '..', '..' , 'makelib')

  if not File.exist? makelib then

    STDERR.puts "error: makefile include library does not exist or not a directory: #{makelib}"

    return 6

  end

  File.open(File.join(cwd, out), "w") do | f |

    f.puts <<-CONTENTS

#  

# Do not edit! Automatically generated by stmkmf.

#

MAKELIB ?= #{top}/../../makelib

include $(MAKELIB)/definitions.make

#{File.exists?(File.join(cwd, 'Make.spec')) ? 'include Make.spec' : ''}

include Make.proto

include $(MAKELIB)/rules.make

CONTENTS

  end

  return 0

end

if __FILE__ == $0

  require 'optparse'

  cwd = '.'

  out = 'makefile'

  optparser = OptionParser.new do | optparser |

    optparser.banner = "Usage: stmkmf.rb [options] [stx-top-directory]"

    optparser.on('-C', '--cd DIRECTORY', "Generates makefile in DIRECTORY. Optional, default is current working cwd.") do | value |

      cwd = value

    end

    optparser.on('-o', '--out FILE', "Write result to FILE. Optional, default is 'makefile'") do | value |

      out = value

    end    

    optparser.on(nil, '--help', "Prints this message") do

      puts DOCUMENTATION

      puts optparser.help()

      exit 0

    end

  end

  optparser.parse!

  top = ARGV[0] || nil

  exit stmkmf(cwd: cwd, out: out, top: top)

end