#
# Author:: Stanislav Vitvitskiy
# Author:: Nuo Yan (nuo@opscode.com)
# Author:: Christopher Walters (<cw@opscode.com>)
# Copyright:: Copyright (c) 2009, 2010 Opscode, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require 'uri'
require 'net/http'
require 'mixlib/authentication/signedheaderauth'
require 'openssl'

class Chef
  # == Chef::CookbookSiteStreamingUploader
  # A streaming multipart HTTP upload implementation. Used to upload cookbooks
  # (in tarball form) to https://supermarket.chef.io
  #
  # inspired by http://stanislavvitvitskiy.blogspot.com/2008/12/multipart-post-in-ruby.html
  class CookbookSiteStreamingUploader

    DefaultHeaders = { 'accept' => 'application/json', 'x-chef-version' => ::Chef::VERSION }

    class << self

      def create_build_dir(cookbook)
        tmp_cookbook_path = Tempfile.new("chef-#{cookbook.name}-build")
        tmp_cookbook_path.close
        tmp_cookbook_dir = tmp_cookbook_path.path
        File.unlink(tmp_cookbook_dir)
        FileUtils.mkdir_p(tmp_cookbook_dir)
        Chef::Log.debug("Staging at #{tmp_cookbook_dir}")
        checksums_to_on_disk_paths = cookbook.checksums
        Chef::CookbookVersion::COOKBOOK_SEGMENTS.each do |segment|
          cookbook.manifest[segment].each do |manifest_record|
            path_in_cookbook = manifest_record[:path]
            on_disk_path = checksums_to_on_disk_paths[manifest_record[:checksum]]
            dest = File.join(tmp_cookbook_dir, cookbook.name.to_s, path_in_cookbook)
            FileUtils.mkdir_p(File.dirname(dest))
            Chef::Log.debug("Staging #{on_disk_path} to #{dest}")
            FileUtils.cp(on_disk_path, dest)
          end
        end

        # First, generate metadata
        Chef::Log.debug("Generating metadata")
        kcm = Chef::Knife::CookbookMetadata.new
        kcm.config[:cookbook_path] = [ tmp_cookbook_dir ]
        kcm.name_args = [ cookbook.name.to_s ]
        kcm.run

        tmp_cookbook_dir
      end

      def post(to_url, user_id, secret_key_filename, params = {}, headers = {})
        make_request(:post, to_url, user_id, secret_key_filename, params, headers)
      end

      def put(to_url, user_id, secret_key_filename, params = {}, headers = {})
        make_request(:put, to_url, user_id, secret_key_filename, params, headers)
      end

      def make_request(http_verb, to_url, user_id, secret_key_filename, params = {}, headers = {})
        boundary = '----RubyMultipartClient' + rand(1000000).to_s + 'ZZZZZ'
        parts = []
        content_file = nil

        timestamp = Time.now.utc.iso8601
        secret_key = OpenSSL::PKey::RSA.new(File.read(secret_key_filename))

        unless params.nil? || params.empty?
          params.each do |key, value|
            if value.kind_of?(File)
              content_file = value
              filepath = value.path
              filename = File.basename(filepath)
              parts << StringPart.new( "--" + boundary + "\r\n" +
                                      "Content-Disposition: form-data; name=\"" + key.to_s + "\"; filename=\"" + filename + "\"\r\n" +
                                      "Content-Type: application/octet-stream\r\n\r\n")
              parts << StreamPart.new(value, File.size(filepath))
              parts << StringPart.new("\r\n")
            else
              parts << StringPart.new( "--" + boundary + "\r\n" +
                                      "Content-Disposition: form-data; name=\"" + key.to_s + "\"\r\n\r\n")
              parts << StringPart.new(value.to_s + "\r\n")
            end
          end
          parts << StringPart.new("--" + boundary + "--\r\n")
        end

        body_stream = MultipartStream.new(parts)

        timestamp = Time.now.utc.iso8601

        url = URI.parse(to_url)

        Chef::Log.logger.debug("Signing: method: #{http_verb}, url: #{url}, file: #{content_file}, User-id: #{user_id}, Timestamp: #{timestamp}")

        # We use the body for signing the request if the file parameter
        # wasn't a valid file or wasn't included. Extract the body (with
        # multi-part delimiters intact) to sign the request.
        # TODO: tim: 2009-12-28: It'd be nice to remove this special case, and
        # always hash the entire request body. In the file case it would just be
        # expanded multipart text - the entire body of the POST.
        content_body = parts.inject("") { |result,part| result + part.read(0, part.size) }
        content_file.rewind if content_file # we consumed the file for the above operation, so rewind it.

        signing_options = {
          :http_method=>http_verb,
          :path=>url.path,
          :user_id=>user_id,
          :timestamp=>timestamp}
        (content_file && signing_options[:file] = content_file) || (signing_options[:body] = (content_body || ""))

        headers.merge!(Mixlib::Authentication::SignedHeaderAuth.signing_object(signing_options).sign(secret_key))

        content_file.rewind if content_file

        # net/http doesn't like symbols for header keys, so we'll to_s each one just in case
        headers = DefaultHeaders.merge(Hash[*headers.map{ |k,v| [k.to_s, v] }.flatten])

        req = case http_verb
              when :put
                Net::HTTP::Put.new(url.path, headers)
              when :post
                Net::HTTP::Post.new(url.path, headers)
              end
        req.content_length = body_stream.size
        req.content_type = 'multipart/form-data; boundary=' + boundary unless parts.empty?
        req.body_stream = body_stream

        http = Chef::HTTP::BasicClient.new(url).http_client
        res = http.request(req)

        # alias status to code and to_s to body for test purposes
        # TODO: stop the following madness!
        class << res
          alias :to_s :body

          # BUGBUG this makes the response compatible with what respsonse_steps expects to test headers (response.headers[] -> response[])
          def headers
            self
          end

          def status
            code.to_i
          end
        end
        res
      end

    end

    class StreamPart
      def initialize(stream, size)
        @stream, @size = stream, size
      end

      def size
        @size
      end

      # read the specified amount from the stream
      def read(offset, how_much)
        @stream.read(how_much)
      end
    end

    class StringPart
      def initialize(str)
        @str = str
      end

      def size
        @str.length
      end

      # read the specified amount from the string startiung at the offset
      def read(offset, how_much)
        @str[offset, how_much]
      end
    end

    class MultipartStream
      def initialize(parts)
        @parts = parts
        @part_no = 0
        @part_offset = 0
      end

      def size
        @parts.inject(0) {|size, part| size + part.size}
      end

      def read(how_much, dst_buf = nil)
        if @part_no >= @parts.size
          dst_buf.replace('') if dst_buf
          return dst_buf
        end

        how_much_current_part = @parts[@part_no].size - @part_offset

        how_much_current_part = if how_much_current_part > how_much
                                  how_much
                                else
                                  how_much_current_part
                                end

        how_much_next_part = how_much - how_much_current_part

        current_part = @parts[@part_no].read(@part_offset, how_much_current_part)

        # recurse into the next part if the current one was not large enough
        if how_much_next_part > 0
          @part_no += 1
          @part_offset = 0
          next_part = read(how_much_next_part)
          result = current_part + if next_part
                                    next_part
          else
            ''
          end
        else
          @part_offset += how_much_current_part
          result = current_part
        end
        dst_buf ? dst_buf.replace(result || '') : result
      end
    end

  end
end
