/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.atlas.web.filters;

import org.apache.atlas.web.service.ActiveInstanceState;
import org.apache.atlas.web.service.ServiceState;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.ws.rs.HttpMethod;

import java.io.IOException;

import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyZeroInteractions;
import static org.mockito.Mockito.when;

public class ActiveServerFilterTest {

    public static final String ACTIVE_SERVER_ADDRESS = "http://localhost:21000/";
    @Mock
    private ActiveInstanceState activeInstanceState;

    @Mock
    private HttpServletRequest servletRequest;

    @Mock
    private HttpServletResponse servletResponse;

    @Mock
    private FilterChain filterChain;

    @Mock
    private ServiceState serviceState;

    @BeforeMethod
    public void setUp() {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void testShouldPassThroughRequestsIfActive() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.ACTIVE);
        when(servletRequest.getRequestURI()).thenReturn("api/atlas/types");

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);

        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(filterChain).doFilter(servletRequest, servletResponse);
    }

    @Test
    public void testShouldFailIfCannotRetrieveActiveServerAddress() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.PASSIVE);
        when(servletRequest.getRequestURI()).thenReturn("api/atlas/types");

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);

        when(activeInstanceState.getActiveServerAddress()).thenReturn(null);

        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(servletResponse).sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
    }

    @Test
    public void testShouldRedirectRequestToActiveServerAddress() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.PASSIVE);
        when(servletRequest.getRequestURI()).thenReturn("api/atlas/types");

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);

        when(activeInstanceState.getActiveServerAddress()).thenReturn(ACTIVE_SERVER_ADDRESS);
        when(servletRequest.getRequestURI()).thenReturn("types");
        when(servletRequest.getMethod()).thenReturn(HttpMethod.GET);

        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(servletResponse).sendRedirect(ACTIVE_SERVER_ADDRESS+"types");
    }

    @Test
    public void testRedirectedRequestShouldContainQueryParameters() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.PASSIVE);
        when(servletRequest.getRequestURI()).thenReturn("api/atlas/types");

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);

        when(activeInstanceState.getActiveServerAddress()).thenReturn(ACTIVE_SERVER_ADDRESS);
        when(servletRequest.getMethod()).thenReturn(HttpMethod.GET);
        when(servletRequest.getRequestURI()).thenReturn("types");
        when(servletRequest.getQueryString()).thenReturn("query=TRAIT");

        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(servletResponse).sendRedirect(ACTIVE_SERVER_ADDRESS+"types?query=TRAIT");

    }

    @Test
    public void testShouldRedirectPOSTRequest() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.PASSIVE);
        when(servletRequest.getRequestURI()).thenReturn("api/atlas/types");

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);

        when(activeInstanceState.getActiveServerAddress()).thenReturn(ACTIVE_SERVER_ADDRESS);
        when(servletRequest.getMethod()).thenReturn(HttpMethod.POST);
        when(servletRequest.getRequestURI()).thenReturn("types");

        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(servletResponse).setHeader("Location", ACTIVE_SERVER_ADDRESS+"types");
        verify(servletResponse).setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT);
    }

    @Test
    public void testShouldRedirectPUTRequest() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.PASSIVE);
        when(servletRequest.getRequestURI()).thenReturn("api/atlas/types");

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);

        when(activeInstanceState.getActiveServerAddress()).thenReturn(ACTIVE_SERVER_ADDRESS);
        when(servletRequest.getMethod()).thenReturn(HttpMethod.PUT);
        when(servletRequest.getRequestURI()).thenReturn("types");

        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(servletResponse).setHeader("Location", ACTIVE_SERVER_ADDRESS+"types");
        verify(servletResponse).setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT);
    }

    @Test
    public void testShouldRedirectDELETERequest() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.PASSIVE);
        when(servletRequest.getRequestURI()).thenReturn("api/atlas/types");

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);

        when(activeInstanceState.getActiveServerAddress()).thenReturn(ACTIVE_SERVER_ADDRESS);
        when(servletRequest.getMethod()).thenReturn(HttpMethod.DELETE);
        when(servletRequest.getRequestURI()).
                thenReturn("api/atlas/entities/6ebb039f-eaa5-4b9c-ae44-799c7910545d/traits/test_tag_ha3");

        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(servletResponse).setHeader("Location", ACTIVE_SERVER_ADDRESS
                + "api/atlas/entities/6ebb039f-eaa5-4b9c-ae44-799c7910545d/traits/test_tag_ha3");
        verify(servletResponse).setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT);
    }

    @Test
    public void testShouldReturnServiceUnavailableIfStateBecomingActive() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.BECOMING_ACTIVE);
        when(servletRequest.getRequestURI()).thenReturn("api/atlas/types");

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);

        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(servletResponse).sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
    }

    @Test
    public void testShouldNotRedirectAdminAPIs() throws IOException, ServletException {
        when(serviceState.getState()).thenReturn(ServiceState.ServiceStateValue.PASSIVE);
        when(servletRequest.getMethod()).thenReturn(HttpMethod.GET);
        when(servletRequest.getRequestURI()).
                thenReturn("api/atlas/admin/asmasn"); // any Admin URI is fine.

        ActiveServerFilter activeServerFilter = new ActiveServerFilter(activeInstanceState, serviceState);
        activeServerFilter.doFilter(servletRequest, servletResponse, filterChain);

        verify(filterChain).doFilter(servletRequest, servletResponse);
        verifyZeroInteractions(activeInstanceState);
    }
}