#!/usr/bin/ruby -w
#
# whatever-dl, a script to download online (web-based) videos.
#
# Copyright Michael Orlitzky
#
# http://michael.orlitzky.com/
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# http://www.fsf.org/licensing/licenses/gpl.html
#

# We need Pathname to get the real filesystem path
# of this script (and not, for example, the path of
# a symlink which points to it.
require 'pathname'

# This bit of magic adds the parent directory (the
# project root) to the list of ruby load paths.
# Thus, our require statements will work regardless of
# how or from where the script was run.
executable = Pathname.new(__FILE__).realpath.to_s
$: << File.dirname(executable) + '/../'

# We require the UriUtilities class to handle
# the download of the video URL.
require 'src/uri_utilities'


# The Dir.glob that's coming up doesn't use the
# Ruby library path so we need to tell it where to
# look explicitly.
websites_pattern = File.dirname(executable) + '/../src/websites/*.rb'

# All of the website classes are located in one
# directory, so we can 'require' them automatically.
Dir.glob(websites_pattern).each do |r|
  require r
end


EXIT_SUCCESS = 0
EXIT_NO_URL = 1
EXIT_INVALID_URL = 2
EXIT_COULDNT_GET_VIDEO_URL = 3
EXIT_OUTPUT_FILE_ALREADY_EXISTS = 4
EXIT_ERROR_READING_FROM_VIDEO_URL = 5
EXIT_CONNECTION_REFUSED = 6
EXIT_HTTP_ERROR = 7
EXIT_ACCESS_DENIED = 8

# Only actually do something if this script was called
# directly (i.e. not from the tests).
if (__FILE__ == $0) then
  if (ARGV.length < 1) then
    # If the user didn't give us a URL, yell
    # at him or her.
    puts 'Usage: whatever-dl <url>'
    Kernel.exit(EXIT_NO_URL)
  end

  # Factory method.
  site = Website.create(ARGV[0])

  if site.nil?
    puts 'Invalid URL.'
    exit(EXIT_INVALID_URL)
  end
  
  video_url = site.get_video_url()

  if video_url.nil?
    puts 'Error retrieving video URL.'
    exit(EXIT_COULDNT_GET_VIDEO_URL)
  end

  video_uri = URI.parse(video_url)
  uu = UriUtilities.new()
  
  if File.exists?(site.get_video_filename())
    puts "Error: output file already exists. Please remove #{site.get_video_filename()}, and try again."
    Kernel.exit(EXIT_OUTPUT_FILE_ALREADY_EXISTS)
  end


  # Attempt to download the file, and rescue and report
  # any (predictable) exceptions.
  begin
    puts "Fetching #{video_url}"
    puts "Saving as #{site.get_video_filename()}."
    puts ""
    uu.download_with_progress_bar(video_uri, site.get_video_filename())
  rescue Errno::ECONNREFUSED => e
    puts 'The connection to the server (to download the video file) was refused. Check your connection, and try again later.'
    Kernel.exit(EXIT_CONNECTION_REFUSED)
  rescue Errno::EACCES => e
    puts "Access denied. Check that you have write permission to the output file/directory. Details: #{e.message}."
  rescue OpenURI::HTTPError => e
    puts "An HTTP error occurred while downloading the video file: #{e.message}."
    Kernel.exit(EXIT_HTTP_ERROR)
  end

  # Write an empty line at the end for aesthetic reasons.
  puts ""
  
  Kernel.exit(EXIT_SUCCESS)
end