/*
 ** The Sleuth Kit 
 **
 ** Brian Carrier [carrier <at> sleuthkit [dot] org]
 ** Copyright (c) 2010-2011 Brian Carrier.  All Rights reserved
 **
 ** This software is distributed under the Common Public License 1.0
 **
 */

/**
 * \file tsk_auto.h
 * Contains the class definitions for the automated file extraction classes.   
 * Note that this file is not meant to be directly included.  
 * It is included by libtsk.h.
 */

/**
 * \defgroup autolib File Extraction Automation Functionality
 */

#ifndef _TSK_AUTO_H
#define _TSK_AUTO_H

#ifdef __cplusplus

// Include the other TSK header files

#include "tsk/base/tsk_base.h"
#include "tsk/img/tsk_img.h"
#include "tsk/vs/tsk_vs.h"
#include "tsk/fs/tsk_fs.h"

#include <string>
#include <vector>


#define TSK_AUTO_TAG 0x9191ABAB

typedef enum {
    TSK_FILTER_CONT = 0x00,     ///< Framework should continue to process this object
    TSK_FILTER_STOP = 0x01,     ///< Framework should stop processing the image
    TSK_FILTER_SKIP = 0x02,     ///< Framework should skip this object and go on to the next
} TSK_FILTER_ENUM;


/** \ingroup autolib
 * C++ class that automatically analyzes a disk image to extract files from it.  This class
 * hides many of the details that are required to use lower-level TSK APIs to analyze volume 
 * and file systems. 
 * 
 * The processFile() method must be implemented and it will be called for each file and 
 * directory that is found. 
 * 
 * An image file must be first opened using openImage().  It can then be analyzed using one
 * of the findFilesInXXXX() methods.  The filterXX() methods can be used to skip volumes
 * and file systems. 
 *
 * This class, by default, will not stop if an error occurs.  It registers the error into an 
 * internal list. Those can be retrieved with getErrorList().  If you want to deal with errors
 * differently, you must implement handleError(). 
 */
class TskAuto {
  public:
    unsigned int m_tag;


     TskAuto();
     virtual ~ TskAuto();

    virtual uint8_t openImage(int, const TSK_TCHAR * const images[],
        TSK_IMG_TYPE_ENUM, unsigned int a_ssize);
    virtual uint8_t openImageUtf8(int, const char *const images[],
        TSK_IMG_TYPE_ENUM, unsigned int a_ssize);
    virtual uint8_t openImageHandle(TSK_IMG_INFO *);
    virtual void closeImage();

    TSK_OFF_T getImageSize() const;
    /**
     * Returns true if all processing and recursion should stop. 
     */
    bool getStopProcessing() const;
    
    uint8_t findFilesInImg();
    uint8_t findFilesInVs(TSK_OFF_T start);
    uint8_t findFilesInVs(TSK_OFF_T start, TSK_VS_TYPE_ENUM vtype);
    uint8_t findFilesInFs(TSK_OFF_T start);
    uint8_t findFilesInFs(TSK_OFF_T start, TSK_FS_TYPE_ENUM ftype);
    uint8_t findFilesInFs(TSK_OFF_T start, TSK_INUM_T inum);
    uint8_t findFilesInFs(TSK_OFF_T start, TSK_FS_TYPE_ENUM ftype,
        TSK_INUM_T inum);
    uint8_t findFilesInFs(TSK_FS_INFO * a_fs_info);
    TSK_RETVAL_ENUM findFilesInFsRet(TSK_OFF_T start,
        TSK_FS_TYPE_ENUM a_ftype);

    void setFileFilterFlags(TSK_FS_DIR_WALK_FLAG_ENUM);
    void setVolFilterFlags(TSK_VS_PART_FLAG_ENUM);

    /**
     * TskAuto calls this method before it processes the volume system that is found in an 
     * image. You can use this to learn about the volume system before it is processed
     * and you can force TskAuto to skip this volume system. 
     * @param vs_info volume system details
     * @returns Value to show if Vs should be processed, skipped, or process should stop.
     */
    virtual TSK_FILTER_ENUM filterVs(const TSK_VS_INFO * vs_info);

    /**
     * TskAuto calls this method before it processes each volume that is found in a 
     * volume system. You can use this to learn about each volume before it is processed
     * and you can force TskAuto to skip this volume.  The setvolFilterFlags() method can be
     * used to configure if TskAuto should process unallocated space. 
     *
     * @param vs_part Parition details
     * @returns Value to show if volume should be processed, skipped, or process should stop.
     */
    virtual TSK_FILTER_ENUM filterVol(const TSK_VS_PART_INFO * vs_part);

    /**
     * TskAuto calls this method before it processes each file system that is found in a 
     * volume. You can use this to learn about each file system before it is processed
     * and you can force TskAuto to skip this file system. 
     * @param fs_info file system details
     * @returns Value to show if FS should be processed, skipped, or process should stop.
     */
    virtual TSK_FILTER_ENUM filterFs(TSK_FS_INFO * fs_info);

    /**
     * TskAuto calls this method for each file and directory that it finds in an image. 
     * The setFileFilterFlags() method can be used to set the criteria for what types of
     * files this should be called for. There are several methods, such as isDir() that
     * can be used by this method to help focus in on the files that you care about. 
     * When errors are encountered, send them to registerError(). 
     *
     * @param fs_file file  details
     * @param path full path of parent directory
     * @returns STOP or OK. All error must have been registered. 
     */
    virtual TSK_RETVAL_ENUM processFile(TSK_FS_FILE * fs_file,
        const char *path) = 0;

    
    /**
     * Internal method that TskAuto calls when it encounters issues while processing an image.
     * It will add the error to an internal list and then call handleError() to allow the
     * sub-class to decide what to do with the error.
     * The tsk global error values must be set before this is called (tsk_error_set_errno, etc.).
     * This method will reset the error values before it returns.
     *
     * @returns 1 if the caller should stop processing (registerError() implementation should
     * also call setStopProcessing() to ensure all processes stop) or 0 if they should continue. 
     */    
    uint8_t registerError();
    
    struct error_record {
        int code;
        std::string msg1;
        std::string msg2;
    };
    
    /**
     * Get the list of errors that were added to 
     * the internal list.  This list could be empty 
     * if the implementing class already acted on 
     * the errors or never called addToErrorList().
     * @returns list of errors.
     */
    const std::vector<error_record> getErrorList();
    
    /**
     * Remove the errors on the internal list.
     */
    void resetErrorList();
    
    static std::string errorRecordToString(error_record &rec);
    

    /**
     * Override this method to get called for each error that 
     * is registered. This method allows you to log the message
     * or stop processing. Use setStopProcessing() to do that.
     *
     * @return 1 to stop the processing flow and 0 to continue. 
     */
    virtual uint8_t handleError();

    /**
    * get volume description of the lastly processed volume
    * @return volume description string of the lastly processed volume
    */
    std::string getCurVsPartDescr() const;

    /**
     * get volume flags of the lastly processed volume.
     * @return flags for lastly processed volume.
     */
    TSK_VS_PART_FLAG_ENUM getCurVsPartFlag() const;

    /**
     * Determine if we are inside of a volume system and 
     * therefore we can trust the results of getCurVsPartFlag/Desc.
     */
    bool isCurVsValid() const;
    
  private:
    TSK_VS_PART_FLAG_ENUM m_volFilterFlags;
    TSK_FS_DIR_WALK_FLAG_ENUM m_fileFilterFlags;
    
    std::vector<error_record> m_errors;

    // prevent copying until we add proper logic to handle it
    TskAuto(const TskAuto&);
    TskAuto & operator=(const TskAuto&);

    static TSK_WALK_RET_ENUM dirWalkCb(TSK_FS_FILE * fs_file,
        const char *path, void *ptr);
    static TSK_WALK_RET_ENUM vsWalkCb(TSK_VS_INFO * vs_info,
        const TSK_VS_PART_INFO * vs_part, void *ptr);

    TSK_RETVAL_ENUM findFilesInFsInt(TSK_FS_INFO *, TSK_INUM_T inum);

    std::string m_curVsPartDescr; ///< description string of the current volume being processed
    TSK_VS_PART_FLAG_ENUM m_curVsPartFlag; ///< Flag of the current volume being processed
    bool m_curVsPartValid;         ///< True if we are inside of a volume system (and therefore m_CurVs are valid)
    void setCurVsPart(const TSK_VS_PART_INFO *);


  protected:
    TSK_IMG_INFO * m_img_info;
    bool m_internalOpen;        ///< True if m_img_info was opened in TskAuto and false if passed in
    bool m_stopAllProcessing;   ///< True if no further processing should occur
    
    
    uint8_t isNtfsSystemFiles(TSK_FS_FILE * fs_file, const char *path);
    uint8_t isFATSystemFiles(TSK_FS_FILE * fs_file);
    uint8_t isDotDir(TSK_FS_FILE * fs_file);
    uint8_t isDir(TSK_FS_FILE * fs_file);
    uint8_t isFile(TSK_FS_FILE * fs_file);
    uint8_t isDefaultType(TSK_FS_FILE * fs_file,
        const TSK_FS_ATTR * fs_attr);
    uint8_t isNonResident(const TSK_FS_ATTR * fs_attr);

    
    TSK_RETVAL_ENUM processAttributes(TSK_FS_FILE * fs_file,
        const char *path);

    /** 
     * Method that is called from processAttributes() for each attribute that a file
     * has.  processAttributes() is not called by default.  It exists so that implementations
     * of processFile() can choose to call it if they want to look at all of the attributes. 
     * You must implement this method to see each attribute and modify processFile() so that
     * it calls processAttributes().
     *
     * @param fs_file File being analyzed.
     * @param fs_attr Attribute of the file.
     * @param path full path of parent directory
     * @returns STOP or OK. All error must have been registered.  
     */
    virtual TSK_RETVAL_ENUM processAttribute(TSK_FS_FILE * fs_file,
                                             const TSK_FS_ATTR * fs_attr, const char *path);
    
    /**
     * When called, will cause TskAuto to not continue to recurse into directories and volumes. 
     */
    void setStopProcessing(); 
};


#endif

#endif
