package ini

import (

	"bytes"

	"sort"

	"strings"

	"github.com/spf13/cast"

	"gopkg.in/ini.v1"

)

// LoadOptions contains all customized options used for load data source(s).

// This type is added here for convenience: this way consumers can import a single package called "ini".

type LoadOptions = ini.LoadOptions

// Codec implements the encoding.Encoder and encoding.Decoder interfaces for INI encoding.

type Codec struct {

	KeyDelimiter string

	LoadOptions  LoadOptions

}

func (c Codec) Encode(v map[string]interface{}) ([]byte, error) {

	cfg := ini.Empty()

	ini.PrettyFormat = false

	flattened := map[string]interface{}{}

	flattened = flattenAndMergeMap(flattened, v, "", c.keyDelimiter())

	keys := make([]string, 0, len(flattened))

	for key := range flattened {

		keys = append(keys, key)

	}

	sort.Strings(keys)

	for _, key := range keys {

		sectionName, keyName := "", key

		lastSep := strings.LastIndex(key, ".")

		if lastSep != -1 {

			sectionName = key[:(lastSep)]

			keyName = key[(lastSep + 1):]

		}

		// TODO: is this a good idea?

		if sectionName == "default" {

			sectionName = ""

		}

		cfg.Section(sectionName).Key(keyName).SetValue(cast.ToString(flattened[key]))

	}

	var buf bytes.Buffer

	_, err := cfg.WriteTo(&buf)

	if err != nil {

		return nil, err

	}

	return buf.Bytes(), nil

}

func (c Codec) Decode(b []byte, v map[string]interface{}) error {

	cfg := ini.Empty(c.LoadOptions)

	err := cfg.Append(b)

	if err != nil {

		return err

	}

	sections := cfg.Sections()

	for i := 0; i < len(sections); i++ {

		section := sections[i]

		keys := section.Keys()

		for j := 0; j < len(keys); j++ {

			key := keys[j]

			value := cfg.Section(section.Name()).Key(key.Name()).String()

			deepestMap := deepSearch(v, strings.Split(section.Name(), c.keyDelimiter()))

			// set innermost value

			deepestMap[key.Name()] = value

		}

	}

	return nil

}

func (c Codec) keyDelimiter() string {

	if c.KeyDelimiter == "" {

		return "."

	}

	return c.KeyDelimiter

}