Add support for the XINFO command

redis/src/main/scala/zio/redis/Input.scala

@@ -268,6 +268,21 @@ object Input {
       Chunk(encodeString("DELCONSUMER"), encodeString(data.key), encodeString(data.group), encodeString(data.consumer))
   }
 
+  case object XInfoGroupInput extends Input[XInfoCommand.Group] {
+    def encode(data: XInfoCommand.Group): Chunk[RespValue.BulkString] =
+      Chunk(encodeString("GROUPS"), encodeString(data.key))
+  }
+
+  case object XInfoStreamInput extends Input[XInfoCommand.Stream] {
+    def encode(data: XInfoCommand.Stream): Chunk[RespValue.BulkString] =
+      Chunk(encodeString("STREAM"), encodeString(data.key))
+  }
+
+  case object XInfoConsumerInput extends Input[XInfoCommand.Consumer] {
+    def encode(data: XInfoCommand.Consumer): Chunk[RespValue.BulkString] =
+      Chunk(encodeString("CONSUMERS"), encodeString(data.key), encodeString(data.group))
+  }
+
   case object BlockInput extends Input[Duration] {
     def encode(data: Duration): Chunk[RespValue.BulkString] =
       Chunk(encodeString("BLOCK"), encodeString(data.toMillis.toString))

redis/src/main/scala/zio/redis/Output.scala

@@ -292,21 +292,158 @@ object Output {
   case object StreamOutput extends Output[Map[String, Map[String, String]]] {
     protected def tryDecode(respValue: RespValue): Map[String, Map[String, String]] =
       respValue match {
-        case RespValue.NullArray => Map.empty[String, Map[String, String]]
-        case RespValue.Array(entities) =>
-          val output = collection.mutable.Map.empty[String, Map[String, String]]
-          entities.foreach {
-            case RespValue.Array(Seq(id @ RespValue.BulkString(_), value)) =>
-              output += (id.asString -> KeyValueOutput.unsafeDecode(value))
+        case RespValue.NullArray       => Map.empty[String, Map[String, String]]
+        case RespValue.Array(entities) => extractMapMap(entities)
+        case other                     => throw ProtocolError(s"$other isn't an array")
+      }
+  }
+
+  private def extractMapMap(entities: Chunk[RespValue]): Map[String, Map[String, String]] = {
+    val output = collection.mutable.Map.empty[String, Map[String, String]]
+    entities.foreach {
+      case RespValue.Array(Seq(id @ RespValue.BulkString(_), value)) =>
+        output += (id.asString -> KeyValueOutput.unsafeDecode(value))
+      case other =>
+        throw ProtocolError(s"$other isn't a valid array")
+    }
+    output.toMap
+  }
+
+  case object StreamGroupInfoOutput extends Output[Chunk[StreamGroupInfo]] {
+    override protected def tryDecode(respValue: RespValue): Chunk[StreamGroupInfo] =
+      respValue match {
+        case RespValue.NullArray => Chunk.empty
+        case RespValue.Array(messages) =>
+          messages.collect {
+            // Note that you should not rely on the fields exact position. see https://redis.io/commands/xinfo
+            case RespValue.Array(elements) if elements.length % 2 == 0 =>
+              var streamGroupInfo: StreamGroupInfo = StreamGroupInfo.empty
+              val len                              = elements.length
+              var pos                              = 0
+              while (pos < len) {
+                (elements(pos), elements(pos + 1)) match {
+                  case (key @ RespValue.BulkString(_), value @ RespValue.BulkString(_)) =>
+                    if (key.asString == XInfoFields.Name)
+                      streamGroupInfo = streamGroupInfo.copy(name = Some(value.asString))
+                    else if (key.asString == XInfoFields.LastDelivered)
+                      streamGroupInfo = streamGroupInfo.copy(lastDeliveredId = Some(value.asString))
+                  case (key @ RespValue.BulkString(_), value @ RespValue.Integer(_)) =>
+                    if (key.asString == XInfoFields.Pending)
+                      streamGroupInfo = streamGroupInfo.copy(pending = Some(value.value))
+                    else if (key.asString == XInfoFields.Consumers)
+                      streamGroupInfo = streamGroupInfo.copy(consumers = Some(value.value))
+                  case _ =>
+                }
+                pos += 2
+              }
+              streamGroupInfo
+            case array @ RespValue.Array(_) =>
+              throw ProtocolError(s"$array doesn't have an even number of elements")
             case other =>
-              throw ProtocolError(s"$other isn't a valid array")
+              throw ProtocolError(s"$other isn't an array")
           }
 
-          output.toMap
-        case other => throw ProtocolError(s"$other isn't an array")
+        case other =>
+          throw ProtocolError(s"$other isn't an array")
       }
   }
 
+  case object StreamConsumerInfoOutput extends Output[Chunk[StreamConsumerInfo]] {
+    override protected def tryDecode(respValue: RespValue): Chunk[StreamConsumerInfo] =
+      respValue match {
+        case RespValue.NullArray => Chunk.empty
+        case RespValue.Array(messages) =>
+          messages.collect {
+            // Note that you should not rely on the fields exact position. see https://redis.io/commands/xinfo
+            case RespValue.Array(elements) if elements.length % 2 == 0 =>
+              var streamConsumerInfo: StreamConsumerInfo = StreamConsumerInfo.empty
+              val len                                    = elements.length
+              var pos                                    = 0
+              while (pos < len) {
+                (elements(pos), elements(pos + 1)) match {
+                  case (key @ RespValue.BulkString(_), value @ RespValue.BulkString(_))
+                      if key.asString == XInfoFields.Name =>
+                    streamConsumerInfo = streamConsumerInfo.copy(name = Some(value.asString))
+                  case (key @ RespValue.BulkString(_), value @ RespValue.Integer(_)) =>
+                    if (key.asString == XInfoFields.Pending)
+                      streamConsumerInfo = streamConsumerInfo.copy(pending = Some(value.value))
+                    else if (key.asString == XInfoFields.Idle)
+                      streamConsumerInfo = streamConsumerInfo.copy(idle = Some(value.value))
+                  case _ =>
+                }
+                pos += 2
+              }
+              streamConsumerInfo
+            case array @ RespValue.Array(_) =>
+              throw ProtocolError(s"$array doesn't have an even number of elements")
+            case other =>
+              throw ProtocolError(s"$other isn't an array")
+          }
+
+        case other =>
+          throw ProtocolError(s"$other isn't an array")
+      }
+  }
+
+  case object StreamInfoOutput extends Output[StreamInfo] {
+    override protected def tryDecode(respValue: RespValue): StreamInfo = {
+      var streamInfo: StreamInfo = StreamInfo.empty
+      respValue match {
+        // Note that you should not rely on the fields exact position. see https://redis.io/commands/xinfo
+        case RespValue.Array(elements) if elements.length % 2 == 0 =>
+          val len = elements.length
+          var pos = 0
+          while (pos < len) {
+            (elements(pos), elements(pos + 1)) match {
+              case (key @ RespValue.BulkString(_), value @ RespValue.Integer(_)) =>
+                if (key.asString == XInfoFields.Length)
+                  streamInfo = streamInfo.copy(length = Some(value.value))
+                else if (key.asString == XInfoFields.RadixTreeNodes)
+                  streamInfo = streamInfo.copy(radixTreeNodes = Some(value.value))
+                else if (key.asString == XInfoFields.RadixTreeKeys)
+                  streamInfo = streamInfo.copy(radixTreeKeys = Some(value.value))
+                else if (key.asString == XInfoFields.Groups)
+                  streamInfo = streamInfo.copy(groups = Some(value.value))
+              case (key @ RespValue.BulkString(_), value @ RespValue.BulkString(_))
+                  if key.asString == XInfoFields.LastGeneratedId =>
+                streamInfo = streamInfo.copy(lastGeneratedId = Some(value.asString))
+              case (key @ RespValue.BulkString(_), value @ RespValue.Array(_)) =>
+                if (key.asString == XInfoFields.FirstEntry)
+                  streamInfo = streamInfo.copy(firstEntry = Some(extractStreamEntry(value)))
+                else if (key.asString == XInfoFields.LastEntry)
+                  streamInfo = streamInfo.copy(lastEntry = Some(extractStreamEntry(value)))
+              case _ =>
+            }
+            pos += 2
+          }
+          streamInfo
+        case array @ RespValue.Array(_) =>
+          throw ProtocolError(s"$array doesn't have an even number of elements")
+
+        case other =>
+          throw ProtocolError(s"$other isn't an array")
+      }
+    }
+  }
+
+  private def extractStreamEntry(es: RespValue): StreamEntry = {
+    val entry           = collection.mutable.Map.empty[String, String]
+    var entryId: String = ""
+    es match {
+      case RespValue.Array(entities) =>
+        entities.foreach {
+          case id @ RespValue.BulkString(_) => entryId = id.asString
+          case RespValue.ArrayValues(id @ RespValue.BulkString(_), value @ RespValue.BulkString(_)) =>
+            entry += (id.asString -> value.asString)
+          case other =>
+            throw ProtocolError(s"$other isn't a valid array")
+        }
+      case other =>
+        throw ProtocolError(s"$other isn't a valid array")
+    }
+    StreamEntry(id = entryId, entry.toMap)
+  }
+
   case object XPendingOutput extends Output[PendingInfo] {
     protected def tryDecode(respValue: RespValue): PendingInfo =
       respValue match {

redis/src/main/scala/zio/redis/api/Streams.scala

@@ -1,8 +1,8 @@
 package zio.redis.api
 
 import zio.duration._
-import zio.redis.Input._
-import zio.redis.Output._
+import zio.redis.Input.{ XInfoConsumerInput, _ }
+import zio.redis.Output.{ StreamGroupInfoOutput, _ }
 import zio.redis._
 import zio.{ Chunk, ZIO }
 
@@ -39,6 +39,38 @@ trait Streams {
   ): ZIO[RedisExecutor, RedisError, String] =
     XAdd.run((key, None, id, (pair, pairs.toList)))
 
+  /**
+   * An introspection command used in order to retrieve different information about the group.
+   *
+   * @param key ID of the stream
+   * @return List of consumer groups associated with the stream stored at the specified key.
+   */
+  final def xInfoGroup(
+    key: String
+  ): ZIO[RedisExecutor, RedisError, Chunk[StreamGroupInfo]] = XInfoGroups.run(XInfoCommand.Group(key))
+
+  /**
+   * An introspection command used in order to retrieve different information about the consumers.
+   *
+   * @param key ID of the stream
+   * @param group ID of the consumer group
+   * @return List of every consumer in a specific consumer group.
+   */
+  final def xInfoConsumers(
+    key: String,
+    group: String
+  ): ZIO[RedisExecutor, RedisError, Chunk[StreamConsumerInfo]] = XInfoConsumers.run(XInfoCommand.Consumer(key, group))
+
+  /**
+   * An introspection command used in order to retrieve different information about the stream.
+   *
+   * @param key ID of the stream
+   * @return General information about the stream stored at the specified key.
+   */
+  final def xInfoStream(
+    key: String
+  ): ZIO[RedisExecutor, RedisError, StreamInfo] = XInfoStream.run(XInfoCommand.Stream(key))
+
   /**
    * Appends the specified stream entry to the stream at the specified key while limiting the size of the stream.
    *
@@ -468,7 +500,14 @@ private object Streams {
   final val XGroupDelConsumer: RedisCommand[XGroupCommand.DelConsumer, Long] =
     RedisCommand("XGROUP", XGroupDelConsumerInput, LongOutput)
 
-  // TODO: implement XINFO command
+  final val XInfoGroups: RedisCommand[XInfoCommand.Group, Chunk[StreamGroupInfo]] =
+    RedisCommand("XINFO", XInfoGroupInput, StreamGroupInfoOutput)
+
+  final val XInfoStream: RedisCommand[XInfoCommand.Stream, StreamInfo] =
+    RedisCommand("XINFO", XInfoStreamInput, StreamInfoOutput)
+
+  final val XInfoConsumers: RedisCommand[XInfoCommand.Consumer, Chunk[StreamConsumerInfo]] =
+    RedisCommand("XINFO", XInfoConsumerInput, StreamConsumerInfoOutput)
 
   final val XLen: RedisCommand[String, Long] = RedisCommand("XLEN", StringInput, LongOutput)
 

redis/src/main/scala/zio/redis/options/Streams.scala

@@ -3,6 +3,7 @@ package zio.redis.options
 import zio.duration._
 
 trait Streams {
+
   case object WithForce {
     private[redis] def stringify = "FORCE"
   }
@@ -18,11 +19,28 @@ trait Streams {
   sealed trait XGroupCommand
 
   object XGroupCommand {
+
     case class Create(key: String, group: String, id: String, mkStream: Boolean) extends XGroupCommand
-    case class SetId(key: String, group: String, id: String)                     extends XGroupCommand
-    case class Destroy(key: String, group: String)                               extends XGroupCommand
-    case class CreateConsumer(key: String, group: String, consumer: String)      extends XGroupCommand
-    case class DelConsumer(key: String, group: String, consumer: String)         extends XGroupCommand
+
+    case class SetId(key: String, group: String, id: String) extends XGroupCommand
+
+    case class Destroy(key: String, group: String) extends XGroupCommand
+
+    case class CreateConsumer(key: String, group: String, consumer: String) extends XGroupCommand
+
+    case class DelConsumer(key: String, group: String, consumer: String) extends XGroupCommand
+
+  }
+
+  sealed trait XInfoCommand
+
+  object XInfoCommand {
+
+    case class Group(key: String) extends XInfoCommand
+
+    case class Stream(key: String) extends XInfoCommand
+
+    case class Consumer(key: String, group: String) extends XInfoCommand
   }
 
   case object MkStream {
@@ -54,4 +72,63 @@ trait Streams {
   type NoAck = NoAck.type
 
   case class MaxLen(approximate: Boolean, count: Long)
+
+  case class StreamEntry(id: String, fields: Map[String, String])
+
+  case class StreamInfo(
+    length: Option[Long],
+    radixTreeKeys: Option[Long],
+    radixTreeNodes: Option[Long],
+    groups: Option[Long],
+    lastGeneratedId: Option[String],
+    firstEntry: Option[StreamEntry],
+    lastEntry: Option[StreamEntry]
+  )
+
+  object StreamInfo {
+    def empty: StreamInfo = StreamInfo(None, None, None, None, None, None, None)
+  }
+
+  case class StreamGroupInfo(
+    name: Option[String],
+    consumers: Option[Long],
+    pending: Option[Long],
+    lastDeliveredId: Option[String]
+  )
+
+  object StreamGroupInfo {
+    def empty: StreamGroupInfo = StreamGroupInfo(None, None, None, None)
+  }
+
+  case class StreamConsumerInfo(
+    name: Option[String],
+    idle: Option[Long],
+    pending: Option[Long]
+  )
+
+  object StreamConsumerInfo {
+    def empty: StreamConsumerInfo = StreamConsumerInfo(None, None, None)
+  }
+
+  private[redis] object XInfoFields {
+    val Name: String    = "name"
+    val Idle: String    = "idle"
+    val Pending: String = "pending"
+
+    val Consumers: String     = "consumers"
+    val LastDelivered: String = "last-delivered-id"
+
+    val Length: String          = "length"
+    val RadixTreeKeys: String   = "radix-tree-keys"
+    val RadixTreeNodes: String  = "radix-tree-nodes"
+    val Groups: String          = "groups"
+    val LastGeneratedId: String = "last-generated-id"
+    val FirstEntry: String      = "first-entry"
+    val LastEntry: String       = "last-entry"
+
+    val Entries: String  = "entries"
+    val PelCount: String = "pel-count"
+    val SeenTime: String = "seen-time"
+  }
+
 }

redis/src/test/scala/zio/redis/InputSpec.scala

@@ -926,6 +926,20 @@ object InputSpec extends BaseSpec {
             .map(assert(_)(equalTo(respArgs("STREAMS", "a", "c", "b", "d"))))
         }
       ),
+      suite("XInfo")(
+        testM("stream info") {
+          Task(XInfoStreamInput.encode(XInfoCommand.Stream("key")))
+            .map(assert(_)(equalTo(respArgs("STREAM", "key"))))
+        },
+        testM("group info") {
+          Task(XInfoGroupInput.encode(XInfoCommand.Group("key")))
+            .map(assert(_)(equalTo(respArgs("GROUPS", "key"))))
+        },
+        testM("consumer info") {
+          Task(XInfoConsumerInput.encode(XInfoCommand.Consumer("key", "group")))
+            .map(assert(_)(equalTo(respArgs("CONSUMERS", "key", "group"))))
+        }
+      ),
       suite("Group")(
         testM("valid value") {
           Task(GroupInput.encode(Group("group", "consumer")))