package formatters

import (
	"bytes"
	"encoding/json"
	"fmt"
	"time"

	"codeberg.org/danjones000/my-log/models"
	"github.com/spf13/viper"
)

const FormatJSON string = "json"

func newJson(ff *viper.Viper) (Formatter, error) {
	js := new(Json)
	err := ff.Unmarshal(js)
	if err != nil {
		return nil, fmt.Errorf("failed to get json config: %w", err)
	}
	return js, nil
}

type Json struct {
	prettPrint bool `mapstructure:"pretty_print"`
}

func (js *Json) Name() string {
	return FormatJSON
}

func (js *Json) marshal(v any) (o []byte, err error) {
	o, err = json.Marshal(v)
	if err != nil {
		return
	}
	if js.prettPrint {
		buff := &bytes.Buffer{}
		err = json.Indent(buff, o, "", "\t")
		if err == nil {
			o = buff.Bytes()
		}
	}
	return
}

func (js *Json) Meta(m models.Meta) ([]byte, error) {
	o := map[string]any{m.Key: m.Value}
	return js.marshal(o)
}

func (js *Json) entryMap(e models.Entry) map[string]any {
	o := map[string]any{
		"title": e.Title,
		"date":  e.Date.Format(time.RFC3339),
	}
	for _, m := range e.Fields {
		o[m.Key] = m.Value
	}
	return o
}

func (js *Json) Entry(e models.Entry) ([]byte, error) {
	return js.marshal(js.entryMap(e))
}

func (js *Json) Log(l models.Log) ([]byte, error) {
	return js.Logs([]models.Log{l})
}

func (js *Json) Logs(logs []models.Log) (out []byte, err error) {
	if len(logs) == 0 {
		return
	}

	o := map[string][]map[string]any{}
	for _, l := range logs {
		es := []map[string]any{}
		for _, e := range l.Entries {
			es = append(es, js.entryMap(e))
		}
		o[l.Name] = es
	}
	return js.marshal(o)
}