# the class that actually walks our resource/property tree, collects the changes,
# and performs them

require 'puppet'
require 'puppet/util/tagging'
require 'puppet/application'

class Puppet::Transaction
  require 'puppet/transaction/event'
  require 'puppet/transaction/event_manager'
  require 'puppet/transaction/resource_harness'
  require 'puppet/resource/status'

  attr_accessor :component, :catalog, :ignoreschedules
  attr_accessor :sorted_resources, :configurator

  # The report, once generated.
  attr_reader :report

  # Routes and stores any events and subscriptions.
  attr_reader :event_manager

  # Handles most of the actual interacting with resources
  attr_reader :resource_harness

  include Puppet::Util
  include Puppet::Util::Tagging

  # Wraps application run state check to flag need to interrupt processing
  def stop_processing?
    Puppet::Application.stop_requested?
  end

  # Add some additional times for reporting
  def add_times(hash)
    hash.each do |name, num|
      report.add_times(name, num)
    end
  end

  # Are there any failed resources in this transaction?
  def any_failed?
    report.resource_statuses.values.detect { |status| status.failed? }
  end

  # Apply all changes for a resource
  def apply(resource, ancestor = nil)
    status = resource_harness.evaluate(resource)
    add_resource_status(status)
    event_manager.queue_events(ancestor || resource, status.events) unless status.failed?
  rescue => detail
    resource.err "Could not evaluate: #{detail}"
  end

  # Find all of the changed resources.
  def changed?
    report.resource_statuses.values.find_all { |status| status.changed }.collect { |status| catalog.resource(status.resource) }
  end

  # Copy an important relationships from the parent to the newly-generated
  # child resource.
  def make_parent_child_relationship(resource, children)
    depthfirst = resource.depthfirst?

    children.each do |gen_child|
      if depthfirst
        edge = [gen_child, resource]
      else
        edge = [resource, gen_child]
      end
      relationship_graph.add_vertex(gen_child)

      unless relationship_graph.edge?(edge[1], edge[0])
        relationship_graph.add_edge(*edge)
      else
        resource.debug "Skipping automatic relationship to #{gen_child}"
      end
    end
  end

  # See if the resource generates new resources at evaluation time.
  def eval_generate(resource)
    generate_additional_resources(resource, :eval_generate)
  end

  # Evaluate a single resource.
  def eval_resource(resource, ancestor = nil)
    if skip?(resource)
      resource_status(resource).skipped = true
    else
      eval_children_and_apply_resource(resource, ancestor)
    end

    # Check to see if there are any events queued for this resource
    event_manager.process_events(resource)
  end

  def eval_children_and_apply_resource(resource, ancestor = nil)
    resource_status(resource).scheduled = true

    # We need to generate first regardless, because the recursive
    # actions sometimes change how the top resource is applied.
    children = eval_generate(resource)

    if ! children.empty? and resource.depthfirst?
      children.each do |child|
        # The child will never be skipped when the parent isn't
        eval_resource(child, ancestor || resource)
      end
    end

    # Perform the actual changes
    apply(resource, ancestor)

    if ! children.empty? and ! resource.depthfirst?
      children.each do |child|
        eval_resource(child, ancestor || resource)
      end
    end
  end

  # This method does all the actual work of running a transaction.  It
  # collects all of the changes, executes them, and responds to any
  # necessary events.
  def evaluate
    prepare

    Puppet.info "Applying configuration version '#{catalog.version}'" if catalog.version

    @sorted_resources.each do |resource|
      next if stop_processing?
      if resource.is_a?(Puppet::Type::Component)
        Puppet.warning "Somehow left a component in the relationship graph"
        next
      end
      ret = nil
      seconds = thinmark do
        ret = eval_resource(resource)
      end

      resource.info "valuated in %0.2f seconds" % seconds if Puppet[:evaltrace] and @catalog.host_config?
      ret
    end

    Puppet.debug "Finishing transaction #{object_id}"
  end

  def events
    event_manager.events
  end

  def failed?(resource)
    s = resource_status(resource) and s.failed?
  end

  # Does this resource have any failed dependencies?
  def failed_dependencies?(resource)
    # First make sure there are no failed dependencies.  To do this,
    # we check for failures in any of the vertexes above us.  It's not
    # enough to check the immediate dependencies, which is why we use
    # a tree from the reversed graph.
    found_failed = false
    relationship_graph.dependencies(resource).each do |dep|
      next unless failed?(dep)
      resource.notice "Dependency #{dep} has failures: #{resource_status(dep).failed}"
      found_failed = true
    end

    found_failed
  end

  # A general method for recursively generating new resources from a
  # resource.
  def generate_additional_resources(resource, method)
    return [] unless resource.respond_to?(method)
    begin
      made = resource.send(method)
    rescue => detail
      puts detail.backtrace if Puppet[:trace]
      resource.err "Failed to generate additional resources using '#{method}': #{detail}"
    end
    return [] unless made
    made = [made] unless made.is_a?(Array)
    made.uniq.find_all do |res|
      begin
        res.tag(*resource.tags)
        @catalog.add_resource(res) do |r|
          r.finish
          make_parent_child_relationship(resource, [r])

          # Call 'generate' recursively
          generate_additional_resources(r, method)
        end
        true
      rescue Puppet::Resource::Catalog::DuplicateResourceError
        res.info "Duplicate generated resource; skipping"
        false
      end
    end
  end

  # Collect any dynamically generated resources.  This method is called
  # before the transaction starts.
  def generate
    list = @catalog.vertices
    newlist = []
    while ! list.empty?
      list.each do |resource|
        newlist += generate_additional_resources(resource, :generate)
      end
      list = newlist
      newlist = []
    end
  end

  # Should we ignore tags?
  def ignore_tags?
    ! (@catalog.host_config? or Puppet[:name] == "puppet")
  end

  # this should only be called by a Puppet::Type::Component resource now
  # and it should only receive an array
  def initialize(catalog, report = nil)
    @catalog = catalog
    @report = report || Report.new("apply", catalog.version)
    @event_manager = Puppet::Transaction::EventManager.new(self)
    @resource_harness = Puppet::Transaction::ResourceHarness.new(self)
  end

  # Prefetch any providers that support it.  We don't support prefetching
  # types, just providers.
  def prefetch
    prefetchers = {}
    @catalog.vertices.each do |resource|
      if provider = resource.provider and provider.class.respond_to?(:prefetch)
        prefetchers[provider.class] ||= {}
        prefetchers[provider.class][resource.name] = resource
      end
    end

    # Now call prefetch, passing in the resources so that the provider instances can be replaced.
    prefetchers.each do |provider, resources|
      Puppet.debug "Prefetching #{provider.name} resources for #{provider.resource_type.name}"
      begin
        provider.prefetch(resources)
      rescue => detail
        puts detail.backtrace if Puppet[:trace]
        Puppet.err "Could not prefetch #{provider.resource_type.name} provider '#{provider.name}': #{detail}"
      end
    end
  end

  # Prepare to evaluate the resources in a transaction.
  def prepare
    # Now add any dynamically generated resources
    generate

    # Then prefetch.  It's important that we generate and then prefetch,
    # so that any generated resources also get prefetched.
    prefetch

    # This will throw an error if there are cycles in the graph.
    @sorted_resources = relationship_graph.topsort
  end

  def relationship_graph
    catalog.relationship_graph
  end

  def add_resource_status(status)
    report.add_resource_status status
  end

  def resource_status(resource)
    report.resource_statuses[resource.to_s] || add_resource_status(Puppet::Resource::Status.new(resource))
  end

  # Is the resource currently scheduled?
  def scheduled?(resource)
    self.ignoreschedules or resource_harness.scheduled?(resource_status(resource), resource)
  end

  # Should this resource be skipped?
  def skip?(resource)
    if missing_tags?(resource)
      resource.debug "Not tagged with #{tags.join(", ")}"
    elsif ! scheduled?(resource)
      resource.debug "Not scheduled"
    elsif failed_dependencies?(resource)
      resource.warning "Skipping because of failed dependencies"
    elsif resource.virtual?
      resource.debug "Skipping because virtual"
    else
      return false
    end
    true
  end

  # The tags we should be checking.
  def tags
    self.tags = Puppet[:tags] unless defined?(@tags)

    super
  end

  def handle_qualified_tags( qualified )
    # The default behavior of Puppet::Util::Tagging is
    # to split qualified tags into parts. That would cause
    # qualified tags to match too broadly here.
    return
  end

  # Is this resource tagged appropriately?
  def missing_tags?(resource)
    return false if ignore_tags?
    return false if tags.empty?

    not resource.tagged?(*tags)
  end
end

require 'puppet/transaction/report'