// SPDX-License-Identifier: Apache-2.0

// Command maglevc is the vpp-maglev CLI. It talks only to maglevd. With no
// arguments it starts an interactive shell (readline, tab-completion, '?' help,
// prefix abbreviation); with arguments it runs one command and exits. The
// command set is a single declarative tree (buildTree) -- dispatch, help, and
// completion are all derived from it, via the git.ipng.ch/ipng/golang-cli
// library.
package main

import (
	"context"
	"fmt"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"

	cli "git.ipng.ch/ipng/golang-cli"
	buildinfo "git.ipng.ch/ipng/vpp-maglev/cmd"
	"git.ipng.ch/ipng/vpp-maglev/internal/grpcapi"
	"git.ipng.ch/ipng/vpp-maglev/internal/netutil"
)

// defaultGRPCPort is the maglevd gRPC port (mirrors the server's -grpc-addr
// default), used when -server is given without an explicit ":<port>".
const defaultGRPCPort = "9090"

func main() {
	(&cli.App[grpcapi.MaglevClient]{
		Name:          "maglevc",
		Version:       buildinfo.Version(),
		Commit:        buildinfo.Commit(),
		Date:          buildinfo.Date(),
		Prompt:        "maglev> ",
		Root:          buildTree(),
		JSON:          true, // commands render via cli.IsJSON() (see json.go)
		DefaultServer: "localhost:9090",
		ServerEnv:     "MAGLEV_SERVER",
		Connect:       connect,
		FormatError:   formatError,
	}).Main()
}

// connect dials maglevd and returns the gRPC client. App resolves -server (env
// MAGLEV_SERVER, default localhost:9090) and hands us the raw address; we ensure
// a port and dial insecure, mirroring maglevd's default transport.
func connect(_ context.Context, server string) (grpcapi.MaglevClient, func(), error) {
	addr := netutil.EnsurePort(server, defaultGRPCPort)
	conn, err := grpc.NewClient(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		return nil, nil, fmt.Errorf("connect %s: %w", addr, err)
	}
	return grpcapi.NewMaglevClient(conn), func() { _ = conn.Close() }, nil
}