# frozen_string_literal: true

module Crys
  class PagesDbManager
    PAGES_KEY = :pages
    PAGE = Struct.new(
      :filename,
      :source,

      :last_updated_at,
      :created_at,

      :in_rss,
      :in_all,

      keyword_init: true)


    def initialize(db_path:)
      @db_path = db_path
    end


    def add_page(page)
      @page = page
      hash = Digest::MD5.hexdigest(page.source)
      known_page = known_page(hash)

      upsert_db(hash, known_page)
    end

    def save
      save_db
    end

    def pages
      db.fetch(:pages).map do |_, data|
        PAGE.new(data)
      end
    end

    private

    attr_reader :hash, :page, :db_path

    def db
      @db ||= YAML.load_file(
        db_path,
        permitted_classes: [Time, Symbol]
      )
    end

    def upsert_db(hash, known_page)
      record = PAGE.new(known_page || { filename: page.filename,
                                        source: page.source,
                                        created_at: Time.now,
                                        in_rss: true,
                                        in_all: true})

      record.last_updated_at = page.last_updated_at

      @db[PAGES_KEY][hash] = record.to_h
    end

    def save_db
      File.write(db_path, db.to_yaml)
    end

    def known_page(hash)
      db[PAGES_KEY][hash]
    end
  end
end