/*---------------------------------------------------------------------------*
  Project:  Revolution archiver library
  File:     arc.c

  Copyright (C)2001-2006 Nintendo  All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law.  They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Log: arc.c,v $
  Revision 1.4  07/04/2006 09:08:44  hiratsu
  Added "const" to arguments.

  Revision 1.3  05/16/2006 02:05:24  kawaset
  Supported archive files created by "darch[D] -c ."

  Revision 1.2  04/19/2006 10:45:39  hiratsu
  Modified include path for Revolution.

  Revision 1.1  01/06/2006 02:31:04  yasuh-to
  initial check in

    
    1     7/02/01 11:42p Hashida
    Initial revision.
    
  $NoKeywords: $
 *---------------------------------------------------------------------------*/

#include <revolution/os.h>
#include <ctype.h>          // for tolower
#include <revolution/arc.h>

typedef struct FSTEntry FSTEntry;

struct FSTEntry
{
    unsigned int    isDirAndStringOff;    // the first byte is for isDir
                                          // the next 3bytes: name offset
    unsigned int    parentOrPosition;     // parent entry (dir entry)
                                          // position (file entry)
    unsigned int    nextEntryOrLength;    // next entry (dir entry)
                                          // length (file entry)
};

#define entryIsDir(fstStart, i)     \
    ( ( ( fstStart[i].isDirAndStringOff & 0xff000000 ) == 0 )? FALSE:TRUE )
#define stringOff(fstStart, i)      \
        ( fstStart[i].isDirAndStringOff & 0x00ffffff )
#define parentDir(fstStart, i)       \
        ( fstStart[i].parentOrPosition )
#define nextDir(fstStart, i)        \
        ( fstStart[i].nextEntryOrLength )
#define filePosition(fstStart, i)       \
        ( fstStart[i].parentOrPosition )
#define fileLength(fstStart, i)         \
        ( fstStart[i].nextEntryOrLength )

BOOL ARCInitHandle(void* arcStart, ARCHandle* handle)
{
    FSTEntry*           FSTEntries;
    ARCHeader*          arcHeader;

    arcHeader = (ARCHeader*)arcStart;

    if (arcHeader->magic != DARCH_MAGIC)
    {
        OSHalt("ARCInitHandle: bad archive format");
    }
    
    handle->archiveStartAddr = arcStart;
    handle->FSTStart = FSTEntries = (void*)((u32)arcStart + arcHeader->fstStart);
    handle->fileStart = (void*)((u32)arcStart + arcHeader->fileStart);

    ASSERTMSG(FSTEntries != NULL, "ARCInitHandle: bad archive format");

    handle->entryNum = nextDir(FSTEntries, 0);
    handle->FSTStringStart = (char*)&(FSTEntries[handle->entryNum]);
    handle->FSTLength = (u32)arcHeader->fstSize;
    handle->currDir = 0;

    return TRUE;
}

BOOL ARCOpen(ARCHandle* handle, const char* fileName, ARCFileInfo* af)
{
    s32         entry;
    char        currentDir[128];
    FSTEntry*   FSTEntries;
    
    ASSERTMSG( handle, "ARCOpen(): NULL pointer is specified to ARCHandle structure" );
    ASSERTMSG( fileName, "ARCOpen(): NULL pointer is specified to fileName" );
    ASSERTMSG( af, "ARCOpen(): NULL pointer is specified to ARCFileInfo structure" );

    FSTEntries = (FSTEntry*)handle->FSTStart;

    entry = ARCConvertPathToEntrynum(handle, fileName);

    if (0 > entry)
    {
#if 1
        ARCGetCurrentDir(handle, currentDir, 128);
#endif
        OSReport("Warning: ARCOpen(): file '%s' was not found under %s in the archive.\n",
                 fileName, currentDir);
        return FALSE;
    }

    ASSERTMSG1( !entryIsDir(FSTEntries, entry), "ARCOpen(): %s is a directory", fileName );

    if ( (entry < 0) || entryIsDir(FSTEntries, entry) )
    {
        return FALSE;
    }

    af->handle      = handle;
    af->startOffset = filePosition(FSTEntries, entry);
    af->length      = fileLength(FSTEntries, entry);

    return TRUE;
}

BOOL ARCFastOpen(ARCHandle* handle, s32 entrynum, ARCFileInfo* af)
{
    FSTEntry*           FSTEntries;

    ASSERTMSG(handle, "ARCFastOpen(): null pointer is specified to ARCHandle address  ");
    ASSERTMSG(af,
              "ARCFastOpen(): null pointer is specified to ARCFileInfo address  ");
    ASSERTMSG1((0 <= entrynum) && (entrynum < handle->entryNum),
               "ARCFastOpen(): specified entry number '%d' is out of range  ",
               entrynum);

    FSTEntries = (FSTEntry*)handle->FSTStart;

    ASSERTMSG1(!entryIsDir(FSTEntries, entrynum),
               "ARCFastOpen(): entry number '%d' is assigned to a directory  ",
               entrynum);

    if ( (entrynum < 0) || (entrynum >= handle->entryNum) ||
         entryIsDir(FSTEntries, entrynum) )
    {
        return FALSE;
    }

    af->handle      = handle;
    af->startOffset = filePosition(FSTEntries, entrynum);
    af->length      = fileLength(FSTEntries, entrynum);

    return TRUE;
}

 /*---------------------------------------------------------------------------*
    Name:               isSame

    Description:        compare two strings up to the first string hits '/' or
                        '\0'

    Arguments:          path     path name
                        string   directory or file name

    Returns:            TRUE if same, FALSE if not
 *---------------------------------------------------------------------------*/
static BOOL isSame(const char* path, const char* string)
{
    while(*string != '\0')
    {
        // compare in case-insensitive
        if (tolower(*path++) != tolower(*string++))
        {
            return FALSE;
        }
    }

    if ( (*path == '/') || (*path == '\0') )
    {
        return TRUE;
    }

    return FALSE;
}


s32 ARCConvertPathToEntrynum(ARCHandle* handle, const char* pathPtr)
{
    const char*  ptr;
    char*        stringPtr;
    BOOL         isDir;
    s32          length; // must be signed
    u32          dirLookAt;
    u32          i;
    const char*  origPathPtr = pathPtr;
    FSTEntry*    FSTEntries;


    ASSERTMSG(handle, "ARCConvertPathToEntrynum(): null pointer is specified to ARCHandle structure");
    ASSERTMSG(pathPtr, "ARCConvertPathToEntrynum(): null pointer is specified to file name");
    

    dirLookAt = handle->currDir;
    FSTEntries = (FSTEntry*)handle->FSTStart;

    while (1)
    {

        // check /, ./, ../
        if (*pathPtr == '\0')
        {
            return (s32)dirLookAt;
        } else if (*pathPtr == '/')
        {
            dirLookAt = 0;
            pathPtr++;
            continue;
        }
        else if (*pathPtr == '.')
        {
            if (*(pathPtr + 1) == '.')
            {
                if (*(pathPtr + 2) == '/')
                {
                    dirLookAt = parentDir(FSTEntries, dirLookAt);
                    pathPtr += 3;
                    continue;
                }
                else if (*(pathPtr + 2) == '\0')
                {
                    return (s32)parentDir(FSTEntries, dirLookAt);
                }
            }
            else if (*(pathPtr + 1) == '/')
            {
                pathPtr += 2;
                continue;
            }
            else if (*(pathPtr + 1) == '\0')
            {
                return (s32)dirLookAt;
            }
        }

        // directory or file? Can be checked by the endmark
        for(ptr = pathPtr; (*ptr != '\0') && (*ptr != '/'); ptr++)
            ;
            
        // it's true that one ends with '/' should be a directory name,
        // but one ends with '\0' is not always a file name.
        isDir = (*ptr == '\0')? FALSE : TRUE;
        length = (s32)(ptr - pathPtr);

        ptr = pathPtr;

        for(i = dirLookAt + 1; i < nextDir(FSTEntries, dirLookAt);
            i = entryIsDir(FSTEntries, i)? nextDir(FSTEntries, i): (i+1) )
        {
dot:
            // isDir == FALSE doesn't mean it's a file.
            // so it's legal to compare it to a directory
            if ( ( entryIsDir(FSTEntries, i) == FALSE ) &&
                 (isDir == TRUE) )
            {
                continue;
            }

            stringPtr = handle->FSTStringStart + stringOff(FSTEntries, i);

            // check "."
            // support archive files created by "darch[D] -c ."
            if (*stringPtr == '.' && *(stringPtr + 1) == '\0') {
                i++;
                goto dot;
            }

            if ( isSame(ptr, stringPtr) == TRUE )
            {
                goto next_hier;
            }

        } // for()

        return -1;

      next_hier:
        if (! isDir)
        {
            return (s32)i;
        }

        dirLookAt = i;
        pathPtr += length + 1;

    } // while(1)

    // NOT REACHED
}

/*---------------------------------------------------------------------------*
  Name:         myStrncpy

  Description:  copy a string. Difference from standard strncpy is:
                    1. do not pad dest with null characters
                    2. do not terminate dest with a null
                    3. return the number of chars copied

  Arguments:    dest        destination
                src         source
                maxlen      maximum length of copy

  Returns:      Num of chars copied
 *---------------------------------------------------------------------------*/
static u32 myStrncpy(char* dest, char* src, u32 maxlen)
{
    u32         i = maxlen;

    while( (i > 0) && (*src != 0) )
    {
        *dest++ = *src++;
        i--;
    }
    
    return (maxlen - i);
}

/*---------------------------------------------------------------------------*
  Name:         entryToPath

  Description:  Convert from fst entry to path. The result is not null
                terminated.

  Arguments:    entry       FST entry
                path        pointer to store the result
                maxlen      size of the buffer start from path

  Returns:      Num of chars copied
 *---------------------------------------------------------------------------*/
static u32 entryToPath(ARCHandle* handle, u32 entry, char* path, u32 maxlen)
{
    char*       name;
    u32         loc;
    FSTEntry*    FSTEntries;

    FSTEntries = (FSTEntry*)handle->FSTStart;

    if (entry == 0)
    {
        return 0;
    }

    name = handle->FSTStringStart + stringOff(FSTEntries, entry);

    loc = entryToPath(handle, parentDir(FSTEntries, entry), path, maxlen);
    
    if (loc == maxlen)
    {
        return loc;
    }

    *(path + loc++) = '/';

    loc += myStrncpy(path + loc, name, maxlen - loc);
    
    return loc;
}


/*---------------------------------------------------------------------------*
  Name:         ARCConvertEntrynumToPath

  Description:  Convert from fst entry to path.

  Arguments:    entrynum    FST entry
                path        pointer to store the result
                maxlen      size of the buffer start from path

  Returns:      TRUE if all the path fits in maxlen. FALSE if not (in this
                case, it's truncated to fit maxlen).
 *---------------------------------------------------------------------------*/
static BOOL ARCConvertEntrynumToPath(ARCHandle* handle, s32 entrynum, char* path, u32 maxlen)
{
    u32         loc;
    FSTEntry*    FSTEntries;


    FSTEntries = (FSTEntry*)handle->FSTStart;
    ASSERTMSG1((0 <= entrynum) && (entrynum < handle->entryNum),
               "ARCConvertEntrynumToPath: specified entrynum(%d) is out of range  ",
                entrynum );
    ASSERTMSG1(1 < maxlen, "ARCConvertEntrynumToPath: maxlen should be more than 1 (%d is specified)",
               maxlen );
    // currently only directories can be converted to path
    // finding the directory where a file is located is not so easy
    // while finding the parent directory of a directory is a piece of cake.
    ASSERTMSG(entryIsDir(FSTEntries, entrynum),
              "ARCConvertEntrynumToPath: cannot convert an entry num for a file to path  ");

    loc = entryToPath(handle, (u32)entrynum, path, maxlen);

    if (loc == maxlen)
    {
        // Overwrite the last char with NULL
        path[maxlen - 1] = '\0';
        return FALSE;
    }

    // For directories, put '/' at the last
    if (entryIsDir(FSTEntries, entrynum))
    {
        if (loc == maxlen - 1)
        {
            // There's no room to put the last '/', so just put '\0' and return FALSE
            path[loc] = '\0';
            return FALSE;
        }

        path[loc++] = '/';
    }
    
    path[loc] = '\0';
    return TRUE;
}

/*---------------------------------------------------------------------------*
  Name:         ARCGetCurrentDir

  Description:  Get current directory

  Arguments:    path        pointer to store the result
                maxlen      size of the buffer start from path

  Returns:      TRUE if all the path fits in maxlen. FALSE if not (in this
                case, it's truncated to fit maxlen).
 *---------------------------------------------------------------------------*/
BOOL ARCGetCurrentDir(ARCHandle* handle, char* path, u32 maxlen)
{
    ASSERTMSG1( 1 < maxlen, "ARCGetCurrentDir: maxlen should be more than 1 (%d is specified)",
                maxlen );

    return ARCConvertEntrynumToPath(handle, (s32)handle->currDir, path, maxlen);
}

void* ARCGetStartAddrInMem(ARCFileInfo* af)
{
    ARCHandle* handle;

    handle = af->handle;

    ASSERTMSG(handle, "ARCGetFileAddr(): af->handle is null pointer. Maybe it's not initialized properly");
    ASSERTMSG(af, "ARCGetFileAddr(): null pointer is specified to ARCFileInfo structure");
    
    return (void*)( (u32)handle->archiveStartAddr + af->startOffset );
}

u32 ARCGetStartOffset(ARCFileInfo* af)
{
    return af->startOffset;
}

u32 ARCGetLength(ARCFileInfo* af)
{
    return af->length;
}


BOOL ARCClose(ARCFileInfo* af)
{
#pragma unused(af)

    return TRUE;
}

BOOL ARCChangeDir(ARCHandle* handle, const char* dirName)
{
    s32         entry;
#ifdef _DEBUG
    char        currentDir[128];
#endif        
    FSTEntry*   FSTEntries;

    ASSERTMSG(handle, "ARCChangeDir(): null pointer is specified to ARCHandle");
    ASSERTMSG(dirName, "ARCChangeDir(): null pointer is specified to dirname");

    entry = ARCConvertPathToEntrynum(handle, dirName);
    FSTEntries = (FSTEntry*)handle->FSTStart;

#ifdef _DEBUG
    if (0 > entry)
    {
        ARCGetCurrentDir(handle, currentDir, 128);
        OSPanic(__FILE__, __LINE__, "ARCOpendir(): directory '%s' is not found under %s  ",
                dirName, currentDir);
    }
#endif
    ASSERTMSG1(entryIsDir(FSTEntries, entry), "ARCChangeDir(): %s is not a directory", dirName );

    if ( (entry < 0) || (entryIsDir(FSTEntries, entry) == FALSE) )
    {
        return FALSE;
    }

    handle->currDir = (u32)entry;

    return TRUE;
}


BOOL ARCOpenDir(ARCHandle* handle, const char* dirName, ARCDir* dir)
{
    s32         entry;
    FSTEntry*   FSTEntries;
#ifdef _DEBUG
    char        currentDir[128];
#endif        

    ASSERTMSG(handle, "ARCOpenDir(): null pointer is specified to ARCHandle");
    ASSERTMSG(dirName, "ARCOpenDir(): null pointer is specified to ARCDir");

    entry = ARCConvertPathToEntrynum(handle, dirName);
    FSTEntries = (FSTEntry*)handle->FSTStart;

#ifdef _DEBUG
    if (entry < 0)
    {
        ARCGetCurrentDir(handle, currentDir, 128);
        OSPanic(__FILE__, __LINE__,
                "ARCOpendir(): directory '%s' is not found under %s  ",
                dirName,
                currentDir);
    }
#endif

    ASSERTMSG1( entryIsDir(FSTEntries, entry), "ARCOpenDir(): %s is a regular file", dirName );

    if ( (entry < 0) || (entryIsDir(FSTEntries, entry) == FALSE) )
        return FALSE;

    dir->handle = handle;
    dir->entryNum = (u32)entry;
    dir->location = (u32)entry + 1;
    dir->next = nextDir(FSTEntries, entry);

    return TRUE;
}

BOOL ARCReadDir(ARCDir* dir, ARCDirEntry* dirent)
{
    u32         loc;
    FSTEntry*   FSTEntries;
    ARCHandle*  handle;

    handle = dir->handle;

    ASSERTMSG(handle, "ARCReadDir: dir->handle is null pointer. Maybe it's not initialized properly");
    
    FSTEntries = (FSTEntry*)handle->FSTStart;

    // Check the next location. loc == dir->next means it reached the
    // end of the directory. Other check is for illegal setting by ARCSeekDir.
    loc = dir->location;
retry:
    if ( (loc <= dir->entryNum) || (dir->next <= loc) )
        return FALSE;

    dirent->handle = handle;
    dirent->entryNum = loc;
    dirent->isDir = entryIsDir(FSTEntries, loc);
    dirent->name = handle->FSTStringStart + stringOff(FSTEntries, loc);

    // check "."
    // support archive files created by "darch[D] -c ."
    if (dirent->name[0] == '.' && dirent->name[1] == '\0') {
        loc++;
        goto retry;
    }

    dir->location = entryIsDir(FSTEntries, loc)? nextDir(FSTEntries, loc) : (loc+1);

    return TRUE;
}

BOOL ARCCloseDir(ARCDir* dir)
{
#pragma unused (dir)

    return TRUE;
}