From 44604e406b1a73b294af519dfa02b1fc1c7e6af0 Mon Sep 17 00:00:00 2001
From: fiatjaf <fiatjaf@gmail.com>
Date: Sat, 1 Jan 2022 20:48:13 -0300
Subject: [PATCH] nip-01 update: everything as arrays on filters.

---
 filter/filter.go | 110 +++++++++--------------------------------------
 filter/utils.go  |  87 +++++++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+), 89 deletions(-)
 create mode 100644 filter/utils.go

diff --git a/filter/filter.go b/filter/filter.go
index f541f56..6f38272 100644
--- a/filter/filter.go
+++ b/filter/filter.go
@@ -5,13 +5,13 @@ import "github.com/fiatjaf/go-nostr/event"
 type EventFilters []EventFilter
 
 type EventFilter struct {
-	ID         string   `json:"id,omitempty"`
-	Kind       *int     `json:"kind,omitempty"`
-	Authors    []string `json:"authors,omitempty"`
-	TagEvent   string   `json:"#e,omitempty"`
-	TagProfile string   `json:"#p,omitempty"`
-	Since      uint32   `json:"since,omitempty"`
-	Until      uint32   `json:"until,omitempty"`
+	IDs     []string `json:"ids,omitempty"`
+	Kinds   []int    `json:"kinds,omitempty"`
+	Authors []string `json:"authors,omitempty"`
+	Since   uint32   `json:"since,omitempty"`
+	Until   uint32   `json:"until,omitempty"`
+	TagE    []string `json:"#e,omitempty"`
+	TagP    []string `json:"#p,omitempty"`
 }
 
 func (eff EventFilters) Match(event *event.Event) bool {
@@ -20,7 +20,6 @@ func (eff EventFilters) Match(event *event.Event) bool {
 			return true
 		}
 	}
-
 	return false
 }
 
@@ -29,82 +28,23 @@ func (ef EventFilter) Matches(event *event.Event) bool {
 		return false
 	}
 
-	if ef.ID != "" && ef.ID != event.ID {
+	if ef.IDs != nil && !stringsContain(ef.IDs, event.ID) {
 		return false
 	}
 
-	if ef.Authors != nil {
-		found := false
-		for _, pubkey := range ef.Authors {
-			if pubkey == event.PubKey {
-				found = true
-				break
-			}
-		}
-		if !found {
-			return false
-		}
+	if ef.Kinds != nil && !intsContain(ef.Kinds, event.Kind) {
+		return false
 	}
 
-	if ef.TagEvent != "" {
-		found := false
-		for _, tag := range event.Tags {
-			if len(tag) < 2 {
-				continue
-			}
-
-			tagType, ok := tag[0].(string)
-			if !ok {
-				continue
-			}
-
-			if tagType == "e" {
-				taggedID, ok := tag[1].(string)
-				if !ok {
-					continue
-				}
-
-				if taggedID == ef.TagEvent {
-					found = true
-					break
-				}
-			}
-		}
-		if !found {
-			return false
-		}
+	if ef.Authors != nil && !stringsContain(ef.Authors, event.PubKey) {
+		return false
 	}
 
-	if ef.TagProfile != "" {
-		found := false
-		for _, tag := range event.Tags {
-			if len(tag) < 2 {
-				continue
-			}
-
-			tagType, ok := tag[0].(string)
-			if !ok {
-				continue
-			}
-
-			if tagType == "p" {
-				taggedID, ok := tag[1].(string)
-				if !ok {
-					continue
-				}
-
-				if taggedID == ef.TagProfile {
-					found = true
-					break
-				}
-			}
-		}
-		if !found {
-			return false
-		}
+	if ef.TagE != nil && !containsAnyTag("e", event.Tags, ef.TagE) {
+		return false
 	}
 
-	if ef.Kind != nil && *ef.Kind != event.Kind {
+	if ef.TagP != nil && !containsAnyTag("p", event.Tags, ef.TagP) {
 		return false
 	}
 
@@ -112,7 +52,7 @@ func (ef EventFilter) Matches(event *event.Event) bool {
 		return false
 	}
 
-	if ef.Until != 0 && event.CreatedAt > ef.Until {
+	if ef.Until != 0 && event.CreatedAt >= ef.Until {
 		return false
 	}
 
@@ -120,31 +60,23 @@ func (ef EventFilter) Matches(event *event.Event) bool {
 }
 
 func Equal(a EventFilter, b EventFilter) bool {
-	if a.Kind == nil && b.Kind != nil ||
-		a.Kind != nil && b.Kind == nil ||
-		a.Kind != b.Kind {
+	if !intsEqual(a.Kinds, b.Kinds) {
 		return false
 	}
 
-	if a.ID != b.ID {
+	if !stringsEqual(a.IDs, b.IDs) {
 		return false
 	}
 
-	if len(a.Authors) != len(b.Authors) {
+	if !stringsEqual(a.Authors, b.Authors) {
 		return false
 	}
 
-	for i, _ := range a.Authors {
-		if a.Authors[i] != b.Authors[i] {
-			return false
-		}
-	}
-
-	if a.TagEvent != b.TagEvent {
+	if !stringsEqual(a.TagE, b.TagE) {
 		return false
 	}
 
-	if a.TagProfile != b.TagProfile {
+	if !stringsEqual(a.TagP, b.TagP) {
 		return false
 	}
 
diff --git a/filter/utils.go b/filter/utils.go
new file mode 100644
index 0000000..9bb89a3
--- /dev/null
+++ b/filter/utils.go
@@ -0,0 +1,87 @@
+package filter
+
+import "github.com/fiatjaf/go-nostr/event"
+
+func stringsEqual(as, bs []string) bool {
+	if len(as) != len(bs) {
+		return false
+	}
+
+	for _, a := range as {
+		for _, b := range bs {
+			if b == a {
+				goto next
+			}
+		}
+		// didn't find a B that corresponded to the current A
+		return false
+
+	next:
+		continue
+	}
+
+	return true
+}
+
+func intsEqual(as, bs []int) bool {
+	if len(as) != len(bs) {
+		return false
+	}
+
+	for _, a := range as {
+		for _, b := range bs {
+			if b == a {
+				goto next
+			}
+		}
+		// didn't find a B that corresponded to the current A
+		return false
+
+	next:
+		continue
+	}
+
+	return true
+}
+
+func stringsContain(haystack []string, needle string) bool {
+	for _, hay := range haystack {
+		if hay == needle {
+			return true
+		}
+	}
+	return false
+}
+
+func intsContain(haystack []int, needle int) bool {
+	for _, hay := range haystack {
+		if hay == needle {
+			return true
+		}
+	}
+	return false
+}
+
+func containsAnyTag(tagName string, tags event.Tags, values []string) bool {
+	for _, tag := range tags {
+		if len(tag) < 2 {
+			continue
+		}
+
+		currentTagName, ok := tag[0].(string)
+		if !ok || currentTagName != tagName {
+			continue
+		}
+
+		currentTagValue, ok := tag[1].(string)
+		if !ok {
+			continue
+		}
+
+		if stringsContain(values, currentTagValue) {
+			return true
+		}
+	}
+
+	return false
+}