common: Add some more JSON primitives

We were missing the `short_channel_id_dir` helpers.

common/json_parse.c

@@ -5,7 +5,6 @@
 #include <bitcoin/privkey.h>
 #include <bitcoin/psbt.h>
 #include <bitcoin/pubkey.h>
-#include <bitcoin/short_channel_id.h>
 #include <bitcoin/tx.h>
 #include <ccan/json_escape/json_escape.h>
 #include <ccan/mem/mem.h>
@@ -574,6 +573,25 @@ bool json_to_short_channel_id(const char *buffer, const jsmntok_t *tok,
 					  tok->end - tok->start, scid));
 }
 
+bool json_to_short_channel_id_dir(const char *buffer, const jsmntok_t *tok,
+				  struct short_channel_id_dir *scidd)
+{
+	jsmntok_t scidtok, numtok;
+	u32 dir;
+
+	if (!split_tok(buffer, tok, '/', &scidtok, &numtok))
+		return false;
+
+	if (!json_to_short_channel_id(buffer, &scidtok, &scidd->scid))
+		return false;
+
+	if (!json_to_u32(buffer, &numtok, &dir) || (dir > 1))
+		return false;
+
+	scidd->dir = dir;
+	return true;
+}
+
 bool json_to_txid(const char *buffer, const jsmntok_t *tok,
 		  struct bitcoin_txid *txid)
 {

common/json_parse.h

@@ -1,6 +1,7 @@
 #ifndef LIGHTNING_COMMON_JSON_PARSE_H
 #define LIGHTNING_COMMON_JSON_PARSE_H
 #include "config.h"
+#include <bitcoin/short_channel_id.h>
 #include <ccan/crypto/sha256/sha256.h>
 #include <common/coin_mvt.h>
 #include <common/errcode.h>
@@ -110,6 +111,10 @@ bool json_to_outpoint(const char *buffer, const jsmntok_t *tok,
 bool json_to_channel_id(const char *buffer, const jsmntok_t *tok,
 			struct channel_id *cid);
 
+/* Extract a channel id + dir from this */
+bool json_to_short_channel_id_dir(const char *buffer, const jsmntok_t *tok,
+				  struct short_channel_id_dir *scidd);
+
 /* Extract a coin movement 'tag' from this */
 bool json_to_coin_mvt_tag(const char *buffer, const jsmntok_t *tok,
 			  enum mvt_tag *tag);

common/json_stream.c

@@ -3,7 +3,6 @@
 #include <bitcoin/preimage.h>
 #include <bitcoin/privkey.h>
 #include <bitcoin/psbt.h>
-#include <bitcoin/short_channel_id.h>
 #include <bitcoin/signature.h>
 #include <bitcoin/tx.h>
 #include <ccan/io/io.h>
@@ -485,6 +484,16 @@ void json_add_short_channel_id(struct json_stream *response,
 			 short_channel_id_outnum(scid));
 }
 
+void json_add_short_channel_id_dir(struct json_stream *response,
+			       const char *fieldname,
+			       struct short_channel_id_dir scidd)
+{
+	json_add_str_fmt(response, fieldname, "%dx%dx%d/%d",
+			 short_channel_id_blocknum(scidd.scid),
+			 short_channel_id_txnum(scidd.scid),
+			 short_channel_id_outnum(scidd.scid), scidd.dir);
+}
+
 static void json_add_address_fields(struct json_stream *response,
 				    const struct wireaddr *addr,
 				    const char *typefield)

common/json_stream.h

@@ -5,6 +5,7 @@
 #define LIGHTNING_COMMON_JSON_STREAM_H
 #include "config.h"
 
+#include <bitcoin/short_channel_id.h>
 #define JSMN_STRICT 1
 # include <external/jsmn/jsmn.h>
 
@@ -313,6 +314,11 @@ void json_add_short_channel_id(struct json_stream *response,
 			       const char *fieldname,
 			       struct short_channel_id id);
 
+/* '"fieldname" : "1234:5:6/1"' */
+void json_add_short_channel_id_dir(struct json_stream *response,
+				   const char *fieldname,
+				   struct short_channel_id_dir idd);
+
 /* JSON serialize a network address for a node */
 void json_add_address(struct json_stream *response, const char *fieldname,
 		      const struct wireaddr *addr);

plugins/offers_offer.c

@@ -350,25 +350,6 @@ static struct command_result *currency_done(struct command *cmd,
 	return maybe_add_path(cmd, offinfo);
 }
 
-static bool json_to_short_channel_id_dir(const char *buffer, const jsmntok_t *tok,
-					 struct short_channel_id_dir *scidd)
-{
-	jsmntok_t scidtok, numtok;
-	u32 dir;
-
-	if (!split_tok(buffer, tok, '/', &scidtok, &numtok))
-		return false;
-
-	if (!json_to_short_channel_id(buffer, &scidtok, &scidd->scid))
-		return false;
-
-	if (!json_to_u32(buffer, &numtok, &dir) || (dir > 1))
-		return false;
-
-	scidd->dir = dir;
-	return true;
-}
-
 static bool json_to_sciddir_or_pubkey(const char *buffer, const jsmntok_t *tok,
 				      struct sciddir_or_pubkey *sciddir_or_pubkey)
 {