discourse/app/controllers/session_controller.rb

class SessionController < ApplicationController

  def create
    requires_parameter(:login, :password)

    login = params[:login].downcase
    login = login[1..-1] if login[0] == "@"

    if login =~ /@/
      @user = User.where(email: login).first
    else
      @user = User.where(username_lower: login).first
    end

    if @user.present?

      # If the site requires user approval and the user is not approved yet
      if SiteSetting.must_approve_users? && !@user.approved?
        render json: {error: I18n.t("login.not_approved")}
        return
      end

      # If their password is correct
      if @user.confirm_password?(params[:password])
        if @user.email_confirmed?
          log_on_user(@user)
          render_serialized(@user, UserSerializer)
          return
        else
          render json: {error: I18n.t("login.not_activated"), reason: 'not_activated', sent_to_email: @user.email_logs.where(email_type: 'signup').order('created_at DESC').first.try(:to_address), current_email: @user.email}
          return
        end
      end
    end

    render json: {error: I18n.t("login.incorrect_username_email_or_password")}
  end

  def forgot_password
    requires_parameter(:username)

    user = User.where('username_lower = :username or email = :username', username: params[:username].downcase).first
    if user.present?
      email_token = user.email_tokens.create(email: user.email)
      Jobs.enqueue(:user_email, type: :forgot_password, user_id: user.id, email_token: email_token.token)
    end
    # always render of so we don't leak information
    render json: {result: "ok"}
  end

  def destroy
    session[:current_user_id] = nil
    cookies[:_t] = nil
    render nothing: true
  end

end