feat: add gRPC handler with event validation and publishing

Handler implementation:
- EventStore interface (consumer-side)
- Server with PublishEvent, QueryEvents, CountEvents, PublishBatch
- pb.Event <-> nostr.Event conversion helpers
- Signature and ID validation using existing nostr package
- Canonical JSON generation for storage

9 tests passing

1 files changed, 143 insertions, 0 deletions

diff --git a/internal/handler/grpc/convert_test.go b/internal/handler/grpc/convert_test.go
new file mode 100644
index 0000000..6da2d89
--- /dev/null
+++ b/internal/handler/grpc/convert_test.go
@@ -0,0 +1,143 @@
+package grpc
+
+import (
+        "testing"
+
+        pb "northwest.io/nostr-grpc/api/nostr/v1"
+        "northwest.io/nostr-grpc/internal/nostr"
+)
+
+func TestNostrToPB(t *testing.T) {
+        nostrEvent := &nostr.Event{
+                ID:        "abc123",
+                PubKey:    "pubkey123",
+                CreatedAt: 1234567890,
+                Kind:      1,
+                Tags:      nostr.Tags{{"e", "event1"}, {"p", "pubkey1"}},
+                Content:   "Hello, Nostr!",
+                Sig:       "sig123",
+        }
+
+        pbEvent := NostrToPB(nostrEvent)
+
+        if pbEvent.Id != nostrEvent.ID {
+                t.Errorf("ID mismatch: expected %s, got %s", nostrEvent.ID, pbEvent.Id)
+        }
+        if pbEvent.Pubkey != nostrEvent.PubKey {
+                t.Errorf("Pubkey mismatch: expected %s, got %s", nostrEvent.PubKey, pbEvent.Pubkey)
+        }
+        if pbEvent.CreatedAt != nostrEvent.CreatedAt {
+                t.Errorf("CreatedAt mismatch: expected %d, got %d", nostrEvent.CreatedAt, pbEvent.CreatedAt)
+        }
+        if pbEvent.Kind != int32(nostrEvent.Kind) {
+                t.Errorf("Kind mismatch: expected %d, got %d", nostrEvent.Kind, pbEvent.Kind)
+        }
+        if pbEvent.Content != nostrEvent.Content {
+                t.Errorf("Content mismatch: expected %s, got %s", nostrEvent.Content, pbEvent.Content)
+        }
+        if pbEvent.Sig != nostrEvent.Sig {
+                t.Errorf("Sig mismatch: expected %s, got %s", nostrEvent.Sig, pbEvent.Sig)
+        }
+
+        if len(pbEvent.Tags) != len(nostrEvent.Tags) {
+                t.Fatalf("Tags length mismatch: expected %d, got %d", len(nostrEvent.Tags), len(pbEvent.Tags))
+        }
+
+        for i, tag := range pbEvent.Tags {
+                if len(tag.Values) != len(nostrEvent.Tags[i]) {
+                        t.Errorf("Tag[%d] values length mismatch", i)
+                        continue
+                }
+                for j, val := range tag.Values {
+                        if val != nostrEvent.Tags[i][j] {
+                                t.Errorf("Tag[%d][%d] mismatch: expected %s, got %s", i, j, nostrEvent.Tags[i][j], val)
+                        }
+                }
+        }
+}
+
+func TestPBToNostr(t *testing.T) {
+        pbEvent := &pb.Event{
+                Id:        "abc123",
+                Pubkey:    "pubkey123",
+                CreatedAt: 1234567890,
+                Kind:      1,
+                Tags:      []*pb.Tag{{Values: []string{"e", "event1"}}, {Values: []string{"p", "pubkey1"}}},
+                Content:   "Hello, Nostr!",
+                Sig:       "sig123",
+        }
+
+        nostrEvent := PBToNostr(pbEvent)
+
+        if nostrEvent.ID != pbEvent.Id {
+                t.Errorf("ID mismatch: expected %s, got %s", pbEvent.Id, nostrEvent.ID)
+        }
+        if nostrEvent.PubKey != pbEvent.Pubkey {
+                t.Errorf("Pubkey mismatch: expected %s, got %s", pbEvent.Pubkey, nostrEvent.PubKey)
+        }
+        if nostrEvent.CreatedAt != pbEvent.CreatedAt {
+                t.Errorf("CreatedAt mismatch: expected %d, got %d", pbEvent.CreatedAt, nostrEvent.CreatedAt)
+        }
+        if nostrEvent.Kind != int(pbEvent.Kind) {
+                t.Errorf("Kind mismatch: expected %d, got %d", pbEvent.Kind, nostrEvent.Kind)
+        }
+        if nostrEvent.Content != pbEvent.Content {
+                t.Errorf("Content mismatch: expected %s, got %s", pbEvent.Content, nostrEvent.Content)
+        }
+        if nostrEvent.Sig != pbEvent.Sig {
+                t.Errorf("Sig mismatch: expected %s, got %s", pbEvent.Sig, nostrEvent.Sig)
+        }
+
+        if len(nostrEvent.Tags) != len(pbEvent.Tags) {
+                t.Fatalf("Tags length mismatch: expected %d, got %d", len(pbEvent.Tags), len(nostrEvent.Tags))
+        }
+
+        for i, tag := range nostrEvent.Tags {
+                if len(tag) != len(pbEvent.Tags[i].Values) {
+                        t.Errorf("Tag[%d] values length mismatch", i)
+                        continue
+                }
+                for j, val := range tag {
+                        if val != pbEvent.Tags[i].Values[j] {
+                                t.Errorf("Tag[%d][%d] mismatch: expected %s, got %s", i, j, pbEvent.Tags[i].Values[j], val)
+                        }
+                }
+        }
+}
+
+func TestRoundTrip(t *testing.T) {
+        original := &nostr.Event{
+                ID:        "roundtrip123",
+                PubKey:    "pubkey_roundtrip",
+                CreatedAt: 9876543210,
+                Kind:      7,
+                Tags:      nostr.Tags{{"e", "evt"}, {"p", "pk", "relay"}},
+                Content:   "Round trip test",
+                Sig:       "signature",
+        }
+
+        pb := NostrToPB(original)
+        backToNostr := PBToNostr(pb)
+
+        if backToNostr.ID != original.ID {
+                t.Errorf("Round trip ID mismatch")
+        }
+        if backToNostr.PubKey != original.PubKey {
+                t.Errorf("Round trip PubKey mismatch")
+        }
+        if backToNostr.CreatedAt != original.CreatedAt {
+                t.Errorf("Round trip CreatedAt mismatch")
+        }
+        if backToNostr.Kind != original.Kind {
+                t.Errorf("Round trip Kind mismatch")
+        }
+        if backToNostr.Content != original.Content {
+                t.Errorf("Round trip Content mismatch")
+        }
+        if backToNostr.Sig != original.Sig {
+                t.Errorf("Round trip Sig mismatch")
+        }
+        if len(backToNostr.Tags) != len(original.Tags) {
+                t.Fatalf("Round trip Tags length mismatch")
+        }
+}