#include <u.h>
#include <libc.h>
#include <thread.h>

#include "girzu.h"

typedef void *(*Transformer)(void *aux, void *data);

/* transformation chains, codec.c */
typedef struct Transform Transform;
struct Transform {
	void *aux;
	Transformer decode;
	Transformer encode;
	char name[32];
};

typedef struct Codec Codec;
struct Codec {
	WaitGroup;
	int nstack;
	Transform *stack;
};

Codec *newcodec(void);
int appendcodec(Codec*, void *aux, Transformer decode, Transformer encode, char *name);
int runcodec(Codec*);
int stopcodec(Codec*);

Codec*
newcodec(void)
{
	return mallocz(sizeof(Codec), 1);
}

typedef struct CodecCtx CodecCtx;
struct CodecCtx {
	WaitGroup *wg;
	Channel *in;
	Channel *out;
	Channel *cancel;
	Transform *t;
};

static void
codecproc(void *v)
{
	int rv, dec, enc;
	void *in, *inr, *out, *outr;
	CodecCtx *ctx;

	ctx = v;
	Alt a[] = {
	[0]	{ ctx->in,		&in,	CHANRCV	},
	[1]	{ ctx->out,		&inr,	CHANNOP },
	[2]	{ ctx->cancel,	nil,	CHANRCV	},
	[3]	{ nil,			nil,	CHANEND	},
	};

	for(;;){
		rv = alt(a);
/*
		switch(rv){
		case -1:
			fprint(2, "codecproc %s: interrupted: %r\n", ctx->t->name);
			goto done;
		case 0:
			inr = ctx->t->decode(ctx->t->aux, in);
		case 1:
		case 2:
		case 3:
		}
*/
	}
done:
	wgdone(ctx->wg);
	threadexits(nil);
}

int
appendcodec(Codec *c, void *aux, Transformer decode, Transformer encode, char *name)
{
	Transform *newstack, *t;

	newstack = realloc(c->stack, c->nstack * sizeof(Transform));
	if(newstack == nil)
		return -1;

	t = &c->stack[c->nstack++];

	t->aux = aux;
	t->decode = decode;
	t->encode = encode;
	snprint(t->name, sizeof(t->name), "%s", name);

	return 0;
}

void
usage(void)
{
	fprint(2, "usage: %s\n", argv0);
	threadexitsall("usage");
}

void
threadmain(int argc, char *argv[])
{
	ARGBEGIN{
	default:
		usage();
	}ARGEND

	threadexitsall(nil);
}