/*
 *
 *	IRBOX, an Ivy driver for infra-red remote controls
 *
 *	Copyright 1998-1999 
 *	Centre d'Etudes de la Navigation Aerienne
 *
 *	Tables for decoding events
 *
 *	$Id$
 *
 */

#include "irtable.h"
#include "irdev.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

typedef struct _irtablecell IrTableCell;

struct _irtablecell {
	IrTable* table;
	unsigned char code[6];
	const char* key;
	IrTableCell*	next;
};


#define KEYCELLS 127
#define CODECELLS 1023

static IrTableCell* KeyToCell [KEYCELLS];
static IrTableCell* CodeToCell [CODECELLS];
static int Initialized = 0;



IrTable*
IrCreateTable ()
{
	if (!Initialized) {
		Initialized = 1;
		memset (KeyToCell, 0, sizeof (KeyToCell));
		memset (CodeToCell, 0, sizeof (CodeToCell));
	}
	return (IrTable*) malloc (sizeof (IrTable));
}

void
IrTableName (IrTable* t, const char* n)
{
	t->name = strdup (n);
}

void
IrTableType (IrTable* t, const char* type)
{
	t->type = strdup (type);
}

void
IrTableAddBrand (IrTable* t, const char* b)
{
}



static unsigned int
IrHashKey (const char* key)
{
	register unsigned int h = 0;
	register const char* p = key;
	while (*p)
		h += (h << 3) + *p++;	/* this hash function was stolen from Tcl */
	return h % KEYCELLS;
}

static unsigned int
IrHashCode (const unsigned char* code)
{
	register unsigned int h = 0;
	register const unsigned char* p = code;
	register const unsigned char* q = p+6;
	while (p < q)
		h += (h << 3) + *p++;	/* A ADAPTER */
	return h % CODECELLS;
}

void
IrTableAddKey (IrTable* t, const char* k, int c0, int c1, int c2, int c3 , int c4, int c5)
{
	IrTableCell* c = (IrTableCell*) malloc (sizeof (IrTableCell));
	IrTableCell** cc;
	IrTableCell* p;

	c->table = t;
	c->code[0] = c0;
	c->code[1] = c1;
	c->code[2] = c2;
	c->code[3] = c3;
	c->code[4] = c4;
	c->code[5] = c5;
	cc = CodeToCell + IrHashCode (c->code);

	/* collision handling */
	p = *cc;
	while (p) {
		if (strncmp (p->code, c->code, 6) == 0) {
			fprintf (stderr, "Code for key \'%s\' on %s", k, t->name);
			fprintf (stderr, " was already registered");
			fprintf (stderr, " for key \'%s\' on %s\n", p->key, p->table->name);
			free (c);
			return;
		}
		p = p->next;
	}

	/* fine, we can keep on storing that key */
	c->key = strdup (k);
	c->next = *cc;
	*cc = c;
}

int
IrTableTranslateCode (const unsigned char* code, IrTable** table, const char** key)
{
	IrTableCell* c;

	c = CodeToCell [IrHashCode (code)];
	while (c) {
		if (strncmp (code, c->code, 6) == 0)
			break;
		c = c->next;
	}
	if (c) {
		if (table) *table = c->table;
		if (key) *key = c->key;
	} else {
		if (table) *table = 0;
		if (key) *key = 0;
	}
	return (int) (c);
}