/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* 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/. */

#ifndef SubstitutingProtocolHandler_h___

#define SubstitutingProtocolHandler_h___

#include "nsISubstitutingProtocolHandler.h"

#include "nsIOService.h"

#include "nsISubstitutionObserver.h"

#include "nsDataHashtable.h"

#include "nsStandardURL.h"

#include "mozilla/chrome/RegistryMessageUtils.h"

#include "mozilla/Maybe.h"

class nsIIOService;

namespace mozilla {

namespace net {

//

// Base class for resource://-like substitution protocols.

//

// If you add a new protocol, make sure to change nsChromeRegistryChrome

// to properly invoke CollectSubstitutions at the right time.

class SubstitutingProtocolHandler

{

public:

  SubstitutingProtocolHandler(const char* aScheme, uint32_t aFlags, bool aEnforceFileOrJar = true);

  explicit SubstitutingProtocolHandler(const char* aScheme);

  NS_INLINE_DECL_REFCOUNTING(SubstitutingProtocolHandler);

  NS_DECL_NON_VIRTUAL_NSIPROTOCOLHANDLER;

  NS_DECL_NON_VIRTUAL_NSISUBSTITUTINGPROTOCOLHANDLER;

  bool HasSubstitution(const nsACString& aRoot) const { return mSubstitutions.Get(aRoot, nullptr); }

  MOZ_MUST_USE nsresult CollectSubstitutions(InfallibleTArray<SubstitutionMapping>& aResources);

protected:

  virtual ~SubstitutingProtocolHandler() = default;

  void ConstructInternal();

  MOZ_MUST_USE nsresult SendSubstitution(const nsACString& aRoot, nsIURI* aBaseURI, uint32_t aFlags);

  nsresult GetSubstitutionFlags(const nsACString& root, uint32_t* flags);

  // Override this in the subclass to try additional lookups after checking

  // mSubstitutions.

  virtual MOZ_MUST_USE nsresult GetSubstitutionInternal(const nsACString& aRoot, nsIURI** aResult, uint32_t* aFlags)

  {

    *aResult = nullptr;

    *aFlags = 0;

    return NS_ERROR_NOT_AVAILABLE;

  }

  // Override this in the subclass to check for special case when resolving URIs

  // _before_ checking substitutions.

  virtual MOZ_MUST_USE bool ResolveSpecialCases(const nsACString& aHost,

                                                const nsACString& aPath,

                                                const nsACString& aPathname,

                                                nsACString& aResult)

  {

    return false;

  }

  // Override this in the subclass to check for special case when opening

  // channels.

  virtual MOZ_MUST_USE nsresult SubstituteChannel(nsIURI* uri, nsILoadInfo* aLoadInfo, nsIChannel** result)

  {

    return NS_OK;

  }

  nsIIOService* IOService() { return mIOService; }

private:

  struct SubstitutionEntry

  {

    SubstitutionEntry()

        : flags(0)

    {

    }

    ~SubstitutionEntry() = default;

    nsCOMPtr<nsIURI> baseURI;

    uint32_t flags;

  };

  // Notifies all observers that a new substitution from |aRoot| to

  // |aBaseURI| has been set/installed for this protocol handler.

  void NotifyObservers(const nsACString& aRoot, nsIURI* aBaseURI);

  nsCString mScheme;

  Maybe<uint32_t> mFlags;

  nsDataHashtable<nsCStringHashKey, SubstitutionEntry> mSubstitutions;

  nsCOMPtr<nsIIOService> mIOService;

  // The list of observers added with AddObserver that will be

  // notified when substitutions are set or unset.

  nsTArray<nsCOMPtr<nsISubstitutionObserver>> mObservers;

  // In general, we expect the principal of a document loaded from a

  // substituting URI to be a codebase principal for that URI (rather than

  // a principal for whatever is underneath). However, this only works if

  // the protocol handler for the underlying URI doesn't set an explicit

  // owner (which chrome:// does, for example). So we want to require that

  // substituting URIs only map to other URIs of the same type, or to

  // file:// and jar:// URIs.

  //

  // Enforcing this for ye olde resource:// URIs could carry compat risks, so

  // we just try to enforce it on new protocols going forward.

  bool mEnforceFileOrJar;

};

// SubstitutingURL : overrides nsStandardURL::GetFile to provide nsIFile resolution

class SubstitutingURL : public nsStandardURL

{

public:

  virtual nsStandardURL* StartClone() override;

  virtual MOZ_MUST_USE nsresult EnsureFile() override;

  NS_IMETHOD GetClassIDNoAlloc(nsCID *aCID) override;

private:

  explicit SubstitutingURL() : nsStandardURL(true) {}

  explicit SubstitutingURL(bool aSupportsFileURL) : nsStandardURL(true) { MOZ_ASSERT(aSupportsFileURL); }

  virtual nsresult Clone(nsIURI** aURI) override { return nsStandardURL::Clone(aURI); }

public:

  class Mutator

    : public TemplatedMutator<SubstitutingURL>

  {

    NS_DECL_ISUPPORTS

  public:

    explicit Mutator() = default;

  private:

    virtual ~Mutator() = default;

    SubstitutingURL* Create() override

    {

      return new SubstitutingURL();

    }

  };

  NS_IMETHOD Mutate(nsIURIMutator** aMutator) override

  {

    RefPtr<SubstitutingURL::Mutator> mutator = new SubstitutingURL::Mutator();

    nsresult rv = mutator->InitFromURI(this);

    if (NS_FAILED(rv)) {

      return rv;

    }

    mutator.forget(aMutator);

    return NS_OK;

  }

  friend BaseURIMutator<SubstitutingURL>;

  friend TemplatedMutator<SubstitutingURL>;

};

} // namespace net

} // namespace mozilla

#endif /* SubstitutingProtocolHandler_h___ */