a README

README.md

@@ -1,39 +1,86 @@
-# Fsrs
+## About The Project
 
-TODO: Delete this and the text below, and describe your gem
+rb-fsrs is a Ruby Gem implements [Free Spaced Repetition Scheduler algorithm](https://github.com/open-spaced-repetition/free-spaced-repetition-scheduler). It helps developers apply FSRS in their flashcard apps.
 
-Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/fsrs`. To experiment with that code, run `bin/console` for an interactive prompt.
+## Getting Started
 
-## Installation
+```
+gem install fsrs
+```
 
-TODO: Replace `UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG` with your gem name right after releasing it to RubyGems.org. Please do not do it earlier due to security reasons. Alternatively, replace this section with instructions to install your gem from git if you don't plan to release to RubyGems.org.
+or 
 
-Install the gem and add to the application's Gemfile by executing:
-
-    $ bundle add UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG
-
-If bundler is not being used to manage dependencies, install the gem by executing:
-
-    $ gem install UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG
+```
+bundle add fsrs
+```
 
 ## Usage
 
-TODO: Write usage instructions here
-
-## Development
-
-After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake test` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
-
-To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and the created tag, and push the `.gem` file to [rubygems.org](https://rubygems.org).
-
-## Contributing
-
-Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/fsrs. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [code of conduct](https://github.com/[USERNAME]/fsrs/blob/master/CODE_OF_CONDUCT.md).
+Create a card and review it at a given time:
+```ruby
+require 'fsrs'
+
+scheduler = Fsrs::Scheduler.new
+card = Fsrs::Card.new
+now = DateTime.now.utc
+scheduling_cards = scheduler.repeat(card, now)
+```
+
+There are four ratings:
+```ruby
+Rating::AGAIN # forget; incorrect response
+Rating::HARD # recall; correct response recalled with serious difficulty
+Rating::GOOD # recall; correct response after a hesitation
+Rating::EASY # recall; perfect response
+```
+
+
+Get the new state of card for each rating:
+```ruby
+scheduling_cards[Rating::AGAIN].card
+scheduling_cards[Rating::HARD].card
+scheduling_cards[Rating::GOOD].card
+scheduling_cards[Rating::EASY].card
+```
+
+Get the scheduled days for each rating:
+```ruby
+card_again.scheduled_days
+card_hard.scheduled_days
+card_good.scheduled_days
+card_easy.scheduled_days
+```
+
+Update the card after rating `GOOD`:
+```ruby
+card = scheduling_cards[Rating::GOOD].card
+```
+
+Get the review log after rating `GOOD`:
+```ruby
+review_log = scheduling_cards[Rating::GOOD].review_log
+```
+
+Get the due date for card:
+```ruby
+due = card.due
+```
+
+There are four states:
+```ruby
+State::NEW # Never been studied
+State::LEARNING # Been studied for the first time recently
+State::REVIEW # Graduate from learning state
+State::RELEARNING # Forgotten in review state
+```
+
+## Acknowledgements
+
+* [Open Spaced Repetition](https://github.com/open-spaced-repetition)
+* [py-fsrs](https://github.com/open-spaced-repetition/py-fsrs)
+
+This library was ported from [py-fsrs](https://github.com/open-spaced-repetition/py-fsrs) to Ruby. Much refactoring to be done, but the core logic is the same.
 
 ## License
 
-The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).
-
-## Code of Conduct
-
-Everyone interacting in the Fsrs project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/[USERNAME]/fsrs/blob/master/CODE_OF_CONDUCT.md).
+Distributed under the MIT License. See `LICENSE` for more information.