package adapter

import (
	"bytes"
	"context"
	"encoding/gob"
	"errors"
	"fmt"
	"time"

	"gitea.dwysokinski.me/twhelp/dcbot/internal/domain"
	"github.com/redis/go-redis/v9"
)

type VillageRedis struct {
	client redis.UniversalClient
}

func NewVillageRedis(client redis.UniversalClient) *VillageRedis {
	return &VillageRedis{client: client}
}

const translateVillageCoordsParamsExp = 72 * time.Hour

type translateVillageCoordsParamsRedis struct {
	VersionCode string
	ServerKey   string
	Coords      []string
	PerPage     int32
	MaxPage     int32
	SHA256      string
}

func (v *VillageRedis) SaveTranslateCoordsParams(ctx context.Context, params domain.TranslateVillageCoordsParams) error {
	buf := bytes.NewBuffer(nil)

	if err := gob.NewEncoder(buf).Encode(translateVillageCoordsParamsRedis{
		VersionCode: params.VersionCode(),
		ServerKey:   params.ServerKey(),
		Coords:      params.Coords(),
		PerPage:     params.PerPage(),
		MaxPage:     params.MaxPage(),
		SHA256:      params.SHA256(),
	}); err != nil {
		return err
	}

	if err := v.client.Set(
		ctx,
		v.buildTranslateCoordsParamsKey(params.SHA256()),
		buf.Bytes(),
		translateVillageCoordsParamsExp,
	).Err(); err != nil {
		return err
	}

	return nil
}

func (v *VillageRedis) GetTranslateCoordsParams(ctx context.Context, sha256Hash string) (domain.TranslateVillageCoordsParams, error) {
	b, err := v.client.Get(ctx, v.buildTranslateCoordsParamsKey(sha256Hash)).Bytes()
	if errors.Is(err, redis.Nil) {
		return domain.TranslateVillageCoordsParams{}, domain.TranslateVillageCoordsParamsNotFoundError{
			SHA256: sha256Hash,
		}
	}
	if err != nil {
		return domain.TranslateVillageCoordsParams{}, err
	}

	var params translateVillageCoordsParamsRedis

	if err = gob.NewDecoder(bytes.NewReader(b)).Decode(&params); err != nil {
		return domain.TranslateVillageCoordsParams{}, err
	}

	res, err := domain.UnmarshalTranslateVillageCoordsParamsFromDatabase(
		params.VersionCode,
		params.ServerKey,
		params.Coords,
		params.PerPage,
		params.MaxPage,
		params.SHA256,
	)
	if err != nil {
		return domain.TranslateVillageCoordsParams{}, fmt.Errorf("couldn't unmarshal TranslateVillageCoordsParams from database: %w", err)
	}

	return res, nil
}

func (v *VillageRedis) buildTranslateCoordsParamsKey(sha256Hash string) string {
	return "translate_village_coords_params_" + sha256Hash
}