// Copyright 2014 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <string>

#include <brillo/any.h>
#include <gtest/gtest.h>

using brillo::GetTypeTag;
using brillo::internal_details::Buffer;

TEST(Buffer, Empty) {
  Buffer buffer;
  EXPECT_TRUE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kExternal, buffer.storage_);
  EXPECT_EQ(nullptr, buffer.GetDataPtr());
}

TEST(Buffer, Store_Int) {
  Buffer buffer;
  buffer.Assign(2);
  EXPECT_FALSE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kContained, buffer.storage_);
  EXPECT_STREQ(GetTypeTag<int>(), buffer.GetDataPtr()->GetTypeTag());
}

TEST(Buffer, Store_Double) {
  Buffer buffer;
  buffer.Assign(2.3);
  EXPECT_FALSE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kContained, buffer.storage_);
  EXPECT_STREQ(GetTypeTag<double>(), buffer.GetDataPtr()->GetTypeTag());
}

TEST(Buffer, Store_Pointers) {
  Buffer buffer;
  // nullptr
  buffer.Assign(nullptr);
  EXPECT_FALSE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kContained, buffer.storage_);
  EXPECT_STREQ(GetTypeTag<std::nullptr_t>(), buffer.GetDataPtr()->GetTypeTag());

  // char *
  buffer.Assign("abcd");
  EXPECT_FALSE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kContained, buffer.storage_);
  EXPECT_STREQ(GetTypeTag<const char*>(), buffer.GetDataPtr()->GetTypeTag());

  // pointer to non-trivial object
  class NonTrivial {
   public:
    virtual ~NonTrivial() {}
  } non_trivial;
  buffer.Assign(&non_trivial);
  EXPECT_FALSE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kContained, buffer.storage_);
  EXPECT_STREQ(GetTypeTag<NonTrivial*>(), buffer.GetDataPtr()->GetTypeTag());
}

TEST(Buffer, Store_NonTrivialObjects) {
  class NonTrivial {
   public:
    virtual ~NonTrivial() {}
  } non_trivial;
  Buffer buffer;
  buffer.Assign(non_trivial);
  EXPECT_FALSE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kExternal, buffer.storage_);
  EXPECT_STREQ(GetTypeTag<NonTrivial>(), buffer.GetDataPtr()->GetTypeTag());
}

TEST(Buffer, Store_Objects) {
  Buffer buffer;

  struct Small {
    double d;
  } small = {};
  buffer.Assign(small);
  EXPECT_FALSE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kContained, buffer.storage_);
  EXPECT_STREQ(GetTypeTag<Small>(), buffer.GetDataPtr()->GetTypeTag());

  struct Large {
    char c[20];
  } large = {};
  buffer.Assign(large);
  EXPECT_FALSE(buffer.IsEmpty());
  EXPECT_EQ(Buffer::kExternal, buffer.storage_);
  EXPECT_STREQ(GetTypeTag<Large>(), buffer.GetDataPtr()->GetTypeTag());
}

TEST(Buffer, Copy) {
  Buffer buffer1;
  Buffer buffer2;

  buffer1.Assign(30);
  buffer1.CopyTo(&buffer2);
  EXPECT_FALSE(buffer1.IsEmpty());
  EXPECT_FALSE(buffer2.IsEmpty());
  EXPECT_STREQ(GetTypeTag<int>(), buffer1.GetDataPtr()->GetTypeTag());
  EXPECT_STREQ(GetTypeTag<int>(), buffer2.GetDataPtr()->GetTypeTag());
  EXPECT_EQ(30, buffer1.GetData<int>());
  EXPECT_EQ(30, buffer2.GetData<int>());

  buffer1.Assign(std::string("abc"));
  buffer1.CopyTo(&buffer2);
  EXPECT_FALSE(buffer1.IsEmpty());
  EXPECT_FALSE(buffer2.IsEmpty());
  EXPECT_STREQ(GetTypeTag<std::string>(), buffer1.GetDataPtr()->GetTypeTag());
  EXPECT_STREQ(GetTypeTag<std::string>(), buffer2.GetDataPtr()->GetTypeTag());
  EXPECT_EQ("abc", buffer1.GetData<std::string>());
  EXPECT_EQ("abc", buffer2.GetData<std::string>());
}

TEST(Buffer, Move) {
  // Move operations essentially leave the source object in a state that is
  // guaranteed to be safe for reuse or destruction. There is no other explicit
  // guarantees on the exact state of the source after move (e.g. that the
  // source Any will be Empty after the move is complete).
  Buffer buffer1;
  Buffer buffer2;

  buffer1.Assign(30);
  buffer1.MoveTo(&buffer2);
  // Contained types aren't flushed, so the source Any doesn't become empty.
  // The contained value is just moved, but for scalars this just copies
  // the data and any retains the actual type.
  EXPECT_FALSE(buffer1.IsEmpty());
  EXPECT_FALSE(buffer2.IsEmpty());
  EXPECT_STREQ(GetTypeTag<int>(), buffer2.GetDataPtr()->GetTypeTag());
  EXPECT_EQ(30, buffer2.GetData<int>());

  buffer1.Assign(std::string("abc"));
  buffer1.MoveTo(&buffer2);
  // External types are moved by just moving the pointer value from src to dest.
  // This will make the source object effectively "Empty".
  EXPECT_TRUE(buffer1.IsEmpty());
  EXPECT_FALSE(buffer2.IsEmpty());
  EXPECT_STREQ(GetTypeTag<std::string>(), buffer2.GetDataPtr()->GetTypeTag());
  EXPECT_EQ("abc", buffer2.GetData<std::string>());
}