// 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/common/pepper_plugin_registry.h"

#include "base/command_line.h"
#include "base/file_util.h"
#include "base/native_library.h"
#include "base/path_service.h"
#include "base/string_split.h"
#include "base/string_util.h"
#include "base/utf_string_conversions.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_switches.h"
#include "content/common/child_process.h"
#include "content/common/content_switches.h"
#include "remoting/client/plugin/pepper_entrypoints.h"
#include "webkit/plugins/npapi/plugin_list.h"

namespace {

const char* kPDFPluginName = "Chrome PDF Viewer";
const char* kPDFPluginMimeType = "application/pdf";
const char* kPDFPluginExtension = "pdf";
const char* kPDFPluginDescription = "Portable Document Format";

const char* kNaClPluginName = "Chrome NaCl";
const char* kNaClPluginMimeType = "application/x-nacl";
const char* kNaClPluginExtension = "nexe";
const char* kNaClPluginDescription = "Native Client Executable";

#if defined(ENABLE_REMOTING)
const char* kRemotingPluginMimeType = "pepper-application/x-chromoting";
#endif

const char* kFlashPluginName = "Shockwave Flash";
const char* kFlashPluginSwfMimeType = "application/x-shockwave-flash";
const char* kFlashPluginSwfExtension = "swf";
const char* kFlashPluginSwfDescription = "Shockwave Flash";
const char* kFlashPluginSplMimeType = "application/futuresplash";
const char* kFlashPluginSplExtension = "spl";
const char* kFlashPluginSplDescription = "FutureSplash Player";

// Appends the known built-in plugins to the given vector. Some built-in
// plugins are "internal" which means they are compiled into the Chrome binary,
// and some are extra shared libraries distributed with the browser (these are
// not marked internal, aside from being automatically registered, they're just
// regular plugins).
void ComputeBuiltInPlugins(std::vector<PepperPluginInfo>* plugins) {
  // PDF.
  //
  // Once we're sandboxed, we can't know if the PDF plugin is available or not;
  // but (on Linux) this function is always called once before we're sandboxed.
  // So the first time through test if the file is available and then skip the
  // check on subsequent calls if yes.
  static bool skip_pdf_file_check = false;
  FilePath path;
  if (PathService::Get(chrome::FILE_PDF_PLUGIN, &path)) {
    if (skip_pdf_file_check || file_util::PathExists(path)) {
      PepperPluginInfo pdf;
      pdf.path = path;
      pdf.name = kPDFPluginName;
      webkit::npapi::WebPluginMimeType pdf_mime_type(kPDFPluginMimeType,
                                                     kPDFPluginExtension,
                                                     kPDFPluginDescription);
      pdf.mime_types.push_back(pdf_mime_type);
      plugins->push_back(pdf);

      skip_pdf_file_check = true;
    }
  }

  // Handle the Native Client plugin just like the PDF plugin.
  static bool skip_nacl_file_check = false;
  if (PathService::Get(chrome::FILE_NACL_PLUGIN, &path)) {
    if (skip_nacl_file_check || file_util::PathExists(path)) {
      PepperPluginInfo nacl;
      nacl.path = path;
      nacl.name = kNaClPluginName;
      webkit::npapi::WebPluginMimeType nacl_mime_type(kNaClPluginMimeType,
                                                      kNaClPluginExtension,
                                                      kNaClPluginDescription);
      nacl.mime_types.push_back(nacl_mime_type);
      plugins->push_back(nacl);

      skip_nacl_file_check = true;
    }
  }

  // Remoting.
#if defined(ENABLE_REMOTING)
  if (CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kEnableRemoting)) {
    PepperPluginInfo info;
    info.is_internal = true;
    info.path = FilePath(FILE_PATH_LITERAL("internal-chromoting"));
    webkit::npapi::WebPluginMimeType remoting_mime_type(kRemotingPluginMimeType,
                                                        std::string(),
                                                        std::string());
    info.mime_types.push_back(remoting_mime_type);
    info.internal_entry_points.get_interface = remoting::PPP_GetInterface;
    info.internal_entry_points.initialize_module =
        remoting::PPP_InitializeModule;
    info.internal_entry_points.shutdown_module = remoting::PPP_ShutdownModule;

    plugins->push_back(info);
  }
#endif
}

// Appends any plugins from the command line to the given vector.
void ComputePluginsFromCommandLine(std::vector<PepperPluginInfo>* plugins) {
  // Flash being out of process is handled separately than general plugins
  // for testing purposes.
  bool out_of_process =
      CommandLine::ForCurrentProcess()->HasSwitch(switches::kPpapiOutOfProcess);
  bool flash_out_of_process = !CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kPpapiFlashInProcess);

  // Handle any Pepper Flash first.
  const CommandLine::StringType flash_path =
      CommandLine::ForCurrentProcess()->GetSwitchValueNative(
          switches::kPpapiFlashPath);
  if (!flash_path.empty()) {
    PepperPluginInfo plugin;
    plugin.is_out_of_process = flash_out_of_process;
    plugin.path = FilePath(flash_path);
    plugin.name = kFlashPluginName;

    const std::string flash_version =
        CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
                switches::kPpapiFlashVersion);
    std::vector<std::string> flash_version_numbers;
    base::SplitString(flash_version, '.', &flash_version_numbers);
    if (flash_version_numbers.size() < 1)
      flash_version_numbers.push_back("10");
    // |SplitString()| puts in an empty string given an empty string. :(
    else if (flash_version_numbers[0].empty())
      flash_version_numbers[0] = "10";
    if (flash_version_numbers.size() < 2)
      flash_version_numbers.push_back("2");
    if (flash_version_numbers.size() < 3)
      flash_version_numbers.push_back("999");
    if (flash_version_numbers.size() < 4)
      flash_version_numbers.push_back("999");
    // E.g., "Shockwave Flash 10.2 r154":
    plugin.description = plugin.name + " " + flash_version_numbers[0] + "." +
        flash_version_numbers[1] + " r" + flash_version_numbers[2];
    plugin.version = JoinString(flash_version_numbers, '.');
    webkit::npapi::WebPluginMimeType swf_mime_type(kFlashPluginSwfMimeType,
                                                   kFlashPluginSwfExtension,
                                                   kFlashPluginSwfDescription);
    plugin.mime_types.push_back(swf_mime_type);
    webkit::npapi::WebPluginMimeType spl_mime_type(kFlashPluginSplMimeType,
                                                   kFlashPluginSplExtension,
                                                   kFlashPluginSplDescription);
    plugin.mime_types.push_back(spl_mime_type);
    plugins->push_back(plugin);
  }

  // Handle other plugins.
  const std::string value =
      CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
          switches::kRegisterPepperPlugins);
  if (value.empty())
    return;

  // FORMAT:
  // command-line = <plugin-entry> + *( LWS + "," + LWS + <plugin-entry> )
  // plugin-entry =
  //    <file-path> +
  //    ["#" + <name> + ["#" + <description> + ["#" + <version>]]] +
  //    *1( LWS + ";" + LWS + <mime-type> )

  std::vector<std::string> modules;
  base::SplitString(value, ',', &modules);
  for (size_t i = 0; i < modules.size(); ++i) {
    std::vector<std::string> parts;
    base::SplitString(modules[i], ';', &parts);
    if (parts.size() < 2) {
      DLOG(ERROR) << "Required mime-type not found";
      continue;
    }

    std::vector<std::string> name_parts;
    base::SplitString(parts[0], '#', &name_parts);

    PepperPluginInfo plugin;
    plugin.is_out_of_process = out_of_process;
#if defined(OS_WIN)
    // This means we can't provide plugins from non-ASCII paths, but
    // since this switch is only for development I don't think that's
    // too awful.
    plugin.path = FilePath(ASCIIToUTF16(name_parts[0]));
#else
    plugin.path = FilePath(name_parts[0]);
#endif
    if (name_parts.size() > 1)
      plugin.name = name_parts[1];
    if (name_parts.size() > 2)
      plugin.description = name_parts[2];
    if (name_parts.size() > 3)
      plugin.version = name_parts[3];
    for (size_t j = 1; j < parts.size(); ++j) {
      webkit::npapi::WebPluginMimeType mime_type(parts[j],
                                                 std::string(),
                                                 plugin.description);
      plugin.mime_types.push_back(mime_type);
    }

    plugins->push_back(plugin);
  }
}

}  // namespace

const char* PepperPluginRegistry::kPDFPluginName = ::kPDFPluginName;

webkit::npapi::WebPluginInfo PepperPluginInfo::ToWebPluginInfo() const {
  webkit::npapi::WebPluginInfo info;

  info.name = name.empty() ? path.BaseName().LossyDisplayName() :
      ASCIIToUTF16(name);
  info.path = path;
  info.version = ASCIIToUTF16(version);
  info.desc = ASCIIToUTF16(description);
  info.mime_types = mime_types;

  webkit::npapi::WebPluginInfo::EnabledStates enabled_state =
      webkit::npapi::WebPluginInfo::USER_ENABLED_POLICY_UNMANAGED;

  // Enable the Native Client Plugin based on the command line.
  // TODO(abarth): This is the wrong place to do this work!
  if (name == kNaClPluginName) {
    bool nacl_enabled =
        CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableNaCl);
    enabled_state = nacl_enabled ?
        webkit::npapi::WebPluginInfo::USER_ENABLED_POLICY_UNMANAGED :
        webkit::npapi::WebPluginInfo::USER_DISABLED_POLICY_UNMANAGED;
  }
  info.enabled = enabled_state;
  return info;
}

PepperPluginInfo::PepperPluginInfo()
    : is_internal(false),
      is_out_of_process(false) {
}

PepperPluginInfo::~PepperPluginInfo() {
}

NaClModuleInfo::NaClModuleInfo() {
}

NaClModuleInfo::~NaClModuleInfo() {
}

// static
PepperPluginRegistry* PepperPluginRegistry::GetInstance() {
  static PepperPluginRegistry* registry = NULL;
  // This object leaks.  It is a temporary hack to work around a crash.
  // http://code.google.com/p/chromium/issues/detail?id=63234
  if (!registry)
    registry = new PepperPluginRegistry;
  return registry;
}

// static
void PepperPluginRegistry::ComputeList(std::vector<PepperPluginInfo>* plugins) {
  ComputeBuiltInPlugins(plugins);
  ComputePluginsFromCommandLine(plugins);
}

// static
void PepperPluginRegistry::PreloadModules() {
  std::vector<PepperPluginInfo> plugins;
  ComputeList(&plugins);
  for (size_t i = 0; i < plugins.size(); ++i) {
    if (!plugins[i].is_internal) {
      base::NativeLibrary library = base::LoadNativeLibrary(plugins[i].path);
      LOG_IF(WARNING, !library) << "Unable to load plugin "
                                << plugins[i].path.value();
    }
  }
}

const PepperPluginInfo* PepperPluginRegistry::GetInfoForPlugin(
    const FilePath& path) const {
  for (size_t i = 0; i < plugin_list_.size(); ++i) {
    if (path == plugin_list_[i].path)
      return &plugin_list_[i];
  }
  return NULL;
}

webkit::ppapi::PluginModule* PepperPluginRegistry::GetLiveModule(
    const FilePath& path) {
  NonOwningModuleMap::iterator it = live_modules_.find(path);
  if (it == live_modules_.end())
    return NULL;
  return it->second;
}

void PepperPluginRegistry::AddLiveModule(const FilePath& path,
                                         webkit::ppapi::PluginModule* module) {
  DCHECK(live_modules_.find(path) == live_modules_.end());
  live_modules_[path] = module;
}

void PepperPluginRegistry::PluginModuleDead(
    webkit::ppapi::PluginModule* dead_module) {
  // DANGER: Don't dereference the dead_module pointer! It may be in the
  // process of being deleted.

  // Modules aren't destroyed very often and there are normally at most a
  // couple of them. So for now we just do a brute-force search.
  for (NonOwningModuleMap::iterator i = live_modules_.begin();
       i != live_modules_.end(); ++i) {
    if (i->second == dead_module) {
      live_modules_.erase(i);
      return;
    }
  }
  NOTREACHED();  // Should have always found the module above.
}

PepperPluginRegistry::~PepperPluginRegistry() {
  // Explicitly clear all preloaded modules first. This will cause callbacks
  // to erase these modules from the live_modules_ list, and we don't want
  // that to happen implicitly out-of-order.
  preloaded_modules_.clear();

  DCHECK(live_modules_.empty());
}

PepperPluginRegistry::PepperPluginRegistry() {
  ComputeList(&plugin_list_);

  // Note that in each case, AddLiveModule must be called before completing
  // initialization. If we bail out (in the continue clauses) before saving
  // the initialized module, it will still try to unregister itself in its
  // destructor.
  for (size_t i = 0; i < plugin_list_.size(); i++) {
    const PepperPluginInfo& current = plugin_list_[i];
    if (current.is_out_of_process)
      continue;  // Out of process plugins need no special pre-initialization.

    scoped_refptr<webkit::ppapi::PluginModule> module =
        new webkit::ppapi::PluginModule(current.name, current.path, this);
    AddLiveModule(current.path, module);
    if (current.is_internal) {
      if (!module->InitAsInternalPlugin(current.internal_entry_points)) {
        DLOG(ERROR) << "Failed to load pepper module: " << current.path.value();
        continue;
      }
    } else {
      // Preload all external plugins we're not running out of process.
      if (!module->InitAsLibrary(current.path)) {
        DLOG(ERROR) << "Failed to load pepper module: " << current.path.value();
        continue;
      }
    }
    preloaded_modules_[current.path] = module;
  }
}

MessageLoop* PepperPluginRegistry::GetIPCMessageLoop() {
  // This is called only in the renderer so we know we have a child process.
  DCHECK(ChildProcess::current()) << "Must be in the renderer.";
  return ChildProcess::current()->io_message_loop();
}

base::WaitableEvent* PepperPluginRegistry::GetShutdownEvent() {
  DCHECK(ChildProcess::current()) << "Must be in the renderer.";
  return ChildProcess::current()->GetShutDownEvent();
}

std::set<PP_Instance>* PepperPluginRegistry::GetGloballySeenInstanceIDSet() {
  // This function is not needed on the host side of the proxy.
  return NULL;
}

void PepperPluginRegistry::RegisterNaClModule(const GURL& url,
                                              const std::string& mime_type) {
  NaClModuleInfo info;
  info.url = url;
  info.mime_type = mime_type;

  DCHECK(FindNaClModule(url) == nacl_module_list_.end());
  nacl_module_list_.push_front(info);
}

void PepperPluginRegistry::UnregisterNaClModule(const GURL& url) {
  NaClModuleInfoList::iterator iter = FindNaClModule(url);
  DCHECK(iter != nacl_module_list_.end());
  nacl_module_list_.erase(iter);
}

void PepperPluginRegistry::UpdatePluginListWithNaClModules() {
  FilePath path;
  PathService::Get(chrome::FILE_NACL_PLUGIN, &path);

  webkit::npapi::PluginList::Singleton()->UnregisterInternalPlugin(path);

  const PepperPluginInfo* pepper_info = GetInfoForPlugin(path);
  webkit::npapi::WebPluginInfo info = pepper_info->ToWebPluginInfo();

  DCHECK(nacl_module_list_.size() <= 1);
  for (NaClModuleInfoList::iterator iter = nacl_module_list_.begin();
       iter != nacl_module_list_.end(); ++iter) {
    webkit::npapi::WebPluginMimeType mime_type_info;
    mime_type_info.mime_type = iter->mime_type;
    mime_type_info.additional_param_names.push_back(UTF8ToUTF16("nacl"));
    mime_type_info.additional_param_values.push_back(
        UTF8ToUTF16(iter->url.spec()));
    info.mime_types.push_back(mime_type_info);
  }

  webkit::npapi::PluginList::Singleton()->RefreshPlugins();
  webkit::npapi::PluginList::Singleton()->RegisterInternalPlugin(info);
}

PepperPluginRegistry::NaClModuleInfoList::iterator
    PepperPluginRegistry::FindNaClModule(const GURL& url) {
  for (NaClModuleInfoList::iterator iter = nacl_module_list_.begin();
       iter != nacl_module_list_.end(); ++iter) {
    if (iter->url == url)
      return iter;
  }
  return nacl_module_list_.end();
}