metadata-2 (#2273)

Initial implementation of draft/metadata-2

irc/metadata.go

@@ -0,0 +1,164 @@
+package irc
+
+import (
+	"errors"
+	"regexp"
+	"strings"
+
+	"github.com/ergochat/ergo/irc/caps"
+	"github.com/ergochat/ergo/irc/modes"
+	"github.com/ergochat/ergo/irc/utils"
+)
+
+var (
+	errMetadataTooManySubs = errors.New("too many subscriptions")
+	errMetadataNotFound    = errors.New("key not found")
+)
+
+type MetadataHaver = interface {
+	SetMetadata(key string, value string)
+	GetMetadata(key string) (string, bool)
+	DeleteMetadata(key string)
+	ListMetadata() map[string]string
+	ClearMetadata() map[string]string
+	CountMetadata() int
+}
+
+func notifySubscribers(server *Server, session *Session, target string, key string, value string) {
+	var notify utils.HashSet[*Session] = make(utils.HashSet[*Session])
+	targetChannel := server.channels.Get(target)
+	targetClient := server.clients.Get(target)
+
+	if targetClient != nil {
+		notify = targetClient.FriendsMonitors(caps.Metadata)
+		// notify clients about changes regarding themselves
+		for _, s := range targetClient.Sessions() {
+			notify.Add(s)
+		}
+	}
+	if targetChannel != nil {
+		members := targetChannel.Members()
+		for _, m := range members {
+			for _, s := range m.Sessions() {
+				if s.capabilities.Has(caps.Metadata) {
+					notify.Add(s)
+				}
+			}
+		}
+	}
+
+	// don't notify the session that made the change
+	notify.Remove(session)
+
+	for s := range notify {
+		if !s.isSubscribedTo(key) {
+			continue
+		}
+
+		if value != "" {
+			s.Send(nil, server.name, "METADATA", target, key, "*", value)
+		} else {
+			s.Send(nil, server.name, "METADATA", target, key, "*")
+		}
+	}
+}
+
+func syncClientMetadata(server *Server, rb *ResponseBuffer, target *Client) {
+	if len(rb.session.MetadataSubscriptions()) == 0 {
+		return
+	}
+
+	batchId := rb.StartNestedBatch("metadata")
+	defer rb.EndNestedBatch(batchId)
+
+	values := target.ListMetadata()
+	for k, v := range values {
+		if rb.session.isSubscribedTo(k) {
+			visibility := "*"
+			rb.Add(nil, server.name, "METADATA", target.Nick(), k, visibility, v)
+		}
+	}
+}
+
+func syncChannelMetadata(server *Server, rb *ResponseBuffer, target *Channel) {
+	if len(rb.session.MetadataSubscriptions()) == 0 {
+		return
+	}
+
+	batchId := rb.StartNestedBatch("metadata")
+	defer rb.EndNestedBatch(batchId)
+
+	values := target.ListMetadata()
+	for k, v := range values {
+		if rb.session.isSubscribedTo(k) {
+			visibility := "*"
+			rb.Add(nil, server.name, "METADATA", target.Name(), k, visibility, v)
+		}
+	}
+
+	for _, client := range target.Members() {
+		values := client.ListMetadata()
+		for k, v := range values {
+			if rb.session.isSubscribedTo(k) {
+				visibility := "*"
+				rb.Add(nil, server.name, "METADATA", client.Nick(), k, visibility, v)
+			}
+		}
+	}
+}
+
+var metadataEvilCharsRegexp = regexp.MustCompile("[^A-Za-z0-9_./:-]+")
+
+func metadataKeyIsEvil(key string) bool {
+	key = strings.TrimSpace(key) // just in case
+
+	return len(key) == 0 || // key needs to contain stuff
+		key[0] == ':' || // key can't start with a colon
+		metadataEvilCharsRegexp.MatchString(key) // key can't contain the stuff it can't contain
+}
+
+func metadataCanIEditThisKey(client *Client, target string, _ string) bool {
+	if !metadataCanIEditThisTarget(client, target) { // you can't edit keys on targets you can't edit.
+		return false
+	}
+
+	// todo: we don't actually do anything regarding visibility yet so there's not much to do here
+
+	return true
+}
+
+func metadataCanIEditThisTarget(client *Client, target string) bool {
+	if !metadataCanISeeThisTarget(client, target) { // you can't edit what you can't see. a wise man told me this once
+		return false
+	}
+
+	if client.HasRoleCapabs("sajoin") { // sajoin opers can do whatever they want
+		return true
+	}
+
+	if target == client.Nick() { // your right to swing your fist ends where my nose begins
+		return true
+	}
+
+	// if you're a channel operator, knock yourself out
+	channel := client.server.channels.Get(target)
+	if channel != nil && channel.ClientIsAtLeast(client, modes.Operator) {
+		return true
+	}
+
+	return false
+}
+
+func metadataCanISeeThisTarget(client *Client, target string) bool {
+	if client.HasRoleCapabs("sajoin") { // sajoin opers can do whatever they want
+		return true
+	}
+
+	// check if the user is in the channel
+	channel := client.server.channels.Get(target)
+	if channel != nil && !channel.hasClient(client) {
+		return false
+	}
+
+	return true
+}