// mmc -- Mattermost client
// Copyright (C) 2023 Sergey Matveev <stargrave@stargrave.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

// Nearly all code is taken from src/cmd/go/internal/auth/netrc.go

package mmc

import (
	"errors"
	"io/fs"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strings"
)

func FindInNetrc(host string) (string, string) {
	netrcPath, ok := os.LookupEnv("NETRC")
	if !ok {
		homeDir, err := os.UserHomeDir()
		if err != nil {
			log.Fatalln(err)
		}
		netrcPath = filepath.Join(homeDir, ".netrc")
	}
	data, err := ioutil.ReadFile(netrcPath)
	if err != nil {
		if errors.Is(err, fs.ErrNotExist) {
			return "", ""
		}
		log.Fatalln(err)
	}
	inMacro := false
	var machine, login, password string
	for _, line := range strings.Split(string(data), "\n") {
		if inMacro {
			if line == "" {
				inMacro = false
			}
			continue
		}
		fields := strings.Fields(line)
		i := 0
		for ; i < len(fields)-1; i += 2 {
			switch fields[i] {
			case "machine":
				machine = fields[i+1]
				login = ""
				password = ""
			case "default":
				break
			case "login":
				login = fields[i+1]
			case "password":
				password = fields[i+1]
			case "macdef":
				inMacro = true
			}
			if machine != "" && login != "" && password != "" {
				if machine == host {
					return login, password
				}
				machine, login, password = "", "", ""
			}
		}
		if i < len(fields) && fields[i] == "default" {
			break
		}
	}
	return "", ""
}