#!/usr/bin/env ruby
## Usage: ronn [ OPTIONS ] [ FILE ]
##        ronn --build FILE ...
##        ronn --install FILE ...
##        ronn --man FILE ...
## Convert ronn FILE to roff man page or HTML and write to standard
## output. With no FILE, ronn reads from standard input. The build,
## install, and man forms accept multiple FILE arguments.
##
## Modes:
##       --pipe                write to standard output (default behavior)
##   -b, --build               write to files instead of standard output
##   -i, --install             write to file in MAN_HOME or system man path
##   -m, --man                 open man page like man(1)
##
## Formats:
##   -r, --roff                generate roff/man text; this is the default behavior
##   -5, --html                generate entire HTML page with layout
##   -f, --fragment            generate HTML fragment instead of entire HTML page
##
## Document attributes:
##       --date=DATE           published date in YYYY-MM-DD format;
##                             displayed bottom-center in footer
##       --manual=NAME         name of the manual this document belongs to;
##                             displayed top-center in header
##       --organization=NAME   publishing group, organization, or individual;
##                             displayed bottom-left in footer
##
##       --help                show this help message
##
require 'date'
require 'optparse'

formats = []
options = {}
build = false
install = false
man = false
groff = "groff -Wall -mtty-char -mandoc -Tascii"
pager = ENV['MANPAGER'] || ENV['PAGER'] || 'more'

def info(message, *args)
  STDERR.puts message % args
end

def usage
  puts File.readlines(__FILE__).
    grep(/^##.*/).
    map { |line| line.chomp[3..-1] }.
    join("\n")
end

# parse command line options
ARGV.options do |option|
  # modes
  option.on("--pipe") { }
  option.on("-b", "--build") { build = true }
  option.on("-i", "--install") { install = true }
  option.on("-m", "--man") { man = true }

  # format options
  option.on("-r", "--roff") { formats << 'roff' }
  option.on("-5", "--html") { formats << 'html' }
  option.on("-f", "--fragment") { formats << 'html_fragment' }

  # manual attribute options
  [:name, :section, :manual, :organization, :date].each do |option_attr|
    option.on("--#{option_attr}=VALUE") { |val| options[option_attr] = val }
  end

  option.on_tail("--help") { usage ; exit }
  option.parse!
end

if ARGV.empty? && STDIN.tty?
  usage
  exit
elsif ARGV.empty?
  ARGV.push '-'
end

# turn the --date arg into a real date object
options[:date] &&= Date.strptime(options[:date], '%Y-%m-%d')

formats = ['roff'] if formats.empty?
formats.delete('html') if formats.include?('html_fragment')
pid = nil

begin
  require 'hpricot'
  require 'rdiscount'
rescue LoadError
  if !defined?(Gem)
    warn "warn: #{$!.to_s}. trying again with rubygems."
    require 'rubygems'
    retry
  end
end

begin
  require 'ronn'
rescue LoadError
  raise if $!.to_s !~ /ronn/
  libdir = File.expand_path("../../lib", __FILE__).sub(/^#{Dir.pwd}/, '.')
  if !$:.include?(libdir)
    warn "warn: #{$!.to_s}. trying again with #{libdir} on load path."
    $:.unshift libdir
    retry
  end
  raise
end

wr = STDOUT
ARGV.each do |file|
  doc = Ronn.new(file, options) { file == '-' ? STDIN.read : File.read(file) }

  # setup the man pipeline if the --man option was specified
  if man && !build
    rd, wr = IO.pipe
    if pid = fork
      rd.close
    else
      wr.close
      STDIN.reopen rd
      exec "#{groff} | #{pager}"
    end
  end

  # write output for each format
  formats.each do |format|
    if build
      path = doc.path_for(format)
      info "building: #{path}" if build
      output = doc.convert(format)
      File.open(path, 'wb') { |f| f.puts(output) }
      system "man #{path}" if man && format == 'roff'
    else
      output = doc.convert(format)
      wr.puts(output)
    end
  end

  if pid
    wr.close
    Process.wait
  end
end