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 * to you under the Apache License, Version 2.0 (the
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 *   http://www.apache.org/licenses/LICENSE-2.0
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 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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 * This software consists of voluntary contributions made by many
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package org.apache.hc.client5.http.impl.cache;

import java.util.Date;

import org.apache.hc.client5.http.cache.HttpCacheEntry;
import org.apache.hc.client5.http.utils.DateUtils;
import org.apache.hc.core5.http.Header;
import org.apache.hc.core5.http.HttpHost;
import org.apache.hc.core5.http.HttpRequest;
import org.apache.hc.core5.http.HttpVersion;
import org.apache.hc.core5.http.message.BasicHeader;
import org.apache.hc.core5.http.message.BasicHttpRequest;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

public class TestCachedResponseSuitabilityChecker {

    private Date now;
    private Date elevenSecondsAgo;
    private Date tenSecondsAgo;
    private Date nineSecondsAgo;

    private HttpHost host;
    private HttpRequest request;
    private HttpCacheEntry entry;
    private CachedResponseSuitabilityChecker impl;

    @Before
    public void setUp() {
        now = new Date();
        elevenSecondsAgo = new Date(now.getTime() - 11 * 1000L);
        tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
        nineSecondsAgo = new Date(now.getTime() - 9 * 1000L);

        host = new HttpHost("foo.example.com");
        request = new BasicHttpRequest("GET", "/foo", HttpVersion.HTTP_1_1);
        entry = HttpTestUtils.makeCacheEntry();

        impl = new CachedResponseSuitabilityChecker(CacheConfig.DEFAULT);
    }

    private HttpCacheEntry getEntry(final Header[] headers) {
        return HttpTestUtils.makeCacheEntry(elevenSecondsAgo, nineSecondsAgo, headers);
    }

    @Test
    public void testNotSuitableIfContentLengthHeaderIsWrong() {
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","1")
        };
        entry = getEntry(headers);
        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableIfCacheEntryIsFresh() {
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertTrue(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testNotSuitableIfCacheEntryIsNotFresh() {
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=5"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testNotSuitableIfRequestHasNoCache() {
        request.addHeader("Cache-Control", "no-cache");
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testNotSuitableIfAgeExceedsRequestMaxAge() {
        request.addHeader("Cache-Control", "max-age=10");
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableIfFreshAndAgeIsUnderRequestMaxAge() {
        request.addHeader("Cache-Control", "max-age=15");
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertTrue(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableIfFreshAndFreshnessLifetimeGreaterThanRequestMinFresh() {
        request.addHeader("Cache-Control", "min-fresh=10");
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertTrue(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testNotSuitableIfFreshnessLifetimeLessThanRequestMinFresh() {
        request.addHeader("Cache-Control", "min-fresh=10");
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=15"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableEvenIfStaleButPermittedByRequestMaxStale() {
        request.addHeader("Cache-Control", "max-stale=10");
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=5"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertTrue(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testNotSuitableIfStaleButTooStaleForRequestMaxStale() {
        request.addHeader("Cache-Control", "max-stale=2");
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=5"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }


    @Test
    public void testMalformedCacheControlMaxAgeRequestHeaderCausesUnsuitableEntry() {
        request.addHeader(new BasicHeader("Cache-Control", "max-age=foo"));
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testMalformedCacheControlMinFreshRequestHeaderCausesUnsuitableEntry() {
        request.addHeader(new BasicHeader("Cache-Control", "min-fresh=foo"));
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);
        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableIfCacheEntryIsHeuristicallyFreshEnough() {
        final Date oneSecondAgo = new Date(now.getTime() - 1 * 1000L);
        final Date twentyOneSecondsAgo = new Date(now.getTime() - 21 * 1000L);

        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(oneSecondAgo)),
                new BasicHeader("Last-Modified", DateUtils.formatDate(twentyOneSecondsAgo)),
                new BasicHeader("Content-Length", "128")
        };

        entry = HttpTestUtils.makeCacheEntry(oneSecondAgo, oneSecondAgo, headers);

        final CacheConfig config = CacheConfig.custom()
            .setHeuristicCachingEnabled(true)
            .setHeuristicCoefficient(0.1f).build();
        impl = new CachedResponseSuitabilityChecker(config);

        Assert.assertTrue(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableIfCacheEntryIsHeuristicallyFreshEnoughByDefault() {
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Content-Length", "128")
        };

        entry = getEntry(headers);

        final CacheConfig config = CacheConfig.custom()
            .setHeuristicCachingEnabled(true)
            .setHeuristicDefaultLifetime(20)
            .build();
        impl = new CachedResponseSuitabilityChecker(config);

        Assert.assertTrue(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableIfRequestMethodisHEAD() {
        final HttpRequest headRequest = new BasicHttpRequest("HEAD", "/foo", HttpVersion.HTTP_1_1);
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = getEntry(headers);

        Assert.assertTrue(impl.canCachedResponseBeUsed(host, headRequest, entry, now));
    }

    @Test
    public void testNotSuitableIfRequestMethodIsGETAndEntryResourceIsNull() {
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = HttpTestUtils.makeHeadCacheEntry(headers);

        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testNotSuitableForGETIfEntryDoesNotSpecifyARequestMethodOrEntity() {
        impl = new CachedResponseSuitabilityChecker(CacheConfig.custom().build());
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = HttpTestUtils.makeCacheEntryWithNoRequestMethodOrEntity(headers);

        Assert.assertFalse(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableForGETIfEntryDoesNotSpecifyARequestMethodButContainsEntity() {
        impl = new CachedResponseSuitabilityChecker(CacheConfig.custom().build());
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = HttpTestUtils.makeCacheEntryWithNoRequestMethod(headers);

        Assert.assertTrue(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableForGETIfHeadResponseCachingEnabledAndEntryDoesNotSpecifyARequestMethodButContains204Response() {
        impl = new CachedResponseSuitabilityChecker(CacheConfig.custom().build());
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600")
        };
        entry = HttpTestUtils.make204CacheEntryWithNoRequestMethod(headers);

        Assert.assertTrue(impl.canCachedResponseBeUsed(host, request, entry, now));
    }

    @Test
    public void testSuitableForHEADIfHeadResponseCachingEnabledAndEntryDoesNotSpecifyARequestMethod() {
        final HttpRequest headRequest = new BasicHttpRequest("HEAD", "/foo", HttpVersion.HTTP_1_1);
        impl = new CachedResponseSuitabilityChecker(CacheConfig.custom().build());
        final Header[] headers = {
                new BasicHeader("Date", DateUtils.formatDate(tenSecondsAgo)),
                new BasicHeader("Cache-Control", "max-age=3600"),
                new BasicHeader("Content-Length","128")
        };
        entry = HttpTestUtils.makeHeadCacheEntryWithNoRequestMethod(headers);

        Assert.assertTrue(impl.canCachedResponseBeUsed(host, headRequest, entry, now));
    }
}
