require 'httparty'

class MicrosoftGraph
  BASE_URL = 'https://graph.microsoft.com/v1.0'.freeze

  def initialize(current_user, client_id, client_secret, tenant_id, scopes)
    @current_user = current_user
    @uid = current_user.microsoft_user_id
    @token = current_user.microsoft_access_token
    @refresh_token = current_user.microsoft_refresh_token
    @token_expires_at = current_user.microsoft_token_expires_at

    @client_id = client_id
    @client_secret = client_secret
    @tenant_id = tenant_id
    @scopes = scopes
  end

  def create_teams_meeting(subject)
    # Obtain new token if token is expired or will expire in less than 5 minutes
    if 5.minutes.from_now.to_i > @token_expires_at.seconds
      refresh_access_token
    end

    response = HTTParty.post(
      "#{BASE_URL}/me/onlineMeetings",
      body: {
        subject: subject,
        participants: {
          organizer: {
            identity: {
              user: {
                id: @uid
              }
            }
          }
        }
      }.to_json,
      headers: {
        Authorization: "Bearer #{@token}",
        'Content-Type': 'application/json'
      }
    )

    raise StandardError, 'Authenticated user does not have a permission to create Teams Online Meeting' if response.code == 403

    if response.code != 201
      Rails.logger.error('[Microsoft Graph Error]')
      Rails.logger.error(response.inspect)
      raise StandardError, "Failed to create teams meeting [#{response.code}]"
    else
      JSON.parse(response.body)
    end
  end

  private

  def refresh_token_url
    "https://login.microsoftonline.com/#{@tenant_id}/oauth2/v2.0/token"
  end

  def refresh_access_token
    response = HTTParty.post(refresh_token_url,
                             headers: {
                               'Content-Type': 'application/x-www-form-urlencoded'
                             },
                             body: {
                               client_id: @client_id,
                               client_secret: @client_secret,
                               refresh_token: @refresh_token,
                               grant_type: 'refresh_token',
                               scope: @scopes
                             })

    if response.code != 200
      Rails.logger.error '[Microsoft Graph Error] Failed to obtain new access token using refresh token'
      Rails.logger.error(response.inspect)
      raise StandardError, 'Failed to obtain new access token'
    end

    parsed_response = JSON.parse(response.body)

    new_access_token = parsed_response['access_token']
    new_refresh_token = parsed_response['refresh_token']
    token_expires_in = parsed_response['expires_in'] # For how long access token is valid (in seconds)
    token_new_expiration_time = Time.now.to_i + token_expires_in

    @current_user.microsoft_access_token = new_access_token
    @current_user.microsoft_refresh_token = new_refresh_token
    @current_user.microsoft_token_expires_at = token_new_expiration_time
    @current_user.save!

    @token = new_access_token
    @refresh_token = new_refresh_token
    @token_expires_at = token_new_expiration_time
  end
end