#!/usr/bin/env ruby
#
# Author: IKARASHI Yoshinori <yoosee@gmail.com>
# Createed: 2006-07-07 22:41:38
# Modified: 2006-07-11 07:22:12
# 
# ** Based on http://hanagasira.s25.xrea.com/php/video.php
# 

require 'uri'
require 'net/http'
require 'open-uri'
require 'progressbar'

require 'nkf'

def filename_locale_encoding
  nkf_encoding_option = '-e' # default
  begin
    charmap = `locale -k charmap`
  rescue
    charmap = 'charmap="EUC-JP"' # also default
  end
  if charmap =~ /charmap=\"([^\"]+)\"/
    case $1
    when "UTF-8"
      nkf_encoding_option = '-w'
    when "SJIS", "Shift_JIS"
      nkf_encoding_option = '-s'
    when "JIS"
      nkf_encoding_option = '-j'
    when "EUC-JP"
      nkf_encoding_option = '-e'
    end
  end
  return nkf_encoding_option
end

def youtube_download_uri(url_string)
  uri=URI.parse(url_string)
  video_id = ''

  if /\/v\/([^&]+)&?/ =~ uri.path
    video_id = $1
  elsif /v=([^&]+)&?/ =~ uri.query
    video_id = $1
  else
    raise "no video_id found"
  end

  filename = video_id + '.flv'
  page = timeout(10) do
    uri.open do |f|
      f.read
    end
  end

  nkf_option = filename_locale_encoding()

  if /<title[^>]*>(.+)<\/title>/i =~ page
    filename = NKF.nkf(nkf_option, $1.gsub(/\n/, '')).gsub(/YouTube - ?/, '').
      gsub(/^\s+/, '').gsub(/ /, '_').gsub(/\//, '_') + '.flv'
  end

  redirect_url = ''
  Net::HTTP.start(uri.host, 80) do |http|
    r= http.get("/watch_video?v=#{video_id}")
    redirect_url = r["location"] # if r == Net::HTTPRedirection
  end

  query = Hash.new('')
  redirect_url.split(/\?/,2)[1].split(/&/).each do |q|
    key, value = q.split(/=/)
    query[key] = value
  end
  flv_url = "#{uri.scheme}://#{uri.host}/get_video?video_id=#{query['video_id']}&t=#{query['t']}"

  return flv_url, filename
end

def get_content(download_url, filename)
  pbar = nil
  open(filename, "w") do |file|
    open(download_url, 
         :content_length_proc => lambda {|t|
           if t && 0 < t
             pbar = ProgressBar.new(filename, t)
             pbar.file_transfer_mode
           end
         },
         :progress_proc => lambda {|s|
           pbar.set s if pbar
         }) do |f|
      file.puts f.read
    end
  end
  return filename
end

def usage
  puts "usage: getmovie [url]"
  puts " * url should contain video_id ( v=... or /v/... )"
  exit
end

if $0 == __FILE__
  url = ARGV.shift
  usage unless url
  puts "opening #{url}"
  begin
    download_uri, filename = youtube_download_uri(url)
    if (FileTest.exist?(filename))
      puts "#{filename} already exists."
      exit
    end
    puts "download movie file: #{filename}"
    get_content(download_uri, filename)
  rescue 
    p $!, $@
  end
end