1 files changed, 269 insertions, 0 deletions
diff --git a/handlers.go b/handlers.go
new file mode 100644
index 0000000..4625f6a
--- /dev/null
+++ b/handlers.go
@@ -0,0 +1,269 @@
+package main
+
+import (
+	"errors"
+	"net"
+	"strconv"
+)
+
+func handleGet(conn net.Conn, key string) {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	value, exists := db.data[key]
+	if !exists {
+		conn.Write(serializeRESP(nil)) 
+        return
+	}
+
+	strValue, ok := value.(string)
+	if !ok {
+		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
+        conn.Write(serializeRESP(err))
+        return
+	}
+
+	conn.Write(serializeRESP(strValue))
+}
+
+func handleExists(conn net.Conn, key string) {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	_, exists := db.data[key]
+	if exists {
+		conn.Write(serializeRESP(1))
+	} else {
+		conn.Write(serializeRESP(0))
+	}
+}
+
+func handleSet(conn net.Conn, key, value string) {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	db.data[key] = value
+	conn.Write(serializeRESP(SimpleString("OK")))
+}
+
+func handleDel(conn net.Conn, key string) {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	_, exists := db.data[key]
+	if exists {
+		delete(db.data, key)
+		conn.Write(serializeRESP(1))
+	} else {
+		conn.Write(serializeRESP(0))
+	}
+}
+
+func handleIncr(conn net.Conn, key string) {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	value, exists := db.data[key]
+	if exists {
+		strValue, ok := value.(string)
+		if !ok {
+			err := errors.New("value is not an integer or out of range")
+			conn.Write(serializeRESP(err))
+			return
+		}
+
+		currentInt, err := strconv.Atoi(strValue)
+		if err != nil {
+			err := errors.New("value is not an integer or out of range")
+			conn.Write(serializeRESP(err))
+			return
+		}
+
+		newValueStr := strconv.Itoa(currentInt + 1)
+		db.data[key] = newValueStr
+		conn.Write(serializeRESP(currentInt + 1))
+	} else {
+		db.data[key] = "1"
+		conn.Write(serializeRESP(1))
+	}
+}
+
+func handleDecr(conn net.Conn, key string) {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	value, exists := db.data[key]
+	if exists {
+		strValue, ok := value.(string)
+		if !ok {
+			err := errors.New("value is not an integer or out of range")
+			conn.Write(serializeRESP(err))
+			return
+		}
+
+		currentInt, err := strconv.Atoi(strValue)
+		if err != nil {
+			err := errors.New("value is not an integer or out of range")
+			conn.Write(serializeRESP(err))
+			return
+		}
+
+		newValueStr := strconv.Itoa(currentInt - 1)
+		db.data[key] = newValueStr
+		conn.Write(serializeRESP(currentInt - 1))
+	} else {
+		db.data[key] = "-1"
+		conn.Write(serializeRESP(-1))
+	}
+}
+
+func handlePing(conn net.Conn) {
+	conn.Write(serializeRESP(SimpleString("PONG")))
+}
+
+func handleFlushall(conn net.Conn) {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	db.data = make(map[string]any)
+	conn.Write(serializeRESP(SimpleString("OK")))
+}
+
+func handleRpush(conn net.Conn, args []string) {
+	key := args[1]
+	newItems := args[2:]
+
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	var list []string
+	existingValue, exists := db.data[key]
+
+	if exists {
+		var ok bool
+		list, ok = existingValue.([]string)
+		if !ok {
+			err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
+			conn.Write(serializeRESP(err))
+			return
+		}
+		} else {
+			list = []string{}
+		}
+	list = append(list, newItems...)
+	db.data[key] = list
+	conn.Write(serializeRESP(len(list)))
+}
+
+func handleLrange(conn net.Conn, key string, start, stop int) {
+    db.mu.Lock()
+    defer db.mu.Unlock()
+
+    value, exists := db.data[key]
+    if !exists {
+        conn.Write(serializeRESP([]string{}))
+
+        return
+    }
+    
+    typedList, ok := value.([]string)
+    if !ok {
+		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
+		conn.Write(serializeRESP(err))
+        return
+    }
+    
+    size := len(typedList)
+
+    if start < 0 {
+        start += size
+        if start < 0 {
+            start = 0
+        }
+    }
+    
+    if stop < 0 {
+        stop += size
+        if stop < 0 {
+            stop = 0
+        }
+    }
+
+    if stop >= size {
+        stop = size - 1
+    }
+
+    if start > stop || start >= size {
+        conn.Write(serializeRESP([]string{}))
+        return
+    }
+
+    resultList := typedList[start : stop+1]
+    conn.Write(serializeRESP(resultList))
+}
+
+func handleLpop(conn net.Conn, key string){
+	db.mu.Lock()
+    defer db.mu.Unlock()
+
+    value, exists := db.data[key]
+    if !exists {
+        conn.Write(serializeRESP(nil))
+        return
+    }
+
+	typedList, ok := value.([]string)
+    if !ok {
+		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
+		conn.Write(serializeRESP(err))
+        return
+    }
+
+	if len(typedList) == 0 {
+        conn.Write(serializeRESP(nil))
+        return
+    }
+
+	item := typedList[0]
+	newList := typedList[1:]
+	if len(newList) <= 0 {
+		delete(db.data, key)
+	}else{
+		db.data[key] = newList
+	}
+	conn.Write(serializeRESP(item))
+
+}
+
+func handleRpop(conn net.Conn, key string){
+	db.mu.Lock()
+    defer db.mu.Unlock()
+
+    value, exists := db.data[key]
+    if !exists {
+        conn.Write(serializeRESP(nil))
+        return
+    }
+
+	typedList, ok := value.([]string)
+    if !ok {
+		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
+		conn.Write(serializeRESP(err))
+        return
+    }
+
+	if len(typedList) == 0 {
+        conn.Write(serializeRESP(nil))
+        return
+    }
+	
+	item := typedList[len(typedList)-1]
+	newList := typedList[:len(typedList)-1]
+	if len(newList) <= 0 {
+		delete(db.data, key)
+	}else{
+		db.data[key] = newList
+	}
+	conn.Write(serializeRESP(item))
+
+}