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#include "googletest.h"

#include "mockmutex.h"
#include "mockfilepathstorage.h"

#include <stringcache.h>

#include <utils/smallstringio.h>

namespace {

using ClangBackEnd::StringCacheException;

using uint64 = unsigned long long;

using Utils::compare;
using Utils::reverseCompare;
using ClangBackEnd::findInSorted;
using StorageIdFunction = std::function<int(Utils::SmallStringView)>;
using StorageStringFunction = std::function<Utils::PathString(int)>;

using Cache = ClangBackEnd::StringCache<Utils::PathString,
                                        int,
                                        NiceMock<MockMutex>,
                                        decltype(&Utils::reverseCompare),
                                        Utils::reverseCompare>;
using CacheEntries = Cache::CacheEntries;

class StringCache : public testing::Test
{
protected:
    void SetUp();

protected:
    NiceMock<MockFilePathStorage> mockStorage;
    StorageIdFunction mockStorageFetchDirectyId = [&] (Utils::SmallStringView string) {
        return mockStorage.fetchDirectoryId(string);
    };
    StorageStringFunction mockStorageFetchDirectyPath = [&] (int id) {
        return mockStorage.fetchDirectoryPath(id);
    };
    Cache cache;
    NiceMock<MockMutex> &mockMutex = cache.mutex();
    Utils::PathString filePath1{"/file/pathOne"};
    Utils::PathString filePath2{"/file/pathTwo"};
    Utils::PathString filePath3{"/file/pathThree"};
    Utils::PathString filePath4{"/file/pathFour"};
    Utils::PathString filePath5{"/file/pathFife"};
    Utils::PathStringVector filePaths{filePath1,
                                      filePath2,
                                      filePath3,
                                      filePath4,
                                      filePath5};
    Utils::PathStringVector reverseFilePaths{filePath1,
                                             filePath2,
                                             filePath3,
                                             filePath4,
                                             filePath5};
};

TEST_F(StringCache, AddFilePath)
{
    auto id = cache.stringId(filePath1);

    ASSERT_THAT(id, 0);
}

TEST_F(StringCache, AddSecondFilePath)
{
    cache.stringId(filePath1);

    auto id = cache.stringId(filePath2);

    ASSERT_THAT(id, 1);
}

TEST_F(StringCache, AddDuplicateFilePath)
{
    cache.stringId(filePath1);

    auto id = cache.stringId(filePath1);

    ASSERT_THAT(id, 0);
}

TEST_F(StringCache, AddDuplicateFilePathBetweenOtherEntries)
{
    cache.stringId(filePath1);
    cache.stringId(filePath2);
    cache.stringId(filePath3);
    cache.stringId(filePath4);

    auto id = cache.stringId(filePath3);

    ASSERT_THAT(id, 2);
}

TEST_F(StringCache, ThrowForGettingPathForNoEntry)
{
    EXPECT_ANY_THROW(cache.string(0));
}

TEST_F(StringCache, GetFilePathForIdWithOneEntry)
{
    cache.stringId(filePath1);

    auto filePath = cache.string(0);

    ASSERT_THAT(filePath, filePath1);
}

TEST_F(StringCache, GetFilePathForIdWithSomeEntries)
{
    cache.stringId(filePath1);
    cache.stringId(filePath2);
    cache.stringId(filePath3);
    cache.stringId(filePath4);

    auto filePath = cache.string(2);

    ASSERT_THAT(filePath, filePath3);
}

TEST_F(StringCache, GetAllFilePaths)
{
    cache.stringId(filePath1);
    cache.stringId(filePath2);
    cache.stringId(filePath3);
    cache.stringId(filePath4);

    const auto &filePaths = cache.strings({0, 1, 2, 3});

    ASSERT_THAT(filePaths, ElementsAre(filePath1, filePath2, filePath3, filePath4));
}

TEST_F(StringCache, AddFilePaths)
{
    auto ids = cache.stringIds({filePath1, filePath2, filePath3, filePath4});

    ASSERT_THAT(ids, ElementsAre(0, 1, 2, 3));
}

TEST_F(StringCache, IsEmpty)
{
    auto isEmpty = cache.isEmpty();

    ASSERT_TRUE(isEmpty);
}

TEST_F(StringCache, IsNotEmpty)
{
    cache.stringId(filePath1);

    auto isEmpty = cache.isEmpty();

    ASSERT_FALSE(isEmpty);
}

TEST_F(StringCache, PopulateWithEmptyVector)
{
    CacheEntries entries;

    cache.uncheckedPopulate(std::move(entries));

    ASSERT_TRUE(cache.isEmpty());
}

TEST_F(StringCache, IsNotEmptyAfterPopulateWithSomeEntries)
{
    CacheEntries entries{{filePath1.clone(), 0},
                         {filePath2.clone(), 1},
                         {filePath3.clone(), 2},
                         {filePath4.clone(), 3}};

    cache.uncheckedPopulate(std::move(entries));

    ASSERT_TRUE(!cache.isEmpty());
}

TEST_F(StringCache, GetEntryAfterPopulateWithSomeEntries)
{
    CacheEntries entries{{filePath1.clone(), 0},
                         {filePath2.clone(), 1},
                         {filePath3.clone(), 2},
                         {filePath4.clone(), 3}};
    cache.uncheckedPopulate(std::move(entries));

    auto string = cache.string(2);

    ASSERT_THAT(string, filePath3);
}

TEST_F(StringCache, EntriesHaveUniqueIds)
{
    CacheEntries entries{{filePath1.clone(), 0},
                         {filePath2.clone(), 1},
                         {filePath3.clone(), 2},
                         {filePath4.clone(), 2}};

    ASSERT_THROW(cache.populate(std::move(entries)), StringCacheException);
}

TEST_F(StringCache, IdsAreHigherLowerEntriesSize)
{
    CacheEntries entries{{filePath1.clone(), 0},
                         {filePath2.clone(), 1},
                         {filePath3.clone(), 4},
                         {filePath4.clone(), 3}};

    ASSERT_THROW(cache.populate(std::move(entries)), std::out_of_range);
}

TEST_F(StringCache, MultipleEntries)
{
    CacheEntries entries{{filePath1.clone(), 0},
                         {filePath1.clone(), 1},
                         {filePath3.clone(), 2},
                         {filePath4.clone(), 3}};

    ASSERT_THROW(cache.populate(std::move(entries)), StringCacheException);
}

TEST_F(StringCache, DontFindInSorted)
{
    auto found = findInSorted(filePaths.cbegin(), filePaths.cend(), "/file/pathFoo", compare);

    ASSERT_FALSE(found.wasFound);
}

TEST_F(StringCache, FindInSortedOne)
{
    auto found = findInSorted(filePaths.cbegin(), filePaths.cend(), "/file/pathOne", compare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, FindInSortedTwo)
{
    auto found = findInSorted(filePaths.cbegin(), filePaths.cend(), "/file/pathTwo", compare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, FindInSortedTree)
{
    auto found = findInSorted(filePaths.cbegin(), filePaths.cend(), "/file/pathThree", compare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, FindInSortedFour)
{
    auto found = findInSorted(filePaths.cbegin(), filePaths.cend(), "/file/pathFour", compare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, FindInSortedFife)
{
    auto found = findInSorted(filePaths.cbegin(), filePaths.cend(), "/file/pathFife", compare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, DontFindInSortedReverse)
{
    auto found = findInSorted(reverseFilePaths.cbegin(), reverseFilePaths.cend(), "/file/pathFoo", reverseCompare);

    ASSERT_FALSE(found.wasFound);
}

TEST_F(StringCache, FindInSortedOneReverse)
{
    auto found = findInSorted(reverseFilePaths.cbegin(), reverseFilePaths.cend(), "/file/pathOne", reverseCompare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, FindInSortedTwoReverse)
{
    auto found = findInSorted(reverseFilePaths.cbegin(), reverseFilePaths.cend(), "/file/pathTwo", reverseCompare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, FindInSortedTreeReverse)
{
    auto found = findInSorted(reverseFilePaths.cbegin(), reverseFilePaths.cend(), "/file/pathThree", reverseCompare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, FindInSortedFourReverse)
{
    auto found = findInSorted(reverseFilePaths.cbegin(), reverseFilePaths.cend(), "/file/pathFour", reverseCompare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, FindInSortedFifeReverse)
{
    auto found = findInSorted(reverseFilePaths.cbegin(), reverseFilePaths.cend(), "/file/pathFife", reverseCompare);

    ASSERT_TRUE(found.wasFound);
}

TEST_F(StringCache, StringIdIsReadAndWriteLockedForUnknownEntry)
{
    InSequence s;

    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());
    EXPECT_CALL(mockMutex, lock());
    EXPECT_CALL(mockMutex, unlock());

    cache.stringId("foo");
}

TEST_F(StringCache, StringIdWithStorageFunctionIsReadAndWriteLockedForUnknownEntry)
{
    InSequence s;

    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());
    EXPECT_CALL(mockMutex, lock());
    EXPECT_CALL(mockStorage, fetchDirectoryId(Eq("foo")));
    EXPECT_CALL(mockMutex, unlock());

    cache.stringId("foo", mockStorageFetchDirectyId);
}

TEST_F(StringCache, StringIdWithStorageFunctionIsReadLockedForKnownEntry)
{
    InSequence s;
    cache.stringId("foo", mockStorageFetchDirectyId);

    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());
    EXPECT_CALL(mockMutex, lock()).Times(0);
    EXPECT_CALL(mockStorage, fetchDirectoryId(Eq("foo"))).Times(0);
    EXPECT_CALL(mockMutex, unlock()).Times(0);

    cache.stringId("foo", mockStorageFetchDirectyId);
}

TEST_F(StringCache, StringIdIsReadLockedForKnownEntry)
{
    cache.stringId("foo");

    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());
    EXPECT_CALL(mockMutex, lock()).Times(0);
    EXPECT_CALL(mockMutex, unlock()).Times(0);

    cache.stringId("foo");
}

TEST_F(StringCache, StringIdsIsLocked)
{
    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());

    cache.stringIds({"foo"});
}

TEST_F(StringCache, StringIsLocked)
{
    auto id = cache.stringId("foo");

    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());

    cache.string(id);
}

TEST_F(StringCache, StringsIsLocked)
{
    auto ids = cache.stringIds({"foo", "bar"});

    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());

    cache.strings(ids);
}

TEST_F(StringCache, StringWithStorageFunctionIsReadAndWriteLockedForUnknownId)
{
    InSequence s;

    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());
    EXPECT_CALL(mockMutex, lock());
    EXPECT_CALL(mockStorage, fetchDirectoryPath(Eq(41)));
    EXPECT_CALL(mockMutex, unlock());

    cache.string(41, mockStorageFetchDirectyPath);
}

TEST_F(StringCache, StringWithStorageFunctionIsReadLockedForKnownId)
{
    InSequence s;
    cache.string(41, mockStorageFetchDirectyPath);

    EXPECT_CALL(mockMutex, lock_shared());
    EXPECT_CALL(mockMutex, unlock_shared());
    EXPECT_CALL(mockMutex, lock()).Times(0);
    EXPECT_CALL(mockStorage, fetchDirectoryPath(Eq(41))).Times(0);
    EXPECT_CALL(mockMutex, unlock()).Times(0);

    cache.string(41, mockStorageFetchDirectyPath);
}

TEST_F(StringCache, StringIdWithStorageFunctionWhichHasNoEntryIsCallingStorageFunction)
{
    EXPECT_CALL(mockStorage, fetchDirectoryId(Eq("foo")));

    cache.stringId("foo", mockStorageFetchDirectyId);
}

TEST_F(StringCache, StringIdWithStorageFunctionWhichHasEntryIsNotCallingStorageFunction)
{
    cache.stringId("foo", mockStorageFetchDirectyId);

    EXPECT_CALL(mockStorage, fetchDirectoryId(Eq("foo"))).Times(0);

    cache.stringId("foo", mockStorageFetchDirectyId);
}

TEST_F(StringCache, IndexOfStringIdWithStorageFunctionWhichHasEntry)
{
    cache.stringId("foo", mockStorageFetchDirectyId);

    auto index = cache.stringId("foo", mockStorageFetchDirectyId);

    ASSERT_THAT(index, 42);
}

TEST_F(StringCache, IndexOfStringIdWithStorageFunctionWhichHasNoEntry)
{
    auto index = cache.stringId("foo", mockStorageFetchDirectyId);

    ASSERT_THAT(index, 42);
}

TEST_F(StringCache, GetEntryByIndexAfterInsertingByCustomIndex)
{
    auto index = cache.stringId("foo", mockStorageFetchDirectyId);

    auto string = cache.string(index, mockStorageFetchDirectyPath);

    ASSERT_THAT(string, Eq("foo"));
}

TEST_F(StringCache, CallFetchDirectoryPathForLowerIndex)
{
    auto index = cache.stringId("foo", mockStorageFetchDirectyId);

    EXPECT_CALL(mockStorage, fetchDirectoryPath(Eq(index - 1)));

    cache.string(index - 1, mockStorageFetchDirectyPath);
}

TEST_F(StringCache, CallFetchDirectoryPathForUnknownIndex)
{
    EXPECT_CALL(mockStorage, fetchDirectoryPath(Eq(0)));

    cache.string(0, mockStorageFetchDirectyPath);
}

TEST_F(StringCache, FetchDirectoryPathForUnknownIndex)
{
    auto string = cache.string(41, mockStorageFetchDirectyPath);

    ASSERT_THAT(string, Eq("bar"));
}

void StringCache::SetUp()
{
    std::sort(filePaths.begin(), filePaths.end(), [] (auto &f, auto &l) { return compare(f, l) < 0;});
    std::sort(reverseFilePaths.begin(), reverseFilePaths.end(), [] (auto &f, auto &l) { return reverseCompare(f, l) < 0;});

    ON_CALL(mockStorage, fetchDirectoryId(Eq("foo")))
            .WillByDefault(Return(42));
    ON_CALL(mockStorage, fetchDirectoryPath(41))
            .WillByDefault(Return(Utils::PathString("bar")));
}
}