package fbs

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"strings"
	"sync"

	"git.loyso.art/frx/eway/internal/entity"

	flatbuffers "github.com/google/flatbuffers/go"
)

var builderPool = sync.Pool{
	New: func() any {
		builder := flatbuffers.NewBuilder(1024)
		return builder
	},
}

func getBuilder() *flatbuffers.Builder {
	builder := builderPool.Get().(*flatbuffers.Builder)
	return builder
}

func putBuilder(builder *flatbuffers.Builder) {
	// builder.Reset()
	// builderPool.Put(builder)
}

func MakeDomainGoodItems(in ...entity.GoodsItem) []byte {
	builder := getBuilder()
	defer putBuilder(builder)

	offsets := make([]flatbuffers.UOffsetT, 0, len(in))
	for _, item := range in {
		inFB := makeDomainGoodItem(builder, item)
		offsets = append(offsets, inFB)
	}

	GoodItemsStartItemsVector(builder, len(offsets))
	for i := len(offsets) - 1; i >= 0; i-- {
		builder.PrependUOffsetT(offsets[i])
	}
	goodItemsVec := builder.EndVector(len(offsets))

	GoodItemsStart(builder)
	GoodItemsAddItems(builder, goodItemsVec)
	out := GoodItemsEnd(builder)
	builder.Finish(out)
	return builder.FinishedBytes()
}

func MakeDomainGoodItemFinished(in entity.GoodsItem) []byte {
	builder := getBuilder()
	defer putBuilder(builder)

	item := makeDomainGoodItem(builder, in)
	builder.Finish(item)

	return builder.FinishedBytes()
}

func makeDomainGoodItem(builder *flatbuffers.Builder, in entity.GoodsItem) flatbuffers.UOffsetT {
	sku := builder.CreateString(in.Articul)
	photo := builder.CreateString(strings.Join(in.PhotoURLs, ";"))
	name := builder.CreateString(in.Name)

	descBase64 := base64.RawStdEncoding.EncodeToString([]byte(in.Description))
	desc := builder.CreateString(descBase64)

	var cat flatbuffers.UOffsetT
	if in.Category != "" {
		cat = builder.CreateString(in.Category)
	}
	t := builder.CreateString(in.Type)

	parametersData, _ := json.Marshal(in.Parameters)
	parameters := builder.CreateByteString(parametersData)

	producer := builder.CreateString(in.Producer)

	GoodItemStart(builder)
	GoodItemAddSku(builder, sku)
	GoodItemAddPhoto(builder, photo)
	GoodItemAddName(builder, name)
	GoodItemAddDescription(builder, desc)
	if in.Category != "" {
		GoodItemAddCategory(builder, cat)
	}
	GoodItemAddType(builder, t)
	GoodItemAddProducer(builder, producer)
	GoodItemAddPack(builder, int16(in.Pack))
	GoodItemAddStep(builder, int16(in.Step))
	GoodItemAddPrice(builder, float32(in.Price))
	GoodItemAddTariff(builder, float32(in.TariffPrice))
	GoodItemAddCart(builder, int64(in.Cart))
	GoodItemAddStock(builder, int16(in.Stock))
	GoodItemAddParameters(builder, parameters)

	return GoodItemEnd(builder)
}

func ParseGoodsItem(data []byte) (item entity.GoodsItem, err error) {
	itemFBS := GetRootAsGoodItem(data, 0)
	item.Articul = string(itemFBS.Sku())
	item.PhotoURLs = strings.Split(string(itemFBS.Photo()), ";")
	item.Name = string(itemFBS.Name())

	description, err := base64.RawStdEncoding.DecodeString(string(itemFBS.Description()))
	if err != nil {
		return item, fmt.Errorf("decoding description from base64: %w", err)
	}

	item.Description = string(description)
	if value := itemFBS.Category(); value != nil {
		item.Category = string(value)
	}
	item.Type = string(itemFBS.Type())
	item.Producer = string(itemFBS.Producer())
	item.Pack = int(itemFBS.Pack())
	item.Step = int(itemFBS.Step())
	item.Price = float64(itemFBS.Price())
	item.TariffPrice = float64(itemFBS.Tariff())
	item.Cart = itemFBS.Cart()
	item.Stock = int(itemFBS.Stock())
	item.Parameters = map[string]string{}
	err = json.Unmarshal(itemFBS.Parameters(), &item.Parameters)
	if err != nil {
		return item, fmt.Errorf("unmarshalling data: %w", err)
	}

	return item, nil
}

func ParseCategory(data []byte) (category entity.Category) {
	categoryFBS := GetRootAsCategory(data, 0)
	category.ID = categoryFBS.Id()
	category.Name = string(categoryFBS.Name())

	return category
}

func MakeCategoryFinished(category entity.Category) []byte {
	builder := getBuilder()
	defer putBuilder(builder)

	offset := makeCategory(builder, category)
	builder.Finish(offset)

	return builder.FinishedBytes()
}

func makeCategory(builder *flatbuffers.Builder, category entity.Category) flatbuffers.UOffsetT {
	name := builder.CreateString(category.Name)

	CategoryStart(builder)
	CategoryAddId(builder, category.ID)
	CategoryAddName(builder, name)

	return CategoryEnd(builder)
}