/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sw=4 sts=4 et cin: */
/* 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/. */

/*

  A protocol handler for ``chrome:''

*/

#include "nsChromeProtocolHandler.h"
#include "nsChromeRegistry.h"
#include "nsCOMPtr.h"
#include "nsContentUtils.h"
#include "nsThreadUtils.h"
#include "nsIChannel.h"
#include "nsIChromeRegistry.h"
#include "nsIFile.h"
#include "nsIFileChannel.h"
#include "nsIIOService.h"
#include "nsILoadGroup.h"
#include "nsIScriptSecurityManager.h"
#include "nsIStandardURL.h"
#include "nsNetUtil.h"
#include "nsNetCID.h"
#include "nsIURL.h"
#include "nsString.h"
#include "nsStandardURL.h"

////////////////////////////////////////////////////////////////////////////////

NS_IMPL_ISUPPORTS(nsChromeProtocolHandler,
                  nsIProtocolHandler,
                  nsISupportsWeakReference)

////////////////////////////////////////////////////////////////////////////////
// nsIProtocolHandler methods:

NS_IMETHODIMP
nsChromeProtocolHandler::GetScheme(nsACString &result)
{
    result.AssignLiteral("chrome");
    return NS_OK;
}

NS_IMETHODIMP
nsChromeProtocolHandler::GetDefaultPort(int32_t *result)
{
    *result = -1;        // no port for chrome: URLs
    return NS_OK;
}

NS_IMETHODIMP
nsChromeProtocolHandler::AllowPort(int32_t port, const char *scheme, bool *_retval)
{
    // don't override anything.
    *_retval = false;
    return NS_OK;
}

NS_IMETHODIMP
nsChromeProtocolHandler::GetProtocolFlags(uint32_t *result)
{
    *result = URI_STD | URI_IS_UI_RESOURCE | URI_IS_LOCAL_RESOURCE;
    return NS_OK;
}

NS_IMETHODIMP
nsChromeProtocolHandler::NewURI(const nsACString &aSpec,
                                const char *aCharset,
                                nsIURI *aBaseURI,
                                nsIURI **result)
{

    // Chrome: URLs (currently) have no additional structure beyond that provided
    // by standard URLs, so there is no "outer" given to CreateInstance

    RefPtr<mozilla::net::nsStandardURL> surl = new mozilla::net::nsStandardURL();

    nsresult rv = surl->Init(nsIStandardURL::URLTYPE_STANDARD, -1, aSpec,
                             aCharset, aBaseURI);
    if (NS_FAILED(rv))
        return rv;

    // Canonify the "chrome:" URL; e.g., so that we collapse
    // "chrome://navigator/content/" and "chrome://navigator/content"
    // and "chrome://navigator/content/navigator.xul".

    rv = nsChromeRegistry::Canonify(surl);
    if (NS_FAILED(rv))
        return rv;

    surl->SetMutable(false);

    surl.forget(result);
    return NS_OK;
}

NS_IMETHODIMP
nsChromeProtocolHandler::NewChannel2(nsIURI* aURI,
                                     nsILoadInfo* aLoadInfo,
                                     nsIChannel** aResult)
{
    nsresult rv;

    NS_ENSURE_ARG_POINTER(aURI);
    NS_ENSURE_ARG_POINTER(aLoadInfo);

    NS_PRECONDITION(aResult, "Null out param");

#ifdef DEBUG
    // Check that the uri we got is already canonified
    nsresult debug_rv;
    nsCOMPtr<nsIURI> debugClone;
    debug_rv = aURI->Clone(getter_AddRefs(debugClone));
    if (NS_SUCCEEDED(debug_rv)) {
        nsCOMPtr<nsIURL> debugURL (do_QueryInterface(debugClone));
        debug_rv = nsChromeRegistry::Canonify(debugURL);
        if (NS_SUCCEEDED(debug_rv)) {
            bool same;
            debug_rv = aURI->Equals(debugURL, &same);
            if (NS_SUCCEEDED(debug_rv)) {
                NS_ASSERTION(same, "Non-canonified chrome uri passed to nsChromeProtocolHandler::NewChannel!");
            }
        }
    }
#endif

    nsCOMPtr<nsIChannel> result;

    if (!nsChromeRegistry::gChromeRegistry) {
        // We don't actually want this ref, we just want the service to
        // initialize if it hasn't already.
        nsCOMPtr<nsIChromeRegistry> reg =
            mozilla::services::GetChromeRegistryService();
        NS_ENSURE_TRUE(nsChromeRegistry::gChromeRegistry, NS_ERROR_FAILURE);
    }

    nsCOMPtr<nsIURI> resolvedURI;
    rv = nsChromeRegistry::gChromeRegistry->ConvertChromeURL(aURI, getter_AddRefs(resolvedURI));
    if (NS_FAILED(rv)) {
#ifdef DEBUG
        printf("Couldn't convert chrome URL: %s\n",
               aURI->GetSpecOrDefault().get());
#endif
        return rv;
    }

    // We don't want to allow the inner protocol handler modify the result principal URI
    // since we want either |aURI| or anything pre-set by upper layers to prevail.
    nsCOMPtr<nsIURI> savedResultPrincipalURI;
    rv = aLoadInfo->GetResultPrincipalURI(getter_AddRefs(savedResultPrincipalURI));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = NS_NewChannelInternal(getter_AddRefs(result),
                               resolvedURI,
                               aLoadInfo);
    NS_ENSURE_SUCCESS(rv, rv);

#ifdef DEBUG
    nsCOMPtr<nsIFileChannel> fileChan(do_QueryInterface(result));
    if (fileChan) {
        nsCOMPtr<nsIFile> file;
        fileChan->GetFile(getter_AddRefs(file));

        bool exists = false;
        file->Exists(&exists);
        if (!exists) {
            nsAutoCString path;
            file->GetNativePath(path);
            printf("Chrome file doesn't exist: %s\n", path.get());
        }
    }
#endif

    // Make sure that the channel remembers where it was
    // originally loaded from.
    rv = aLoadInfo->SetResultPrincipalURI(savedResultPrincipalURI);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = result->SetOriginalURI(aURI);
    if (NS_FAILED(rv)) return rv;

    // Get a system principal for content files and set the owner
    // property of the result
    nsCOMPtr<nsIURL> url = do_QueryInterface(aURI);
    nsAutoCString path;
    rv = url->GetPath(path);
    if (StringBeginsWith(path, NS_LITERAL_CSTRING("/content/"))) {
        result->SetOwner(nsContentUtils::GetSystemPrincipal());
    }

    // XXX Removed dependency-tracking code from here, because we're not
    // tracking them anyways (with fastload we checked only in DEBUG
    // and with startupcache not at all), but this is where we would start
    // if we need to re-add.
    // See bug 531886, bug 533038.
    result->SetContentCharset(NS_LITERAL_CSTRING("UTF-8"));

    *aResult = result;
    NS_ADDREF(*aResult);
    return NS_OK;
}

NS_IMETHODIMP
nsChromeProtocolHandler::NewChannel(nsIURI* aURI,
                                    nsIChannel* *aResult)
{
  return NewChannel2(aURI, nullptr, aResult);
}

////////////////////////////////////////////////////////////////////////////////
