/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the NPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the NPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */
#ifndef nsIDocument_h___
#define nsIDocument_h___

#include "nsISupports.h"
#include "nsEvent.h"
#include "nsString.h"
#include "nsChangeHint.h"
#include "nsCOMArray.h"
#include "nsIDocumentObserver.h"
#include "nsCOMPtr.h"
#include "nsIURI.h"
#include "nsIBindingManager.h"
#include "nsINodeInfo.h"
#include "nsWeakPtr.h"
#include "nsIWeakReferenceUtils.h"
#include "nsILoadGroup.h"
#include "nsReadableUtils.h"
#include "nsCRT.h"

class nsIAtom;
class nsIContent;
class nsIPresContext;
class nsIPresShell;

class nsIStreamListener;
class nsIStreamObserver;
class nsStyleSet;
class nsIStyleSheet;
class nsIStyleRule;
class nsIViewManager;
class nsIScriptGlobalObject;
class nsIDOMEvent;
class nsIDeviceContext;
class nsIParser;
class nsIDOMNode;
class nsIDOMDocumentFragment;
class nsILineBreaker;
class nsIWordBreaker;
class nsISelection;
class nsIChannel;
class nsIPrincipal;
class nsIDOMDocument;
class nsIDOMDocumentType;
class nsIObserver;
class nsISupportsArray;
class nsIScriptLoader;
class nsIContentSink;
class nsIScriptEventManager;
class nsICSSLoader;
class nsIHTMLStyleSheet;
class nsIHTMLCSSStyleSheet;

// IID for the nsIDocument interface
#define NS_IDOCUMENT_IID      \
{ 0xa492d7cf, 0x1777, 0x4c7a, \
  {0xaa, 0x8f, 0x94, 0x08, 0x28, 0x05, 0x55, 0xc9} }

// The base value for the content ID counter.
// This counter is used by the document to 
// assign a monotonically increasing ID to each content
// object it creates
#define NS_CONTENT_ID_COUNTER_BASE 10000


// Flag for AddStyleSheet().
#define NS_STYLESHEET_FROM_CATALOG                (1 << 0)


//----------------------------------------------------------------------

// Document interface
class nsIDocument : public nsISupports
{
public:
  NS_DEFINE_STATIC_IID_ACCESSOR(NS_IDOCUMENT_IID)
  NS_DECL_AND_IMPL_ZEROING_OPERATOR_NEW

  nsIDocument()
    : mCharacterSet(NS_LITERAL_CSTRING("ISO-8859-1")),
      mNextContentID(NS_CONTENT_ID_COUNTER_BASE) { }

  virtual ~nsIDocument() { }

  virtual nsresult StartDocumentLoad(const char* aCommand,
                                     nsIChannel* aChannel,
                                     nsILoadGroup* aLoadGroup,
                                     nsISupports* aContainer,
                                     nsIStreamListener **aDocListener,
                                     PRBool aReset,
                                     nsIContentSink* aSink = nsnull) = 0;

  virtual void StopDocumentLoad() = 0;

  /**
   * Return the title of the document. May return null.
   */
  const nsAFlatString& GetDocumentTitle() const
  {
    return mDocumentTitle;
  }

  /**
   * Return the URI for the document. May return null.
   */
  nsIURI* GetDocumentURI() const
  {
    return mDocumentURI;
  }
  void SetDocumentURI(nsIURI* aURI)
  {
    mDocumentURI = aURI;
  }

  /**
   * Return the principal responsible for this document.
   */
  virtual nsIPrincipal* GetPrincipal() = 0;

  /**
   * Set the principal responsible for this document.
   */
  virtual void SetPrincipal(nsIPrincipal *aPrincipal) = 0;

  /**
   * Return the LoadGroup for the document. May return null.
   */
  already_AddRefed<nsILoadGroup> GetDocumentLoadGroup() const
  {
    nsILoadGroup *group = nsnull;
    if (mDocumentLoadGroup)
      CallQueryReferent(mDocumentLoadGroup.get(), &group);

    return group;
  }

  /**
   * Return the base URI for relative URIs in the document (the document uri
   * unless it's overridden by SetBaseURI, HTML <base> tags, etc.).  The
   * returned URI could be null if there is no document URI.
   */
  nsIURI* GetBaseURI() const
  {
    return mDocumentBaseURI ? mDocumentBaseURI : mDocumentURI;
  }
  virtual nsresult SetBaseURI(nsIURI* aURI) = 0;

  /**
   * Get/Set the base target of a link in a document.
   */
  virtual void GetBaseTarget(nsAString &aBaseTarget) const = 0;
  virtual void SetBaseTarget(const nsAString &aBaseTarget) = 0;

  /**
   * Return a standard name for the document's character set. This
   * will trigger a startDocumentLoad if necessary to answer the
   * question.
   */
  const nsAFlatCString& GetDocumentCharacterSet() const
  {
    return mCharacterSet;
  }

  /**
   * Set the document's character encoding. |aCharSetID| should be canonical. 
   * That is, callers are responsible for the charset alias resolution. 
   */
  virtual void SetDocumentCharacterSet(const nsACString& aCharSetID) = 0;

  PRInt32 GetDocumentCharacterSetSource() const
  {
    return mCharacterSetSource;
  }

  void SetDocumentCharacterSetSource(PRInt32 aCharsetSource)
  {
    mCharacterSetSource = aCharsetSource;
  }

  /**
   * Add an observer that gets notified whenever the charset changes.
   */
  virtual nsresult AddCharSetObserver(nsIObserver* aObserver) = 0;

  /**
   * Remove a charset observer.
   */
  virtual void RemoveCharSetObserver(nsIObserver* aObserver) = 0;

  /**
   * Get the Content-Type of this document.
   * (This will always return NS_OK, but has this signature to be compatible
   *  with nsIDOMNSDocument::GetContentType())
   */
  NS_IMETHOD GetContentType(nsAString& aContentType) = 0;

  /**
   * Set the Content-Type of this document.
   */
  virtual void SetContentType(const nsAString& aContentType) = 0;

  /**
   * Return the language of this document.
   */
  void GetContentLanguage(nsAString& aContentLanguage) const
  {
    CopyASCIItoUCS2(mContentLanguage, aContentLanguage);
  }

  // The state BidiEnabled should persist across multiple views
  // (screen, print) of the same document.

  /**
   * Check if the document contains bidi data.
   * If so, we have to apply the Unicode Bidi Algorithm.
   */
  PRBool GetBidiEnabled() const
  {
    return mBidiEnabled;
  }

  /**
   * Indicate the document contains bidi data.
   * Currently, we cannot disable bidi, because once bidi is enabled,
   * it affects a frame model irreversibly, and plays even though
   * the document no longer contains bidi data.
   */
  void SetBidiEnabled(PRBool aBidiEnabled)
  {
    mBidiEnabled = aBidiEnabled;
  }

  /**
   * Return the Line Breaker for the document
   */
  virtual nsILineBreaker* GetLineBreaker() = 0;
  virtual void SetLineBreaker(nsILineBreaker* aLineBreaker) = 0;
  virtual nsIWordBreaker* GetWordBreaker() = 0;
  virtual void SetWordBreaker(nsIWordBreaker* aWordBreaker) = 0;

  /**
   * Access HTTP header data (this may also get set from other
   * sources, like HTML META tags).
   */
  virtual void GetHeaderData(nsIAtom* aHeaderField, nsAString& aData) const = 0;
  virtual void SetHeaderData(nsIAtom* aheaderField, const nsAString& aData) = 0;

  /**
   * Create a new presentation shell that will use aContext for its
   * presentation context (presentation contexts <b>must not</b> be
   * shared among multiple presentation shells).
   */
  virtual nsresult CreateShell(nsIPresContext* aContext,
                               nsIViewManager* aViewManager,
                               nsStyleSet* aStyleSet,
                               nsIPresShell** aInstancePtrResult) = 0;
  virtual PRBool DeleteShell(nsIPresShell* aShell) = 0;
  virtual PRUint32 GetNumberOfShells() const = 0;
  virtual nsIPresShell *GetShellAt(PRUint32 aIndex) const = 0;

  /**
   * Return the parent document of this document. Will return null
   * unless this document is within a compound document and has a
   * parent. Note that this parent chain may cross chrome boundaries.
   */
  nsIDocument *GetParentDocument() const
  {
    return mParentDocument;
  }

  /**
   * Set the parent document of this document.
   */
  void SetParentDocument(nsIDocument* aParent)
  {
    mParentDocument = aParent;
  }

  /**
   * Set the sub document for aContent to aSubDoc.
   */
  virtual nsresult SetSubDocumentFor(nsIContent *aContent,
                                     nsIDocument* aSubDoc) = 0;

  /**
   * Get the sub document for aContent
   */
  virtual nsIDocument *GetSubDocumentFor(nsIContent *aContent) const = 0;

  /**
   * Find the content node for which aDocument is a sub document.
   */
  virtual nsIContent *FindContentForSubDocument(nsIDocument *aDocument) const = 0;

  /**
   * Return the root content object for this document.
   */
  nsIContent *GetRootContent() const
  {
    return mRootContent;
  }
  virtual void SetRootContent(nsIContent* aRoot) = 0;

  /** 
   * Get the direct children of the document - content in
   * the prolog, the root content and content in the epilog.
   */
  virtual nsIContent *GetChildAt(PRUint32 aIndex) const = 0;
  virtual PRInt32 IndexOf(nsIContent* aPossibleChild) const = 0;
  virtual PRUint32 GetChildCount() const = 0;

  /**
   * Accessors to the collection of stylesheets owned by this document.
   * Style sheets are ordered, most significant last.
   */

  /**
   * Get the number of stylesheets
   *
   * @param aIncludeSpecialSheets if this is set to true, all sheets
   *   that are document sheets (including "special" sheets like
   *   attribute sheets and inline style sheets) will be returned.  If
   *   false, only "normal" stylesheets will be returned   
   * @return the number of stylesheets
   * @throws no exceptions
   */
  virtual PRInt32 GetNumberOfStyleSheets(PRBool aIncludeSpecialSheets) const = 0;
  
  /**
   * Get a particular stylesheet
   * @param aIndex the index the stylesheet lives at.  This is zero-based
   * @param aIncludeSpecialSheets see GetNumberOfStyleSheets.  If this
   *   is false, not all sheets will be returnable
   * @return the stylesheet at aIndex.  Null if aIndex is out of range.
   * @throws no exceptions
   */
  virtual nsIStyleSheet* GetStyleSheetAt(PRInt32 aIndex,
                                         PRBool aIncludeSpecialSheets) const = 0;
  
  /**
   * Insert a sheet at a particular spot in the stylesheet list (zero-based)
   * @param aSheet the sheet to insert
   * @param aIndex the index to insert at.  This index will be
   *   adjusted for the "special" sheets.
   * @throws no exceptions
   */
  virtual void InsertStyleSheetAt(nsIStyleSheet* aSheet, PRInt32 aIndex) = 0;

  /**
   * Get the index of a particular stylesheet.  This will _always_
   * consider the "special" sheets as part of the sheet list.
   * @param aSheet the sheet to get the index of
   * @return aIndex the index of the sheet in the full list
   */
  virtual PRInt32 GetIndexOfStyleSheet(nsIStyleSheet* aSheet) const = 0;

  /**
   * Replace the stylesheets in aOldSheets with the stylesheets in
   * aNewSheets. The two lists must have equal length, and the sheet
   * at positon J in the first list will be replaced by the sheet at
   * position J in the second list.  Some sheets in the second list
   * may be null; if so the corresponding sheets in the first list
   * will simply be removed.
   */
  virtual void UpdateStyleSheets(nsCOMArray<nsIStyleSheet>& aOldSheets,
                                 nsCOMArray<nsIStyleSheet>& aNewSheets) = 0;

  /**
   * Add a stylesheet to the document
   */
  virtual void AddStyleSheet(nsIStyleSheet* aSheet, PRUint32 aFlags) = 0;

  /**
   * Remove a stylesheet from the document
   */
  virtual void RemoveStyleSheet(nsIStyleSheet* aSheet) = 0;

  /**
   * Notify the document that the applicable state of the sheet changed
   * and that observers should be notified and style sets updated
   */
  virtual void SetStyleSheetApplicableState(nsIStyleSheet* aSheet,
                                            PRBool aApplicable) = 0;  

  /**
   * Get this document's CSSLoader.  May return null in error
   * conditions (OOM)
   */
  virtual nsICSSLoader* GetCSSLoader() = 0;

  /**
   * Get this document's attribute stylesheet.  May return null if
   * there isn't one.
   */
  virtual nsIHTMLStyleSheet* GetAttributeStyleSheet() const = 0;

  /**
   * Get this document's inline style sheet.  May return null if there
   * isn't one
   */
  virtual nsIHTMLCSSStyleSheet* GetInlineStyleSheet() const = 0;
  
  /**
   * Set the object from which a document can get a script context.
   * This is the context within which all scripts (during document 
   * creation and during event handling) will run.
   */
  virtual nsIScriptGlobalObject* GetScriptGlobalObject() const = 0;
  virtual void SetScriptGlobalObject(nsIScriptGlobalObject* aGlobalObject) = 0;

  /**
   * Get the script loader for this document
   */ 
  virtual nsIScriptLoader* GetScriptLoader() = 0;

  //----------------------------------------------------------------------

  // Document notification API's

  /**
   * Add a new observer of document change notifications. Whenever
   * content is changed, appended, inserted or removed the observers are
   * informed.
   */
  virtual void AddObserver(nsIDocumentObserver* aObserver) = 0;

  /**
   * Remove an observer of document change notifications. This will
   * return false if the observer cannot be found.
   */
  virtual PRBool RemoveObserver(nsIDocumentObserver* aObserver) = 0;

  // Observation hooks used to propagate notifications to document observers.
  // BeginUpdate must be called before any batch of modifications of the
  // content model or of style data, EndUpdate must be called afterward.
  // To make this easy and painless, use the mozAutoDocUpdate helper class.
  virtual void BeginUpdate(nsUpdateType aUpdateType) = 0;
  virtual void EndUpdate(nsUpdateType aUpdateType) = 0;
  virtual void BeginLoad() = 0;
  virtual void EndLoad() = 0;
  virtual void CharacterDataChanged(nsIContent* aContent, PRBool aAppend) = 0;
  // notify that one or two content nodes changed state
  // either may be nsnull, but not both
  virtual void ContentStatesChanged(nsIContent* aContent1,
                                    nsIContent* aContent2,
                                    PRInt32 aStateMask) = 0;
  virtual void AttributeWillChange(nsIContent* aChild,
                                   PRInt32 aNameSpaceID,
                                   nsIAtom* aAttribute) = 0;
  virtual void AttributeChanged(nsIContent* aChild,
                                PRInt32 aNameSpaceID,
                                nsIAtom* aAttribute,
                                PRInt32 aModType) = 0;
  virtual void ContentAppended(nsIContent* aContainer,
                               PRInt32 aNewIndexInContainer) = 0;
  virtual void ContentInserted(nsIContent* aContainer,
                               nsIContent* aChild,
                               PRInt32 aIndexInContainer) = 0;
  virtual void ContentReplaced(nsIContent* aContainer,
                               nsIContent* aOldChild,
                               nsIContent* aNewChild,
                               PRInt32 aIndexInContainer) = 0;
  virtual void ContentRemoved(nsIContent* aContainer,
                              nsIContent* aChild,
                              PRInt32 aIndexInContainer) = 0;

  // Observation hooks for style data to propagate notifications
  // to document observers
  virtual void StyleRuleChanged(nsIStyleSheet* aStyleSheet,
                                nsIStyleRule* aOldStyleRule,
                                nsIStyleRule* aNewStyleRule) = 0;
  virtual void StyleRuleAdded(nsIStyleSheet* aStyleSheet,
                              nsIStyleRule* aStyleRule) = 0;
  virtual void StyleRuleRemoved(nsIStyleSheet* aStyleSheet,
                                nsIStyleRule* aStyleRule) = 0;

  virtual nsresult HandleDOMEvent(nsIPresContext* aPresContext,
                                  nsEvent* aEvent, nsIDOMEvent** aDOMEvent,
                                  PRUint32 aFlags,
                                  nsEventStatus* aEventStatus) = 0;

  virtual void FlushPendingNotifications(PRBool aFlushReflows=PR_TRUE,
                                         PRBool aUpdateViews=PR_FALSE) = 0;

  PRInt32 GetAndIncrementContentID()
  {
    return mNextContentID++;
  }

  nsIBindingManager* GetBindingManager() const
  {
    return mBindingManager;
  }

  nsINodeInfoManager* GetNodeInfoManager() const
  {
    return mNodeInfoManager;
  }

  virtual void Reset(nsIChannel* aChannel, nsILoadGroup* aLoadGroup) = 0;
  /**
   * Reset this document to aURI and aLoadGroup.  aURI must not be null.
   */
  virtual void ResetToURI(nsIURI *aURI, nsILoadGroup* aLoadGroup) = 0;

  virtual void AddReference(void *aKey, nsISupports *aReference) = 0;
  virtual already_AddRefed<nsISupports> RemoveReference(void *aKey) = 0;

  /**
   * Set the container (docshell) for this document.
   */
  void SetContainer(nsISupports *aContainer)
  {
    mDocumentContainer = do_GetWeakReference(aContainer);
  }

  /**
   * Get the container (docshell) for this document.
   */
  already_AddRefed<nsISupports> GetContainer() const
  {
    nsISupports* container = nsnull;
    if (mDocumentContainer)
      CallQueryReferent(mDocumentContainer.get(), &container);

    return container;
  }

  virtual nsIScriptEventManager* GetScriptEventManager() = 0;

  /**
   * Set and get XML declaration. Notice that if version is empty,
   * there can be no XML declaration (it is a required part).
   */
  virtual void SetXMLDeclaration(const nsAString& aVersion,
                                 const nsAString& aEncoding,
                                 const nsAString& Standalone) = 0;
  virtual void GetXMLDeclaration(nsAString& aVersion,
                                 nsAString& aEncoding,
                                 nsAString& Standalone) = 0;

  virtual PRBool IsCaseSensitive()
  {
    return PR_TRUE;
  }

  virtual PRBool IsScriptEnabled() = 0;

protected:
  nsString mDocumentTitle;
  nsCOMPtr<nsIURI> mDocumentURI;
  nsCOMPtr<nsIURI> mDocumentBaseURI;

  nsWeakPtr mDocumentLoadGroup;

  nsWeakPtr mDocumentContainer;

  nsCString mCharacterSet;
  PRInt32 mCharacterSetSource;

  // This is just a weak pointer; the parent document owns its children.
  nsIDocument* mParentDocument;

  // A weak reference to the only child element, or null if no
  // such element exists.
  nsIContent* mRootContent;

  // A content ID counter used to give a monotonically increasing ID
  // to the content objects in the document's content model
  PRInt32 mNextContentID;

  nsCOMPtr<nsIBindingManager> mBindingManager;
  nsCOMPtr<nsINodeInfoManager> mNodeInfoManager;

  // True if BIDI is enabled.
  PRBool mBidiEnabled;

  nsXPIDLCString mContentLanguage;
  nsCString mContentType;
};


/**
 * Helper class to automatically handle batching of document updates.  This
 * class will call BeginUpdate on construction and EndUpdate on destruction on
 * the given document with the given update type.  The document could be null,
 * in which case no updates will be called.  The constructor also takes a
 * boolean that can be set to false to prevent notifications.
 */
class mozAutoDocUpdate
{
public:
  mozAutoDocUpdate(nsIDocument* aDocument, nsUpdateType aUpdateType,
                   PRBool aNotify) :
    mDocument(aNotify ? aDocument : nsnull),
    mUpdateType(aUpdateType)
  {
    if (mDocument) {
      mDocument->BeginUpdate(mUpdateType);
    }
  }

  ~mozAutoDocUpdate()
  {
    if (mDocument) {
      mDocument->EndUpdate(mUpdateType);
    }
  }

private:
  nsCOMPtr<nsIDocument> mDocument;
  nsUpdateType mUpdateType;
};

// XXX These belong somewhere else
nsresult
NS_NewHTMLDocument(nsIDocument** aInstancePtrResult);

nsresult
NS_NewXMLDocument(nsIDocument** aInstancePtrResult);

#ifdef MOZ_SVG
nsresult
NS_NewSVGDocument(nsIDocument** aInstancePtrResult);
#endif

nsresult
NS_NewImageDocument(nsIDocument** aInstancePtrResult);

nsresult
NS_NewDocumentFragment(nsIDOMDocumentFragment** aInstancePtrResult,
                       nsIDocument* aOwnerDocument);
nsresult
NS_NewDOMDocument(nsIDOMDocument** aInstancePtrResult,
                  const nsAString& aNamespaceURI, 
                  const nsAString& aQualifiedName, 
                  nsIDOMDocumentType* aDoctype,
                  nsIURI* aBaseURI);
nsresult
NS_NewPluginDocument(nsIDocument** aInstancePtrResult);

#endif /* nsIDocument_h___ */
