// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
//	Handles WAD file header, directory, lump I/O.
//
//-----------------------------------------------------------------------------


static const char
rcsid[] = "$Id: w_wad.c,v 1.5 1997/02/03 16:47:57 b1 Exp $";


#include "doomtype.h"
#include "m_swap.h"
#include "i_system.h"
#include "z_zone.h"

#ifdef __GNUG__
#pragma implementation "w_wad.h"
#endif
#include "w_wad.h"






//
// GLOBALS
//

// Location of each lump on disk.
lumpinfo_t*		lumpinfo;		
int			numlumps;

void**			lumpcache;


#define strcmpi	strcasecmp

void strupr (char* s)
{
    while (*s) { *s = toupper(*s); s++; }
}

int filelength (int handle) 
{ 
    return I_FileSize(handle);
}


void
ExtractFileBase
( char*		path,
  char*		dest )
{
    char*	src;
    int		length;

    src = path + strlen(path) - 1;
    
    // back up until a \ or the start
    while (src != path
	   && *(src-1) != '\\'
	   && *(src-1) != '/')
    {
	src--;
    }
    
    // copy up to eight characters
    memset (dest,0,8);
    length = 0;
    
    while (*src && *src != '.')
    {
	if (++length == 9)
	    I_Error ("Filename base of %s >8 chars",path);

	*dest++ = toupper((int)*src++);
    }
}





//
// LUMP BASED ROUTINES.
//

//
// W_AddFile
// All files are optional, but at least one file must be
//  found (PWAD, if all required lumps are present).
// Files with a .wad extension are wadlink files
//  with multiple lumps.
// Other files are single lumps with the base filename
//  for the lump name.
//
// If filename starts with a tilde, the file is handled
//  specially to allow map reloads.
// But: the reload feature is a fragile hack...

int			reloadlump;
char*			reloadname;


void W_AddFile (char *filename)
{
    wadinfo_t		header;
    lumpinfo_t*		lump_p;
    unsigned		i;
    int			handle;
    int			length;
    int			startlump;
    filelump_t*		fileinfo;
    filelump_t		singleinfo;
    int			storehandle;
    
    // open the file and add to directory

    // handle reload indicator.
    if (filename[0] == '~')
    {
	filename++;
	reloadname = filename;
	reloadlump = numlumps;
    }
		
    if ( (handle = I_FileOpenRead(filename)) == -1)
    {
	I_printf (" couldn't open %s\n",filename);
	return;
    }

    I_printf (" adding %s\n",filename);
    startlump = numlumps;
	
    if (strcmp (filename+strlen(filename)-3 , "wad" ) && strcmp (filename+strlen(filename)-3 , "WAD" ) )
    {
	// single lump file
	fileinfo = &singleinfo;
	singleinfo.filepos = 0;
	singleinfo.size = LONG(filelength(handle));
	ExtractFileBase (filename, singleinfo.name);
	numlumps++;
    }
    else 
    {
	// WAD file
	I_FileRead (handle, &header, sizeof(header));
	if (strncmp(header.identification,"IWAD",4))
	{
	    // Homebrew levels?
	    if (strncmp(header.identification,"PWAD",4))
	    {
		I_Error ("Wad file %s doesn't have IWAD "
			 "or PWAD id\n", filename);
	    }
	    
	    // ???modifiedgame = true;		
	}
	header.numlumps = LONG(header.numlumps);
	header.infotableofs = LONG(header.infotableofs);
	length = header.numlumps*sizeof(filelump_t);
	fileinfo = alloca (length);
	I_FilePos(handle, header.infotableofs);
	I_FileRead(handle, fileinfo, length);
	numlumps += header.numlumps;
    }

    
    // Fill in lumpinfo
    lumpinfo = I_Realloc (lumpinfo, numlumps*sizeof(lumpinfo_t));

    if (!lumpinfo)
	I_Error ("Couldn't realloc lumpinfo");

    lump_p = &lumpinfo[startlump];
	
    storehandle = reloadname ? -1 : handle;
	
    for (i=startlump ; i<numlumps ; i++,lump_p++, fileinfo++)
    {
	lump_p->handle = storehandle;
	lump_p->position = LONG(fileinfo->filepos);
	lump_p->size = LONG(fileinfo->size);
	strncpy (lump_p->name, fileinfo->name, 8);
    }
	
    if (reloadname)
	I_FileClose(handle);
}




//
// W_Reload
// Flushes any of the reloadable lumps in memory
//  and reloads the directory.
//
void W_Reload (void)
{
    wadinfo_t		header;
    int			lumpcount;
    lumpinfo_t*		lump_p;
    unsigned		i;
    int			handle;
    int			length;
    filelump_t*		fileinfo;
	
    if (!reloadname)
	return;
		
    if ( (handle = I_FileOpenRead(reloadname)) == -1)
	I_Error ("W_Reload: couldn't open %s",reloadname);

    I_FileRead(handle, &header, sizeof(header));
    lumpcount = LONG(header.numlumps);
    header.infotableofs = LONG(header.infotableofs);
    length = lumpcount*sizeof(filelump_t);
    fileinfo = alloca (length);
    I_FilePos(handle, header.infotableofs);
    I_FileRead(handle, fileinfo, length);
    
    // Fill in lumpinfo
    lump_p = &lumpinfo[reloadlump];
	
    for (i=reloadlump ;
	 i<reloadlump+lumpcount ;
	 i++,lump_p++, fileinfo++)
    {
	if (lumpcache[i])
	    Z_Free (lumpcache[i]);

	lump_p->position = LONG(fileinfo->filepos);
	lump_p->size = LONG(fileinfo->size);
    }
	
    I_FileClose(handle);
}



//
// W_InitMultipleFiles
// Pass a null terminated list of files to use.
// All files are optional, but at least one file
//  must be found.
// Files with a .wad extension are idlink files
//  with multiple lumps.
// Other files are single lumps with the base filename
//  for the lump name.
// Lump names can appear multiple times.
// The name searcher looks backwards, so a later file
//  does override all earlier ones.
//
void W_InitMultipleFiles (char** filenames)
{	
    int		size;
    
    // open all the files, load headers, and count lumps
    numlumps = 0;

    // will be realloced as lumps are added
    lumpinfo = I_Malloc(1);

    for ( ; *filenames ; filenames++)
	W_AddFile (*filenames);

    if (!numlumps)
	I_Error ("W_InitFiles: no files found");
    
    // set up caching
    size = numlumps * sizeof(*lumpcache);
    lumpcache = I_Malloc (size);
    
    if (!lumpcache)
	I_Error ("Couldn't allocate lumpcache");

    memset (lumpcache,0, size);
}




//
// W_InitFile
// Just initialize from a single file.
//
void W_InitFile (char* filename)
{
    char*	names[2];

    names[0] = filename;
    names[1] = NULL;
    W_InitMultipleFiles (names);
}



//
// W_NumLumps
//
int W_NumLumps (void)
{
    return numlumps;
}



//
// W_CheckNumForName
// Returns -1 if name not found.
//

int W_CheckNumForName (char* name)
{
    union {
	char	s[9];
	int	x[2];
	
    } name8;
    
    int		v1;
    int		v2;
    lumpinfo_t*	lump_p;

    // make the name into two integers for easy compares
    strncpy (name8.s,name,8);

    // in case the name was a fill 8 chars
    name8.s[8] = 0;

    // case insensitive
    strupr (name8.s);		

    v1 = name8.x[0];
    v2 = name8.x[1];


    // scan backwards so patch lump files take precedence
    lump_p = lumpinfo + numlumps;

    while (lump_p-- != lumpinfo)
    {
	if ( *(int *)lump_p->name == v1
	     && *(int *)&lump_p->name[4] == v2)
	{
	    return lump_p - lumpinfo;
	}
    }

    // TFB. Not found.
    return -1;
}




//
// W_GetNumForName
// Calls W_CheckNumForName, but bombs out if not found.
//
int W_GetNumForName (char* name)
{
    int	i;

    i = W_CheckNumForName (name);
    
    if (i == -1)
      I_Error ("W_GetNumForName: %s not found!", name);
      
    return i;
}


//
// W_LumpLength
// Returns the buffer size needed to load the given lump.
//
int W_LumpLength (int lump)
{
    if (lump >= numlumps)
	I_Error ("W_LumpLength: %i >= numlumps",lump);

    return lumpinfo[lump].size;
}



//
// W_ReadLump
// Loads the lump into the given buffer,
//  which must be >= W_LumpLength().
//
void
W_ReadLump
( int		lump,
  void*		dest )
{
    int		c;
    lumpinfo_t*	l;
    int		handle;
	
    if (lump >= numlumps)
	I_Error ("W_ReadLump: %i >= numlumps",lump);

    l = lumpinfo+lump;
	
    // ??? I_BeginRead ();
	
    if (l->handle == -1)
    {
	// reloadable file, so use open / read / close
	if ( (handle = I_FileOpenRead(reloadname)) == -1)
	    I_Error ("W_ReadLump: couldn't open %s",reloadname);
    }
    else
	handle = l->handle;
		
    I_FilePos(handle, l->position);
    c = I_FileRead(handle, dest, l->size);

    if (c < l->size)
	I_Error ("W_ReadLump: only read %i of %i on lump %i",
		 c,l->size,lump);	

    if (l->handle == -1)
	I_FileClose (handle);
		
    // ??? I_EndRead ();
}




//
// W_CacheLumpNum
//
void*
W_CacheLumpNum
( int		lump,
  int		tag )
{
    byte*	ptr;

    if ((unsigned)lump >= numlumps)
	I_Error ("W_CacheLumpNum: %i >= numlumps",lump);
		
    if (!lumpcache[lump])
    {
	// read the lump in
	
	//I_printf ("cache miss on lump %i\n",lump);
	ptr = Z_Malloc (W_LumpLength (lump), tag, &lumpcache[lump]);
	W_ReadLump (lump, lumpcache[lump]);
    }
    else
    {
	//I_printf ("cache hit on lump %i\n",lump);
	Z_ChangeTag (lumpcache[lump],tag);
    }
	
    return lumpcache[lump];
}



//
// W_CacheLumpName
//
void*
W_CacheLumpName
( char*		name,
  int		tag )
{
    return W_CacheLumpNum (W_GetNumForName(name), tag);
}


//
// W_Profile
//
int		info[2500][10];
int		profilecount;

void W_Profile (void)
{
    int		i;
    memblock_t*	block;
    void*	ptr;
    char	ch;
    FILE*	f;
    int		j;
    char	name[9];
	
	
    for (i=0 ; i<numlumps ; i++)
    {	
	ptr = lumpcache[i];
	if (!ptr)
	{
	    ch = ' ';
	    continue;
	}
	else
	{
	    block = (memblock_t *) ( (byte *)ptr - sizeof(memblock_t));
	    if (block->tag < PU_PURGELEVEL)
		ch = 'S';
	    else
		ch = 'P';
	}
	info[i][profilecount] = ch;
    }
    profilecount++;

#if 0	// AJH uGFX HACK
    f = fopen ("waddump.txt","w");
    name[8] = 0;

    for (i=0 ; i<numlumps ; i++)
    {
	memcpy (name,lumpinfo[i].name,8);

	for (j=0 ; j<8 ; j++)
	    if (!name[j])
		break;

	for ( ; j<8 ; j++)
	    name[j] = ' ';

	fprintf (f,"%s ",name);

	for (j=0 ; j<profilecount ; j++)
	    fprintf (f,"    %c",info[i][j]);

	fprintf (f,"\n");
    }
    fclose (f);
#endif
}