Upload file to Microsoft's OneDrive

client.rb

# Usage:
# - Store refresh token on Redis under one_drive:refresh_token
# - Do OneDrive::Client.new.upload_file('/path/to/file')

module OneDrive
  class Client
    REFRESH_TOKEN = 'one_drive:refresh_token'.freeze

    class NoTokens < StandardError; end

    def initialize
      refresh_token = Rails.cache.read REFRESH_TOKEN
      refresh_token, access_token = get_tokens(refresh_token)
      Rails.cache.write REFRESH_TOKEN, refresh_token
      @access_token = access_token
    end

    def upload_file(filename)
      connection = Faraday.new(
        'https://graph.microsoft.com',
        headers: {
          'Authorization' => 'Bearer ' << @access_token,
          'Content-Type' => 'text/plain',
        }
      )
      file = filename.split('/').last
      request = connection.put("/v1.0/me/drive/root:/MyFolder/#{Rails.env}/#{file}:/content", File.read(filename))
      return Response.new(success: false, data: request.status) if request.status != 201

      Response.new(success: true, data: JSON.parse(request.body)['webUrl'])
    end

    private

    def get_tokens(refresh_token)
      connection = Faraday.new('https://login.microsoftonline.com')
      request = connection.post '/common/oauth2/v2.0/token', {
        refresh_token: refresh_token,
        client_id: ENV['ONEDRIVE_CLIENT_ID'],
        client_secret: ENV['ONEDRIVE_CLIENT_SECRET'],
        scope: 'offline_access files.readwrite',
        redirect_uri: 'http://localhost:3003',
        grant_type: 'refresh_token',
      }
      raise NoTokens if request.status != 200

      body = JSON.parse(request.body)
      [body['refresh_token'], body['access_token']]
    end
  end
end