#!/usr/bin/ruby -wKU
#
# 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
#

# This should load everything we need for us.
require 'whatever-dl'

# And getoptlong to check for our one option, --continue.
require 'getoptlong'

log = Logger.new(STDOUT)
log.level = Logger::WARN

def usage()
  puts <<EOF

Usage: whatever-dl [options] <url>

Options:
  -c, --continue        Continue downloading a previously-attempted file.

EOF

end


# Default options.
options = { :continue => false }

# Parse the command-line options into the options hash.
opts = GetoptLong.new(["--continue", "-c", GetoptLong::NO_ARGUMENT],
                      ["--help", "-h", GetoptLong::NO_ARGUMENT])

opts.each do |opt, arg|
  case opt
  when '--help'
    usage()
    Kernel.exit(ExitCodes::EXIT_SUCCESS)
  when '--continue'
    options[:continue] = true
  end
end

cfg = Configuration.new()

# Warn about nonsensical options.
if options[:continue] and not cfg.download_method == 'wget'
  log.warn("The --continue flag does nothing unless download_method is wget.")
end

# Note that GetoptLong steals its arguments from ARGV, so we don't need
# to take optional arguments into account when figuring out whether or not
# we were passed a URL.
if (ARGV.length < 1) then
  # If the user didn't give us a URL, yell
  # at him or her.
  usage()
  Kernel.exit(ExitCodes::EXIT_NO_URL)
end


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

if site.nil?
  log.error('Invalid URL.')
  exit(ExitCodes::EXIT_INVALID_URL)
end
  
video_url = site.get_video_url()

if video_url.nil?
  msg  = 'Error retrieving video URL: '
  msg += "Site not supported, and the generic parser couldn't find any videos."
  log.error(msg)
  exit(ExitCodes::EXIT_COULDNT_GET_VIDEO_URL)
end

# The Downloader class is a factory; it should decide
# which subclass we get.
puts "download_method: #{cfg.download_method}"
downloader = Downloader.create(cfg.download_method)

# Attempt to download the file, and rescue and report
# any (predictable) exceptions. The wget downloader will
# naturally not report any of these, since it will die in
# its own process.
begin
  downloader.download(video_url,
                      site.get_video_filename(),
                      site.headers(),
                      continue=options[:continue])

rescue Errno::ECONNREFUSED => e
  msg =  'The connection to the server (to download the video file) '
  msg += 'was refused. Check your connection, and try again later.'
  log.error(msg)
  Kernel.exit(ExitCodes::EXIT_CONNECTION_REFUSED)

rescue Errno::EACCES => e
  msg =  'Access denied. Check that you have write permission '
  msg += "to the output file/directory. Details: #{e.message}."
  log.error(msg)
  Kernel.exit(ExitCodes::EXIT_ACCESS_DENIED)

rescue OpenURI::HTTPError => e
  msg =  'An HTTP error occurred while downloading '
  msg += " the video file: #{e.message}."
  log.error(msg)
  Kernel.exit(ExitCodes::EXIT_HTTP_ERROR)

rescue IOError => e
  log.error("Input/Output Error: #{e.message}")
  Kernel.exit(ExitCodes::EXIT_IO_ERROR)

end

# Write an empty line at the end for aesthetic reasons.
puts ''

Kernel.exit(ExitCodes::EXIT_SUCCESS)