/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

// Original authors: ekr@rtfm.com; ryan@tokbox.com

#ifndef MTRANSPORT_DUMMY_SOCKET_H_
#define MTRANSPORT_DUMMY_SOCKET_H_

#include "mediapacket.h"
#include "mozilla/UniquePtr.h"
#include "nr_socket.h"
#include "nr_socket_prsock.h"
#include "r_errors.h"
#include "transport_addr.h"

#define GTEST_HAS_RTTI 0
#include "gtest/gtest.h"
#include "gtest_utils.h"

namespace mozilla {

static UniquePtr<MediaPacket> merge(UniquePtr<MediaPacket> a,
                                    UniquePtr<MediaPacket> b) {
  if (a && a->len() && b && b->len()) {
    UniquePtr<uint8_t[]> data(new uint8_t[a->len() + b->len()]);
    memcpy(data.get(), a->data(), a->len());
    memcpy(data.get() + a->len(), b->data(), b->len());

    UniquePtr<MediaPacket> merged(new MediaPacket);
    merged->Take(std::move(data), a->len() + b->len());
    return merged;
  }

  if (a && a->len()) {
    return a;
  }

  if (b && b->len()) {
    return b;
  }

  return nullptr;
}

class DummySocket : public NrSocketBase {
 public:
  DummySocket()
      : writable_(UINT_MAX),
        write_buffer_(nullptr),
        readable_(UINT_MAX),
        read_buffer_(nullptr),
        cb_(nullptr),
        cb_arg_(nullptr),
        self_(nullptr) {}

  // the nr_socket APIs
  virtual int create(nr_transport_addr* addr) override { return 0; }

  virtual int sendto(const void* msg, size_t len, int flags,
                     const nr_transport_addr* to) override {
    MOZ_CRASH();
    return 0;
  }

  virtual int recvfrom(void* buf, size_t maxlen, size_t* len, int flags,
                       nr_transport_addr* from) override {
    MOZ_CRASH();
    return 0;
  }

  virtual int getaddr(nr_transport_addr* addrp) override {
    MOZ_CRASH();
    return 0;
  }

  virtual void close() override {}

  virtual int connect(const nr_transport_addr* addr) override {
    nr_transport_addr_copy(&connect_addr_, addr);
    return 0;
  }

  virtual int listen(int backlog) override { return 0; }

  virtual int accept(nr_transport_addr* addrp, nr_socket** sockp) override {
    return 0;
  }

  virtual int write(const void* msg, size_t len, size_t* written) override {
    size_t to_write = std::min(len, writable_);

    if (to_write) {
      UniquePtr<MediaPacket> msgbuf(new MediaPacket);
      msgbuf->Copy(static_cast<const uint8_t*>(msg), to_write);
      write_buffer_ = merge(std::move(write_buffer_), std::move(msgbuf));
    }

    *written = to_write;

    return 0;
  }

  virtual int read(void* buf, size_t maxlen, size_t* len) override {
    if (!read_buffer_.get()) {
      return R_WOULDBLOCK;
    }

    size_t to_read = std::min(read_buffer_->len(), std::min(maxlen, readable_));

    memcpy(buf, read_buffer_->data(), to_read);
    *len = to_read;

    if (to_read < read_buffer_->len()) {
      MediaPacket* newPacket = new MediaPacket;
      newPacket->Copy(read_buffer_->data() + to_read,
                      read_buffer_->len() - to_read);
      read_buffer_.reset(newPacket);
    } else {
      read_buffer_.reset();
    }

    return 0;
  }

  // Implementations of the async_event APIs.
  // These are no-ops because we handle scheduling manually
  // for test purposes.
  virtual int async_wait(int how, NR_async_cb cb, void* cb_arg, char* function,
                         int line) override {
    EXPECT_EQ(nullptr, cb_);
    cb_ = cb;
    cb_arg_ = cb_arg;

    return 0;
  }

  virtual int cancel(int how) override {
    cb_ = nullptr;
    cb_arg_ = nullptr;

    return 0;
  }

  // Read/Manipulate the current state.
  void CheckWriteBuffer(const uint8_t* data, size_t len) {
    if (!len) {
      EXPECT_EQ(nullptr, write_buffer_.get());
    } else {
      EXPECT_NE(nullptr, write_buffer_.get());
      ASSERT_EQ(len, write_buffer_->len());
      ASSERT_EQ(0, memcmp(data, write_buffer_->data(), len));
    }
  }

  void ClearWriteBuffer() { write_buffer_.reset(); }

  void SetWritable(size_t val) { writable_ = val; }

  void FireWritableCb() {
    NR_async_cb cb = cb_;
    void* cb_arg = cb_arg_;

    cb_ = nullptr;
    cb_arg_ = nullptr;

    cb(this, NR_ASYNC_WAIT_WRITE, cb_arg);
  }

  void SetReadBuffer(const uint8_t* data, size_t len) {
    EXPECT_EQ(nullptr, write_buffer_.get());
    read_buffer_.reset(new MediaPacket);
    read_buffer_->Copy(data, len);
  }

  void ClearReadBuffer() { read_buffer_.reset(); }

  void SetReadable(size_t val) { readable_ = val; }

  nr_socket* get_nr_socket() {
    if (!self_) {
      int r = nr_socket_create_int(this, vtbl(), &self_);
      AddRef();
      if (r) return nullptr;
    }

    return self_;
  }

  nr_transport_addr* get_connect_addr() { return &connect_addr_; }

  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(DummySocket, override);

 private:
  ~DummySocket() = default;

  DISALLOW_COPY_ASSIGN(DummySocket);

  size_t writable_;  // Amount we allow someone to write.
  UniquePtr<MediaPacket> write_buffer_;
  size_t readable_;  // Amount we allow someone to read.
  UniquePtr<MediaPacket> read_buffer_;

  NR_async_cb cb_;
  void* cb_arg_;
  nr_socket* self_;

  nr_transport_addr connect_addr_;
};

}  // namespace mozilla

#endif