watch

#!/usr/bin/env ruby

# The MIT License
#
# Copyright (c) 2011 Ryan Funduk, David Francisco
#
# 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.

#
# First install the dependencies (it may take some minutes):
#   gem install watchr
#   gem install thin
# Then execute the following command:
#   ./watch [options]
# (if don't have execute permission, try "ruby watch")
#
require 'optparse'
require 'watchr'
require 'thin'
require 'erb'
require 'rake'

# Default options
$settings = {
  :source => 'src',
  :master => 'master.html',
  :live => true,
  :output => 'slideshow.html',
  :multiple => false,
  :port => 6543,
  :binding => "0.0.0.0"
}
$partials = 0


module Builder
  # This module is based on a blog post by Ryan Funduk
  # To see the original source visit http://ryanfunduk.com/simple-partials/

  def self.write_output(filename, result)
    if $settings[:output] && !$settings[:multiple]
      filename = $settings[:output]
    else
      # If there are N .html files in the source folder (excluding the partials), the result will be N html files
      ext = filename.split('.').last

      filename = filename.split '/'
      filename.delete $settings[:source]
      filename.insert -2, ext unless ext == 'html'
      filename = filename.join '/'

      result.gsub! /V%/, '<%'
      result.gsub! /%V/, '%>'
    end

    f = File.open(filename, 'wb')
    f.write(result)
    f.close
    puts "WROTE     : #{filename}"
  end

  def self.partial(name)
    filename = "#{$settings[:source]}/#{name}.partial"

    if File.exists? filename
      $partials += 1
      puts "LOADED    : #{name}.partial"
      f = File.open(filename, 'rb')
      # _partial_ is the var where the result is stored, since we're inside a ERB.new already!
      # The rand() was added in case partials contain partials themselves too
      page = ERB.new(f.read, nil, nil, "_partial_#{rand(2010)}") # TODO add collision detection
      f.close
    else
      puts "ERROR     : #{filename}"
    end
    page.result
  end

  # Build the compiled html file that includes the layout and all partials
  def self.build
    $partials = 0

    if !$settings[:multiple]
      # If the result should be only one html file, then only one .html should exist
      sources = ["#{$settings[:source]}/#{$settings[:master]}"]
    else
      sources = FileList["#{$settings[:source]}/*.*"].exclude("#{$settings[:source]}/*.partial")
    end

    sources.each do |source|
      puts "\nCOMPILING : #{source}"
      f = File.open(source, 'rb')
      page = ERB.new(f.read)
      f.close
      write_output source, page.result
    end

    puts "\nDONE      : Compiled #{sources.size} sources w/ #{$partials} partials."
  end
end

module Options
  $optparse

  # Check if the specified options are valid
  def self.valid_options?
    dir_exists = File.directory? $settings[:source]
    if !dir_exists && $settings[:custom_source]
      puts "Invalid directory specified with the --source option."
    elsif !dir_exists
      puts "Could not find the slideshow folder." \
           "Please use the --source option if you want to use a custom value (default is '#{$settings[:source]}')."
    end

    master_exists = File.exists? "#{$settings[:source]}/#{$settings[:master]}"
    if !master_exists && $settings[:custom_master] && !$settings[:multiple]
      puts "Invalid file name for the master slide specified with the --input option."
    elsif !master_exists && !$settings[:multiple]
      puts "Could not find the master slide file. " \
           "Please use the --input option if you want to use a custom value (default is '#{$settings[:master]}')."
    else
      master_exists = true # It doesn't really exist, but we'll handle several master slides
    end

    dir_exists && master_exists
  end

  def self.init
    $optparse = OptionParser.new do |opts|
      # Help
      opts.on( '-h', '--help', 'Show this help message' ) do
        puts opts
        exit
      end
      # Slideshow folder
      opts.on( '-s', '--source DIR', 'Creates a slideshow using the files on the specified folder' ) do |dir|
        $settings[:source] = dir
        $settings[:custom_source] = true # This var is only used to print a better error message
      end
      # Name of the resulting html file
      opts.on( '-o', '--output FILENAME', 'Name of the resulting html file' ) do |filename|
        $settings[:output] = filename
      end
      # Name of the master slide html file
      opts.on( '-i', '--input FILENAME', 'Name of the master slide file' ) do |filename|
        $settings[:master] = filename
        $settings[:custom_master] = true # This var is only used to print a better error message
      end
      # Allow several slideshows inside the source folder
      opts.on( '-m', '--multiple', 'Allow several slideshows inside the source folder' ) do
        $settings[:multiple] = true
      end
      # Excluding live.js
      opts.on( '-n', '--nolive', 'Excludes the live.js library' ) do
        $settings[:live] = false
      end
      # Port number
      opts.on( '-p', '--port PORT', 'Runs on the specified port' ) do |port|
        $settings[:port] = port
      end
      # Binding address
      opts.on( '-b', '--binding IP', 'Binds to the specified ip' ) do |binding|
        $settings[:binding] = binding
      end
    end
  end

  # Parse the given command line parameters
  def self.parse!
    init unless $optparse
    $optparse.parse!
  end
end

# Parse the given command line parameters
Options::parse!

# Merge some required defaults
$settings.merge!({
  :root => Dir.pwd,
  :watched_files => "#{$settings[:source]}/.*",
})

# Simpler way of calling the "partial" method from views
define_singleton_method(:partial) { |name| Builder::partial(name) }
@root = $settings[:source]
@live = $settings[:live]

# Check if the specified options are valid
exit unless Options::valid_options?

puts ">>> Watching #{$settings[:root]}/#{$settings[:watched_files]}"
puts ">>> Check your slideshow at http://#{$settings[:binding]}:#{$settings[:port]}/index.html"
puts ">>> Your slideshow will be built and refreshed automagically\n\n"

# Launch the watcher
Thread.new do
  script = Watchr::Script.new
  Builder::build
  script.watch $settings[:watched_files] do
    Builder::build
  end
  controller = Watchr::Controller.new(script, Watchr.handler.new)
  controller.run
end

# Run the thin server
Thin::Server.start($settings[:binding], $settings[:port]) do
  run Rack::Directory.new("#{$settings[:root]}")
end