module ArchSpec::RailsReflector

# File lib/archspec/rails_reflector.rb, line 32
def capture(graph, models:, environment:, facts_path: 'archspec_facts')
  sites = association_sites(graph).group_by { |site| [site.macro, site.name] }
  references = []
  methods = []
  gaps = []
  reflections = models.flat_map(&:reflect_on_all_associations)
                      .uniq { |reflection| [reflection.active_record.name, reflection.name] }
  reflections.sort_by { |reflection| [reflection.active_record.name.to_s, reflection.name.to_s] }.each do |reflection|
    model = reflection.active_record
    next if model.name.nil? || graph.constants_named(model.name).empty?

    ancestors = graph.ancestor_names(model.name).first | Set[model.name]
    candidates = sites.fetch([reflection.macro, reflection.name.to_s], []).select { |site| ancestors.include?(site.owner) }
    source = source_node(graph, model, candidates)
    next unless source

    if candidates.size != 1
      gaps << entry_for(graph, source, source.location).merge('source' => model.name,
        'message' => "association #{model.name}.#{reflection.name}: no unique literal declaration")
      next
    end
    site = candidates.first
    entry = entry_for(graph, source, site.location)
    generated = model.generated_association_methods.instance_methods(false).map(&:to_s)
    names = [reflection.name.to_s, "#{reflection.name}="] & generated
    unless names.empty?
      methods << entry.merge('owner' => model.name, 'scope' => 'instance', 'names' => names.sort)
    end
    if reflection.polymorphic?
      gaps << entry.merge('source' => model.name, 'message' => "polymorphic association #{model.name}.#{reflection.name}")
      next
    end
    begin
      target = reflection.klass.name
      raise Error, 'association target is anonymous' if target.nil? || target.empty?

      references << entry.merge('source' => model.name, 'target' => target)
    rescue NameError, ArgumentError, ActiveRecord::ActiveRecordError, Error => error
      gaps << entry.merge('source' => model.name,
        'message' => "unresolved association #{model.name}.#{reflection.name}: #{error.message.lines.first.strip}")
    end
  end
  {
    'version' => Facts::VERSION,
    'producer' => 'active_record',
    'environment' => environment,
    'snapshot' => Facts.snapshot(graph, excluding: facts_path),
    'references' => references,
    'methods' => methods,
    'gaps' => gaps
  }
end

# File lib/archspec/rails_reflector.rb, line 15
def run(config_path:, root:, output_path:, environment:)
  rails = File.join(root, 'bin/rails')
  raise Error, "no #{rails} found; reflection requires a Rails application" unless File.file?(rails)

  environment_variables = {
    'ARCHSPEC_REFLECTION_CONFIG' => File.expand_path(config_path),
    'ARCHSPEC_REFLECTION_OUTPUT' => output_path
  }
  stdout, stderr, status = Open3.capture3(environment_variables, RbConfig.ruby, rails,
    'runner', '-e', environment, File.expand_path('reflect_runner.rb', __dir__), chdir: root)
  raise Error, "Rails reflection failed (exit #{status.exitstatus}):\n#{stderr}#{stdout}" unless status.success?

  stdout
rescue SystemCallError => error
  raise Error, "could not start Rails reflection: #{error.message}"
end