/* 
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

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

   This program 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 General Public License for more details.

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


   ### File Specific:
   main-programmer: Christian Meyer
   co-programmer: ...
*/

#include "datatank.h"

using namespace std;

//////////////////
// DataTank
//////////////////

DataTank::DataTank()
{
	loader = new DataLoader;
	tree = NULL;
}

DataTank::~DataTank()
{
	// free DataTree
	tree_delete();
	// free DataLoader
	if( loader) delete loader;
}

void DataTank::tree_add( void* r, char* filename, int type)
{
	DataTree *act;
	
	if( tree == NULL)
	{
		tree = (DataTree*) malloc( sizeof( DataTree));
		tree->type = type;
		memset( tree->filename, 0, MAX_FILENAME_LENGHT);
		strncpy( tree->filename, filename, MAX_FILENAME_LENGHT-1);
		tree->parent = NULL;
		tree->up = NULL;
		tree->down = NULL;
		tree->resource = r;
		return;
	}
	
	act = tree;
	while( act != NULL)
	{
		if( strcmp( act->filename, filename) > 0)
		{
			if( act->up != NULL) act = act->up;
			else
			{
				act->up = (DataTree*) malloc( sizeof( DataTree));
				act->up->type = type;
				memset( act->up->filename, 0, MAX_FILENAME_LENGHT);
				strncpy( act->up->filename, filename, MAX_FILENAME_LENGHT-1);
				act->up->parent = act;
				act->up->up = NULL;
				act->up->down = NULL;
				act->up->resource = r;
				break;
			}
		}
		else
		{
			if( act->down != NULL) act = act->down;
			else
			{
				act->down = (DataTree*) malloc( sizeof( DataTree));
				act->down->type = type;
				memset( act->down->filename, 0, MAX_FILENAME_LENGHT);
				strncpy( act->down->filename, filename, MAX_FILENAME_LENGHT-1);
				act->down->parent = act;
				act->down->up = NULL;
				act->down->down = NULL;
				act->down->resource = r;
				break;
			}
		}
	}
}

DataTree* DataTank::tree_find( char* file)
{
	DataTree *act;
	
	if( tree == NULL) return NULL;
	
	act = tree;
	
	while( act != NULL)
	{
		if( strcmp( act->filename, file) == 0) break;
		else if( strcmp( act->filename, file) > 0)
			act = act->up;
		else
			act = act->down;
	}
	
	return act;
}

DataTree* DataTank::tree_highest( DataTree* t)
{
	DataTree* act;
	
	if( t == NULL) return NULL;
	
	act = t;
	
	while( act != NULL)
	{
		if( act->up == NULL) break;
		act = act->up;
	}
	
	return act;
}

DataTree* DataTank::tree_lowest( DataTree* t)
{
	DataTree* act;
	
	if( t == NULL) return NULL;
	
	act = t;
	
	while( act != NULL)
	{
		if( act->down == NULL) break;
		act = act->down;
	}
	
	return act;
}

void DataTank::tree_remove( DataTree* rem)
{
	DataTree *rep;
	void* tempv;
	int tempi;
	char tempn[MAX_FILENAME_LENGHT];
	
	if( rem != NULL)
	{
		if( rem->up == NULL && rem->down == NULL)
		{
				// leaf
			if( rem->parent == NULL) tree = NULL;
			else
			{
				if( rem->parent->up == rem) rem->parent->up = NULL;
				else rem->parent->down = NULL;
			}
			loader->free_file( rem->resource, rem->type);
			free( rem);
		}
		else if( rem->up != NULL && rem->down == NULL)
		{
				// branch up
			if( rem->parent == NULL)
			{
				tree = rem->up;
				rem->up->parent = NULL;
			}
			else
			{
				if( rem->parent->up == rem) rem->parent->up = rem->up;
				else rem->parent->down = rem->up;
				rem->up->parent = rem->parent;
			}
			loader->free_file( rem->resource, rem->type);
			free( rem);			
		}
		else if( rem->up == NULL && rem->down != NULL)
		{
				// branch down
			if( rem->parent == NULL)
			{
				tree = rem->down;
				rem->down->parent = NULL;
			}
			else
			{
				if( rem->parent->up == rem) rem->parent->up = rem->down;
				else rem->parent->down = rem->down;
				rem->down->parent = rem->parent;
			}
			loader->free_file( rem->resource, rem->type);
			free( rem);			
		}
		else
		{
				// fork
			// get highest from down tree
			rep = tree_highest( rem->down);
			
			// swap contents
			tempv = rep->resource;
			tempi = rep->type;
			strcpy( tempn, rep->filename);
			
			rep->resource = rem->resource;
			rep->type = rem->type;
			strcpy( rep->filename, rem->filename);
			
			rem->resource = tempv;
			rem->type = tempi;
			strcpy( rem->filename, tempn);
			
			// remove rep
			tree_remove( rep);
		}
	}
}

void DataTank::tree_delete()
{
	DataTree *act, *kil;
	
	if( tree != NULL)
	{
		act = tree;
		while( act != NULL)
		{
			if( act->up != NULL)
			{
				act = act->up;
				continue;
			}
			if( act->down != NULL)
			{
				act = act->down;
				continue;
			}
			kil = act;
			act = act->parent;
			if( act != NULL)
			{
				if( kil == act->up)	act->up = NULL;
				if( kil == act->down) act->down = NULL;
			}
			loader->free_file( kil->resource, kil->type);
			free( kil);
		}
	}
}

void* DataTank::get( char* file)
{
	DataTree* t;
	void* new_res;
	int type;
	
	t = tree_find( file);
	
	if( t == NULL)
	{
		type = loader->get_type( file);
		if( type == -1) return NULL;
		new_res = loader->load_file( file, type);
		if( new_res == NULL)
		{
			// return placeholder
		}
		else
		{
			tree_add( new_res, file, type);
			return new_res;
		}
	}
	else
	{
		return t->resource;
	}
}

void DataTank::unload( char* file)
{
	DataTree* rem;
	
	rem = tree_find( file);
	
	tree_remove( rem);
}

void DataTank::precache( char* resfile, void(*pfunc)(int, float, char*, char*))
{
}

void DataTank::save_precache( char* filename)
{
	FILE* out;
	DataTree* act;
	
	out = fopen( filename, "w");
	if( out == NULL) return;
	
	if( tree != NULL) save_node( tree, out);
	
	fclose( out);
}

void DataTank::save_node( DataTree* act, FILE* out)
{
	fprintf(out, "%s\n", act->filename);
	
	if( act->down) save_node( act->down, out);
	if( act->up) save_node( act->up, out);
	
	return;
}

int DataTank::add_filetype( char* postfix, void*(*lfunc)(char*), void(*ffunc)(void*), char* placeholderfile)
{
	return loader->add_filetype( postfix, lfunc, ffunc, placeholderfile);
}

////////////////
// DataLoader
////////////////

DataLoader::DataLoader()
{
	ntypes = 0;
	load_funcs = NULL;
	free_funcs = NULL;
	postfixes = NULL;
	placeholders = NULL;
}

DataLoader::~DataLoader()
{
	int i;
	
	for( i = 0; i < ntypes; i++)
	{
		if( placeholders[i] != NULL) free_funcs[i]( placeholders[i]);
		if( postfixes[i] != NULL) free( postfixes[i]);
	}
	
	if( postfixes) free( postfixes);
	if( placeholders) free( placeholders);
	if( free_funcs) free( free_funcs);
	if( load_funcs) free( load_funcs);
}

int DataLoader::add_filetype( char* postfix, void*(*lfunc)(char*), void(*ffunc)(void*), char* placeholderfile)
{
	int type = 0;
	char testfile[MAX_FILENAME_LENGHT];
	
	if( !postfix || !lfunc || !ffunc || !placeholderfile) return -1;
	
	sprintf( testfile, "blabla.%s", postfix);
	if( (type = get_type( testfile)) != -1)
	{
		load_funcs[type] = lfunc;
		free_funcs[type] = ffunc;
		placeholders[type] = lfunc( placeholderfile);
		return type;
	}
	
	// backup
	void*(**old_load_funcs)(char*) = load_funcs;
 	void(**old_free_funcs)(void*) = free_funcs;
 	char** old_postfixes = postfixes;
 	void** old_placeholders = placeholders;
	
	// realloc
	load_funcs = (void*(**)(char*)) malloc( sizeof( void*(*)(char*)) * (ntypes + 1));
	free_funcs = (void(**)(void*)) malloc( sizeof( void(*)(void*)) * (ntypes + 1));
	postfixes = (char**) malloc( sizeof( char*) * POSTFIX_LENGHT * (ntypes + 1));
	placeholders = (void**) malloc( sizeof( void*) * (ntypes + 1));
	
	// copy
	memcpy( load_funcs, old_load_funcs, sizeof( void*(*)(char*)) * ntypes);
	memcpy( free_funcs, old_free_funcs, sizeof( void*(*)(void*)) * ntypes);
	memcpy( postfixes, old_postfixes, sizeof( char*) * POSTFIX_LENGHT * ntypes);
	memcpy( placeholders, old_placeholders, sizeof( void*) * ntypes);
	
	// add
	type = ntypes;
	ntypes++;
	
	load_funcs[type] = lfunc;
	free_funcs[type] = ffunc;
	memset( postfixes[type], 0, 5);
	strncpy( postfixes[type], postfix, 5);
	placeholders[type] = lfunc( placeholderfile);
	
	return type;
}

void* DataLoader::load_file( char* file, int type)
{
	if( type <= ntypes && type >= 0) return load_funcs[type]( file);
	else return NULL;
}

int DataLoader::get_type( char* file)
{
	int i, n;
	char* posterior;
	
	if( file == NULL) return -1;
	
	i = 0;
	n = -1;
	while( file[i] != 0)
	{
		if( file[i] == '.') n = i;
		i++;
	}
	
	if( n == -1) return -1;
	
	posterior = &(file[n]);
	
	for( i = 0; i < ntypes; i++)
	{
		if( strcmp( posterior, postfixes[i]) == 0) return i;
	}
	
	return -1;
}

void DataLoader::free_file( void* resource, int type)
{
	if( type <= ntypes && type >= 0) free_funcs[type]( resource);
}

void* DataLoader::get_placeholder( int type)
{
	if( type <= ntypes && type >= 0) return placeholders[type];
	else return NULL;
}