// Copyright 2014 The Chromium 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 <stddef.h>
#include <stdint.h>

#include <memory>
#include <string>
#include <vector>

#include "base/bind.h"
#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "base/files/file.h"
#include "base/files/file_path.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/memory/ref_counted.h"
#include "base/path_service.h"
#include "base/process/process_handle.h"
#include "base/run_loop.h"
#include "base/scoped_observer.h"
#include "base/single_thread_task_runner.h"
#include "base/stl_util.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/time/time.h"
#include "device/base/device_client.h"
#include "device/test/usb_test_gadget.h"
#include "device/usb/usb_device.h"
#include "device/usb/usb_device_handle.h"
#include "device/usb/usb_service.h"
#include "net/base/escape.h"
#include "net/proxy_resolution/proxy_resolution_service.h"
#include "net/traffic_annotation/network_traffic_annotation_test_helper.h"
#include "net/url_request/url_fetcher.h"
#include "net/url_request/url_fetcher_delegate.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_context_builder.h"
#include "net/url_request/url_request_context_getter.h"
#include "url/gurl.h"

namespace device {

class UsbTestGadgetImpl : public UsbTestGadget {
 public:
  UsbTestGadgetImpl(
      scoped_refptr<net::URLRequestContextGetter> request_context_getter,
      UsbService* usb_service,
      scoped_refptr<UsbDevice> device);
  ~UsbTestGadgetImpl() override;

  bool Unclaim() override;
  bool Disconnect() override;
  bool Reconnect() override;
  bool SetType(Type type) override;
  UsbDevice* GetDevice() const override;

 private:
  std::string device_address_;
  scoped_refptr<UsbDevice> device_;
  scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
  UsbService* usb_service_;

  DISALLOW_COPY_AND_ASSIGN(UsbTestGadgetImpl);
};

namespace {

static const char kCommandLineSwitch[] = "enable-gadget-tests";
static const int kReenumeratePeriod = 100;  // 0.1 seconds

struct UsbTestGadgetConfiguration {
  UsbTestGadget::Type type;
  const char* http_resource;
  uint16_t product_id;
};

static const struct UsbTestGadgetConfiguration kConfigurations[] = {
    {UsbTestGadget::DEFAULT, "/unconfigure", 0x58F0},
    {UsbTestGadget::KEYBOARD, "/keyboard/configure", 0x58F1},
    {UsbTestGadget::MOUSE, "/mouse/configure", 0x58F2},
    {UsbTestGadget::HID_ECHO, "/hid_echo/configure", 0x58F3},
    {UsbTestGadget::ECHO, "/echo/configure", 0x58F4},
};

bool ReadFile(const base::FilePath& file_path, std::string* content) {
  base::File file(file_path, base::File::FLAG_OPEN | base::File::FLAG_READ);
  if (!file.IsValid()) {
    LOG(ERROR) << "Cannot open " << file_path.MaybeAsASCII() << ": "
               << base::File::ErrorToString(file.error_details());
    return false;
  }

  base::STLClearObject(content);
  int rv;
  do {
    char buf[4096];
    rv = file.ReadAtCurrentPos(buf, sizeof buf);
    if (rv == -1) {
      LOG(ERROR) << "Cannot read " << file_path.MaybeAsASCII() << ": "
                 << base::File::ErrorToString(file.error_details());
      return false;
    }
    content->append(buf, rv);
  } while (rv > 0);

  return true;
}

bool ReadLocalVersion(std::string* version) {
  base::FilePath file_path;
  CHECK(base::PathService::Get(base::DIR_EXE, &file_path));
  file_path = file_path.AppendASCII("usb_gadget.zip.md5");

  return ReadFile(file_path, version);
}

bool ReadLocalPackage(std::string* package) {
  base::FilePath file_path;
  CHECK(base::PathService::Get(base::DIR_EXE, &file_path));
  file_path = file_path.AppendASCII("usb_gadget.zip");

  return ReadFile(file_path, package);
}

std::unique_ptr<net::URLFetcher> CreateURLFetcher(
    scoped_refptr<net::URLRequestContextGetter> request_context_getter,
    const GURL& url,
    net::URLFetcher::RequestType request_type,
    net::URLFetcherDelegate* delegate) {
  std::unique_ptr<net::URLFetcher> url_fetcher = net::URLFetcher::Create(
      url, request_type, delegate, TRAFFIC_ANNOTATION_FOR_TESTS);

  url_fetcher->SetRequestContext(request_context_getter.get());

  return url_fetcher;
}

class URLRequestContextGetter : public net::URLRequestContextGetter {
 public:
  URLRequestContextGetter(
      scoped_refptr<base::SingleThreadTaskRunner> network_task_runner)
      : network_task_runner_(network_task_runner) {}

 private:
  ~URLRequestContextGetter() override = default;

  // net::URLRequestContextGetter implementation
  net::URLRequestContext* GetURLRequestContext() override {
    if (!context_) {
      net::URLRequestContextBuilder context_builder;
      context_builder.set_proxy_resolution_service(
          net::ProxyResolutionService::CreateDirect());
      context_ = context_builder.Build();
    }
    return context_.get();
  }

  scoped_refptr<base::SingleThreadTaskRunner> GetNetworkTaskRunner()
      const override {
    return network_task_runner_;
  }

  std::unique_ptr<net::URLRequestContext> context_;
  scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;
};

class URLFetcherDelegate : public net::URLFetcherDelegate {
 public:
  URLFetcherDelegate() = default;
  ~URLFetcherDelegate() override = default;

  void WaitForCompletion() { run_loop_.Run(); }

  void OnURLFetchComplete(const net::URLFetcher* source) override {
    run_loop_.Quit();
  }

 private:
  base::RunLoop run_loop_;

  DISALLOW_COPY_AND_ASSIGN(URLFetcherDelegate);
};

int SimplePOSTRequest(
    scoped_refptr<net::URLRequestContextGetter> request_context_getter,
    const GURL& url,
    const std::string& form_data) {
  URLFetcherDelegate delegate;
  std::unique_ptr<net::URLFetcher> url_fetcher = CreateURLFetcher(
      request_context_getter, url, net::URLFetcher::POST, &delegate);

  url_fetcher->SetUploadData("application/x-www-form-urlencoded", form_data);
  url_fetcher->Start();
  delegate.WaitForCompletion();

  return url_fetcher->GetResponseCode();
}

class UsbGadgetFactory : public UsbService::Observer,
                         public net::URLFetcherDelegate {
 public:
  UsbGadgetFactory(scoped_refptr<base::SingleThreadTaskRunner> io_task_runner)
      : observer_(this), weak_factory_(this) {
    usb_service_ = DeviceClient::Get()->GetUsbService();
    request_context_getter_ = new URLRequestContextGetter(io_task_runner);

    static uint32_t next_session_id;
    base::ProcessId process_id = base::GetCurrentProcId();
    session_id_ =
        base::StringPrintf("%" CrPRIdPid "-%d", process_id, next_session_id++);

    observer_.Add(usb_service_);
  }

  ~UsbGadgetFactory() override = default;

  std::unique_ptr<UsbTestGadget> WaitForDevice() {
    EnumerateDevices();
    run_loop_.Run();
    return std::make_unique<UsbTestGadgetImpl>(request_context_getter_,
                                               usb_service_, device_);
  }

 private:
  void EnumerateDevices() {
    if (!device_) {
      usb_service_->GetDevices(base::Bind(
          &UsbGadgetFactory::OnDevicesEnumerated, weak_factory_.GetWeakPtr()));
    }
  }

  void OnDevicesEnumerated(
      const std::vector<scoped_refptr<UsbDevice>>& devices) {
    for (const scoped_refptr<UsbDevice>& device : devices) {
      OnDeviceAdded(device);
    }

    if (!device_) {
      // TODO(reillyg): This timer could be replaced by a way to use long-
      // polling to wait for claimed devices to become unclaimed.
      base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
          FROM_HERE,
          base::BindOnce(&UsbGadgetFactory::EnumerateDevices,
                         weak_factory_.GetWeakPtr()),
          base::TimeDelta::FromMilliseconds(kReenumeratePeriod));
    }
  }

  void OnDeviceAdded(scoped_refptr<UsbDevice> device) override {
    if (device_.get()) {
      // Already trying to claim a device.
      return;
    }

    if (device->vendor_id() != 0x18D1 || device->product_id() != 0x58F0 ||
        device->serial_number().empty()) {
      return;
    }

    std::string serial_number = base::UTF16ToUTF8(device->serial_number());
    if (serial_number == serial_number_) {
      // We were waiting for the device to reappear after upgrade.
      device_ = device;
      run_loop_.Quit();
      return;
    }

    device_ = device;
    serial_number_ = serial_number;
    Claim();
  }

  void Claim() {
    VLOG(1) << "Trying to claim " << serial_number_ << ".";

    GURL url("http://" + serial_number_ + "/claim");
    std::string form_data = base::StringPrintf(
        "session_id=%s", net::EscapeUrlEncodedData(session_id_, true).c_str());
    url_fetcher_ = CreateURLFetcher(request_context_getter_, url,
                                    net::URLFetcher::POST, this);
    url_fetcher_->SetUploadData("application/x-www-form-urlencoded", form_data);
    url_fetcher_->Start();
  }

  void GetVersion() {
    GURL url("http://" + serial_number_ + "/version");
    url_fetcher_ = CreateURLFetcher(request_context_getter_, url,
                                    net::URLFetcher::GET, this);
    url_fetcher_->Start();
  }

  bool Update(const std::string& version) {
    LOG(INFO) << "Updating " << serial_number_ << " to " << version << "...";

    GURL url("http://" + serial_number_ + "/update");
    url_fetcher_ = CreateURLFetcher(request_context_getter_, url,
                                    net::URLFetcher::POST, this);
    std::string mime_header = base::StringPrintf(
        "--foo\r\n"
        "Content-Disposition: form-data; name=\"file\"; "
        "filename=\"usb_gadget-%s.zip\"\r\n"
        "Content-Type: application/octet-stream\r\n"
        "\r\n",
        version.c_str());
    std::string mime_footer("\r\n--foo--\r\n");

    std::string package;
    if (!ReadLocalPackage(&package)) {
      return false;
    }

    url_fetcher_->SetUploadData("multipart/form-data; boundary=foo",
                                mime_header + package + mime_footer);
    url_fetcher_->Start();
    device_ = nullptr;
    return true;
  }

  void OnURLFetchComplete(const net::URLFetcher* source) override {
    DCHECK(!serial_number_.empty());

    int response_code = source->GetResponseCode();
    if (!claimed_) {
      // Just completed a /claim request.
      if (response_code == 200) {
        claimed_ = true;
        GetVersion();
      } else {
        if (response_code != 403) {
          LOG(WARNING) << "Unexpected HTTP " << response_code
                       << " from /claim.";
        }
        Reset();
      }
    } else if (version_.empty()) {
      // Just completed a /version request.
      if (response_code != 200) {
        LOG(WARNING) << "Unexpected HTTP " << response_code
                     << " from /version.";
        Reset();
        return;
      }

      if (!source->GetResponseAsString(&version_)) {
        LOG(WARNING) << "Failed to read body from /version.";
        Reset();
        return;
      }

      std::string local_version;
      if (!ReadLocalVersion(&local_version)) {
        Reset();
        return;
      }

      if (version_ == local_version) {
        run_loop_.Quit();
      } else {
        if (!Update(local_version)) {
          Reset();
        }
      }
    } else {
      // Just completed an /update request.
      if (response_code != 200) {
        LOG(WARNING) << "Unexpected HTTP " << response_code << " from /update.";
        Reset();
        return;
      }

      // Must wait for the device to reconnect.
    }
  }

  void Reset() {
    device_ = nullptr;
    serial_number_.clear();
    claimed_ = false;
    version_.clear();

    // Wait a bit and then try again to find an available device.
    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
        FROM_HERE,
        base::BindOnce(&UsbGadgetFactory::EnumerateDevices,
                       weak_factory_.GetWeakPtr()),
        base::TimeDelta::FromMilliseconds(kReenumeratePeriod));
  }

  UsbService* usb_service_ = nullptr;
  scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
  std::string session_id_;
  std::unique_ptr<net::URLFetcher> url_fetcher_;
  scoped_refptr<UsbDevice> device_;
  std::string serial_number_;
  bool claimed_ = false;
  std::string version_;
  base::RunLoop run_loop_;
  ScopedObserver<UsbService, UsbService::Observer> observer_;
  base::WeakPtrFactory<UsbGadgetFactory> weak_factory_;
};

class DeviceAddListener : public UsbService::Observer {
 public:
  DeviceAddListener(UsbService* usb_service,
                    const std::string& serial_number,
                    int product_id)
      : usb_service_(usb_service),
        serial_number_(serial_number),
        product_id_(product_id),
        observer_(this),
        weak_factory_(this) {
    observer_.Add(usb_service_);
  }
  ~DeviceAddListener() override = default;

  scoped_refptr<UsbDevice> WaitForAdd() {
    usb_service_->GetDevices(base::Bind(&DeviceAddListener::OnDevicesEnumerated,
                                        weak_factory_.GetWeakPtr()));
    run_loop_.Run();
    return device_;
  }

 private:
  void OnDevicesEnumerated(
      const std::vector<scoped_refptr<UsbDevice>>& devices) {
    for (const scoped_refptr<UsbDevice>& device : devices) {
      OnDeviceAdded(device);
    }
  }

  void OnDeviceAdded(scoped_refptr<UsbDevice> device) override {
    if (device->vendor_id() == 0x18D1 && !device->serial_number().empty()) {
      const uint16_t product_id = device->product_id();
      if (product_id_ == -1) {
        bool found = false;
        for (size_t i = 0; i < base::size(kConfigurations); ++i) {
          if (product_id == kConfigurations[i].product_id) {
            found = true;
            break;
          }
        }
        if (!found) {
          return;
        }
      } else {
        if (product_id_ != product_id) {
          return;
        }
      }

      if (serial_number_ != base::UTF16ToUTF8(device->serial_number())) {
        return;
      }

      device_ = device;
      run_loop_.Quit();
    }
  }

  UsbService* usb_service_;
  const std::string serial_number_;
  const int product_id_;
  base::RunLoop run_loop_;
  scoped_refptr<UsbDevice> device_;
  ScopedObserver<UsbService, UsbService::Observer> observer_;
  base::WeakPtrFactory<DeviceAddListener> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(DeviceAddListener);
};

class DeviceRemoveListener : public UsbService::Observer {
 public:
  DeviceRemoveListener(UsbService* usb_service, scoped_refptr<UsbDevice> device)
      : usb_service_(usb_service),
        device_(device),
        observer_(this),
        weak_factory_(this) {
    observer_.Add(usb_service_);
  }
  ~DeviceRemoveListener() override = default;

  void WaitForRemove() {
    usb_service_->GetDevices(
        base::Bind(&DeviceRemoveListener::OnDevicesEnumerated,
                   weak_factory_.GetWeakPtr()));
    run_loop_.Run();
  }

 private:
  void OnDevicesEnumerated(
      const std::vector<scoped_refptr<UsbDevice>>& devices) {
    bool found = false;
    for (const scoped_refptr<UsbDevice>& device : devices) {
      if (device_ == device) {
        found = true;
      }
    }
    if (!found) {
      run_loop_.Quit();
    }
  }

  void OnDeviceRemoved(scoped_refptr<UsbDevice> device) override {
    if (device_ == device) {
      run_loop_.Quit();
    }
  }

  UsbService* usb_service_;
  base::RunLoop run_loop_;
  scoped_refptr<UsbDevice> device_;
  ScopedObserver<UsbService, UsbService::Observer> observer_;
  base::WeakPtrFactory<DeviceRemoveListener> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(DeviceRemoveListener);
};

}  // namespace

bool UsbTestGadget::IsTestEnabled() {
  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  return command_line->HasSwitch(kCommandLineSwitch);
}

std::unique_ptr<UsbTestGadget> UsbTestGadget::Claim(
    scoped_refptr<base::SingleThreadTaskRunner> io_task_runner) {
  UsbGadgetFactory gadget_factory(io_task_runner);
  return gadget_factory.WaitForDevice();
}

UsbTestGadgetImpl::UsbTestGadgetImpl(
    scoped_refptr<net::URLRequestContextGetter> request_context_getter_,
    UsbService* usb_service,
    scoped_refptr<UsbDevice> device)
    : device_address_(base::UTF16ToUTF8(device->serial_number())),
      device_(device),
      request_context_getter_(request_context_getter_),
      usb_service_(usb_service) {
}

UsbTestGadgetImpl::~UsbTestGadgetImpl() {
  if (!device_address_.empty()) {
    Unclaim();
  }
}

UsbDevice* UsbTestGadgetImpl::GetDevice() const {
  return device_.get();
}

bool UsbTestGadgetImpl::Unclaim() {
  VLOG(1) << "Releasing the device at " << device_address_ << ".";

  GURL url("http://" + device_address_ + "/unclaim");
  int response_code = SimplePOSTRequest(request_context_getter_, url, "");

  if (response_code != 200) {
    LOG(ERROR) << "Unexpected HTTP " << response_code << " from /unclaim.";
    return false;
  }

  device_address_.clear();
  return true;
}

bool UsbTestGadgetImpl::SetType(Type type) {
  const struct UsbTestGadgetConfiguration* config = NULL;
  for (size_t i = 0; i < base::size(kConfigurations); ++i) {
    if (kConfigurations[i].type == type) {
      config = &kConfigurations[i];
    }
  }
  CHECK(config);

  GURL url("http://" + device_address_ + config->http_resource);
  int response_code = SimplePOSTRequest(request_context_getter_, url, "");

  if (response_code != 200) {
    LOG(ERROR) << "Unexpected HTTP " << response_code
               << " from " << config->http_resource << ".";
    return false;
  }

  // Release the old reference to the device and try to open a new one.
  DeviceAddListener add_listener(usb_service_, device_address_,
                                 config->product_id);
  device_ = add_listener.WaitForAdd();
  DCHECK(device_.get());
  return true;
}

bool UsbTestGadgetImpl::Disconnect() {
  GURL url("http://" + device_address_ + "/disconnect");
  int response_code = SimplePOSTRequest(request_context_getter_, url, "");

  if (response_code != 200) {
    LOG(ERROR) << "Unexpected HTTP " << response_code << " from " << url << ".";
    return false;
  }

  // Release the old reference to the device and wait until it can't be found.
  DeviceRemoveListener remove_listener(usb_service_, device_);
  remove_listener.WaitForRemove();
  device_ = nullptr;
  return true;
}

bool UsbTestGadgetImpl::Reconnect() {
  GURL url("http://" + device_address_ + "/reconnect");
  int response_code = SimplePOSTRequest(request_context_getter_, url, "");

  if (response_code != 200) {
    LOG(ERROR) << "Unexpected HTTP " << response_code << " from " << url << ".";
    return false;
  }

  DeviceAddListener add_listener(usb_service_, device_address_, -1);
  device_ = add_listener.WaitForAdd();
  DCHECK(device_.get());
  return true;
}

}  // namespace device