#!/usr/bin/env ruby
# CodeRay Executable
#
# Version: 0.2
# Author: murphy

def err msg
  $stderr.puts msg
end

def read
  if file = ARGV[2]
    File.read file
  else
    $stdin.read
  end
end

begin
  require 'coderay'

  if ARGV.empty?
    puts <<-USAGE
CodeRay #{CodeRay::VERSION} (http://coderay.rubychan.de)

Usage:
  coderay -<lang> [-<format>] < file > output
  coderay file [-<format>]

Examples:
  coderay -ruby -statistic < foo.rb
  coderay -ruby < foo.rb  # colorized output to terminal
  coderay -ruby -page foo.rb  # HTML page output to terminal
  coderay -ruby -page foo.rb > foo.html  # HTML page output to file
  coderay codegen.c  # generates codegen.c.html
    USAGE
  end

  first, second = ARGV

  if first
    if first[/-(\w+)/] == first
      lang = $1
      input = read
      tokens = :scan
    elsif first == '-'
      lang = $1
      input = read
      tokens = :scan
    else
      file = first
      tokens = CodeRay.scan_file file
      output_filename, output_ext = file, /#{Regexp.escape(File.extname(file))}$/
    end
  else
    puts 'No lang/file given.'
    exit 1
  end

  if second
    if second[/-(\w+)/] == second
      format = $1
    else
      raise 'invalid format (must be -xxx)'
    end
  else
    if $stdout.tty?
      format = :term
    else
      $stderr.puts 'No format given; setting to default (HTML Page).'
      format = :page
    end
  end
  
  if tokens == :scan
    output = CodeRay::Duo[lang => format].highlight input
  else
    output = tokens.encode format
  end
  out = $stdout
  if output_filename
    output_filename += '.' + CodeRay::Encoders[format]::FILE_EXTENSION.to_s
    if File.exist? output_filename
      err 'File %s already exists.' % output_filename
      exit
    else
      out = File.open output_filename, 'w'
      puts "Writing to #{output_filename}..."
    end
  end
  out.puts output

rescue => boom
  err "Error: #{boom.message}\n"
  err boom.backtrace
  err '-' * 50
  err ARGV
  exit 1
end