package command

import (
	"github.com/seaweedfs/seaweedfs/weed/glog"
	"github.com/seaweedfs/seaweedfs/weed/mq/kafka/gateway"
)

var (
	mqKafkaGatewayOptions mqKafkaGatewayOpts
)

type mqKafkaGatewayOpts struct {
	listen       *string
	agentAddress *string
	seaweedMode  *bool
}

func init() {
	cmdMqKafkaGateway.Run = runMqKafkaGateway
	mqKafkaGatewayOptions.listen = cmdMqKafkaGateway.Flag.String("listen", ":9092", "Kafka gateway listen address")
	mqKafkaGatewayOptions.agentAddress = cmdMqKafkaGateway.Flag.String("agent", "", "SeaweedMQ Agent address (e.g., localhost:17777)")
	mqKafkaGatewayOptions.seaweedMode = cmdMqKafkaGateway.Flag.Bool("seaweedmq", false, "Use SeaweedMQ backend instead of in-memory stub")
}

var cmdMqKafkaGateway = &Command{
	UsageLine: "mq.kafka.gateway [-listen=:9092] [-agent=localhost:17777] [-seaweedmq]",
	Short:     "start a Kafka wire-protocol gateway for SeaweedMQ",
	Long: `Start a Kafka wire-protocol gateway translating Kafka client requests to SeaweedMQ.

By default, uses an in-memory stub for development and testing.
Use -seaweedmq -agent=<address> to connect to a real SeaweedMQ Agent for production.

This is experimental and currently supports a minimal subset for development.
`,
}

func runMqKafkaGateway(cmd *Command, args []string) bool {
	// Validate options
	if *mqKafkaGatewayOptions.seaweedMode && *mqKafkaGatewayOptions.agentAddress == "" {
		glog.Fatalf("SeaweedMQ mode requires -agent address")
		return false
	}

	srv := gateway.NewServer(gateway.Options{
		Listen:       *mqKafkaGatewayOptions.listen,
		AgentAddress: *mqKafkaGatewayOptions.agentAddress,
		UseSeaweedMQ: *mqKafkaGatewayOptions.seaweedMode,
	})

	mode := "in-memory"
	if *mqKafkaGatewayOptions.seaweedMode {
		mode = "SeaweedMQ (" + *mqKafkaGatewayOptions.agentAddress + ")"
	}
	glog.V(0).Infof("Starting MQ Kafka Gateway on %s with %s backend", *mqKafkaGatewayOptions.listen, mode)
	if err := srv.Start(); err != nil {
		glog.Fatalf("mq kafka gateway start: %v", err)
		return false
	}

	// Set up graceful shutdown
	defer func() {
		glog.V(0).Infof("Shutting down MQ Kafka Gateway...")
		if err := srv.Close(); err != nil {
			glog.Errorf("mq kafka gateway close: %v", err)
		}
	}()

	// Serve blocks until closed
	if err := srv.Wait(); err != nil {
		glog.Errorf("mq kafka gateway wait: %v", err)
		return false
	}
	return true
}