class Rage::LogProcessor

def add_custom_context(context_objects)
  @custom_context = context_objects
  rebuild!
end

def add_custom_tags(tag_objects)
  @custom_tags = tag_objects
  rebuild!
end

def build_dynamic_context_proc
  calls = @custom_context&.filter_map&.with_index do |context_object, i|
    if context_object.respond_to?(:call)
      "@custom_context[#{i}].call || DEFAULT_LOG_CONTEXT"
    end
  end
  return unless calls&.any?
  eval <<~RUBY
    ->() do
      {}.merge!(#{calls.join(", ")})
    end
  RUBY
end

def build_dynamic_tags_proc
  calls = @custom_tags&.filter_map&.with_index do |tag_object, i|
    if tag_object.respond_to?(:call)
      "*@custom_tags[#{i}].call"
    end
  end
  return unless calls&.any?
  eval <<~RUBY
    ->() do
      [#{calls.join(", ")}]
    end
  RUBY
end

def build_static_context
  calls = @custom_context&.filter_map&.with_index do |context_object, i|
    "@custom_context[#{i}]" if context_object.is_a?(Hash)
  end
  unless calls&.any?
    return "DEFAULT_LOG_CONTEXT"
  end
  if calls.one?
    calls[0]
  else
    "{}.merge!(#{calls.join(", ")})"
  end
end

def build_static_tags
  calls = @custom_tags&.filter_map&.with_index do |tag_object, i|
    if tag_object.is_a?(String)
      "@custom_tags[#{i}]"
    elsif tag_object.respond_to?(:to_str)
      "@custom_tags[#{i}].to_str"
    end
  end
  unless calls&.any?
    return "[env[\"rage.request_id\"]]"
  end
  "[env[\"rage.request_id\"], #{calls.join(", ")}]"
end

def finalize_request_logger(env, response, params)
  duration = (
    (Process.clock_gettime(Process::CLOCK_MONOTONIC) - Fiber[:__rage_logger_request_start]) * 1000
  ).round(2)
  Fiber[:__rage_logger_final] = { env:, params:, response:, duration: }
  Rage.logger.info(nil)
  Fiber[:__rage_logger_final] = nil
end

def initialize
  rebuild!
end

def rebuild!
  @dynamic_tags = build_dynamic_tags_proc
  @dynamic_context = build_dynamic_context_proc
  self.class.class_eval <<~RUBY, __FILE__, __LINE__ + 1
    def init_request_logger(env)
      env["rage.request_id"] ||= Iodine::Rack::Utils.gen_request_tag
      Fiber[:__rage_logger_tags] = #{build_static_tags}
      Fiber[:__rage_logger_context] = #{build_static_context}
      Fiber[:__rage_logger_request_start] = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    end
  RUBY
end