package cnf

import (
	"encoding/json"
	"io"
	"strings"
)

type Json struct {
	data   interface{}
	parsed bool
}

// Parse extract a reader as its JSON representation
func (d *Json) Parse(_reader io.Reader) error {

	// 1. get json decoder
	decoder := json.NewDecoder(_reader)
	err := decoder.Decode(&d.data)
	if err != nil {
		return err
	}

	d.parsed = true
	return nil

}

// Get returns the value of a dot-separated path, and if it exists
func (d *Json) Get(_path string) (string, bool) {

	// 1. extract path
	path := strings.Split(_path, ".")

	// 2. Iterate over path / nested fields
	current := d.data
	for _, field := range path {
		fmap, ok := current.(map[string]interface{})
		if !ok { // incomplete path
			return "", false
		}

		child, ok := fmap[field]
		if !ok { // incomplete path
			return "", false
		}

		current = child
	}

	// 3. Only return if string value
	value, ok := current.(string)
	return value, ok
}