require 'forge/s3_signature'
class S3DirectUpload
  include S3SwfUpload::Signature
  attr_accessor :bucket, :access_key_id, :secret_access_key, :options
  
  def initialize(opts = {})
    self.options           = default_options.merge(opts.symbolize_keys)

    config                 = YAML.load_file(options[:config_file])
    self.bucket            = config[Rails.env]['bucket']
    self.access_key_id     = config[Rails.env]['access_key_id']
    self.secret_access_key = config[Rails.env]['secret_access_key']
  end 
  
  def post_params
    {
      "key" => "#{options[:key]}/#{time}-${filename}",  
      "AWSAccessKeyId" => "#{access_key_id}",
      "acl" => "#{options[:acl]}",
      "policy" => "#{policy}",
      "signature" => "#{signature}",
      "success_action_status" => "201",
      "__utma" => "1",
      "__utmb" => "1",
      "__utmc" => "1",
      "__utmz" => "1",
      "auth_token" => "1"
    }
  end
  
  def upload_url
    "http://#{bucket}.s3.amazonaws.com/"
  end
  
  private
    def default_options
      {
         :config_file     => File.join(Rails.root, 'config', 's3.yml'), 
         :key             => 'videos',
         :acl             => 'public-read',
         :expiration_date => 10.hours.from_now.utc.strftime('%Y-%m-%dT%H:%M:%S.000Z'),
         :max_filesize    => 2.gigabyte
      }
    end
    
    def policy
      Base64.encode64(
        "{'expiration': '#{options[:expiration_date]}',
          'conditions': [
            {'bucket': '#{bucket}'},
            ['starts-with', '$key', '#{options[:key]}'],
            {'acl': '#{options[:acl]}'},
            {'success_action_status': '201'},
            ['starts-with', '$Filename', ''],
            ['starts-with', '$__utmz', ''],
            ['starts-with', '$__utma', ''],
            ['starts-with', '$__utmc', ''],
            ['starts-with', '$__utmb', ''],
            ['starts-with', '$auth_token', ''],
            ['content-length-range', 0, #{options[:max_filesize]}],
          ]
        }").gsub(/\n|\r/, '')
    end
  
    def signature
      b64_hmac_sha1(secret_access_key, policy)
    end
    
    def time
      time = Digest::MD5.hexdigest(Time.now.to_s)
    end
end