class UploadsController < ApplicationController

  def finalize
    @file = StoredFile.find(params[:file])
    @file.upload_done!
  end

  def authorize
    authorize_write_to_s3 do |stored_file, errors|
      success = stored_file.save

      errors = []
      unless success
        errors += stored_file.errors.full_messages
      end
      [success, errors]
    end
  end

  protected

  def authorize_write_to_s3(https = false)
    raise "no block given" unless block_given?

    bucket          = S3Config.bucket
    access_key_id   = S3Config.access_key_id
    acl             = S3Config.acl
    content_type    = params[:content_type].to_s
    file_size       = params[:file_size].to_i
    unchecked_key   = params[:file_name].to_s

    stored_file = StoredFile.new do |file|
      file.easy_setup(unchecked_key, content_type)
      file.size = file_size
    end

    success, errors = yield stored_file

    if success
      content_type    = stored_file.content_type
      full_key        = stored_file.base_path
      expiration_date = 2.hours.from_now.utc.strftime('%Y-%m-%dT%H:%M:%S.000Z')

      # ['starts-with', '$Filename', ''],

      policy = Base64.encode64(
        "{
    'expiration': '#{expiration_date}',
    'conditions': [
        {'bucket': '#{bucket}'},
        {'key': '#{full_key}'},
        {'acl': '#{acl}'},
        {'Content-Type': '#{content_type}'},
        {'success_action_status': '201'},
        ['content-length-range', #{file_size}, #{file_size}],
        ['starts-with', '$filename', ''],
    ]
}").gsub(/\n|\r/, '')

      signature = self.sign(policy, S3Config.secret_access_key)
      full_url = "#{https ? 'https' : 'http'}://#{S3Config.server}/"

      respond_to do |wants|
        wants.json do
          render :json => {
            :ok   => true,
            :url  => full_url,
            :file => stored_file.id.to_s,
            :headers => [],
            :params => ActiveSupport::OrderedHash[*([
              ["key",            full_key],
              ["AWSAccessKeyId", access_key_id],
              ["acl",            acl],
              ["Content-Type",   content_type],
              ["success_action_status", "201"],
              ["policy",         policy],
              ["signature",      signature],
              ["Filename",       ""]
            ].flatten)]
          }
        end
      end
    else
      errors = [errors] unless errors.is_a? Array
      errors = ["Unknown Error"] if errors.blank?

      respond_to do |wants|
        wants.json do
          render :json => {
            :ok => false,
            :alerts => errors
          }
        end
      end
    end
  end

  def sign(message, secret)
    raise 'missing secret' unless secret

    hmac = HMAC::SHA1.new(secret)
    hmac.update(message)
    hmaced = hmac.digest.to_s
    Base64.encode64(hmaced).chomp.gsub(/\n/,'')
  end
end