require "active_support/core_ext/hash"
require "watir"

module ScrapKit
  class Recipe
    def initialize(url: nil, steps: [], attributes: {})
      @url = url
      @steps = steps
      @attributes = attributes
    end

    def run
      output = {}

      browser = Watir::Browser.new(:chrome, headless: true)
      browser.goto @url

      @steps.each do |step|
        run_step(browser, step)
      end

      @attributes.each do |attribute_name, selector|
        output[attribute_name] = extract_attribute(browser, selector)
      end

      browser.close
      browser = nil

      output
    end

    def run_step(browser, step)
    end

    def extract_attribute(browser_or_element, selector_or_hash)
      if selector_or_hash.is_a?(String)
        browser_or_element.element(css: selector_or_hash)&.text_content
      elsif selector_or_hash.is_a?(Hash)
        selector = selector_or_hash[:selector]
        selector_for_children_attributes = selector_or_hash[:children_attributes]

        browser_or_element.elements(css: selector).map do |element|
          output = {}

          selector_for_children_attributes.each do |child_attribute_name, child_selector|
            output[child_attribute_name] = extract_attribute(element, child_selector)
          end

          output
        end
      end
    end

    class << self
      def load(source)
        input = if source.is_a?(Hash)
          source
        elsif source.is_a?(IO)
          JSON.parse(source.read)
        else
          JSON.parse(File.read(source))
        end

        new(input.deep_symbolize_keys)
      end
    end
  end
end