github.com/mysteriumnetwork/node@v0.0.0-20240516044423-365054f76801/config/viper.go

/*
 * Copyright (C) 2019 The "MysteriumNetwork/node" Authors.
 *
 * 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/>.
 */

/*
The MIT License (MIT)

Copyright (c) 2014 Steve Francia

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

package config

import (
	"fmt"
	"strings"

	"github.com/spf13/cast"
)

// Contains snippets from https://github.com/spf13/viper

// SearchMap recursively searches for a value for path in source map.
// Returns nil if not found.
// Note: This assumes that the path entries and map keys are lower cased.
func SearchMap(source map[string]interface{}, path []string) interface{} {
	if len(path) == 0 {
		return source
	}

	next, ok := source[path[0]]
	if ok {
		// Fast path
		if len(path) == 1 {
			return next
		}

		// Nested case
		switch next := next.(type) {
		case map[interface{}]interface{}:
			return SearchMap(cast.ToStringMap(next), path[1:])
		case map[string]interface{}:
			// Type assertion is safe here since it is only reached
			// if the type of `next` is the same as the type being asserted
			return SearchMap(next, path[1:])
		default:
			// got a value but nested key expected, return "nil" for not found
			return nil
		}
	}
	return nil
}

// deepSearch scans deep maps, following the key indexes listed in the
// sequence "path".
// The last value is expected to be another map, and is returned.
//
// In case intermediate keys do not exist, or map to a non-map value,
// a new map is created and inserted, and the search continues from there:
// the initial map "m" may be modified!
func deepSearch(m map[string]interface{}, path []string) map[string]interface{} {
	for _, k := range path {
		m2, ok := m[k]
		if !ok {
			// intermediate key does not exist
			// => create it and continue from there
			m3 := make(map[string]interface{})
			m[k] = m3
			m = m3
			continue
		}
		m3, ok := m2.(map[string]interface{})
		if !ok {
			// intermediate key is a value
			// => replace with a new map
			m3 = make(map[string]interface{})
			m[k] = m3
		}
		// continue search from here
		m = m3
	}
	return m
}

func keyExists(k string, m map[string]interface{}) string {
	lk := strings.ToLower(k)
	for mk := range m {
		lmk := strings.ToLower(mk)
		if lmk == lk {
			return mk
		}
	}
	return ""
}

func castToMapStringInterface(
	src map[interface{}]interface{}) map[string]interface{} {
	tgt := map[string]interface{}{}
	for k, v := range src {
		tgt[fmt.Sprintf("%v", k)] = v
	}
	return tgt
}

// mergeMaps merges two maps. The `itgt` parameter is for handling go-yaml's
// insistence on parsing nested structures as `map[interface{}]interface{}`
// instead of using a `string` as the key for nest structures beyond one level
// deep. Both map types are supported as there is a go-yaml fork that uses
// `map[string]interface{}` instead.
func mergeMaps(
	src, tgt map[string]interface{}, itgt map[interface{}]interface{}) {
	for sk, sv := range src {
		tk := keyExists(sk, tgt)
		if tk == "" {
			tgt[sk] = sv
			if itgt != nil {
				itgt[sk] = sv
			}
			continue
		}

		tv, ok := tgt[tk]
		if !ok {
			tgt[sk] = sv
			if itgt != nil {
				itgt[sk] = sv
			}
			continue
		}

		switch ttv := tv.(type) {
		case map[interface{}]interface{}:
			tsv := sv.(map[interface{}]interface{})
			ssv := castToMapStringInterface(tsv)
			stv := castToMapStringInterface(ttv)
			mergeMaps(ssv, stv, ttv)
		case map[string]interface{}:
			mergeMaps(sv.(map[string]interface{}), ttv, nil)
		default:
			tgt[tk] = sv
			if itgt != nil {
				itgt[tk] = sv
			}
		}
	}
}