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

/* 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/. */

/**

 * Implementation of moz-page-thumb protocol. This accesses and displays

 * screenshots for URLs that are stored in the profile directory.

 */

#include "nsIPageThumbsStorageService.h"

#include "PageThumbsProtocol.h"

#include "nsIURI.h"

#include "nsIFileURL.h"

#include "nsIFile.h"

#include "nsIChannel.h"

#include "nsComponentManagerUtils.h"

#include "nsNetUtil.h"

#include "mozilla/dom/URLSearchParams.h"

#include "nsStandardURL.h"

using mozilla::dom::URLParams;

using mozilla::net::nsStandardURL;

NS_IMPL_ISUPPORTS(PageThumbsProtocol, nsIProtocolHandler);

// PageThumbsProtocol::GetScheme

NS_IMETHODIMP

PageThumbsProtocol::GetScheme(nsACString& aScheme)

{

  aScheme.AssignLiteral("moz-page-thumb");

  return NS_OK;

}

// PageThumbsProtocol::GetDefaultPort

NS_IMETHODIMP

PageThumbsProtocol::GetDefaultPort(int32_t *aDefaultPort)

{

  *aDefaultPort = -1;

  return NS_OK;

}

// PageThumbsProtocol::GetProtocolFlags

NS_IMETHODIMP

PageThumbsProtocol::GetProtocolFlags(uint32_t *aProtocolFlags)

{

  *aProtocolFlags = (URI_DANGEROUS_TO_LOAD | URI_IS_LOCAL_RESOURCE |

                     URI_NORELATIVE | URI_NOAUTH);

  return NS_OK;

}

// PageThumbsProtocol::NewURI

NS_IMETHODIMP

PageThumbsProtocol::NewURI(const nsACString& aSpec,

                           const char *aOriginCharset,

                           nsIURI *aBaseURI, nsIURI **_retval)

{

  return NS_MutateURI(NS_SIMPLEURIMUTATOR_CONTRACTID)

           .SetSpec(aSpec)

           .Finalize(_retval);

}

// PageThumbsProtocol::NewChannel

NS_IMETHODIMP

PageThumbsProtocol::NewChannel2(nsIURI* aURI,

                                nsILoadInfo *aLoadInfo,

                                nsIChannel** _retval)

{

  // Get the file path for the URL

  nsCOMPtr <nsIFile> filePath;

  nsresult rv = GetFilePathForURL(aURI, getter_AddRefs(filePath));

  if (NS_WARN_IF(NS_FAILED(rv))) return rv;

  // Get a file URI from the local file path

  nsCOMPtr <nsIURI> fileURI;

  rv = NS_NewFileURI(getter_AddRefs(fileURI), filePath);

  if (NS_WARN_IF(NS_FAILED(rv))) return rv;

  // Create a new channel with the file URI created

  nsCOMPtr <nsIChannel> channel;

  nsCOMPtr <nsIIOService> ios = do_GetIOService();

  rv = ios->NewChannelFromURIWithLoadInfo(fileURI, aLoadInfo, getter_AddRefs(channel));

  if (NS_WARN_IF(NS_FAILED(rv))) return rv;

  channel->SetOriginalURI(aURI);

  channel.forget(_retval);

  return NS_OK;

}

NS_IMETHODIMP

PageThumbsProtocol::NewChannel(nsIURI* aURI, nsIChannel** _retval)

{

  return NewChannel2(aURI, nullptr, _retval);

}

// PageThumbsProtocol::AllowPort

NS_IMETHODIMP

PageThumbsProtocol::AllowPort(int32_t aPort, const char *aScheme, bool *_retval)

{

  *_retval = false;

  return NS_OK;

}

// PageThumbsProtocol::ParseProtocolURL

//

//    Extracts the URL from the query parameter. The URI is passed in in the form:

//    'moz-page-thumb://thumbnail/?url=http%3A%2F%2Fwww.mozilla.org%2F'.

nsresult

PageThumbsProtocol::ParseProtocolURL(nsIURI* aURI, nsString& aParsedURL)

{

  nsAutoCString spec;

  aURI->GetSpec(spec);

  // Check that we have the correct host

  nsAutoCString host;

  host = Substring(spec, spec.FindChar(':') + 3, 9);

  if (!host.EqualsLiteral("thumbnail")) {

    return NS_ERROR_NOT_AVAILABLE;

  }

  // Get the path out of the URI

  nsAutoCString path;

  nsresult rv = aURI->GetPathQueryRef(path);

  if (NS_WARN_IF(NS_FAILED(rv))) return rv;

  // Since this is a protocol URI and it doesn't parse nicely, we split on where

  // the start of the query is and parse it from there

  int32_t queryBegins = path.FindChar('?');

  if (queryBegins <= 0) {

    return NS_ERROR_MALFORMED_URI;

  }

  URLParams::Extract(Substring(path, queryBegins + 1),

                     NS_LITERAL_STRING("url"),

                     aParsedURL);

  // If there's no URL as part of the query params, there will be no thumbnail

  if (aParsedURL.IsVoid()) {

    return NS_ERROR_NOT_AVAILABLE;

  }

  return NS_OK;

}

// PageThumbsProtocol::GetFilePathForURL

//

//    Returns the thumbnail's file path for a given URL

nsresult

PageThumbsProtocol::GetFilePathForURL(nsIURI* aURI, nsIFile **_retval)

{

  nsresult rv;

  // Use PageThumbsStorageService to get the local file path of the screenshot

  // for the given URL

  nsAutoString filePathForURL;

  nsCOMPtr <nsIPageThumbsStorageService> pageThumbsStorage =

            do_GetService("@mozilla.org/thumbnails/pagethumbs-service;1", &rv);

  if (NS_WARN_IF(NS_FAILED(rv))) return rv;

  // Parse the protocol URL to extract the thumbnail's URL

  nsAutoString parsedURL;

  rv = ParseProtocolURL(aURI, parsedURL);

  if (NS_WARN_IF(NS_FAILED(rv))) return rv;

  rv = pageThumbsStorage->GetFilePathForURL(parsedURL, filePathForURL);

  if (NS_WARN_IF(NS_FAILED(rv))) return rv;

  // Find the local file containing the screenshot

  nsCOMPtr <nsIFile> filePath = do_CreateInstance(NS_LOCAL_FILE_CONTRACTID);

  rv = filePath->InitWithPath(filePathForURL);

  if (NS_WARN_IF(NS_FAILED(rv))) return rv;

  filePath.forget(_retval);

  return NS_OK;

}