#!/usr/bin/env ruby
#
# git-remote-monitor(1)
#
# The MIT License
# Copyright © 2009
#   * Magnus Bergmark
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#

# Add ../lib/ as a load path in case we are doing development
$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))

REQUIRED_GEMS = ['rubygems']
begin
  REQUIRED_GEMS.each { |g| require g }
rescue LoadError => e
  failed_gem = e.to_s.slice(/-- (.*)$/, 1)
  $stderr.puts "ERROR: Could not load #{failed_gem}."
  $stderr.puts "#{$0} needs the following gems:"
  $stderr.puts REQUIRED_GEMS.collect { |g| "\t* #{g}" }.join("\n")
  Kernel.exit(1)
end

require 'git_remote_monitor'
require 'getoptlong'
require 'rdoc/usage'

$usage = %Q{
= Synopsis
Monitors the HEAD's (current branch) remote for changes at a fixed interval. Changes will be fetched
and you will be notified about them in any notification system you specify.

= Usage
git remote-monitor [OPTIONS] [DIR]

When no DIR is specified, current working directory will be used.

== Options
-h, --help:
   displays this usage information

-V, --version:
   displays version information

-i TIME, --interval=TIME:
   time, in seconds, between each fetch. Defaults to 60 seconds.

-p, --list-plugins:
   list all notification plugins and show which ones are active on your system, then quit.

== Daemon
Since this utility is in an early stage, no daemon capabilities have yet been added. It is recommended that
you start the command in the background (append a single & to the end of the command line) so you can keep
using your term to other things while the program is running.
}

#
# Usage information
#
# Shamefully stolen from RDoc#usage. We cannot use RDoc::usage because
# RubyGems will call this from a wrapper, and #usage is hardcoded to look
# at the top-level file instead of the current one. I have changed this
# code to instead just parse a string.
def usage_information
  markup = SM::SimpleMarkup.new
  flow_convertor = SM::ToFlow.new

  flow = markup.convert($usage, flow_convertor)

  options = RI::Options.instance
  formatter = options.formatter.new(options, "")
  formatter.display_flow(flow)
end

def version_information
  require 'yaml'
  version = YAML::load_file(File.join(GitRemoteMonitor.root, 'VERSION.yml'))
  stability = (version[:minor] % 2 == 0) ? "stable" : "unstable"
  puts "#{File.basename($0)} version #{version[:major]}.#{version[:minor]}.#{version[:patch]} (#{stability})"
  puts "Run in ruby #{RUBY_VERSION} (#{RUBY_PLATFORM}) released #{RUBY_RELEASE_DATE}, patchlevel #{RUBY_PATCHLEVEL}"
end

def list_plugins
  loaded = GitRemoteMonitor::Notifiers.notifier_plugins
  available = GitRemoteMonitor::Notifiers.available_notifiers
  preferred = GitRemoteMonitor::Notifiers.preferred_notifier
  
  puts "Plugins currently in this version of git-remote-monitor:"
  loaded.each do |plugin|
    status = if plugin == preferred
      " (Available, Active)"
    elsif available.include?(plugin)
      " (Available)"
    else
      ""
    end
    plugin_name = plugin.to_s.sub(/^.*::/, '')
    puts "\t* #{plugin_name}#{status}"
  end
end

#
# Command line arguments parser
#
def parse_command_line_arguments!
  opts = GetoptLong.new(
    [ '--help',         '-h', GetoptLong::NO_ARGUMENT ],
    [ '--version',      '-V', GetoptLong::NO_ARGUMENT ],
    [ '--list-plugins', '-p', GetoptLong::NO_ARGUMENT ],
    [ '--interval',     '-i', GetoptLong::REQUIRED_ARGUMENT]
  )
  
  opts.each do |opt, arg|
    case opt
    when '--help'
      usage_information
      exit(0)
    when '--version'
      version_information
      exit(0)
    when '--list-plugins'
      list_plugins
      exit(0)
    when '--interval'
      interval = arg.to_i
      unless interval > 10
        puts "ERROR: Interval must be larger than 10"
        exit 1
      end
      $interval = interval
    end
  end
  
  # ARGV now contains all non-params. Check for only one extra param, max. This is the DIR.
  if $ARGV.size > 1
    $stderr.puts "Only one directory may be specified!"
    Kernel.exit(1)
  elsif $ARGV.size == 1
    $dir = $ARGV.first
  end
end

# Default values for the command line options
$interval = 60
$dir      = Dir.pwd

begin
  parse_command_line_arguments!
  
  notifier = GitRemoteMonitor::Notifier.new
  monitor  = GitRemoteMonitor::Monitor.new($dir, $interval, notifier)
  
  monitor.start_monitoring!
rescue => e
  $stderr.puts "-- Unhandled Exception! ------"
  $stderr.puts e
  $stderr.puts e.backtrace
  Kernel.exit(1)
end