package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"os"

	"gitea.dohertylan.com/dohertj2/mxaccessgw/clients/go/mxgateway"
)

type versionOutput struct {
	ClientVersion          string `json:"clientVersion"`
	GatewayProtocolVersion uint32 `json:"gatewayProtocolVersion"`
	WorkerProtocolVersion  uint32 `json:"workerProtocolVersion"`
}

func main() {
	if err := run(os.Args[1:]); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(2)
	}
}

func run(args []string) error {
	if len(args) == 0 {
		return fmt.Errorf("usage: mxgw-go version [-json]")
	}

	switch args[0] {
	case "version":
		return runVersion(args[1:])
	default:
		return fmt.Errorf("unknown command %q", args[0])
	}
}

func runVersion(args []string) error {
	flags := flag.NewFlagSet("version", flag.ContinueOnError)
	flags.SetOutput(os.Stderr)
	jsonOutput := flags.Bool("json", false, "write JSON output")

	if err := flags.Parse(args); err != nil {
		return err
	}

	output := versionOutput{
		ClientVersion:          mxgateway.ClientVersion,
		GatewayProtocolVersion: mxgateway.GatewayProtocolVersion,
		WorkerProtocolVersion:  mxgateway.WorkerProtocolVersion,
	}

	if *jsonOutput {
		encoder := json.NewEncoder(os.Stdout)
		encoder.SetIndent("", "  ")
		return encoder.Encode(output)
	}

	fmt.Fprintf(os.Stdout, "mxgw-go %s\n", output.ClientVersion)
	fmt.Fprintf(os.Stdout, "gateway protocol %d\n", output.GatewayProtocolVersion)
	fmt.Fprintf(os.Stdout, "worker protocol %d\n", output.WorkerProtocolVersion)
	return nil
}