#
# Author:: Daniel DeLeo (<dan@opscode.com>)
# Author:: Prajakta Purohit (prajakta@opscode.com>)
# Auther:: Tyler Cloke (<tyler@opscode.com>)
#
# Copyright:: Copyright (c) 2012 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 'securerandom'
require 'chef/event_dispatch/base'

class Chef
  class ResourceReporter < EventDispatch::Base

    class ResourceReport < Struct.new(:new_resource,
                                      :current_resource,
                                      :action,
                                      :exception,
                                      :elapsed_time)

      def self.new_with_current_state(new_resource, action, current_resource)
        report = new
        report.new_resource = new_resource
        report.action = action
        report.current_resource = current_resource
        report
      end

      def self.new_for_exception(new_resource, action)
        report = new
        report.new_resource = new_resource
        report.action = action
        report
      end

      # Future: Some resources store state information that does not convert nicely
      # to json. We can't call a resource's state method here, since there are conflicts
      # with some LWRPs, so we can't override a resource's state method to return
      # json-friendly state data.
      #
      # The registry key resource returns json-friendly state data through its state
      # attribute, and uses a read-only variable for fetching true state data. If
      # we have conflicts with other resources reporting json incompatible state, we
      # may want to extend the state_attrs API with the ability to rename POST'd
      # attrs.
      def for_json
        as_hash = {}
        as_hash["type"]   = new_resource.class.dsl_name
        as_hash["name"]   = new_resource.name.to_s
        as_hash["id"]     = new_resource.identity.to_s
        as_hash["after"]  = state(new_resource)
        as_hash["before"] = current_resource ? state(current_resource) : {}
        as_hash["duration"] = (elapsed_time * 1000).to_i.to_s
        as_hash["delta"]  = new_resource.diff if new_resource.respond_to?("diff")
        as_hash["delta"]  = "" if as_hash["delta"].nil?

        # TODO: rename as "action"
        as_hash["result"] = action.to_s
        if success?
        else
          #as_hash["result"] = "failed"
        end
        if new_resource.cookbook_name
          as_hash["cookbook_name"] = new_resource.cookbook_name
          as_hash["cookbook_version"] = new_resource.cookbook_version.version
        end

        as_hash
      end

      def finish
        self.elapsed_time = new_resource.elapsed_time
      end

      def success?
        !self.exception
      end

      def state(r)
        r.class.state_attrs.inject({}) do |state_attrs, attr_name|
          state_attrs[attr_name] = r.send(attr_name)
          state_attrs
        end
      end
    end # End class ResouceReport

    attr_reader :updated_resources
    attr_reader :status
    attr_reader :exception
    attr_reader :run_id
    attr_reader :error_descriptions

    PROTOCOL_VERSION = '0.1.0'

    def initialize(rest_client)
      if Chef::Config[:enable_reporting] && !Chef::Config[:why_run]
        @reporting_enabled = true
      else
        @reporting_enabled = false
      end
      @updated_resources = []
      @total_res_count = 0
      @pending_update  = nil
      @status = "success"
      @exception = nil
      @rest_client = rest_client
      @error_descriptions = {}
    end

    def run_started(run_status)
      @run_status = run_status

      if reporting_enabled?
        begin
          resource_history_url = "reports/nodes/#{node_name}/runs"
          server_response = @rest_client.post_rest(resource_history_url, {:action => :start, :run_id => run_id,
                                                                          :start_time => start_time.to_s}, headers)
        rescue Timeout::Error, Errno::EINVAL, Errno::ECONNRESET, EOFError, Net::HTTPBadResponse, Net::HTTPHeaderSyntaxError, Net::ProtocolError => e
          handle_error_starting_run(e, resource_history_url)
        end
      end
    end

    def handle_error_starting_run(e, url)
      message = "Reporting error starting run. URL: #{url} "
      code = if e.response.code
               e.response.code.to_s
             else
               "Exception Code Empty"
             end

      if !e.response || (code != "404" && code != "406")
        exception = "Exception: #{code} "
        if Chef::Config[:enable_reporting_url_fatals]
          reporting_status = "Reporting fatals enabled. Aborting run. "
          Chef::Log.error(message + exception + reporting_status)
          raise
        else
          reporting_status = "Disabling reporting for run."
          Chef::Log.info(message + exception + reporting_status)
        end
      else
        reason = "Received #{code}. "
        if code == "406"
          reporting_status = "Client version not supported. Please update the client. Disabling reporting for run."
          Chef::Log.info(message + reason + reporting_status)
        else
          reporting_status = "Disabling reporting for run."
          Chef::Log.debug(message + reason + reporting_status)
        end
      end

      @reporting_enabled = false
    end

    def run_id
      @run_status.run_id
    end

    def resource_current_state_loaded(new_resource, action, current_resource)
      unless nested_resource?(new_resource)
        @pending_update = ResourceReport.new_with_current_state(new_resource, action, current_resource)
      end
    end

    def resource_up_to_date(new_resource, action)
      @total_res_count += 1
      @pending_update = nil unless nested_resource?(new_resource)
    end

    def resource_skipped(resource, action, conditional)
      @total_res_count += 1
      @pending_update = nil unless nested_resource?(resource)
    end

    def resource_updated(new_resource, action)
      @total_res_count += 1
    end

    def resource_failed(new_resource, action, exception)
      @total_res_count += 1
      unless nested_resource?(new_resource)
        @pending_update ||= ResourceReport.new_for_exception(new_resource, action)
        @pending_update.exception = exception
      end
      description = Formatters::ErrorMapper.resource_failed(new_resource, action, exception)
      @error_descriptions = description.for_json
    end

    def resource_completed(new_resource)
      if @pending_update && !nested_resource?(new_resource)
        @pending_update.finish
        @updated_resources << @pending_update
        @pending_update = nil
      end
    end

    def run_completed(node)
      @status = "success"
      post_reporting_data
    end

    def run_failed(exception)
      @exception = exception
      @status = "failure"
      # If we failed before we received the run_started callback, there's not much we can do
      # in terms of reporting
      if @run_status
          post_reporting_data
      end
    end

    def post_reporting_data
      if reporting_enabled?
        run_data = prepare_run_data
        resource_history_url = "reports/nodes/#{node_name}/runs/#{run_id}"
        Chef::Log.info("Sending resource update report (run-id: #{run_id})")
        Chef::Log.debug run_data.inspect
        compressed_data = encode_gzip(Chef::JSONCompat.to_json(run_data))
        Chef::Log.debug("Sending compressed run data...")
        # Since we're posting compressed data we can not directly call post_rest which expects JSON
        reporting_url = @rest_client.create_url(resource_history_url)
        begin
          @rest_client.raw_http_request(:POST, reporting_url, headers({'Content-Encoding' => 'gzip'}), compressed_data)
        rescue StandardError => e
          if e.respond_to? :response
            Chef::FileCache.store("failed-reporting-data.json", Chef::JSONCompat.to_json_pretty(run_data), 0640)
            Chef::Log.error("Failed to post reporting data to server (HTTP #{e.response.code}), saving to #{Chef::FileCache.load("failed-reporting-data.json", false)}")
          else
            Chef::Log.error("Failed to post reporting data to server (#{e})")
          end
        end
      else
        Chef::Log.debug("Server doesn't support resource history, skipping resource report.")
      end
    end

    def headers(additional_headers = {})
      options = {'X-Ops-Reporting-Protocol-Version' => PROTOCOL_VERSION}
      options.merge(additional_headers)
    end

    def node_name
      @run_status.node.name
    end

    def start_time
      @run_status.start_time
    end

    def end_time
      @run_status.end_time
    end

    def prepare_run_data
      run_data = {}
      run_data["action"] = "end"
      run_data["resources"] = updated_resources.map do |resource_record|
        resource_record.for_json
      end
      run_data["status"] = @status
      run_data["run_list"] = Chef::JSONCompat.to_json(@run_status.node.run_list)
      run_data["total_res_count"] = @total_res_count.to_s
      run_data["data"] = {}
      run_data["start_time"] = start_time.to_s
      run_data["end_time"] = end_time.to_s

      if exception
        exception_data = {}
        exception_data["class"] = exception.inspect
        exception_data["message"] = exception.message
        exception_data["backtrace"] = Chef::JSONCompat.to_json(exception.backtrace)
        exception_data["description"] =  @error_descriptions
        run_data["data"]["exception"] = exception_data
      end
      run_data
    end

    def run_list_expand_failed(node, exception)
      description = Formatters::ErrorMapper.run_list_expand_failed(node, exception)
      @error_descriptions = description.for_json
    end

    def cookbook_resolution_failed(expanded_run_list, exception)
      description = Formatters::ErrorMapper.cookbook_resolution_failed(expanded_run_list, exception)
      @error_descriptions = description.for_json
    end

    def cookbook_sync_failed(cookbooks, exception)
      description = Formatters::ErrorMapper.cookbook_sync_failed(cookbooks, exception)
      @error_descriptions = description.for_json
    end

    def reporting_enabled?
      @reporting_enabled
    end

    private

    # If we are getting messages about a resource while we are in the middle of
    # another resource's update, we assume that the nested resource is just the
    # implementation of a provider, and we want to hide it from the reporting
    # output.
    def nested_resource?(new_resource)
      @pending_update && @pending_update.new_resource != new_resource
    end

    def encode_gzip(data)
      "".tap do |out|
        Zlib::GzipWriter.wrap(StringIO.new(out)){|gz| gz << data }
      end
    end

  end
end