#!/usr/bin/env ruby
#
# See the man page or http://software.clapper.org/grizzled-ruby/grinc/
# for documentation.
#--
# This software is released under a BSD license, adapted from
# http://opensource.org/licenses/bsd-license.php
#
# Copyright (c) 2011, Brian M. Clapper
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright notice,
#   this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
#
# * Neither the names "clapper.org", "Grizzled Ruby Library", nor the
#   names of its contributors may be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#++

require 'optparse'
require 'grizzled/fileutil/includer'

include Grizzled::FileUtil

# ---------------------------------------------------------------------------
# Constants
# ---------------------------------------------------------------------------

DEFAULT_MAX_NEST = 100
PROGRAM_NAME = 'grinc'

# ---------------------------------------------------------------------------
# Classes
# ---------------------------------------------------------------------------

class Parameters
  attr_reader :output, :max_nesting, :input_paths

  def initialize(options_hash, argv)
    @output = options_hash[:output]
    @max_nesting = options_hash[:max_nesting] || DEFAULT_MAX_NEST
    @input_paths = argv.length == 0 ? nil : argv
  end

  def to_s
    inspect
  end
end

class UsageError < StandardError; end

# ---------------------------------------------------------------------------
# Parameter parsing
# ---------------------------------------------------------------------------

def parse_params
  options_hash = {}
  error = nil
  option_parser = OptionParser.new do |opts|
    opts.program_name = PROGRAM_NAME
    opts.banner = "Usage: #{opts.program_name} [OPTIONS] inputfile ..."
    opts.separator ''
    opts.separator 'OPTIONS:'

    opts.on('-o FILE', 'Output file. Default: standard output.') do |f|
      options_hash[:output] = f
    end

    opts.on('-n', '--nesting n',
            "Max nesting. Default: #{DEFAULT_MAX_NEST}") do |n|
      if n !~ /^[0-9]+$/
        error = "Non-numeric parameter \"#{n}\" to -n option."
      end
      options_hash[:max_nesting] = n.to_i
    end
  end

  begin
    option_parser.parse!(ARGV)
  rescue OptionParser::InvalidOption => ex
    error = ex.to_s
  end

  if error
    $stderr.puts(error) unless error.nil?
    option_parser.display
    raise UsageError.new
  end

  if ARGV.length == 0
    options_hash[:input_files] = nil
  else
    options_hash[:input_files] = ARGV
  end

  Parameters.new(options_hash, ARGV)
end

def process_include(input_file, output_file, max_nesting = 100)
  Includer.new(input_file, :max_nesting => max_nesting).each do |line|
    output_file.write(line)
  end
end

# ---------------------------------------------------------------------------
# Main logic
# ---------------------------------------------------------------------------

begin
  params = parse_params
  out = params.output.nil? ? $stderr : File.open(params.output, 'w')

  if params.input_paths.nil?
    process_include($stdin, out, params.max_nesting)
  else
    params.input_paths.each do |f|
      process_include(File.open(f), out, params.max_nesting)
    end
  end

rescue UsageError
  exit 1

rescue
  $stderr.puts("#{PROGRAM_NAME}: #{$!}")
  exit 1

else
  exit 0
end