package apple

import (
	"context"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"time"

	"github.com/google/uuid"
	"github.com/hibiken/asynq"
	iapmodel "github.com/perfect-panel/server/internal/model/iap/apple"
	"github.com/perfect-panel/server/internal/model/user"
	"github.com/perfect-panel/server/internal/svc"
	"github.com/perfect-panel/server/internal/types"
	"github.com/perfect-panel/server/pkg/constant"
	iapapple "github.com/perfect-panel/server/pkg/iap/apple"
	"github.com/perfect-panel/server/pkg/logger"
	"github.com/perfect-panel/server/pkg/xerr"
	queueType "github.com/perfect-panel/server/queue/types"
	"github.com/pkg/errors"
	"gorm.io/gorm"
)

type AttachTransactionLogic struct {
	logger.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

func NewAttachTransactionLogic(ctx context.Context, svcCtx *svc.ServiceContext) *AttachTransactionLogic {
	return &AttachTransactionLogic{
		Logger: logger.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

func (l *AttachTransactionLogic) Attach(req *types.AttachAppleTransactionRequest) (*types.AttachAppleTransactionResponse, error) {
	u, ok := l.ctx.Value(constant.CtxKeyUser).(*user.User)
	if !ok || u == nil {
		return nil, errors.Wrapf(xerr.NewErrCode(xerr.InvalidAccess), "invalid access")
	}
	txPayload, err := iapapple.VerifyTransactionJWS(req.SignedTransactionJWS)
	if err != nil {
		return nil, errors.Wrapf(xerr.NewErrCode(xerr.ERROR), "invalid jws")
	}
	// idempotency: check existing transaction by original id
	var existTx *iapmodel.Transaction
	existTx, _ = iapmodel.NewModel(l.svcCtx.DB, l.svcCtx.Redis).FindByOriginalId(l.ctx, txPayload.OriginalTransactionId)
	pm, _ := iapapple.ParseProductMap(l.svcCtx.Config.Site.CustomData)
	m, ok := pm.Items[txPayload.ProductId]
	var duration int64
	var tier string
	var subscribeId int64
	if ok {
		duration = m.DurationDays
		tier = m.Tier
		subscribeId = m.SubscribeId
	} else {
		// fallback from order_no if provided
		if req.OrderNo != "" {
			if ord, e := l.svcCtx.OrderModel.FindOneByOrderNo(l.ctx, req.OrderNo); e == nil && ord != nil && ord.Id != 0 {
				duration = ord.Quantity
				subscribeId = ord.SubscribeId
			}
		}
		// final fallback: use request fields
		if duration <= 0 {
			duration = req.DurationDays
		}
		if tier == "" {
			tier = req.Tier
		}
		if subscribeId <= 0 {
			subscribeId = req.SubscribeId
		}
		if duration <= 0 || subscribeId <= 0 {
			return nil, errors.Wrapf(xerr.NewErrCode(xerr.ERROR), "unknown product")
		}
	}
	exp := iapapple.CalcExpire(txPayload.PurchaseDate, duration)
	sum := sha256.Sum256([]byte(req.SignedTransactionJWS))
	jwsHash := hex.EncodeToString(sum[:])
	iapTx := &iapmodel.Transaction{
		UserId:                u.Id,
		OriginalTransactionId: txPayload.OriginalTransactionId,
		TransactionId:         txPayload.TransactionId,
		ProductId:             txPayload.ProductId,
		PurchaseAt:            txPayload.PurchaseDate,
		RevocationAt:          txPayload.RevocationDate,
		JWSHash:               jwsHash,
	}
	err = l.svcCtx.DB.Transaction(func(tx *gorm.DB) error {
		if existTx == nil || existTx.Id == 0 {
			if e := tx.Model(&iapmodel.Transaction{}).Create(iapTx).Error; e != nil {
				return e
			}
		}
		// insert user_subscribe
		userSub := user.Subscribe{
			UserId:      u.Id,
			SubscribeId: subscribeId,
			StartTime:   time.Now(),
			ExpireTime:  exp,
			Traffic:     0,
			Download:    0,
			Upload:      0,
			Token:       fmt.Sprintf("iap:%s", txPayload.OriginalTransactionId),
			UUID:        uuid.New().String(),
			Status:      1,
		}
		if e := l.svcCtx.UserModel.InsertSubscribe(l.ctx, &userSub, tx); e != nil {
			return e
		}
		// optional: mark related order as paid and enqueue activation
		if req.OrderNo != "" {
			orderInfo, e := l.svcCtx.OrderModel.FindOneByOrderNo(l.ctx, req.OrderNo)
			if e != nil {
				// do not fail transaction if order not found; just continue
				return nil
			}
			if orderInfo.Status == 1 {
				if e := l.svcCtx.OrderModel.UpdateOrderStatus(l.ctx, req.OrderNo, 2, tx); e != nil {
					return e
				}
			}
			// enqueue activation regardless (idempotent handler downstream)
			payload := queueType.ForthwithActivateOrderPayload{OrderNo: req.OrderNo}
			bytes, _ := json.Marshal(payload)
			task := asynq.NewTask(queueType.ForthwithActivateOrder, bytes)
			if _, e := l.svcCtx.Queue.EnqueueContext(l.ctx, task); e != nil {
				// non-fatal
				l.Errorw("enqueue activate task error", logger.Field("error", e.Error()))
			}
		}
		return nil
	})
	if err != nil {
		return nil, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseInsertError), "insert error: %v", err.Error())
	}
	return &types.AttachAppleTransactionResponse{
		ExpiresAt: exp.Unix(),
		Tier:      tier,
	}, nil
}