You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: caddyfile.go
    path of file: ./repos/caddy/modules/caddyhttp/caddyauth
    
    the code of the file until where you have to start completion: // Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package caddyauth

import (
	"github.com/caddyserver/caddy/v2"
	"github.com/caddyserver/caddy/v2/caddyconfig"
	"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
)

func init() {
	httpcaddyfile.RegisterHandlerDirective("basicauth", parseCaddyfile) // deprecated
	httpcaddyfile.RegisterHandlerDirective("basic_auth", parseCaddyfile)
}

// parseCaddyfile sets up the handler from Caddyfile tokens. Syntax:
//
//	basic_auth [<matcher>] [<hash_algorithm> [<realm>]] {
//	    <username> <hashed_password>
//	    ...
//	}
//

    
func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
	h.Next() // consume directive name

	// "basicauth" is deprecated, replaced by "basic_auth"
	if h.Val() == "basicauth" {
		caddy.Log().Named("config.adapter.caddyfile").Warn("the 'basicauth' directive is deprecated, please use 'basic_auth' instead!")
	}

	var ba HTTPBasicAuth
	ba.HashCache = new(Cache)

	var cmp Comparer
	args := h.RemainingArgs()

	var hashName string
	switch len(args) {
	case 0:
		hashName = "bcrypt"
	case 1:
		hashName = args[0]
	case 2:
		hashName = args[0]
		ba.Realm = args[1]
	default:
		return nil, h.ArgErr()
	}

	switch hashName {
	case "bcrypt":
		cmp = BcryptHash{}
	default:
		return nil, h.Errf("unrecognized hash algorithm: %s", hashName)
	}

	ba.HashRaw = caddyconfig.JSONModuleObject(cmp, "algorithm", hashName, nil)

	for h.NextBlock(0) {
		username := h.Val()

		var b64Pwd string
		h.Args(&b64Pwd)
		if h.NextArg() {
			return nil, h.ArgErr()
		}

		if username == "" || b64Pwd == "" {
			return nil, h.Err("username and password cannot be empty or missing")
		}

		ba.AccountList = append(ba.AccountList, Account{
			Username: username,
			Password: b64Pwd,
		})
	}

	return Authentication{
		ProvidersRaw: caddy.ModuleMap{
			"http_basic": caddyconfig.JSON(ba, nil),
		},
	}, nil
}