delpay: refactoring logic inside the command and update command doc

Changelog-Added: JSON-RPC: delpay a new method
to delete the payment completed or failed.

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

common/jsonrpc_errors.h

@@ -40,6 +40,7 @@ static const errcode_t PAY_INVOICE_EXPIRED = 207;
 static const errcode_t PAY_NO_SUCH_PAYMENT = 208;
 static const errcode_t PAY_UNSPECIFIED_ERROR = 209;
 static const errcode_t PAY_STOPPED_RETRYING = 210;
+static const errcode_t PAY_STATUS_UNEXPECTED = 211;
 
 /* `fundchannel` or `withdraw` errors */
 static const errcode_t FUND_MAX_EXCEEDED = 300;

doc/Makefile

@@ -16,6 +16,7 @@ MANPAGES := doc/lightning-cli.1 \
 	doc/lightning-decodepay.7 \
 	doc/lightning-delexpiredinvoice.7 \
 	doc/lightning-delinvoice.7 \
+	doc/lightning-delpay.7 \
 	doc/lightning-dev-sendcustommsg.7 \
 	doc/lightning-disconnect.7 \
 	doc/lightning-feerates.7 \

doc/index.rst

@@ -38,6 +38,7 @@ c-lightning Documentation
    lightning-decodepay <lightning-decodepay.7.md>
    lightning-delexpiredinvoice <lightning-delexpiredinvoice.7.md>
    lightning-delinvoice <lightning-delinvoice.7.md>
+   lightning-delpay <lightning-delpay.7.md>
    lightning-dev-sendcustommsg <lightning-dev-sendcustommsg.7.md>
    lightning-disconnect <lightning-disconnect.7.md>
    lightning-feerates <lightning-feerates.7.md>

doc/lightning-delpay.7.md

@@ -0,0 +1,83 @@
+lightning-delpay -- Command for removing a completed or failed payment
+============================================================
+
+SYNOPSIS
+--------
+
+**delpay** *payment_hash* \[status\]
+
+DESCRIPTION
+-----------
+
+The **delpay** RPC command removes a payment as given in **listsendpays** or **listpays** with a complete or failed
+status. However, the command doesn't permit to remove a pending payment.
+
+- *payment_hash*: Rapresents the unique identifier of a payment. To find it, you can run **listpays** or **listsendpays**;
+- *status*: Represents a payment status. Otherwise, if it is not specified it is equal to *complete*.
+
+EXAMPLE JSON REQUEST
+------------
+```json
+{
+  "id": 82,
+  "method": "delpay",
+  "params": {
+    "payment_hash": "4fa2f1b001067ec06d7f95b8695b8acd9ef04c1b4d1110e3b94e1fa0687bb1e0",
+    "status": "complete"
+  }
+}
+```
+
+RETURN VALUE
+------------
+
+On success, the command will return a payment object, such as the **listsendpays**. In addition, if the payment is a MPP (Multi part payment) the command return a list of 
+payments; a payment object for each partid.
+
+On failure, an error is returned and any payment is deleted. If the lightning process fails before responding, the
+caller should use lightning-listsentpays(7) or lightning-listpays(7) to query whether this payment was deleted or not.
+
+The following error codes may occur:
+
+- -32602: Some parameter missed or some parameter is malformed;
+- 211: Payment with payment_hash have a wrong status. To check the correct status run the command **paystatus**;
+- 208: Payment with payment_hash not found.
+
+EXAMPLE JSON RESPONSE
+-----
+```json
+{
+   "payments": [
+      {
+         "id": 2,
+         "payment_hash": "8dfd6538eeb33811c9114a75f792a143728d7f05643f38c3d574d3097e8910c0",
+         "destination": "0219f8900ee78a89f050c24d8b69492954f9fdbabed753710845eb75d3a75a5880",
+         "msatoshi": 1000,
+         "amount_msat": "1000msat",
+         "msatoshi_sent": 1000,
+         "amount_sent_msat": "1000msat",
+         "created_at": 1596224858,
+         "status": "complete",
+         "payment_preimage": "35bd4e2b481a1a84a22215b5372672cf81460a671816960ddb206464359e1822",
+         "bolt11": "lntb10n1p0jga20pp53h7k2w8wkvuprjg3ff6l0y4pgdeg6lc9vsln3s74wnfsjl5fzrqqdqdw3jhxazldahx2xqyjw5qcqp2sp5wut5jnhr6n7jd5747ky2g5flmw7hgx9yjnqzu60ps2jf6f7tc0us9qy9qsqu2a0k37nckl62005p69xavlkydkvhnypk4dphffy4x09zltwh9437ad7xkl83tefdarzhu5t30ju5s56wlrg97qkx404pq3srfc425cq3ke9af"
+      }
+   ]
+}
+
+```
+
+
+AUTHOR
+------
+
+Vincenzo Palazzo <<vincenzo.palazzo@protonmail.com>> is mainly responsible.
+
+SEE ALSO
+--------
+
+lightning-listpays(7), lightning-listsendpays(7), lightning-paystatus(7).
+
+RESOURCES
+---------
+
+Main web site: <https://github.com/ElementsProject/lightning>

lightningd/pay.c

@@ -42,6 +42,31 @@ struct sendpay_command {
 	struct command *cmd;
 };
 
+static enum wallet_payment_status string_to_payment_status(const char *status_str)
+{
+	if (streq(status_str, "complete")) {
+		return PAYMENT_COMPLETE;
+	} else if (streq(status_str, "failed")) {
+		return PAYMENT_FAILED;
+	} else if (streq(status_str, "pending")) {
+		return PAYMENT_PENDING;
+	}
+	return -1;
+}
+
+static const char *payment_status_to_string(const enum wallet_payment_status status)
+{
+	switch (status) {
+	case PAYMENT_COMPLETE:
+		return "complete";
+	case PAYMENT_FAILED:
+		return "failed";
+	default:
+		return "pending";
+	}
+}
+
+
 static void destroy_sendpay_command(struct sendpay_command *pc)
 {
 	list_del(&pc->list);
@@ -1496,6 +1521,77 @@ static const struct json_command listsendpays_command = {
 };
 AUTODATA(json_command, &listsendpays_command);
 
+
+static struct command_result *json_delpay(struct command *cmd,
+						const char *buffer,
+						const jsmntok_t *obj UNNEEDED,
+						const jsmntok_t *params)
+{
+	struct json_stream *response;
+	const struct wallet_payment **payments;
+	const char *status_str;
+	enum wallet_payment_status status;
+	struct sha256 *payment_hash;
+
+	if (!param(cmd, buffer, params,
+		p_req("payment_hash", param_sha256, &payment_hash),
+		p_opt("status", param_string, &status_str),
+		NULL))
+		return command_param_failed();
+
+	if (!payment_hash)
+		return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+						"missing required parameter: payment_hash");
+
+
+	status = status_str == NULL ? PAYMENT_COMPLETE : string_to_payment_status(status_str);
+
+	if (status == -1)
+		return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+						"status insert %s wrong", status_str);
+
+	if (status == PAYMENT_PENDING)
+		return command_fail(cmd, PAY_STATUS_UNEXPECTED, "invalid status: %s",
+							payment_status_to_string(status));
+
+	payments = wallet_payment_list(cmd, cmd->ld->wallet, payment_hash);
+
+	if (tal_count(payments) == 0)
+		return command_fail(cmd, PAY_NO_SUCH_PAYMENT,
+			"unknown payment with payment_hash: %s",
+				    type_to_string(tmpctx, struct sha256, payment_hash));
+
+	for (int i = 0; i < tal_count(payments); i++) {
+		if (payments[i]->status != status) {
+			return command_fail(cmd, PAY_STATUS_UNEXPECTED,
+					"payment with hash %s has %s status but it should be %s",
+					type_to_string(tmpctx, struct sha256, payment_hash),
+					payment_status_to_string(payments[i]->status),
+				        payment_status_to_string(status));
+		}
+	}
+
+	wallet_payment_delete_by_hash(cmd->ld->wallet, payment_hash);
+
+	response = json_stream_success(cmd);
+	json_array_start(response, "payments");
+	for (int i = 0; i < tal_count(payments); i++) {
+		json_object_start(response, NULL);
+		json_add_payment_fields(response, payments[i]);
+		json_object_end(response);
+	}
+	json_array_end(response);
+	return command_success(cmd, response);
+}
+
+static const struct json_command delpay_command = {
+	"delpay",
+	"payment",
+	json_delpay,
+	"Delete payment with {payment_hash} and {status}",
+};
+AUTODATA(json_command, &delpay_command);
+
 static struct command_result *json_createonion(struct command *cmd,
 						const char *buffer,
 						const jsmntok_t *obj UNNEEDED,