Feature: multiple IP addresses per PIA server

internal/updater/providers/pia/servers.go

@@ -20,21 +20,22 @@ func GetServers(ctx context.Context, client *http.Client, minServers int) (
 		return nil, err
 	}
 
+	nts := make(nameToServer)
+
 	for _, region := range data.Regions {
-		// Deduplicate servers with the same common name
-		commonNameToProtocols := dedupByProtocol(region)
+		for _, server := range region.Servers.UDP {
+			const tcp, udp = false, true
+			nts.add(server.CN, region.DNS, region.Name, tcp, udp, region.PortForward, server.IP)
+		}
 
-		// newServers can support only UDP or both TCP and UDP
-		newServers := dataToServers(region.Servers.UDP, region.Name,
-			region.DNS, region.PortForward, commonNameToProtocols)
-		servers = append(servers, newServers...)
-
-		// tcpServers only support TCP as mixed servers were found above.
-		tcpServers := dataToServers(region.Servers.TCP, region.Name,
-			region.DNS, region.PortForward, commonNameToProtocols)
-		servers = append(servers, tcpServers...)
+		for _, server := range region.Servers.TCP {
+			const tcp, udp = true, false
+			nts.add(server.CN, region.DNS, region.Name, tcp, udp, region.PortForward, server.IP)
+		}
 	}
 
+	servers = nts.toServersSlice()
+
 	if len(servers) < minServers {
 		return nil, fmt.Errorf("%w: %d and expected at least %d",
 			ErrNotEnoughServers, len(servers), minServers)
@@ -44,48 +45,3 @@ func GetServers(ctx context.Context, client *http.Client, minServers int) (
 
 	return servers, nil
 }
-
-type protocols struct {
-	tcp bool
-	udp bool
-}
-
-// Deduplicate servers with the same common name for different protocols.
-func dedupByProtocol(region regionData) (commonNameToProtocols map[string]protocols) {
-	commonNameToProtocols = make(map[string]protocols)
-	for _, udpServer := range region.Servers.UDP {
-		protocols := commonNameToProtocols[udpServer.CN]
-		protocols.udp = true
-		commonNameToProtocols[udpServer.CN] = protocols
-	}
-	for _, tcpServer := range region.Servers.TCP {
-		protocols := commonNameToProtocols[tcpServer.CN]
-		protocols.tcp = true
-		commonNameToProtocols[tcpServer.CN] = protocols
-	}
-	return commonNameToProtocols
-}
-
-func dataToServers(data []serverData, region, hostname string,
-	portForward bool, commonNameToProtocols map[string]protocols) (
-	servers []models.PIAServer) {
-	servers = make([]models.PIAServer, 0, len(data))
-	for _, serverData := range data {
-		proto, ok := commonNameToProtocols[serverData.CN]
-		if !ok {
-			continue // server already added
-		}
-		delete(commonNameToProtocols, serverData.CN)
-		server := models.PIAServer{
-			Region:      region,
-			Hostname:    hostname,
-			ServerName:  serverData.CN,
-			TCP:         proto.tcp,
-			UDP:         proto.udp,
-			PortForward: portForward,
-			IP:          serverData.IP,
-		}
-		servers = append(servers, server)
-	}
-	return servers
-}