// Copyright (c) 2011 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 "chrome/browser/component_updater/flash_component_installer.h"

#include <string.h>

#include "base/base_paths.h"
#include "base/compiler_specific.h"
#include "base/file_path.h"
#include "base/file_util.h"
#include "base/logging.h"
#include "base/path_service.h"
#include "base/string_util.h"
#include "base/stringprintf.h"
#include "base/values.h"
#include "chrome/browser/component_updater/component_updater_service.h"
#include "chrome/common/chrome_paths.h"
#include "content/browser/browser_thread.h"
#include "content/common/pepper_plugin_registry.h"
#include "ppapi/c/private/ppb_pdf.h"
#include "webkit/plugins/npapi/plugin_list.h"
#include "webkit/plugins/plugin_constants.h"
#include "webkit/plugins/ppapi/plugin_module.h"

namespace {

// CRX hash. The extension id is: mimojjlkmoijpicakmndhoigimigcmbb.
const uint8 sha2_hash[] = {0xc8, 0xce, 0x99, 0xba, 0xce, 0x89, 0xf8, 0x20,
                           0xac, 0xd3, 0x7e, 0x86, 0x8c, 0x86, 0x2c, 0x11,
                           0xb9, 0x40, 0xc5, 0x55, 0xaf, 0x08, 0x63, 0x70,
                           0x54, 0xf9, 0x56, 0xd3, 0xe7, 0x88, 0xba, 0x8c};

// File name of the Pepper Flash plugin on different platforms.
const FilePath::CharType kPepperFlashPluginFileName[] =
#if defined(OS_MACOSX)
    FILE_PATH_LITERAL("PepperFlashPlayer.plugin");
#elif defined(OS_WIN)
    FILE_PATH_LITERAL("pepflashplayer.dll");
#else  // OS_LINUX, etc.
    FILE_PATH_LITERAL("libpepflashplayer.so");
#endif

// File name of the Pepper Flash component manifest on different platforms.
const char kPepperFlashManifestName[] =
#if defined(OS_MACOSX)
    "MacFlapper";
#elif defined(OS_WIN)
    "WinFlapper";
#else  // OS_LINUX, etc.
    "NixFlapper";
#endif

// The pepper flash plugins are in a directory with this name.
const FilePath::CharType kPepperFlashBaseDirectory[] =
    FILE_PATH_LITERAL("PepperFlash");

// If we don't have a flash pepper component, this is the version we claim.
const char kNullVersion[] = "0.0.0.0";

// The base directory on windows looks like:
// <profile>\AppData\Local\Google\Chrome\User Data\PepperFlash\.
FilePath GetPepperFlashBaseDirectory() {
  FilePath result;
  PathService::Get(chrome::DIR_USER_DATA, &result);
  return result.Append(kPepperFlashBaseDirectory);
}

// Pepper flash plugins have the version encoded in the path itself
// so we need to enumerate the directories to find the full path.
// On success it returns something like:
// <profile>\AppData\Local\Google\Chrome\User Data\PepperFlash\10.3.44.555\.
bool GetLatestPepperFlashDirectory(FilePath* result, Version* latest) {
  *result = GetPepperFlashBaseDirectory();
  bool found = false;
  file_util::FileEnumerator
      file_enumerator(*result, false, file_util::FileEnumerator::DIRECTORIES);
  for (FilePath path = file_enumerator.Next(); !path.value().empty();
       path = file_enumerator.Next()) {
    Version version(path.BaseName().MaybeAsASCII());
    if (!version.IsValid())
      continue;
    if (version.CompareTo(*latest) > 0) {
      *latest = version;
      *result = path;
      found = true;
    }
  }
  return found;
}

// Returns true if the pepper |interface_name| is implemented  by this browser.
// It does not check if the interface is proxied.
bool SupportsPepperInterface(const char* interface_name) {
  static webkit::ppapi::PluginModule::GetInterfaceFunc get_itf =
      webkit::ppapi::PluginModule::GetLocalGetInterfaceFunc();
  if (get_itf(interface_name))
    return true;
  // It might be that flapper is using as a temporary hack the PDF interface
  // so we need to check for that as well. TODO(cpu): make this more sane.
  return (strcmp(interface_name, PPB_PDF_INTERFACE) == 0);
}

}  // namespace

bool MakePepperFlashPluginInfo(const FilePath& flash_path,
                               const Version& flash_version,
                               bool out_of_process,
                               bool enabled,
                               PepperPluginInfo* plugin_info) {
  if (!flash_version.IsValid())
    return false;
  const std::vector<uint16> ver_nums = flash_version.components();
  if (ver_nums.size() < 3)
    return false;

  plugin_info->is_internal = false;
  plugin_info->is_out_of_process = out_of_process;
  plugin_info->path = flash_path;
  plugin_info->name = kFlashPluginName;
  plugin_info->enabled = enabled;

  // The description is like "Shockwave Flash 10.2 r154".
  plugin_info->description = StringPrintf("%s %d.%d r%d",
      kFlashPluginName, ver_nums[0], ver_nums[1], ver_nums[2]);

  plugin_info->version = flash_version.GetString();

  webkit::WebPluginMimeType swf_mime_type(kFlashPluginSwfMimeType,
                                          kFlashPluginSwfExtension,
                                          kFlashPluginName);
  plugin_info->mime_types.push_back(swf_mime_type);
  webkit::WebPluginMimeType spl_mime_type(kFlashPluginSplMimeType,
                                          kFlashPluginSplExtension,
                                          kFlashPluginName);
  plugin_info->mime_types.push_back(spl_mime_type);
  return true;
}

void RegisterPepperFlashWithChrome(const FilePath& path,
                                   const Version& version) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  PepperPluginInfo plugin_info;
  // Register it as out-of-process and disabled.
  if (!MakePepperFlashPluginInfo(path, version, true, false, &plugin_info))
    return;
  webkit::npapi::PluginList::Singleton()->RegisterInternalPlugin(
      plugin_info.ToWebPluginInfo());
  webkit::npapi::PluginList::Singleton()->RefreshPlugins();
}

class PepperFlashComponentInstaller : public ComponentInstaller {
 public:
  explicit PepperFlashComponentInstaller(const Version& version);

  virtual ~PepperFlashComponentInstaller() {}

  virtual void OnUpdateError(int error) OVERRIDE;

  virtual bool Install(base::DictionaryValue* manifest,
                       const FilePath& unpack_path) OVERRIDE;

 private:
  Version current_version_;
};

PepperFlashComponentInstaller::PepperFlashComponentInstaller(
    const Version& version) : current_version_(version) {
  DCHECK(version.IsValid());
}

void PepperFlashComponentInstaller::OnUpdateError(int error) {
  NOTREACHED() << "pepper flash update error :" << error;
}

bool PepperFlashComponentInstaller::Install(base::DictionaryValue* manifest,
                                            const FilePath& unpack_path) {
  std::string name;
  manifest->GetStringASCII("name", &name);
  if (name != kPepperFlashManifestName)
    return false;
  std::string proposed_version;
  manifest->GetStringASCII("version", &proposed_version);
  Version version(proposed_version.c_str());
  if (!version.IsValid())
    return false;
  if (current_version_.CompareTo(version) > 0)
    return false;
  if (!file_util::PathExists(unpack_path.Append(kPepperFlashPluginFileName)))
    return false;

  // Check that we implement the required interfaces.
  base::ListValue* interfaces = NULL;
  if (manifest->GetList("x-ppapi-required-interfaces", &interfaces)) {
    for (size_t ix = 0; ix != interfaces->GetSize(); ++ix) {
      std::string interface_name;
      if (!interfaces->GetString(ix, &interface_name))
        return false;
      if (!SupportsPepperInterface(interface_name.c_str()))
        return false;
    }
  }

  // Passed the basic tests. Time to install it.
  FilePath path =
      GetPepperFlashBaseDirectory().AppendASCII(version.GetString());
  if (file_util::PathExists(path))
    return false;
  if (!file_util::Move(unpack_path, path))
    return false;
  // Installation is done. Now tell the rest of chrome. Both the path service
  // and to the plugin service.
  current_version_ = version;
  path = path.Append(kPepperFlashPluginFileName);
  PathService::Override(chrome::FILE_PEPPER_FLASH_PLUGIN, path);
  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
      NewRunnableFunction(&RegisterPepperFlashWithChrome, path, version));
  return true;
}

void FinishPepperFlashUpdateRegistration(ComponentUpdateService* cus,
                                         const Version& version) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  CrxComponent pepflash;
  pepflash.name = "pepper_flash";
  pepflash.installer = new PepperFlashComponentInstaller(version);
  pepflash.version = version;
  pepflash.pk_hash.assign(sha2_hash, &sha2_hash[sizeof(sha2_hash)]);
  if (cus->RegisterComponent(pepflash) != ComponentUpdateService::kOk) {
    NOTREACHED() << "pepper flash component registration fail";
  }
}

void StartPepperFlashUpdateRegistration(ComponentUpdateService* cus) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  FilePath path = GetPepperFlashBaseDirectory();
  if (!file_util::PathExists(path)) {
    if (!file_util::CreateDirectory(path)) {
      NOTREACHED() << "cannot create pepper flash directory";
      return;
    }
  }

  Version version(kNullVersion);
  if (GetLatestPepperFlashDirectory(&path, &version)) {
    path = path.Append(kPepperFlashPluginFileName);
    if (file_util::PathExists(path)) {
      BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
          NewRunnableFunction(&RegisterPepperFlashWithChrome, path, version));
    } else {
      version = Version(kNullVersion);
    }
  }

  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
      NewRunnableFunction(&FinishPepperFlashUpdateRegistration, cus, version));
}

void RegisterPepperFlashComponent(ComponentUpdateService* cus) {
#if defined(OS_WIN) && defined(GOOGLE_CHROME_BUILD)
  // TODO(cpu): support Mac and Linux flash pepper.
  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
      NewRunnableFunction(&StartPepperFlashUpdateRegistration, cus));
#endif
}