From 084400d936efcb7aefee8639bae3f7beb9cda3e0 Mon Sep 17 00:00:00 2001
From: Marcin Gorzynski <marcin@gorzynski.me>
Date: Fri, 1 Dec 2023 10:41:43 +0100
Subject: [PATCH] Add Intent.IsValid & BasePacket.IsValid

---
 intents/intent.go         | 24 ++++++++++++++++++++++++
 intents/packets/packet.go |  7 +++++++
 2 files changed, 31 insertions(+)

diff --git a/intents/intent.go b/intents/intent.go
index 699c5116..208e5b41 100644
--- a/intents/intent.go
+++ b/intents/intent.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/0xsequence/go-sequence/intents/packets"
 	"github.com/gibson042/canonicaljson-go"
 
 	"github.com/0xsequence/ethkit/go-ethereum/common"
@@ -77,6 +78,29 @@ func (intent *Intent) Signers() []string {
 	return signers
 }
 
+func (intent *Intent) IsValid() bool {
+	// Check if there are any signatures
+	if len(intent.signatures) == 0 {
+		return false
+	}
+
+	// Check if all signatures are valid
+	for _, signature := range intent.signatures {
+		if !intent.isValidSignature(signature.Session, signature.Signature) {
+			return false
+		}
+	}
+
+	// Check if the packet is valid
+	var packet packets.BasePacket
+	err := json.Unmarshal(intent.Packet, &packet)
+	if err != nil {
+		return false
+	}
+
+	return packet.IsValid()
+}
+
 func (intent *Intent) isValidSignature(session string, signature string) bool {
 	// Get hash of the packet
 	hash, err := intent.Hash()
diff --git a/intents/packets/packet.go b/intents/packets/packet.go
index eb966665..4ccaa406 100644
--- a/intents/packets/packet.go
+++ b/intents/packets/packet.go
@@ -1,11 +1,18 @@
 package packets
 
+import "time"
+
 type BasePacket struct {
 	Code    string `json:"code"`
 	Issued  uint64 `json:"issued"`
 	Expires uint64 `json:"expires"`
 }
 
+func (p *BasePacket) IsValid() bool {
+	now := uint64(time.Now().Unix())
+	return p.Code != "" && p.Issued <= now && p.Expires > now
+}
+
 type BasePacketForWallet struct {
 	BasePacket
 	Wallet string `json:"wallet"`