require 'rails_helper'

RSpec.describe Rs::OauthController, type: :controller do
  let(:user) { create :user }

  before do
    allow_any_instance_of(AppCatalog::WebApp).to receive(:update_metadata).and_return(true)
    allow_any_instance_of(RemoteStorageAuthorization).to receive(:remove_token_expiry_job).and_return(nil)
  end

  describe "GET /rs/oauth/:username" do
    context "when user is signed in" do
      before do
        sign_in user
      end

      context "when username is different than current user" do
        let(:other_user) { create :user, id: 23, cn: "jomokenyatta", email: "jomo@hotmail.com" }

        before do
          get :new, params: {
            username: other_user.cn,
            redirect_uri: "https://example.com",
            client_id: "example.com",
            scope: "examples"
          }
        end

        it "logs out the users and repeats the request" do
          url = new_rs_oauth_url other_user.cn,
            redirect_uri: "https://example.com",
            client_id: "example.com",
            scope: "examples"

          expect(response).to redirect_to(url)
        end
      end

      context "when no valid token exists" do
        before do
          get :new, params: {
            username: user.cn,
            redirect_uri: "https://example.com",
            client_id: "example.com",
            scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
            state: "foobar123"
          }
        end

        it "returns a 200" do
          expect(response.response_code).to eq(200)
        end

        it "sets the instance variables" do
          expected_scopes = %w(documents photos contacts:rw videos:r tasks/work:r)

          expect(assigns["user"]).to eq(user)
          expect(assigns["redirect_uri"]).to eq("https://example.com")
          expect(assigns["scopes"]).to eq(expected_scopes)
          expect(assigns["client_id"]).to eq("example.com")
          expect(assigns["root_access_requested"]).to eq(false)
          expect(assigns["state"]).to eq("foobar123")
          expect(assigns["denial_url"]).to eq("https://example.com#error=access_denied&state=foobar123")
        end

        context "no redirect_uri" do
          before do
            get :new, params: {
              username: user.cn,
              scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
              client_id: "https://example.com"
            }
          end

          it "returns a 400" do
            expect(response.response_code).to eq(400)
          end
        end

        context "no client_id" do
          before do
            get :new, params: {
              username: user.cn,
              scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
              redirect_uri: "https://example.com"
            }
          end

          it "redirects with invalid_request error" do
            expect(response).to redirect_to("https://example.com#error=invalid_request")
          end
        end

        context "different host for client_id and redirect_uri" do
          before do
            get :new, params: {
              username: user.cn,
              scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
              redirect_uri: "https://example.com/foobar",
              client_id: "https://google.com"
            }
          end

          it "redirects with invalid_client error" do
            expect(response).to redirect_to("https://example.com/foobar#error=invalid_client")
          end
        end
      end

      context "when valid token already exists" do
        before do
          @auth = user.remote_storage_authorizations.create!(
            permissions: %w(documents photos contacts:rw videos:r tasks/work:r),
            client_id: "example.com", redirect_uri: "https://example.com",
            expire_at: 1.day.from_now
          )
        end

        after { @auth.destroy }

        context "with same host for client_id and redirect_uri" do
          before do
            get :new, params: {
              username: user.cn,
              scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
              redirect_uri: "https://example.com",
              client_id: "https://example.com"
            }
          end

          it "does not reuse the existing token (renders the consent dialog)" do
            expect(response.response_code).to eq(200)
          end
        end

        context "with different host for client_id and redirect_uri" do
          before do
            get :new, params: {
              username: user.cn,
              scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
              redirect_uri: "https://app.example.com",
              client_id: "https://example.com"
            }
          end

          it "redirects with invalid_client error" do
            expect(response).to redirect_to("https://app.example.com#error=invalid_client")
          end
        end
      end

      context "when response_type is code" do
        before do
          get :new, params: {
            username: user.cn,
            redirect_uri: "https://example.com",
            client_id: "example.com",
            scope: "documents",
            response_type: "code",
            code_challenge: "challenge123",
            code_challenge_method: "S256",
            state: "foobar123"
          }
        end

        it "renders the consent dialog and exposes the code challenge" do
          expect(response.response_code).to eq(200)
          expect(assigns["response_type"]).to eq("code")
          expect(assigns["code_challenge"]).to eq("challenge123")
          expect(assigns["code_challenge_method"]).to eq("S256")
        end

        it "uses a query-based denial url" do
          expect(assigns["denial_url"]).to eq("https://example.com?error=access_denied&state=foobar123")
        end
      end

      context "when response_type is code without a code_challenge" do
        before do
          get :new, params: {
            username: user.cn,
            redirect_uri: "https://example.com",
            client_id: "example.com",
            scope: "documents",
            response_type: "code",
            state: "foobar123"
          }
        end

        it "redirects with invalid_request using a query param" do
          expect(response).to redirect_to("https://example.com?error=invalid_request&state=foobar123")
        end
      end

      context "when response_type is code with the plain method" do
        before do
          get :new, params: {
            username: user.cn,
            redirect_uri: "https://example.com",
            client_id: "example.com",
            scope: "documents",
            response_type: "code",
            code_challenge: "challenge123",
            code_challenge_method: "plain"
          }
        end

        it "redirects with invalid_request" do
          expect(response).to redirect_to("https://example.com?error=invalid_request")
        end
      end

      context "no scope" do
        before do
          get :new, params: {
            username: user.cn,
            redirect_uri: "https://example.com",
            client_id: "https://example.com",
            state: "foobar123"
          }
        end

        it "redirects to the redirect_uri with an error code" do
          expect(response).to redirect_to("https://example.com#error=invalid_scope&state=foobar123")
        end
      end

      context "empty scope" do
        before do
          get :new, params: {
            username: user.cn,
            scope: "",
            redirect_uri: "https://example.com",
            client_id: "https://example.com",
            state: "foobar123"
          }
        end

        it "redirects to the redirect_uri with an error code" do
          expect(response).to redirect_to("https://example.com#error=invalid_scope&state=foobar123")
        end
      end
    end

    context "when user is not signed in" do
      it "redirects to the signin page with username pre-filled" do
        get :new, params: {
          username: user.cn,
          scope: "documents,photos",
          redirect_uri: "https://example.com"
        }

        expect(response).to redirect_to(new_user_session_path(cn: user.cn, ou: user.ou))
      end

      context "without a redirect_uri" do
        it "returns a 400 without storing the return location" do
          get :new, params: {
            username: user.cn,
            scope: "documents,photos",
            client_id: "https://example.com"
          }

          expect(response.response_code).to eq(400)
          expect(session[:user_return_to]).to be_nil
        end
      end
    end

    describe "root access" do
      before do
        sign_in user
      end

      describe "full" do
        before do
          get :new, params: {
            username: user.cn,
            scope: "*:rw",
            redirect_uri: "https://example.com",
            client_id: "example.com"
          }
        end

        it "sets the instance variables" do
          expect(assigns["scopes"]).to eq([":rw"])
          expect(assigns["root_access_requested"]).to be(true)
        end
      end

      describe "read-only" do
        before do
          get :new, params: {
            username: user.cn,
            scope: "*:r",
            redirect_uri: "https://example.com",
            client_id: "example.com"
          }
        end

        it "sets the instance variables" do
          expect(assigns["scopes"]).to eq([":r"])
          expect(assigns["root_access_requested"]).to be(true)
        end
      end
    end
  end

  describe "POST /rs/oauth/:username" do
    context "when user is signed in" do
      before do
        sign_in user
        request.user_agent = "RSpec Device"
      end

      after do
        user.remote_storage_authorizations.destroy_all
        RsAuthorizationCode.destroy_all
      end

      context "when no valid token exists" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
            redirect_uri: "https://example.com",
            client_id: "example.com",
            state: "foobar123",
            expire_at: 1.day.from_now
          }
          @auth = user.reload.remote_storage_authorizations.first
        end

        it "creates a new token" do
          expect(@auth.permissions).to eq(%w(documents photos contacts:rw videos:r tasks/work:r))
        end

        it "stores the device's user agent" do
          expect(@auth.user_agent).to eq("RSpec Device")
        end

        it "redirects to the redirect_uri" do
          expect(response).to redirect_to("https://example.com#access_token=#{@auth.token}&state=foobar123")
        end
      end

      context "when token is expired" do
        before do
          @auth = user.remote_storage_authorizations.create!(
            permissions: %w(documents),
            client_id: "example.com",
            redirect_uri: "https://example.com",
            expire_at: 1.day.ago,
            token: nil
          )
          post :create, params: {
            user_id: user.id,
            scope: "documents",
            redirect_uri: "https://example.com",
            client_id: "example.com",
            state: "foobar123",
            expire_at: 1.month.from_now
          }
        end

        it "updates the token" do
          expect(@auth.reload.token).not_to be_nil
        end
      end

      context "root access with several scopes" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "*:rw contacts:r",
            redirect_uri: "https://example.com",
            client_id: "example.com",
            expire_at: 1.month.from_now
          }
          @auth = user.reload.remote_storage_authorizations.first
        end

        it "removes all scopes except for the root permission" do
          expect(@auth.permissions).to eq(%w(:rw))
        end
      end

      context "no redirect_uri" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
            client_id: "example.com",
            expire_at: 1.month.from_now
          }
        end

        it "returns a 400" do
          expect(response.response_code).to eq(400)
        end
      end

      context "no client_id" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
            redirect_uri: "https://example.com",
            expire_at: 1.month.from_now
          }
        end

        it "redirects with invalid_request error" do
          expect(response).to redirect_to("https://example.com#error=invalid_request")
        end
      end

      context "hostnames of client_id and redirect_uri do not match" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "documents,[photos], contacts:rw videos:r tasks/work/:r",
            client_id: "fishing.com",
            redirect_uri: "https://example.com",
            expire_at: 1.month.from_now
          }
        end

        it "redirects with invalid_client error" do
          expect(response).to redirect_to("https://example.com#error=invalid_client")
        end
      end

      context "empty scope" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "",
            redirect_uri: "https://example.com",
            client_id: "example.com",
            state: "foobar123",
            expire_at: 1.month.from_now
          }
        end

        it "redirects to the redirect_uri with an error code" do
          expect(response).to redirect_to("https://example.com#error=invalid_scope&state=foobar123")
        end
      end

      context "with response_type=code" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "documents,[photos], contacts:rw",
            redirect_uri: "https://example.com",
            client_id: "example.com",
            state: "foobar123",
            response_type: "code",
            code_challenge: "challenge123",
            code_challenge_method: "S256",
            expire_at: 1.month.from_now
          }
          @code = RsAuthorizationCode.last
        end

        it "creates an authorization code" do
          expect(@code.permissions).to eq(%w(documents photos contacts:rw))
          expect(@code.code_challenge).to eq("challenge123")
          expect(@code.code_challenge_method).to eq("S256")
          expect(@code.user_agent).to eq("RSpec Device")
        end

        it "does not create a remote storage authorization" do
          expect(user.reload.remote_storage_authorizations.count).to eq(0)
        end

        it "redirects with the code in the query string" do
          location = response.location
          expect(location).to match(%r{\Ahttps://example\.com\?code=.+&state=foobar123\z})

          raw_code = CGI.parse(URI.parse(location).query)["code"].first
          expect(RsAuthorizationCode.find_by_code(raw_code)).to eq(@code)
        end
      end

      context "with response_type=code but no code_challenge" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "documents",
            redirect_uri: "https://example.com",
            client_id: "example.com",
            state: "foobar123",
            response_type: "code",
            expire_at: 1.month.from_now
          }
        end

        it "redirects with invalid_request using a query param" do
          expect(response).to redirect_to("https://example.com?error=invalid_request&state=foobar123")
        end

        it "does not create an authorization code" do
          expect(RsAuthorizationCode.count).to eq(0)
        end
      end

      context "when the user_id is different from the signed in user" do
        before do
          post :create, params: {
            user_id: user.id,
            scope: "documents,photos",
            redirect_uri: "https://example.com",
            client_id: "example.com",
            expire_at: 1.month.from_now
          }
        end

        it "returns a 403" do
          post :create, params: {
            user_id: "69",
            scope: "documents,photos",
            redirect_uri: "https://example.com",
            client_id: "example.com",
            expire_at: 1.month.from_now
          }

          expect(response.response_code).to eq(403)
        end
      end
    end

    context "when user is not signed in" do
      it "redirects to the signin page" do
        post :create, params: {
          user_id: user.id,
          scope: "documents,photos",
          redirect_uri: "https://example.com",
          client_id: "example.com",
          expire_at: 1.month.from_now
        }

        expect(response).to redirect_to(new_user_session_path)
      end
    end
  end

  describe "POST /rs/oauth/token" do
    # Example values from RFC 7636, Appendix B
    let(:code_verifier)  { "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk" }
    let(:code_challenge) { "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM" }

    def issue_code
      RsOauthManager::IssueCode.call(
        user: user,
        client_id: "example.com",
        redirect_uri: "https://example.com",
        permissions: %w(documents:rw),
        code_challenge: code_challenge,
        code_challenge_method: "S256"
      )
    end

    def token_params(code, **overrides)
      {
        grant_type: "authorization_code",
        code: code.code,
        client_id: "https://example.com",
        redirect_uri: "https://example.com",
        code_verifier: code_verifier
      }.merge(overrides)
    end

    after do
      user.remote_storage_authorizations.destroy_all
      RsAuthorizationCode.destroy_all
    end

    context "with a valid code" do
      before do
        @code = issue_code
        post :token, params: token_params(@code)
      end

      it "returns an access token" do
        expect(response.response_code).to eq(200)

        json = JSON.parse(response.body)
        expect(json["access_token"]).to be_present
        expect(json["token_type"]).to eq("bearer")
        expect(json["scope"]).to eq("documents:rw")
      end

      it "does not cache the response" do
        expect(response.headers["Cache-Control"]).to eq("no-store")
      end

      it "sets CORS headers" do
        expect(response.headers["Access-Control-Allow-Origin"]).to eq("*")
      end
    end

    context "with a bad code_verifier" do
      before do
        @code = issue_code
        post :token, params: token_params(@code, code_verifier: "wrong-verifier")
      end

      it "returns invalid_grant" do
        expect(response.response_code).to eq(400)
        expect(JSON.parse(response.body)["error"]).to eq("invalid_grant")
      end
    end

    context "with an unsupported grant_type" do
      before { post :token, params: { grant_type: "password" } }

      it "returns unsupported_grant_type" do
        expect(response.response_code).to eq(400)
        expect(JSON.parse(response.body)["error"]).to eq("unsupported_grant_type")
      end
    end
  end
end