// Copyright 2016 Google Inc. All rights reserved.
//
// 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 gitindex

import (
	"bytes"

	"github.com/go-git/go-git/v5/plumbing/format/config"
)

// SubmoduleEntry represent one entry in a .gitmodules file
type SubmoduleEntry struct {
	Path   string
	URL    string
	Branch string
}

// ParseGitModules parses the contents of a .gitmodules file.
func ParseGitModules(content []byte) (map[string]*SubmoduleEntry, error) {
	dec := config.NewDecoder(bytes.NewBuffer(content))
	cfg := &config.Config{}

	if err := dec.Decode(cfg); err != nil {
		return nil, err
	}

	result := map[string]*SubmoduleEntry{}
	for _, s := range cfg.Sections {
		if s.Name != "submodule" {
			continue
		}

		for _, ss := range s.Subsections {
			name := ss.Name
			e := &SubmoduleEntry{}
			for _, o := range ss.Options {
				switch o.Key {
				case "branch":
					e.Branch = o.Value
				case "path":
					e.Path = o.Value
				case "url":
					e.URL = o.Value
				}
			}

			result[name] = e
		}
	}

	return result, nil
}