module Preact::FunctionComponent::NativeComponentConstructor
  def self.extended(base)
    component_name = base.to_s
    %x{
      base.instance_init = function(initial) {
        let ruby_state = { instance: #{base.new(`{}`)} };
        ruby_state.instance.__ruby_instance = ruby_state.instance;
        return ruby_state;
      }
      base.instance_reducer = function(state, action) { return state; }
      base.preact_component = function(props) {
        const oper = Opal.Preact;
        oper.render_buffer.push([]);
        const [__ruby_state, __ruby_dispatch] = Opal.global.PreactHooks.useReducer(base.instance_reducer, null, base.instance_init);
        const __ruby_instance = __ruby_state.instance;
        __ruby_instance.props = props;
        oper.register_active_component(__ruby_instance);
        try {
          let block_result = #{`__ruby_instance`.instance_exec(&`base.render_block`)};
          if (block_result && block_result !== nil) { oper.render_block_result(block_result); }
        } catch (e) {
          if (oper.using_did_catch) { throw e; }
          else { console.error(e.message === nil ? 'error at' : e.message, e.stack); }
        }
        oper.unregister_active_component(__ruby_instance);
        let result = oper.render_buffer.pop();
        return (result.length === 1) ? result[0] : result;
      }
      base.preact_component.displayName = #{component_name};
    }

    base_module = base.to_s.deconstantize
    if base_module != ''
      base_module.constantize.define_singleton_method(base.to_s.demodulize) do |*args, &block|
        `Opal.Preact.internal_prepare_args_and_render(#{base}.preact_component, args, block)`
      end
    else
      Object.define_method(base.to_s) do |*args, &block|
        `Opal.Preact.internal_prepare_args_and_render(#{base}.preact_component, args, block)`
      end
    end

    def render(&block)
      `base.render_block = #{block}`
    end
  end
end