# frozen_string_literal: true

# This file should be identical in GitLab Community Edition and Enterprise Edition

class Projects::GitHttpClientController < Projects::ApplicationController
  include ActionController::HttpAuthentication::Basic
  include KerberosSpnegoHelper

  attr_reader :authentication_result, :redirected_path

  delegate :actor, :authentication_abilities, to: :authentication_result, allow_nil: true
  delegate :type, to: :authentication_result, allow_nil: true, prefix: :auth_result

  alias_method :user, :actor
  alias_method :authenticated_user, :actor

  # Git clients will not know what authenticity token to send along
  skip_before_action :verify_authenticity_token
  skip_before_action :repository
  before_action :authenticate_user

  private

  def download_request?
    raise NotImplementedError
  end

  def upload_request?
    raise NotImplementedError
  end

  def authenticate_user
    @authentication_result = Gitlab::Auth::Result.new

    if allow_basic_auth? && basic_auth_provided?
      login, password = user_name_and_password(request)

      if handle_basic_authentication(login, password)
        return # Allow access
      end
    elsif allow_kerberos_spnego_auth? && spnego_provided?
      kerberos_user = find_kerberos_user

      if kerberos_user
        @authentication_result = Gitlab::Auth::Result.new(
          kerberos_user, nil, :kerberos, Gitlab::Auth.full_authentication_abilities)

        send_final_spnego_response
        return # Allow access
      end
    elsif project && download_request? && Guest.can?(:download_code, project)
      @authentication_result = Gitlab::Auth::Result.new(nil, project, :none, [:download_code])

      return # Allow access
    end

    send_challenges
    render plain: "HTTP Basic: Access denied\n", status: :unauthorized
  rescue Gitlab::Auth::MissingPersonalAccessTokenError
    render_missing_personal_access_token
  end

  def basic_auth_provided?
    has_basic_credentials?(request)
  end

  def send_challenges
    challenges = []
    challenges << 'Basic realm="GitLab"' if allow_basic_auth?
    challenges << spnego_challenge if allow_kerberos_spnego_auth?
    headers['Www-Authenticate'] = challenges.join("\n") if challenges.any?
  end

  def project
    parse_repo_path unless defined?(@project)

    @project
  end

  def parse_repo_path
    @project, @repo_type, @redirected_path = Gitlab::RepoPath.parse("#{params[:namespace_id]}/#{params[:project_id]}")
  end

  def render_missing_personal_access_token
    render plain: "HTTP Basic: Access denied\n" \
                  "You must use a personal access token with 'read_repository' or 'write_repository' scope for Git over HTTP.\n" \
                  "You can generate one at #{profile_personal_access_tokens_url}",
           status: :unauthorized
  end

  def repository
    repo_type.repository_for(project)
  end

  def wiki?
    repo_type.wiki?
  end

  def repo_type
    parse_repo_path unless defined?(@repo_type)

    @repo_type
  end

  def handle_basic_authentication(login, password)
    @authentication_result = Gitlab::Auth.find_for_git_client(
      login, password, project: project, ip: request.ip)

    @authentication_result.success?
  end

  def ci?
    authentication_result.ci?(project)
  end
end
