From a53062b84a5a482a0fc32dbdc96bd4a628021f43 Mon Sep 17 00:00:00 2001
From: William Casarin <jb55@jb55.com>
Date: Thu, 5 May 2022 16:50:08 -0700
Subject: [PATCH] nip13: commit to difficulty

Signed-off-by: William Casarin <jb55@jb55.com>
---
 nostril.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/nostril.c b/nostril.c
index cbf49cf..4c34d92 100644
--- a/nostril.c
+++ b/nostril.c
@@ -348,20 +348,30 @@ static int parse_num(const char *arg, uint64_t *t)
 	return errno != EINVAL;
 }
 
-static int nostr_add_tag(struct nostr_event *ev, const char *t1, const char *t2)
+static int nostr_add_tag_n(struct nostr_event *ev, const char **ts, int n_ts)
 {
+	int i;
 	struct nostr_tag *tag;
 
 	if (ev->num_tags + 1 > MAX_TAGS)
 		return 0;
 
 	tag = &ev->tags[ev->num_tags++];
-	tag->strs[0] = t1;
-	tag->strs[1] = t2;
-	tag->num_elems = 2;
+
+	tag->num_elems = n_ts;
+	for (i = 0; i < n_ts; i++) {
+		tag->strs[i] = ts[i];
+	}
+
 	return 1;
 }
 
+static int nostr_add_tag(struct nostr_event *ev, const char *t1, const char *t2)
+{
+	const char *ts[] = {t1, t2};
+	return nostr_add_tag_n(ev, ts, 2);
+}
+
 
 static int parse_args(int argc, const char *argv[], struct args *args, struct nostr_event *ev)
 {
@@ -508,8 +518,9 @@ static int copyx(unsigned char *output, const unsigned char *x32, const unsigned
 	return 1;
 }
 
-static int ensure_nonce_tag(struct nostr_event *ev, int *index)
+static int ensure_nonce_tag(struct nostr_event *ev, int target, int *index)
 {
+	char *str_target = malloc(8);
 	struct nostr_tag *tag;
 	int i;
 
@@ -522,7 +533,11 @@ static int ensure_nonce_tag(struct nostr_event *ev, int *index)
 	}
 
 	*index = ev->num_tags;
-	return nostr_add_tag(ev, "nonce", "0");
+
+	snprintf(str_target, 7, "%d", target);
+	const char *ts[] = { "nonce", "0", str_target };
+
+	return nostr_add_tag_n(ev, ts, 3);
 }
 
 static int mine_event(struct nostr_event *ev, int difficulty)
@@ -532,11 +547,11 @@ static int mine_event(struct nostr_event *ev, int difficulty)
 	uint64_t nonce;
 	int index, res;
 
-	if (!ensure_nonce_tag(ev, &index))
+	if (!ensure_nonce_tag(ev, difficulty, &index))
 		return 0;
 
 	tag = &ev->tags[index];
-	assert(tag->num_elems == 2);
+	assert(tag->num_elems == 3);
 	assert(!strcmp(tag->strs[0], "nonce"));
 	tag->strs[1] = strnonce;