/*
    This file is part of the KDE libraries

    Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
    Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
    Copyright (C) 2003 Apple Computer, Inc.

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.

    This class provides all functionality needed for loading images, style sheets and html
    pages from the web. It has a memory cache for these objects.
*/
#ifndef _khtml_loader_h
#define _khtml_loader_h

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <time.h>

#include "loader_client.h"
#ifdef HAVE_LIBJPEG
#include "loader_jpeg.h"
#endif

#include <stdlib.h>
#include <qptrlist.h>
#include <qobject.h>
#include <qptrdict.h>
#include <qdict.h>
#include <qpixmap.h>
#include <qbuffer.h>
#include <qstringlist.h>
#include <qtextcodec.h>

#include <kurl.h>
#include <kio/global.h>

#include <khtml_settings.h>
#include <dom/dom_string.h>

class QMovie;
class KHTMLPart;

namespace KIO {
  class Job;
  class TransferJob;
}

namespace DOM
{
    class CSSStyleSheetImpl;
    class DocumentImpl;
};

#if APPLE_CHANGES
class KWQLoader;
#endif

namespace khtml
{
    class CachedObject;
    class Request;
    class DocLoader;

 #define MAX_LRU_LISTS 20
    
    struct LRUList {
        CachedObject* m_head;
        CachedObject* m_tail;
    
        LRUList();
        ~LRUList();
    };
    
    /**
     * @internal
     *
     * A cached object. Classes who want to use this object should derive
     * from CachedObjectClient, to get the function calls in case the requested data has arrived.
     *
     * This class also does the actual communication with kio and loads the file.
     */
    class CachedObject
    {
    public:
	enum Type {
	    Image,
	    CSSStyleSheet,
	    Script
	};

	enum Status {
	    NotCached,    // this URL is not cached
	    Unknown,      // let imagecache decide what to do with it
	    New,          // inserting new image
        Pending,      // only partially loaded
	    Persistent,   // never delete this pixmap
	    Cached,       // regular case
	    Uncacheable   // too big to be cached,
	};  	          // will be destroyed as soon as possible

	CachedObject(const DOM::DOMString &url, Type type, KIO::CacheControl _cachePolicy, time_t _expireDate, int size = 0)
	{
	    m_url = url;
	    m_type = type;
	    m_status = Pending;
	    m_size = size;
	    m_free = false;
	    m_cachePolicy = _cachePolicy;
	    m_request = 0;
#if APPLE_CHANGES
        m_response = 0;
#endif            
	    m_expireDate = _expireDate;
        m_deleted = false;
        m_expireDateChanged = false;
        
        m_accessCount = 0;
        
        m_nextInLRUList = 0;
        m_prevInLRUList = 0;
	}
	virtual ~CachedObject();

	virtual void data( QBuffer &buffer, bool eof) = 0;
	virtual void error( int err, const char *text ) = 0;

	const DOM::DOMString &url() const { return m_url; }
	Type type() const { return m_type; }

	virtual void ref(CachedObjectClient *consumer);
	virtual void deref(CachedObjectClient *consumer);

	int count() const { return m_clients.count(); }

	Status status() const { return m_status; }

	int size() const { return m_size; }

    int accessCount() const { return m_accessCount; }
    void increaseAccessCount() { m_accessCount++; }
    
	/**
	 * computes the status of an object after loading.
	 * the result depends on the objects size and the size of the cache
	 * also updates the expire date on the cache entry file
	 */
	void finish();

        /**
         * Called by the cache if the object has been removed from the cache dict
         * while still being referenced. This means the object should kill itself
         * if its reference counter drops down to zero.
         */
        void setFree( bool b ) { m_free = b; }

        KIO::CacheControl cachePolicy() const { return m_cachePolicy; }

        void setRequest(Request *_request);

#if APPLE_CHANGES
        void *response() { return m_response; }
        void setResponse (void *response);
#endif
        bool canDelete() const { return (m_clients.count() == 0 && !m_request); }

	void setExpireDate(time_t _expireDate, bool changeHttpCache);
	
	bool isExpired() const;

        virtual bool schedule() const { return false; }

        /**
         * List of acceptable mimetypes seperated by ",". A mimetype may contain a wildcard.
         */
        // e.g. "text/*"
        QString accept() const { return m_accept; }
        void setAccept(const QString &_accept) { m_accept = _accept; }

    protected:
        void setSize(int size);
        
        QPtrDict<CachedObjectClient> m_clients;

	DOM::DOMString m_url;
        QString m_accept;
        Request *m_request;
#if APPLE_CHANGES
        void *m_response;
#endif
	Type m_type;
	Status m_status;
    private:
	int m_size;
    int m_accessCount;
    
    protected:
	time_t m_expireDate;
	KIO::CacheControl m_cachePolicy;
        bool m_free : 1;
        bool m_deleted : 1;
        bool m_loading : 1;
        bool m_expireDateChanged : 1;
    
    private:
        bool allowInLRUList() { return canDelete() && status() != Persistent; }
        
        CachedObject *m_nextInLRUList;
        CachedObject *m_prevInLRUList;
        friend class Cache;
    };


    /**
     * a cached style sheet
     */
    class CachedCSSStyleSheet : public CachedObject
    {
    public:
	CachedCSSStyleSheet(DocLoader* dl, const DOM::DOMString &url, KIO::CacheControl cachePolicy, time_t _expireDate, const QString& charset);
	CachedCSSStyleSheet(const DOM::DOMString &url, const QString &stylesheet_data);
	virtual ~CachedCSSStyleSheet();

	const DOM::DOMString &sheet() const { return m_sheet; }

	virtual void ref(CachedObjectClient *consumer);
	virtual void deref(CachedObjectClient *consumer);

	virtual void data( QBuffer &buffer, bool eof );
	virtual void error( int err, const char *text );

        virtual bool schedule() const { return true; }

	void checkNotify();

    protected:
	DOM::DOMString m_sheet;
        QTextCodec* m_codec;
    };

    /**
     * a cached script
     */
    class CachedScript : public CachedObject
    {
    public:
	CachedScript(DocLoader* dl, const DOM::DOMString &url, KIO::CacheControl cachePolicy, time_t _expireDate, const QString& charset);
	CachedScript(const DOM::DOMString &url, const QString &script_data);
	virtual ~CachedScript();

	const DOM::DOMString &script() const { return m_script; }

	virtual void ref(CachedObjectClient *consumer);
	virtual void deref(CachedObjectClient *consumer);

	virtual void data( QBuffer &buffer, bool eof );
	virtual void error( int err, const char *text );

        virtual bool schedule() const { return false; }

	void checkNotify();

        bool isLoaded() const { return !m_loading; }

    protected:
	DOM::DOMString m_script;
        QTextCodec* m_codec;
    };

    class ImageSource;

    /**
     * a cached image
     */
    class CachedImage : public QObject, public CachedObject
    {
	Q_OBJECT
    public:
	CachedImage(DocLoader* dl, const DOM::DOMString &url, KIO::CacheControl cachePolicy, time_t _expireDate);
	virtual ~CachedImage();

	const QPixmap &pixmap() const;
	const QPixmap &tiled_pixmap(const QColor& bg);

        QSize pixmap_size() const;    // returns the size of the complete (i.e. when finished) loading
        QRect valid_rect() const;     // returns the rectangle of pixmap that has been loaded already

        void ref(CachedObjectClient *consumer);
	virtual void deref(CachedObjectClient *consumer);

	virtual void data( QBuffer &buffer, bool eof );
	virtual void error( int err, const char *text );

        bool isTransparent() const { return isFullyTransparent; }
        bool isErrorImage() const { return errorOccured; }

        void setShowAnimations( KHTMLSettings::KAnimationAdvice );

        virtual bool schedule() const { return true; }

	void checkNotify();

    protected:
	void clear();

    private slots:
	/**
	 * gets called, whenever a QMovie changes frame
	 */
	void movieUpdated( const QRect &rect );
        void movieStatus(int);
        void movieResize(const QSize&);
        void deleteMovie();

    private:
        void do_notify(const QPixmap& p, const QRect& r);

	QMovie* m;
        QPixmap* p;
	QPixmap* bg;
        QRgb bgColor;
        mutable QPixmap* pixPart;

        ImageSource* imgSource;
        const char* formatType;  // Is the name of the movie format type

	int width;
	int height;

	// Is set if movie format type ( incremental/animation) was checked
	bool typeChecked : 1;
        bool isFullyTransparent : 1;
        bool errorOccured : 1;
        bool monochrome : 1;
        KHTMLSettings::KAnimationAdvice m_showAnimations : 2;

        friend class Cache;

#if APPLE_CHANGES
    public:
        int dataSize() const { return m_dataSize; }
    private:
        int m_dataSize;
#endif
    };

    /**
     * @internal
     *
     * Manages the loading of scripts/images/stylesheets for a particular document
     */
    class DocLoader
    {
    public:
 	DocLoader(KHTMLPart*, DOM::DocumentImpl*);
 	~DocLoader();

	CachedImage *requestImage( const DOM::DOMString &url);
	CachedCSSStyleSheet *requestStyleSheet( const DOM::DOMString &url, const QString& charset);
        CachedScript *requestScript( const DOM::DOMString &url, const QString& charset);

	bool autoloadImages() const { return m_bautoloadImages; }
        KIO::CacheControl cachePolicy() const { return m_cachePolicy; }
        KHTMLSettings::KAnimationAdvice showAnimations() const { return m_showAnimations; }
        time_t expireDate() const { return m_expireDate; }
        KHTMLPart* part() const { return m_part; }
        DOM::DocumentImpl* doc() const { return m_doc; }

        void setExpireDate( time_t );
        void setAutoloadImages( bool );
        void setCachePolicy( KIO::CacheControl cachePolicy );
        void setShowAnimations( KHTMLSettings::KAnimationAdvice );
        void removeCachedObject( CachedObject*) const;

    private:
        bool needReload(const KURL &fullUrl);

        friend class Cache;
        friend class DOM::DocumentImpl;

        QStringList m_reloadedURLs;
        mutable QPtrList<CachedObject> m_docObjects;
	time_t m_expireDate;
	KIO::CacheControl m_cachePolicy;
        bool m_bautoloadImages : 1;
        KHTMLSettings::KAnimationAdvice m_showAnimations : 2;
        KHTMLPart* m_part;
        DOM::DocumentImpl* m_doc;
    };

    /**
     * @internal
     */
    class Request
    {
    public:
	Request(DocLoader* dl, CachedObject *_object, bool _incremental);
	~Request();
	bool incremental;
	QBuffer m_buffer;
	CachedObject *object;
        DocLoader* m_docLoader;
     };

    /**
     * @internal
     */
    class Loader : public QObject
    {
	Q_OBJECT

    public:
	Loader();
	~Loader();

	void load(DocLoader* dl, CachedObject *object, bool incremental = true);

        int numRequests( DocLoader* dl ) const;
        void cancelRequests( DocLoader* dl );

        // may return 0L
        KIO::Job *jobForRequest( const DOM::DOMString &url ) const;

#if APPLE_CHANGES
        KWQLoader *kwq;
#endif

    signals:
        void requestStarted( khtml::DocLoader* dl, khtml::CachedObject* obj );
	void requestDone( khtml::DocLoader* dl, khtml::CachedObject *obj );
	void requestFailed( khtml::DocLoader* dl, khtml::CachedObject *obj );

    protected slots:
	void slotFinished( KIO::Job * );
#if APPLE_CHANGES
	void slotData( KIO::Job *, const char *data, int size );
        void slotReceivedResponse ( KIO::Job *, void *response );
#else
	void slotData( KIO::Job *, const QByteArray & );
#endif

    private:
	void servePendingRequests();

	QPtrList<Request> m_requestsPending;
	QPtrDict<Request> m_requestsLoading;
#ifdef HAVE_LIBJPEG
        KJPEGFormatType m_jpegloader;
#endif
    };

        /**
     * @internal
     *
     * Provides a cache/loader for objects needed for displaying the html page.
     * At the moment these are stylesheets, scripts and images
     */
    class Cache
    {
	friend class DocLoader;
    public:
	/**
	 * init the cache in case it's not already. This needs to get called once
	 * before using it.
	 */
	static void init();

	/**
	 * Ask the cache for some url. Will return a cachedObject, and
	 * load the requested data in case it's not cahced
         * if the DocLoader is zero, the url must be full-qualified.
         * Otherwise, it is automatically base-url expanded
	 */
	static CachedImage *requestImage( DocLoader* l, const DOM::DOMString &url, bool reload=false, time_t _expireDate=0);

	/**
	 * Ask the cache for some url. Will return a cachedObject, and
	 * load the requested data in case it's not cached
	 */
	static CachedCSSStyleSheet *requestStyleSheet( DocLoader* l, const DOM::DOMString &url, bool reload=false, time_t _expireDate=0, const QString& charset = QString::null);

        /**
         * Pre-loads a stylesheet into the cache.
         */
        static void preloadStyleSheet(const QString &url, const QString &stylesheet_data);

	/**
	 * Ask the cache for some url. Will return a cachedObject, and
	 * load the requested data in case it's not cahced
	 */
	static CachedScript *requestScript( DocLoader* l, const DOM::DOMString &url, bool reload=false, time_t _expireDate=0, const QString& charset=QString::null);

        /**
         * Pre-loads a script into the cache.
         */
        static void preloadScript(const QString &url, const QString &script_data);

	/**
	 * sets the size of the cache. This will only hod approximately, since the size some
	 * cached objects (like stylesheets) take up in memory is not exaclty known.
	 */
	static void setSize( int bytes );
	/**
	 * returns the size of the cache
	 */
	static int size() { return maxSize; };

	/**
	 * prints some statistics to stdout
	 */
	static void statistics();

	/**
	 * clean up cache
	 */
	static void flush(bool force=false);

	/**
	 * clears the cache
	 * Warning: call this only at the end of your program, to clean
	 * up memory (useful for finding memory holes)
	 */
	static void clear();

	static Loader *loader() { return m_loader; }

    	static QPixmap *nullPixmap;
        static QPixmap *brokenPixmap;

        static void removeCacheEntry( CachedObject *object );

#if APPLE_CHANGES
        struct TypeStatistic {
            int count;
            int size;
            TypeStatistic() : count(0), size(0) { }
        };
        
        struct Statistics {
            TypeStatistic images;
            TypeStatistic movies;
            TypeStatistic styleSheets;
            TypeStatistic scripts;
            TypeStatistic other;
        };

        static Statistics getStatistics();
        static void flushAll();
        static void setCacheDisabled(bool);
#endif

        static void insertInLRUList(CachedObject *);
        static void removeFromLRUList(CachedObject *);
        static bool adjustSize(CachedObject *, int sizeDelta);
        
        static LRUList* getLRUListFor(CachedObject* o);
        
        static void checkLRUAndUncacheableListIntegrity();

    protected:
        static QDict<CachedObject> *cache;
        static QPtrList<DocLoader>* docloader;
    
        static int maxSize;
        static int flushCount;
    
        static Loader *m_loader;
    
        static unsigned long s_ulRefCnt;
    
        static void moveToHeadOfLRUList(CachedObject *);
    
        static LRUList *m_LRULists;
        static int m_totalSizeOfLRULists;
            
        static CachedObject *m_headOfUncacheableList;
            
        static int m_countOfLRUAndUncacheableLists;
    };

};

#endif