// Copyright 2017 The NXT Authors
//
// 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.

#include <gtest/gtest.h>

#include "backend/common/BitSetIterator.h"

// This is ANGLE's BitSetIterator_unittests.cpp file.

using namespace backend;

class BitSetIteratorTest : public testing::Test {
    protected:
        std::bitset<40> mStateBits;
};

// Simple iterator test.
TEST_F(BitSetIteratorTest, Iterator) {
    std::set<unsigned long> originalValues;
    originalValues.insert(2);
    originalValues.insert(6);
    originalValues.insert(8);
    originalValues.insert(35);

    for (unsigned long value : originalValues) {
        mStateBits.set(value);
    }

    std::set<unsigned long> readValues;
    for (unsigned long bit : IterateBitSet(mStateBits)) {
        EXPECT_EQ(1u, originalValues.count(bit));
        EXPECT_EQ(0u, readValues.count(bit));
        readValues.insert(bit);
    }

    EXPECT_EQ(originalValues.size(), readValues.size());
}

// Test an empty iterator.
TEST_F(BitSetIteratorTest, EmptySet) {
    // We don't use the FAIL gtest macro here since it returns immediately,
    // causing an unreachable code warning in MSVS
    bool sawBit = false;
    for (unsigned long bit : IterateBitSet(mStateBits)) {
        sawBit = true;
    }
    EXPECT_FALSE(sawBit);
}

// Test iterating a result of combining two bitsets.
TEST_F(BitSetIteratorTest, NonLValueBitset) {
    std::bitset<40> otherBits;

    mStateBits.set(1);
    mStateBits.set(2);
    mStateBits.set(3);
    mStateBits.set(4);

    otherBits.set(0);
    otherBits.set(1);
    otherBits.set(3);
    otherBits.set(5);

    std::set<unsigned long> seenBits;

    for (unsigned long bit : IterateBitSet(mStateBits & otherBits)) {
        EXPECT_EQ(0u, seenBits.count(bit));
        seenBits.insert(bit);
        EXPECT_TRUE(mStateBits[bit]);
        EXPECT_TRUE(otherBits[bit]);
    }

    EXPECT_EQ((mStateBits & otherBits).count(), seenBits.size());
}