wechat-oauth2

gem “omniauth-wechat-oauth2”

devise_for :users, controllers: {
    registrations: "user/registrations",
    omniauth_callbacks: 'omniauth_callback'
  }

# Use this hook to configure devise mailer, warden hooks and so forth.
# Many of these configuration options can be set straight in your model.
Devise.setup do |config|

  config.omniauth :wechat,
  ENV['WECHAT_MP_APPID'],
  ENV['WECHAT_MP_SECRET'],
  :authorize_params => {:scope => "snsapi_userinfo"}

# ....

class OmniauthCallbackController < Devise::OmniauthCallbacksController

  def wechat
    @user = User.from_omniauth(request.env["omniauth.auth"])
    if @user.persisted?
      sign_in_and_redirect @user, :event => :authentication
    else
      session["devise.wechat_data"] = request.env["omniauth.auth"]
      redirect_to new_user_registration_url
    end
  end

end

class User < ApplicationRecord
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :omniauthable,
         :omniauth_providers => [:wechat]

  def self.from_omniauth(auth)
    where(provider: auth.provider, uid: auth.uid).first_or_create do |user|
        user.provider = auth.provider
        user.uid = auth.uid
        user.email = auth.info.email || "#{auth.uid}@herego.com"
        user.name = auth.info.nickname
        user.portrait_url = auth.info.headimgurl
        user.password = Devise.friendly_token[0,20]
        user.save
      end
  end

end