// Config: parse packages.yaml

// Copyright (C) 2021-2022  Simon Ruderich
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package config

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"gopkg.in/yaml.v2"
)

func LoadPackages(group string) ([]string, error) {
	path := filepath.Join(group, "packages.yaml")

	var res []string
	x, err := os.ReadFile(path)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, nil
		}
		return nil, err
	}
	err = yaml.UnmarshalStrict(x, &res)
	if err != nil {
		return nil, fmt.Errorf("%s: failed to load: %v", path, err)
	}

	// Sanity checks
	for _, x := range res {
		if len(strings.Fields(x)) != 1 {
			return nil, fmt.Errorf(
				"%s: package name %q must not contain whitespace",
				path, x)
		}
	}

	return res, nil
}