gem 'crepe', github: 'crepe/crepe'

# config.ru
require 'bundler/setup'
require 'crepe'

module Gist
  class API < Crepe::API
    # Like `let` in RSpec, this defines a lazy-loading helper.
    let(:current_user) { User.authorize!(request.headers['Authorization']) }

    namespace :gists do
      let(:gist_params) { params.slice(:files, :description, :public) }

      get do
        begin
          current_user.gists.limit(30)
        rescue User::Unauthorized
          Gist.limit(30)
        end
      end

      post { Gist.create(gist_params) }

      get(:public) { Gist.limit(30) }

      get(:starred) { current_user.starred_gists }

      # Specify a parameter as part of the namespace: /gists/:id/...
      param :id do
        let(:gist) { Gist.find(params[:id]) }

        get    { gist }
        put    { gist.update_attributes(gist_params) }
        patch  { gist.update_attributes(gist_params) }
        delete do
          if gist.user == current_user
            gist.destroy and head :no_content
          else
            error! :unauthorized
          end
        end

        # Specify a parameter constraint, e.g. a 40-character hex string
        param(sha: /\h{40}/) { gist.revisions.find(params[:sha]) }
        get(:commits) { gist.commits.limit(30) }

        get :star do
          if current_user.starred?(gist)
            head :no_content
          else
            head :not_found
          end
        end
        put(:star)    { current_user.star(gist) }
        delete(:star) { current_user.unstar(gist) }

        get(:forks)  { gist.forks.limit(30) }
        post(:forks) { current_user.fork(gist) }
      end
    end

    rescue_from ActiveRecord::RecordNotFound do |e|
      error! :not_found, e.message
    end

    rescue_from ActiveRecord::InvalidRecord do |e|
      error! :unprocessable_entity, e.message, errors: e.record.errors
    end

    rescue_from User::Unauthorized do |e|
      unauthorized! realm: 'Gist API'
    end
  end
end

run Gist::API