discourse-rewind/app/services/discourse_rewind/rewind/action/reading_time.rb

# frozen_string_literal: true

# For showcasing the reading time of a user
# Should we show book covers or just the names?
module DiscourseRewind
  class Rewind::Action::ReadingTime < Rewind::Action::BaseReport
    def call
      reading_time = UserVisit.where(user_id: user.id).where(visited_at: date).sum(:time_read)

      {
        data: {
          reading_time: reading_time,
          book: best_book_fit(reading_time)[:title],
          isbn: best_book_fit(reading_time)[:isbn]
        },
        identifier: "reading-time",
      }
    end

    def popular_books
      {
        "The Hunger Games" => { reading_time: 19_740, isbn: "978-0439023481" },
        "The Metamorphosis" => { reading_time: 3120, isbn: "978-0553213690" },
        "To Kill a Mockingbird" => { reading_time: 22_800, isbn: "978-0061120084" },
        "Pride and Prejudice" => { reading_time: 25_200, isbn: "978-1503290563" },
        "1984" => { reading_time: 16_800, isbn: "978-0451524935" },
        "The Lord of the Rings" => { reading_time: 108_000, isbn: "978-0544003415" },
        "Harry Potter and the Sorcerer's Stone" => { reading_time: 24_600, isbn: "978-0590353427" },
        "The Great Gatsby" => { reading_time: 12_600, isbn: "978-0743273565" },
        "The Little Prince" => { reading_time: 5400, isbn: "978-0156012195" },
        "Animal Farm" => { reading_time: 7200, isbn: "978-0451526342" },
        "The Catcher in the Rye" => { reading_time: 18_000, isbn: "978-0316769488" },
        "Jane Eyre" => { reading_time: 34_200, isbn: "978-0141441146" },
        "Fahrenheit 451" => { reading_time: 15_000, isbn: "978-1451673319" },
        "The Hobbit" => { reading_time: 27_000, isbn: "978-0547928227" },
        "The Da Vinci Code" => { reading_time: 37_800, isbn: "978-0307474278" },
        "Little Women" => { reading_time: 30_000, isbn: "978-0147514011" },
        "One Hundred Years of Solitude" => { reading_time: 46_800, isbn: "978-0060883287" },
        "And Then There Were None" => { reading_time: 16_200, isbn: "978-0062073488" },
        "The Alchemist" => { reading_time: 10_800, isbn: "978-0061122415" },
        "The Hitchhiker's Guide to the Galaxy" => { reading_time: 12_600, isbn: "978-0345391803" },
      }.symbolize_keys
    end

    def best_book_fit(reading_time)
      reading_time_rest = reading_time
      books = []

      while reading_time_rest > 0
        best_fit = popular_books.min_by { |_, v| (v[:reading_time] - reading_time_rest).abs }
        break if best_fit.nil?

        books << best_fit.first
        reading_time_rest -= best_fit.last[:reading_time]
      end

      book_title = books.group_by { |book| book }
                        .transform_values(&:count)
                        .max_by { |_, count| count }
                        .first
      # popular_books[book_title]

      {
        title: book_title,
        isbn: popular_books[book_title][:isbn],
      }
    end
  end
end