#include <stdplus/str/buf.hpp>
#include <stdplus/str/cexpr.hpp>

#include <gtest/gtest.h>

namespace stdplus
{

static constexpr auto makeIncStr(std::size_t len)
{
    stdplus::StrBuf ret;
    auto ptr = ret.append(len);
    for (std::size_t i = 0; i < len; i++)
    {
        ptr[i] = 'A' + (i % 26);
    }
    return ret;
}

constexpr auto data = cexprSv<[]() { return makeIncStr(sizeof(StrBuf) + 10); }>;

TEST(StrBuf, BasicInline)
{
    StrBuf buf;
    EXPECT_EQ(buf.size(), 0);
    auto old_ptr = buf.begin();

    // Ensure that we inline small amounts of data only
    std::copy(data.begin(), data.begin() + 4, std::back_inserter(buf));
    EXPECT_EQ(buf.begin(), old_ptr);
    EXPECT_EQ(buf.size(), 4);
    EXPECT_EQ(std::string_view(data).substr(0, 4), buf);

    // Ensure that the max data size inline doesn't dynamically allocate
    constexpr std::size_t max_size = sizeof(StrBuf) - sizeof(std::size_t);
    buf.append(max_size - 4);
    EXPECT_EQ(buf.begin(), old_ptr);
    EXPECT_EQ(buf.size(), max_size);
}

TEST(StrBuf, DynamicAppend)
{
    constexpr std::size_t seg = 15;

    StrBuf buf;
    auto old_ptr = buf.begin();
    std::copy(data.begin(), data.begin() + seg, buf.append(seg));

    // Ensure that inline -> dynamic is working
    std::copy(data.begin() + seg, data.end(), buf.append(data.size() - seg));
    EXPECT_NE(buf.begin(), old_ptr);
    EXPECT_EQ(data, buf);
    EXPECT_EQ(data.size(), buf.size());

    // Ensure dynamic allocation is large enough to allow additional
    // small appends with no reallocation
    old_ptr = buf.begin();
    std::copy(data.begin(), data.begin() + seg, buf.append(seg));
    EXPECT_EQ(buf.begin(), old_ptr);
    EXPECT_EQ(data.size() + seg, buf.size());
    EXPECT_EQ(data.substr(0, seg), std::string_view{buf}.substr(data.size()));

    // Ensure new dynamic allocations copy
    std::copy(data.begin() + seg, data.end(), buf.append(data.size() - seg));
    EXPECT_NE(buf.begin(), old_ptr);
    EXPECT_EQ(data.size() << 1, buf.size());
    EXPECT_EQ(data, std::string_view{buf}.substr(0, data.size()));
    EXPECT_EQ(data, std::string_view{buf}.substr(data.size()));
}

TEST(StrBuf, CopiesInline)
{
    StrBuf buf1;
    buf1.append(1)[0] = 'a';
    StrBuf buf2 = buf1;
    EXPECT_EQ(buf1, buf2);
    buf1.append(1)[0] = 'b';
    StrBuf buf3 = buf1;
    EXPECT_EQ("ab", buf3);
    EXPECT_EQ("ab", buf1);
    EXPECT_EQ("a", buf2);
    buf3 = buf2;
    EXPECT_EQ("a", buf3);
    EXPECT_EQ("ab", buf1);
    EXPECT_EQ("a", buf2);
}

TEST(StrBuf, MoveInline)
{
    StrBuf buf1;
    buf1.append(1)[0] = 'a';
    StrBuf buf2 = std::move(buf1);
    EXPECT_EQ("a", std::string_view{buf2});
    buf2.append(1)[0] = 'b';
    // NOLINTNEXTLINE(clang-analyzer-cplusplus.Move)
    EXPECT_EQ(0, buf1.size());
    StrBuf buf3 = buf1;
    EXPECT_EQ(0, buf3.size());
    buf3 = std::move(buf2);
    // NOLINTNEXTLINE(clang-analyzer-cplusplus.Move)
    EXPECT_EQ(0, buf2.size());
    EXPECT_EQ("ab", std::string_view{buf3});
}

TEST(StrBuf, CopyInlToDyn)
{
    StrBuf buf1;
    buf1.append(1)[0] = 'a';
    StrBuf buf2;
    buf2.append(sizeof(StrBuf) + 10);
    buf2 = buf1;
    EXPECT_EQ("a", buf2);
}

TEST(StrBuf, MoveInlToDyn)
{
    StrBuf buf1;
    buf1.append(1)[0] = 'a';
    StrBuf buf2;
    buf2.append(sizeof(StrBuf) + 10);
    // NOLINTNEXTLINE(clang-analyzer-cplusplus.Move)
    buf2 = std::move(buf1);
    EXPECT_EQ("", buf1);
    EXPECT_EQ("a", buf2);
}

TEST(StrBuf, MoveDynToInl)
{
    StrBuf buf1;
    std::copy(data.begin(), data.end(), buf1.append(data.size()));
    StrBuf buf2;
    buf2.append(1)[0] = 'a';
    // NOLINTNEXTLINE(clang-analyzer-cplusplus.Move)
    buf2 = std::move(buf1);
    EXPECT_EQ("", buf1);
    EXPECT_EQ(data, buf2);
}

TEST(StrBuf, MoveDynToDyn)
{
    StrBuf buf1;
    std::copy(data.begin(), data.end(), buf1.append(data.size()));
    StrBuf buf2;
    buf2.append(data.size());
    // NOLINTNEXTLINE(clang-analyzer-cplusplus.Move)
    buf2 = std::move(buf1);
    EXPECT_EQ("", buf1);
    EXPECT_EQ(data, buf2);
}

TEST(StrBuf, CopyDynToInl)
{
    StrBuf buf1;
    buf1.append(data.size());
    buf1.clear();
    buf1.append(1)[0] = 'a';
    StrBuf buf2 = buf1;
    StrBuf buf3;
    buf3.append(1)[0] = 'b';
    buf3 = buf1;
    EXPECT_EQ("a", buf1);
    EXPECT_EQ("a", buf2);
    EXPECT_EQ("a", buf3);
}

TEST(StrBuf, CopyDynToDyn)
{
    StrBuf buf1;
    std::copy(data.begin(), data.end(), buf1.append(data.size()));
    std::copy(data.begin(), data.end(), buf1.append(data.size()));
    StrBuf buf2 = buf1;
    StrBuf buf3;
    std::copy(data.begin(), data.end(), buf3.append(data.size()));
    buf3 = buf1;
    EXPECT_EQ(buf2, buf1);
    EXPECT_EQ(buf3, buf1);
    buf3.append(1)[0] = 'a';
    buf1 = buf3;
    EXPECT_EQ(buf3, buf1);
}

} // namespace stdplus