#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>

#include "k_debug.h"
#include "msp_ir.h"

typedef struct s_bitparse {
	/* init part */
	unsigned char *cmd;
	int cmdlen;
	int mint;
	int  (*nextbit)( struct s_bitparse *p );
	void (*reset)  ( struct s_bitparse *p );
	/* reset part */
	int pos;
	int hl;
	int bits;
	int dt;
	/* return */
	int mode;
	int addr;
	int code;
	int repeat;
} t_bitparse;

static void RCParserReset( struct s_bitparse *p )
{
	p->pos  = 0;
	p->dt   = 0;
	p->hl   = 1; /* start with signal high */
	p->bits = 0;
	/* return */
	p->addr = 0;
	p->code = 0;
	p->repeat = 0;
}

static int RCParserNextBit( struct s_bitparse *p )
{
	if( p->dt<=0 ) {
	  int actcmd = p->mint;
	  if( p->pos<p->cmdlen )
	    actcmd = p->cmd[p->pos++];
	  if( actcmd==0xff && !(p->bits) )
	    return -1;
	  p->dt = (actcmd)/p->mint;
	  _D("[%02x:%d]",actcmd,p->dt);
	  p->hl = !(p->hl);
	}
	if( p->dt ) {
	  p->dt--;
	  p->bits++;
	  _D("%d",p->hl);
	  return p->hl;  
	}
	return -2;
}

static int RCParserInit( struct s_bitparse *p, unsigned char *cmd, int len )
{
	int i;
	int val;
	int RC6  = 0;
	int mint = 0xff;

	memset( p, 0, sizeof(*p) );
	p->nextbit = RCParserNextBit;
	p->reset   = RCParserReset;

	p->cmd = cmd;
	p->cmdlen = len;
	for( i=0 ; i<len ; i++ ) {
	  val = (int)(cmd[i]);
	  if( val<mint ) 
	    mint=val;
	}
	if( mint<=0 || mint==0xff ) return -1;
	_D("t:%d\n",mint);
	p->mint = mint;
	p->reset(p);
	return 0;
}

static int ParseManchester( struct s_bitparse *p, int len, int *value )
{
	int i;
	int bit1 = 0;
	int code = *value;
	for( i=0 ; i<len ; i++ ) {
	  bit1 = (p->nextbit(p)<<1)|p->nextbit(p);
	  if( bit1<0 ) return -1;
	  _D("(m:%d)",bit1);
	  code <<= 1;
	  switch( bit1 ) {
	    case 1: code|=bit1;
	    case 2: break;
	    default: return -1;
	  }
	}
	*value = code;
	return 0;
}
#if 0
static int parseRC5( struct s_bitparse *p )
{
	int code=0;
	int bit1 = 0;
	
	p->reset(p);
	/* start */
	bit1 = p->nextbit(p);
	if( bit1!=0 ) return -1;
	/* code */
	if( ParseManchester(p,13,&code)<0 )  
	  return -1;
	code = ~code & 0x1fff;
	p->code = (code >> 0) & 0x3f;
	p->addr = (code >> 6) & 0x1f;
	_I("->%04x bits=%d : toggle=%d addr=%02x code=%02x\n",code,p->bits,code>>11,p->addr,p->code);
	return 0;
}
#endif
static int parseRC6( struct s_bitparse *p )
{
	int i;
	int bit1 = 0;
	int bit2 = 0;
	int mode = 0;
	int addr = 0;
	int code = 0;
	int byte[2] = { 0, 0 };
	
	_D("RC6\n");
	p->reset(p);

	/* check header 00000011(mb2,mb1,mb0)10(TTTT=0011 o. 1100) */
	/* Leader: 00000011 */
	_D("Header:");
	for( i=0 ; i<6 ; i++ ) {
	  bit1 = p->nextbit(p);
	  if( bit1!=0 ) return -1;
	}
	for( i=0 ; i<2 ; i++ ) {
	  bit1 = p->nextbit(p);
	  if( bit1!=1 ) return -1;
	}
	/* Start Bit */
	bit1 = (p->nextbit(p)<<1)|p->nextbit(p);
	if( bit1!=1 ) return -1;
	/* RC6 mode */
	_D("\nMode:");
	bit1 = ParseManchester( p, 3, &mode );
	if( bit1 < 0 ) return -1;
	_D("->%d\n",mode);
	/* Toggle bits 0011 o. 1100 */
	_D("T:");
	bit1 = (p->nextbit(p)<<1)|p->nextbit(p);
	if( bit1<0 ) return -1;
	switch( bit1 ) {
	  case 0: 
	  case 3: break;
	  default: return -1;
	}
	bit2 = (p->nextbit(p)<<1)|p->nextbit(p);
	if( bit2<0 ) return -1;
	switch( bit2 ) {
	  case 0: 
	  case 3: break;
	  default: return -1;
	}
	if( bit1 && bit2 ) return -1;
	if( !bit1 && !bit2 ) return -1;
	_D("->%d%d\n",bit1,bit2);
	/* header ok */
	/* control field */
	/* 0 = short customer code */
	/* 1 = long  customer code */
	_D("S");
	bit1 = ParseManchester( p, 8, &code );
	if( bit1 < 0 ) return -1;
	_D("->%02x\n",code);
	if( code & 0x0080 ) {
	  _D("L");
	  bit1 = ParseManchester( p, 8, &code );
	  if( bit1 < 0 ) return -1;
	}
	_D("->%02x\n",code);
	/* info field */
	_D("B");
	bit1 = ParseManchester( p, 8, byte );
	if( bit1 < 0 ) return -1;
	_D("->%d\n",byte[0]);
	_D("B");
	bit1 = ParseManchester( p, 8, byte+1 );
	if( bit1 < 0 ) return -1;
	_D("->%d\n",byte[1]);

	p->mode = mode; 
	p->addr = code; 
	p->code = (byte[0]<<8) | byte[1];
	_D("->%04x bits=%d : mode=%d custcode=0x%02x toggle=%d addr=%d code=%d [0x%02x]\n",p->code,p->bits,mode,p->addr,p->code>>15,(p->code>>8) & 0x7F,p->code & 0xff,p->code & 0xff);
	return 0;
}

int parseIR( unsigned char *cmd, int len, unsigned int custcode, unsigned int mode, unsigned int *code )
{
	int rv;
	struct s_bitparse p;
	
	rv = RCParserInit( &p, cmd, len );
	if( rv<0 ) {
	  //_D("->ERROR unknown timing\n");
	  return -1;
	}
	if( parseRC6(&p)<0 ) {
	  _D("->ERROR\n");
	  return -1;
	}

	if( mode!=(unsigned int)p.mode ) {
	  _D("->wrong mode\n");
	  return -1;
	}
	if( custcode!=(unsigned int)p.addr ) {
	  _D("->wrong customer codes\n");
	  return -1;
	}
	*code = (unsigned int)p.code;
	
	return 0;
}