From 74fea27a32043e86ff7d87bc5f404bcc8c4337fb Mon Sep 17 00:00:00 2001
From: Kelvin Clement Mwinuka <kelvinmwinuka@hotmail.co.uk>
Date: Sat, 8 Jul 2023 19:30:26 +0800
Subject: [PATCH] Implemented llen command

---
 server/plugins/commands/list/list.go | 33 ++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/server/plugins/commands/list/list.go b/server/plugins/commands/list/list.go
index 039d252..ec507a2 100644
--- a/server/plugins/commands/list/list.go
+++ b/server/plugins/commands/list/list.go
@@ -44,6 +44,9 @@ func (p *plugin) HandleCommand(cmd []string, server interface{}, conn *bufio.Wri
 	c := strings.ToLower(cmd[0])
 
 	switch {
+	case c == "llen":
+		handleLLen(cmd, server.(Server), conn)
+
 	case c == "lrange":
 		handleLRange(cmd, server.(Server), conn)
 
@@ -58,6 +61,29 @@ func (p *plugin) HandleCommand(cmd []string, server interface{}, conn *bufio.Wri
 	}
 }
 
+func handleLLen(cmd []string, server Server, conn *bufio.Writer) {
+	if len(cmd) != 2 {
+		conn.Write([]byte("-Error wrong number of args for LLEN command\r\n\n"))
+		conn.Flush()
+		return
+	}
+
+	server.Lock()
+
+	list, ok := server.GetData(cmd[1]).([]interface{})
+
+	if !ok {
+		server.Unlock()
+		conn.Write([]byte("-Error LLEN command on non-list item\r\n\n"))
+		conn.Flush()
+		return
+	}
+
+	server.Unlock()
+	conn.Write([]byte(fmt.Sprintf(":%d\r\n\n", len(list))))
+	conn.Flush()
+}
+
 func handleLRange(cmd []string, server Server, conn *bufio.Writer) {
 	if len(cmd) != 4 {
 		conn.Write([]byte("-Error wrong number of arguments for LRANGE command\r\n\n"))
@@ -257,13 +283,6 @@ func handlePop(cmd []string, server Server, conn *bufio.Writer) {
 		return
 	}
 
-	if list == nil {
-		server.Unlock()
-		conn.Write([]byte("-Error no list at key\r\n\n"))
-		conn.Flush()
-		return
-	}
-
 	switch strings.ToLower(cmd[0]) {
 	default:
 		server.SetData(cmd[1], list[1:])