#!/usr/bin/env ruby
ENV["LANG"]="en_US.utf-8"
ENV["LC_CTYPE"]="en_US.utf-8"
ENV["KRAMDOWN_PERSISTENT"]="yes"


require 'optparse'
require 'ostruct'
require 'socket'
require 'tempfile'

require_relative "../lib/kdwatch/version"

KDWATCH_PORT = 7991             # currently unregistered...

def socket_is_free(host, port, uri)
  host = "localhost" if host == "::"
  begin
    TCPSocket.new(host, port, connect_timeout: 1)
  rescue Errno::ECONNREFUSED => e
    return true
  rescue => e
    warn "*** #{uri} -- #{e.inspect}"
    return nil                  # break, but don't use
  end
  return false
end

options = OpenStruct.new

op = OptionParser.new do |opts|
  opts.banner = <<BANNER
Usage: kdwatch [options] draft-foo.md|.mkd|.xml
Version: #{Kdwatch::VERSION}
BANNER
  opts.on("-V", "--version", "Show version and exit") do |v|
    puts "kdwatch #{Kdwatch::Version}"
    exit
  end
  opts.on("-H", "--help", "Show option summary and exit") do |v|
    puts opts
    exit
  end
  opts.on("-e", "--[no-]end", "End existing server and exit")
  opts.on("-r", "--[no-]replace", "Replace existing server")
  opts.on("-oNAME", "--host=NAME", String, "Server host (127.0.0.1)")
  opts.on("-i", "--internet", 'Abbr. "on the Internet" (host = "::")')
  opts.on("-pNUM", "--port=NUM", Integer, "Port number (#{KDWATCH_PORT}...)")
  opts.on("-[1-6]", "--[1-6]", Integer, "Abbr. port number (#{KDWATCH_PORT/10}x), must be last")
end
begin
  op.parse!(into: options)
rescue OptionParser::InvalidOption => e
  warn "** #{e}"
  warn op
  exit 1
end

if options.internet
  warn "** overriding host #{options.host} with ::" if options.host
  options.host = "::"
else
  options.host ||= "127.0.0.1"
end
if short_port = options[""]
  port = short_port + KDWATCH_PORT/10*10
  warn "** overriding port #{options.port} with #{port}" if options.port
  options.port = port
else
  unless options.port
    port = KDWATCH_PORT
    host = options.host
    host = "[#{host}]" if host =~ /:/
    uri = nil
    found = false
    100.times do
      uri = "http://#{host}:#{port}"
      # warn "Trying URI #{uri}"
      found = socket_is_free(options.host, port, uri)
      break unless found == false
      port += 1
    end
    unless found
      warn "*** Cannot find port number available to serve from!"
      exit 1
    end
    warn "*** Using URI: #{uri}"
    options.port = port
  end
end

# p options

## -r: Kill any previous kdwatch and continue ("restart")
## -e: Kill any previous kdwatch and exit
if options.replace || options.end
  require 'open3'

  status = 1

  lsof_host = case options.host
              when "::", "0.0.0.0"
                ""              # can't do more specific with lsof; hope for the best
              when /:/
                "@'[#{options.host}]'"
              else
                "@'#{options.host}'"
              end

  stdout_str, stderr_str, s = Open3.capture3("lsof -ti #{lsof_host}:#{options.port} -s TCP:LISTEN")
  pids = if s.success? && stdout_str =~ /\A[0-9\s]*\z/ && stderr_str
           stdout_str.split
         else
           text = stdout_str + stderr_str
           warn "** lsof, status #{s}, says: #{text}" if text != "" || s.exitstatus != 1
           []
         end
  if pids == []
    warn "** Nothing listening on kdwatch port" unless options.replace
  elsif pids.size != 1
    warn "** More than one process listening on kdwatch port, nothing done"
  else
    begin
      status = Process.kill(2, Integer(pids[0])) - 1 # should be 1 for 1 kill, exit 0 then
    rescue Errno => e
      warn "** #{pids[0]}: #{e.inspect}"
    end
  end
  exit(status) if options.end
end

## Find an .mkd or a draft-*.md (excluding README.md and such)
if ARGV == []
   ARGV.replace Dir.glob(["draft-*.md", "*.mkd"])
   warn_replace = 1
end

if ARGV.size != 1
   warn op
   if warn_replace
     if ARGV.size > 1
       warn "**   More than one draft file found #{ARGV.inspect}"
       warn "**   Please select one for watching."
     else
       warn "**   No draft file draft-*.md or *.mkd found."
     end
   end
   exit 1
end

ENV["KDWATCH_SRC"] = ARGV[0]
ENV["KDWATCH_HOST"] = options.host
ENV["KDWATCH_PORT"] = options.port.to_s
live_reload_port = options.port + 51234 # move up into ephemeral space
ENV["KDWATCH_LRPORT"] = live_reload_port.to_s

tf = Tempfile.new('kdwatch-config-ru-')
path = tf.path
rupath = "#{path}.ru"

tf.write(<<HERE)
require 'rack-livereload'
use Rack::LiveReload, min_delay: 500, source: :vendored, no_swf: true, port: #{live_reload_port}, live_reload_port: #{live_reload_port}
require 'kdwatch-app.rb'
run Sinatra::Application
File.delete("#{rupath}")
HERE

tf.close
File.rename(path, rupath)

exec("rackup -E production -s thin -o #{options.host} -p #{options.port} #{rupath}")