/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed 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 android.core;

import android.test.AndroidTestCase;
import org.apache.http.util.CharArrayBuffer;

import android.net.http.Headers;
import android.util.Log;
import android.webkit.CacheManager;
import android.webkit.CacheManager.CacheResult;

import java.lang.reflect.Method;

public class HttpHeaderTest extends AndroidTestCase {

    static final String LAST_MODIFIED = "Last-Modified: Fri, 18 Jun 2010 09:56:47 GMT";
    static final String CACHE_CONTROL_MAX_AGE = "Cache-Control:max-age=15";
    static final String CACHE_CONTROL_PRIVATE = "Cache-Control: private";
    static final String CACHE_CONTROL_COMPOUND = "Cache-Control: no-cache, max-age=200000";
    static final String CACHE_CONTROL_COMPOUND2 = "Cache-Control: max-age=200000, no-cache";

    /**
     * Tests that cache control header supports multiple instances of the header,
     * according to HTTP specification.
     *
     * The HTTP specification states the following about the fields:
     * Multiple message-header fields with the same field-name MAY be present
     * in a message if and only if the entire field-value for that header field
     * is defined as a comma-separated list [i.e., #(values)]. It MUST be
     * possible to combine the multiple header fields into one "field-name:
     * field-value" pair, without changing the semantics of the message, by
     * appending each subsequent field-value to the first, each separated by a
     * comma. The order in which header fields with the same field-name are
     * received is therefore significant to the interpretation of the combined
     * field value, and thus a proxy MUST NOT change the order of these field
     * values when a message is forwarded.
     */
    public void testCacheControl() throws Exception {
        Headers h = new Headers();
        CharArrayBuffer buffer = new CharArrayBuffer(64);

        buffer.append(CACHE_CONTROL_MAX_AGE);
        h.parseHeader(buffer);

        buffer.clear();
        buffer.append(LAST_MODIFIED);
        h.parseHeader(buffer);
        assertEquals("max-age=15", h.getCacheControl());

        buffer.clear();
        buffer.append(CACHE_CONTROL_PRIVATE);
        h.parseHeader(buffer);
        assertEquals("max-age=15,private", h.getCacheControl());
    }

    // Test that cache behaves correctly when receiving a compund
    // cache-control statement containing no-cache and max-age argument.
    //
    // If a cache control header contains both a max-age arument and
    // a no-cache argument the max-age argument should be ignored.
    // The resource can be cached, but a validity check must be done on
    // every request. Test case checks that the expiry time is 0 for
    // this item, so item will be validated on subsequent requests.
    public void testCacheControlMultipleArguments() throws Exception {
        // get private method CacheManager.parseHeaders()
        Method m = CacheManager.class.getDeclaredMethod("parseHeaders",
                new Class[] {int.class, Headers.class, String.class});
        m.setAccessible(true);

        // create indata
        Headers h = new Headers();
        CharArrayBuffer buffer = new CharArrayBuffer(64);
        buffer.append(CACHE_CONTROL_COMPOUND);
        h.parseHeader(buffer);

        CacheResult c = (CacheResult)m.invoke(null, 200, h, "text/html");

        // Check that expires is set to 0, to ensure that no-cache has overridden
        // the max-age argument
        assertEquals(0, c.getExpires());

        // check reverse order
        buffer.clear();
        buffer.append(CACHE_CONTROL_COMPOUND2);
        h.parseHeader(buffer);

        c = (CacheResult)m.invoke(null, 200, h, "text/html");
        assertEquals(0, c.getExpires());
    }
}