// Copyright 2021 Google LLC
//
// 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 "util.hpp"

#include <flasher/mutate/asymmetric.hpp>
#include <flasher/ops.hpp>

#include <cstring>
#include <memory>
#include <optional>
#include <stdexcept>

#include <gmock/gmock.h>
#include <gtest/gtest.h>

namespace flasher
{
namespace ops
{

using testing::ElementsAre;
using testing::SizeIs;

class WriteTest : public OpTest<testing::NiceMock<MockOrFakeDevice>>
{
  protected:
    WriteTest()
    {
        fillFileInc(f, 0, 12);
        EXPECT_CALL(d, eraseBlocks).Times(0);
    }
};

TEST_F(WriteTest, InvalidOffset)
{
    EXPECT_THROW(write(d, /*dev_offset=*/13, f, /*file_offset=*/0, m,
                       /*max_size=*/0, /*stride_size=*/std::nullopt,
                       /*noread=*/false),
                 std::invalid_argument);
}

TEST_F(WriteTest, InvalidStride)
{
    EXPECT_THROW(write(d, /*dev_offset=*/0, f, /*file_offset=*/0, m,
                       /*max_size=*/0, /*stride_size=*/0, /*noread=*/false),
                 std::invalid_argument);
}

TEST_F(WriteTest, SimpleOverwrite)
{
    memset(f.data.data(), 0, f.data.size());
    EXPECT_NE(f.data, df.data);
    write(d, /*dev_offset=*/0, f, /*file_offset=*/0, m, /*max_size=*/20,
          /*stride_size=*/4, /*noread=*/false);
    EXPECT_EQ(f.data, df.data);
}

TEST_F(WriteTest, SimpleOverwriteNoRead)
{
    memset(f.data.data(), 0, f.data.size());
    EXPECT_NE(f.data, df.data);
    write(d, /*dev_offset=*/0, f, /*file_offset=*/0, m, /*max_size=*/20,
          /*stride_size=*/4, /*noread=*/true);
    EXPECT_EQ(f.data, df.data);
}

TEST_F(WriteTest, SmallFile)
{
    f.data.resize(4);
    memset(f.data.data(), 0, f.data.size());
    write(d, /*dev_offset=*/0, f, /*file_offset=*/0, m, /*max_size=*/20,
          /*stride_size=*/std::nullopt, /*noread=*/false);
    df.data.resize(4);
    EXPECT_EQ(f.data, df.data);
}

TEST_F(WriteTest, FileTooBig)
{
    fillFileInc(f, 0, 13);
    EXPECT_THROW(write(d, /*dev_offset=*/0, f, /*file_offset=*/0, m,
                       /*max_size=*/20, /*stride_size=*/std::nullopt,
                       /*noread=*/false),
                 std::runtime_error);
    EXPECT_THROW(write(d, /*dev_offset=*/0, f, /*file_offset=*/0, m,
                       /*max_size=*/20, /*stride_size=*/std::nullopt,
                       /*noread=*/true),
                 std::runtime_error);
}

TEST_F(WriteTest, ValidSubset)
{
    fillFileInc(f, 2, 10);
    memset(df.data.data(), 0xff, df.data.size());
    write(d, /*dev_offset=*/3, f, /*file_offset=*/1, m, /*max_size=*/5,
          /*stride_size=*/std::nullopt, /*noread=*/false);
    EXPECT_THAT(df.data, ElementsAre(0xff_b, 0xff_b, 0xff_b, 3_b, 4_b, 5_b, 6_b,
                                     7_b, 0xff_b, 0xff_b, 0xff_b, 0xff_b));
}

TEST_F(WriteTest, ValidSubsetNoRead)
{
    fillFileInc(f, 2, 10);
    memset(df.data.data(), 0xff, df.data.size());
    write(d, /*dev_offset=*/3, f, /*file_offset=*/1, m, /*max_size=*/5,
          /*stride_size=*/3, /*noread=*/true);
    EXPECT_THAT(df.data, ElementsAre(0xff_b, 0xff_b, 0xff_b, 3_b, 4_b, 5_b, 6_b,
                                     7_b, 0xff_b, 0xff_b, 0xff_b, 0xff_b));
}

TEST_F(WriteTest, TooBigSubset)
{
    fillFileInc(f, 2, 11);
    EXPECT_THROW(write(d, /*dev_offset=*/3, f, /*file_offset=*/1, m,
                       /*max_size=*/20, /*stride_size=*/std::nullopt,
                       /*noread=*/false),
                 std::runtime_error);
    EXPECT_THROW(write(d, /*dev_offset=*/3, f, /*file_offset=*/1, m,
                       /*max_size=*/20, /*stride_size=*/std::nullopt,
                       /*noread=*/true),
                 std::runtime_error);
}

TEST_F(WriteTest, MutateApplied)
{
    m.mutations.push_back(std::make_unique<mutate::Asymmetric>());
    memset(f.data.data(), 0, f.data.size());
    memset(df.data.data(), 0xff, df.data.size());
    write(d, /*dev_offset=*/1, f, /*file_offset=*/1, m, /*max_size=*/4,
          /*stride_size=*/std::nullopt, /*noread=*/false);
    EXPECT_THAT(df.data, ElementsAre(0xff_b, 1_b, 2_b, 3_b, 4_b, 0xff_b, 0xff_b,
                                     0xff_b, 0xff_b, 0xff_b, 0xff_b, 0xff_b));
}

TEST_F(WriteTest, OnlyNeededWrites)
{
    f.data = {3_b, 3_b, 3_b, 3_b, 3_b, 3_b, 3_b, 3_b};
    df.data = {3_b, 1_b, 2_b, 3_b, 3_b, 3_b, 4_b, 3_b};
    EXPECT_CALL(d, writeAt(SizeIs(1), 6));
    write(d, /*dev_offset=*/0, f, /*file_offset=*/0, m, /*max_size=*/8,
          /*stride_size=*/4, /*noread=*/false);
}

} // namespace ops
} // namespace flasher