/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 */

#include <cppunit/TestAssert.h>
#include <cppunit/TestFixture.h>
#include <cppunit/extensions/HelperMacros.h>

#include <o3tl/lru_map.hxx>

#include <o3tl/hash_combine.hxx>

using namespace ::o3tl;

class lru_map_test : public CppUnit::TestFixture
{
public:
    void testBaseUsage();
    void testReplaceKey();
    void testReplaceValue();
    void testLruRemoval();
    void testCustomHash();
    void testRemoveIf();
    void testChangeMaxSize();
    void testCustomItemSize();

    CPPUNIT_TEST_SUITE(lru_map_test);
    CPPUNIT_TEST(testBaseUsage);
    CPPUNIT_TEST(testReplaceKey);
    CPPUNIT_TEST(testReplaceValue);
    CPPUNIT_TEST(testLruRemoval);
    CPPUNIT_TEST(testCustomHash);
    CPPUNIT_TEST(testRemoveIf);
    CPPUNIT_TEST(testChangeMaxSize);
    CPPUNIT_TEST(testCustomItemSize);
    CPPUNIT_TEST_SUITE_END();
};

void lru_map_test::testBaseUsage()
{
    o3tl::lru_map<int, int> lru(10);
    lru.insert(std::make_pair<int, int>(1, 1));

    std::pair<int, int> pair;
    for (int i = 2; i < 7; i++)
    {
        pair.first = pair.second = i;
        lru.insert(pair);
    }

    CPPUNIT_ASSERT_EQUAL(size_t(6), lru.size());

    o3tl::lru_map<int, int>::const_iterator it;

    it = lru.find(2);
    CPPUNIT_ASSERT(it != lru.end());
    CPPUNIT_ASSERT_EQUAL(2, it->second);

    it = lru.find(5);
    CPPUNIT_ASSERT(it != lru.end());
    CPPUNIT_ASSERT_EQUAL(5, it->second);

    it = lru.find(0);
    CPPUNIT_ASSERT(bool(it == lru.end()));
}

void lru_map_test::testReplaceValue()
{
    o3tl::lru_map<int, int> lru(2);
    // check if map is empty
    CPPUNIT_ASSERT_EQUAL(size_t(0), lru.size());

    // check if inserting entry with same key replaces the value

    // inserting new entry
    lru.insert(std::make_pair<int, int>(1, 2));
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());
    CPPUNIT_ASSERT_EQUAL(2, lru.find(1)->second);

    // inserting new entry with key that already exists
    lru.insert(std::make_pair<int, int>(1, 4));
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());
    CPPUNIT_ASSERT_EQUAL(4, lru.find(1)->second);

    // inserting new entry
    lru.insert(std::make_pair<int, int>(2, 200));
    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());
    CPPUNIT_ASSERT_EQUAL(4, lru.find(1)->second);
    CPPUNIT_ASSERT_EQUAL(200, lru.find(2)->second);

    // check if insert with same key, moves the entry back of the lru queue

    // inserting new entry with key that already exists
    lru.insert(std::make_pair<int, int>(1, 6));
    // inserting new entry, lru removed
    lru.insert(std::make_pair<int, int>(3, 300));

    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());
    CPPUNIT_ASSERT_EQUAL(6, lru.find(1)->second);
    CPPUNIT_ASSERT_EQUAL(300, lru.find(3)->second);
}

void lru_map_test::testReplaceKey()
{
    o3tl::lru_map<int, int> lru(2);

    // inserting new entry
    lru.insert(std::make_pair<int, int>(1, 100));
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());
    CPPUNIT_ASSERT_EQUAL(100, lru.find(1)->second);
    CPPUNIT_ASSERT(bool(lru.find(2) == lru.end()));
    CPPUNIT_ASSERT(bool(lru.find(3) == lru.end()));

    // inserting new entry
    lru.insert(std::make_pair<int, int>(2, 200));
    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());
    CPPUNIT_ASSERT_EQUAL(100, lru.find(1)->second);
    CPPUNIT_ASSERT_EQUAL(200, lru.find(2)->second);
    CPPUNIT_ASSERT(bool(lru.find(3) == lru.end()));

    // inserting new entry, lru entry is removed
    lru.insert(std::make_pair<int, int>(3, 300));
    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());
    CPPUNIT_ASSERT(bool(lru.find(1) == lru.end()));
    CPPUNIT_ASSERT_EQUAL(200, lru.find(2)->second);
    CPPUNIT_ASSERT_EQUAL(300, lru.find(3)->second);

    // inserting new entry, lru entry is removed
    std::pair<int, int> pair(4, 400);
    lru.insert(pair);
    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());
    CPPUNIT_ASSERT(bool(lru.find(1) == lru.end()));
    CPPUNIT_ASSERT(bool(lru.find(2) == lru.end()));
    CPPUNIT_ASSERT_EQUAL(300, lru.find(3)->second);
    CPPUNIT_ASSERT_EQUAL(400, lru.find(4)->second);
}

void lru_map_test::testLruRemoval()
{
    o3tl::lru_map<int, int> lru(5);
    CPPUNIT_ASSERT_EQUAL(size_t(0), lru.size());

    // fill up...
    lru.insert(std::make_pair<int, int>(1, 100));
    lru.insert(std::make_pair<int, int>(2, 200));
    lru.insert(std::make_pair<int, int>(3, 300));
    lru.insert(std::make_pair<int, int>(4, 400));
    lru.insert(std::make_pair<int, int>(5, 500));
    CPPUNIT_ASSERT_EQUAL(size_t(5), lru.size());
    CPPUNIT_ASSERT_EQUAL(100, lru.find(1)->second);
    CPPUNIT_ASSERT_EQUAL(200, lru.find(2)->second);
    CPPUNIT_ASSERT_EQUAL(300, lru.find(3)->second);
    CPPUNIT_ASSERT_EQUAL(400, lru.find(4)->second);
    CPPUNIT_ASSERT_EQUAL(500, lru.find(5)->second);

    // add one more entry - lru entry should be removed
    lru.insert(std::make_pair<int, int>(6, 600));

    CPPUNIT_ASSERT_EQUAL(size_t(5), lru.size());
    CPPUNIT_ASSERT_EQUAL(200, lru.find(2)->second);
    CPPUNIT_ASSERT_EQUAL(300, lru.find(3)->second);
    CPPUNIT_ASSERT_EQUAL(400, lru.find(4)->second);
    CPPUNIT_ASSERT_EQUAL(500, lru.find(5)->second);
    CPPUNIT_ASSERT_EQUAL(600, lru.find(6)->second);

    // access the lru entry to put it at the back of the lru queue
    lru.find(2);
    // add new entry - lru entry should be removed
    lru.insert(std::make_pair<int, int>(7, 700));

    CPPUNIT_ASSERT_EQUAL(size_t(5), lru.size());
    CPPUNIT_ASSERT_EQUAL(200, lru.find(2)->second);
    CPPUNIT_ASSERT_EQUAL(400, lru.find(4)->second);
    CPPUNIT_ASSERT_EQUAL(500, lru.find(5)->second);
    CPPUNIT_ASSERT_EQUAL(600, lru.find(6)->second);
    CPPUNIT_ASSERT_EQUAL(700, lru.find(7)->second);
}

namespace
{
struct TestClassKey
{
    int mA;
    int mB;

    TestClassKey(int a, int b)
        : mA(a)
        , mB(b)
    {
    }

    bool operator==(TestClassKey const& aOther) const { return mA == aOther.mA && mB == aOther.mB; }
};

struct TestClassKeyHashFunction
{
    std::size_t operator()(TestClassKey const& aKey) const
    {
        std::size_t seed = 0;
        o3tl::hash_combine(seed, aKey.mA);
        o3tl::hash_combine(seed, aKey.mB);
        return seed;
    }
};
}

void lru_map_test::testCustomHash()
{
    // check lru_map with custom hash function
    o3tl::lru_map<TestClassKey, int, TestClassKeyHashFunction> lru(2);
    CPPUNIT_ASSERT_EQUAL(size_t(0), lru.size());

    lru.insert(std::make_pair<TestClassKey, int>(TestClassKey(1, 1), 2));
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());

    lru.insert(std::make_pair<TestClassKey, int>(TestClassKey(1, 1), 7));
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());

    lru.insert(std::make_pair<TestClassKey, int>(TestClassKey(1, 2), 9));
    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());

    CPPUNIT_ASSERT(bool(lru.end() == lru.find(TestClassKey(0, 0)))); // non existent
    CPPUNIT_ASSERT_EQUAL(7, lru.find(TestClassKey(1, 1))->second);
    CPPUNIT_ASSERT_EQUAL(9, lru.find(TestClassKey(1, 2))->second);

    lru.insert(std::make_pair<TestClassKey, int>(TestClassKey(2, 1), 13));

    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());

    CPPUNIT_ASSERT(bool(lru.end() == lru.find(TestClassKey(1, 1))));
    CPPUNIT_ASSERT_EQUAL(9, lru.find(TestClassKey(1, 2))->second);
    CPPUNIT_ASSERT_EQUAL(13, lru.find(TestClassKey(2, 1))->second);
}

void lru_map_test::testRemoveIf()
{
    typedef o3tl::lru_map<int, int> IntMap;
    typedef IntMap::key_value_pair_t IntMapPair;
    struct limit_except : public std::exception
    {
    };

    IntMap lru(6);
    int i = 0;
    for (; i < 8; i++)
        lru.insert({ i, i });
    CPPUNIT_ASSERT_EQUAL(size_t(6), lru.size());
    // now contains 7..2

    // remove everything < 4 from the back
    try
    {
        lru.remove_if([](IntMapPair const& rPair) {
            if (rPair.first >= 4)
                throw limit_except();
            return true;
        });
        CPPUNIT_ASSERT(false); // not reached
    }
    catch (limit_except&)
    {
        // contains 7..4
        CPPUNIT_ASSERT_EQUAL(size_t(4), lru.size());
    }

    // remove all even numbers
    lru.remove_if([](IntMapPair const& rPair) { return (0 == rPair.first % 2); });
    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());
    // contains 7, 5

    lru.insert({ 5, 5 });
    // contains 5, 7

    i = 5;
    for (auto& rPair : lru)
    {
        CPPUNIT_ASSERT_EQUAL(i, rPair.first);
        i += 2;
    }

    // remove the first item
    lru.remove_if([](IntMapPair const& rPair) { return (rPair.first == 5); });
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());

    // remove the only item
    lru.remove_if([](IntMapPair const& rPair) { return (rPair.first == 7); });
    CPPUNIT_ASSERT_EQUAL(size_t(0), lru.size());
}

void lru_map_test::testChangeMaxSize()
{
    o3tl::lru_map<int, int> lru(3);
    CPPUNIT_ASSERT_EQUAL(size_t(0), lru.size());
    lru.insert({ 0, 0 });
    lru.insert({ 1, 1 });
    lru.insert({ 2, 2 });
    CPPUNIT_ASSERT_EQUAL(size_t(3), lru.size());
    lru.setMaxSize(1);
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());
}

void lru_map_test::testCustomItemSize()
{
    struct cost_is_value
    {
        size_t operator()(int i) { return i; };
    };
    o3tl::lru_map<int, int, std::hash<int>, std::equal_to<int>, cost_is_value> lru(5);
    lru.insert({ 1, 1 });
    lru.insert({ 2, 2 });
    // Adding this one will remove the first one, since then the total
    // cost would be 6, more than the maximum 5.
    lru.insert({ 3, 3 });
    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.size());
    CPPUNIT_ASSERT_EQUAL(size_t(5), lru.total_size());
    // Drop the last item.
    lru.remove_if([](std::pair<int, int> i) { return i.first == 3; });
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());
    CPPUNIT_ASSERT_EQUAL(size_t(2), lru.total_size());
    // This should drop everything except for keeping this one (an exception that
    // keeps the last item inserted regardless of limit).
    lru.insert({ 4, 4 });
    CPPUNIT_ASSERT_EQUAL(size_t(1), lru.size());
    CPPUNIT_ASSERT_EQUAL(size_t(4), lru.total_size());
    lru.clear();
    CPPUNIT_ASSERT_EQUAL(size_t(0), lru.size());
    CPPUNIT_ASSERT_EQUAL(size_t(0), lru.total_size());
}

CPPUNIT_TEST_SUITE_REGISTRATION(lru_map_test);

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