package agentrecharge

import (
	"context"
	cryptorand "crypto/rand"
	stderrors "errors"
	"fmt"
	"math/big"
	"strings"
	"time"

	"gorm.io/gorm"

	domain "github.com/break/junhong_cmp_fiber/internal/domain/agentrecharge"
	"github.com/break/junhong_cmp_fiber/internal/model"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	apperrors "github.com/break/junhong_cmp_fiber/pkg/errors"
	"github.com/break/junhong_cmp_fiber/pkg/idempotency"
)

const onlineCreationOperation = "agent-recharge.create-online"

// CreateOnlineCommand 描述从认证上下文构造的在线充值命令。
type CreateOnlineCommand struct {
	AccountID     uint
	UserType      int
	CurrentShopID uint
	Amount        int64
	PaymentMethod string
	RequestID     string
	PayerClientIP string
}

// CreateOnlineResult 返回在线充值单、支付单及支付链接。
type CreateOnlineResult struct {
	Recharge *model.AgentRechargeRecord
	Payment  *model.Payment
}

// AvailablePaymentMethodsResult 返回当前可用渠道及在线金额边界。
type AvailablePaymentMethodsResult struct {
	Methods   []string
	MinAmount int64
	MaxAmount int64
}

// OnlineCreationService 创建代理在线扫码充值单。
type OnlineCreationService struct {
	db     *gorm.DB
	wechat OnlinePaymentPort
	alipay OnlinePaymentPort
	audit  PaymentAuditWriter
}

// NewOnlineCreationService 创建代理在线充值用例并以结构体字段注入两个渠道 Adapter。
func NewOnlineCreationService(db *gorm.DB, wechat, alipay OnlinePaymentPort, audit PaymentAuditWriter) *OnlineCreationService {
	return &OnlineCreationService{db: db, wechat: wechat, alipay: alipay, audit: audit}
}

// Execute 以短事务建单，事务外生成支付链接，再条件保存链接或关闭失败订单。
func (s *OnlineCreationService) Execute(ctx context.Context, command CreateOnlineCommand) (*CreateOnlineResult, error) {
	if s == nil || s.db == nil || s.wechat == nil || s.alipay == nil || s.audit == nil {
		return nil, apperrors.New(apperrors.CodeServiceUnavailable, "代理在线充值能力未配置")
	}
	command.PaymentMethod = strings.TrimSpace(command.PaymentMethod)
	command.RequestID = strings.TrimSpace(command.RequestID)
	if err := domain.ValidateOnlineCreation(command.UserType, command.Amount, command.PaymentMethod); err != nil {
		return nil, err
	}
	if command.AccountID == 0 || command.CurrentShopID == 0 || len(command.RequestID) > 64 ||
		!idempotency.ValidateScope(onlineCreationScope(command.AccountID), command.RequestID) {
		return nil, apperrors.New(apperrors.CodeInvalidParam)
	}
	fingerprint, err := idempotency.Fingerprint(struct {
		Amount        int64  `json:"amount"`
		PaymentMethod string `json:"payment_method"`
	}{command.Amount, command.PaymentMethod})
	if err != nil {
		return nil, apperrors.Wrap(apperrors.CodeInternalError, err, "生成在线充值请求指纹失败")
	}
	if replay, found, err := s.loadReplay(ctx, command, fingerprint); err != nil || found {
		return replay, err
	}
	account, shop, wallet, config, adapter, err := s.loadCreationFacts(ctx, command)
	if err != nil {
		return nil, err
	}
	result, err := s.createLocalFacts(ctx, command, fingerprint.Value, account, shop, wallet, config)
	if err != nil {
		if replay, found, replayErr := s.loadReplay(ctx, command, fingerprint); replayErr != nil || found {
			return replay, replayErr
		}
		return nil, err
	}
	paymentResult, err := adapter.CreatePaymentURL(ctx, OnlinePaymentRequest{
		PaymentID: result.Payment.ID, PaymentNo: result.Payment.PaymentNo, CorrelationID: result.Payment.PaymentNo,
		Description: "代理主钱包充值", Amount: command.Amount,
		ExpireAt: *result.Payment.ExpireAt, PayerClientIP: command.PayerClientIP, Config: config,
	})
	if err != nil {
		if !isUnknownPaymentResult(err) {
			if closeErr := s.closeFailedCreation(ctx, result); closeErr != nil {
				return nil, apperrors.Wrap(apperrors.CodeDatabaseError, closeErr, "支付链接生成失败且关闭本地订单失败")
			}
		}
		return nil, err
	}
	if strings.TrimSpace(paymentResult.QRContent) == "" {
		if closeErr := s.closeFailedCreation(ctx, result); closeErr != nil {
			return nil, closeErr
		}
		return nil, apperrors.New(apperrors.CodeServiceUnavailable, "支付渠道未返回支付链接")
	}
	update := s.db.WithContext(ctx).Model(&model.Payment{}).
		Where("id = ? AND status = ? AND qr_content = ''", result.Payment.ID, model.PaymentRecordStatusPending).
		Update("qr_content", paymentResult.QRContent)
	if update.Error != nil {
		return nil, apperrors.Wrap(apperrors.CodeDatabaseError, update.Error, "保存支付链接失败")
	}
	if update.RowsAffected != 1 {
		return nil, apperrors.New(apperrors.CodeConflict, "在线充值支付链接已变化")
	}
	result.Payment.QRContent = paymentResult.QRContent
	return result, nil
}

// AvailablePaymentMethods 按固定顺序返回配置完整的在线支付方式。
func (s *OnlineCreationService) AvailablePaymentMethods(ctx context.Context, userType int) (AvailablePaymentMethodsResult, error) {
	result := AvailablePaymentMethodsResult{
		Methods: []string{}, MinAmount: constants.AgentOnlineRechargeMinAmount, MaxAmount: constants.AgentRechargeMaxAmount,
	}
	if userType != constants.UserTypeAgent {
		return result, apperrors.New(apperrors.CodeForbidden, "仅代理账号可以查询在线支付方式")
	}
	var config model.WechatConfig
	if err := s.db.WithContext(ctx).Where("is_active = ?", true).First(&config).Error; err != nil {
		if stderrors.Is(err, gorm.ErrRecordNotFound) {
			return result, nil
		}
		return result, apperrors.Wrap(apperrors.CodeDatabaseError, err, "查询生效支付配置失败")
	}
	if s.wechat.Available(&config) {
		result.Methods = append(result.Methods, constants.RechargeMethodWechat)
	}
	if s.alipay.Available(&config) {
		result.Methods = append(result.Methods, constants.RechargeMethodAlipay)
	}
	return result, nil
}

func (s *OnlineCreationService) loadCreationFacts(
	ctx context.Context,
	command CreateOnlineCommand,
) (*model.Account, *model.Shop, *model.AgentWallet, *model.WechatConfig, OnlinePaymentPort, error) {
	var account model.Account
	if err := s.db.WithContext(ctx).Where("id = ? AND user_type = ? AND status = ?", command.AccountID, constants.UserTypeAgent, constants.StatusEnabled).First(&account).Error; err != nil || account.ShopID == nil || *account.ShopID != command.CurrentShopID {
		if err != nil && !stderrors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil, nil, nil, nil, apperrors.Wrap(apperrors.CodeDatabaseError, err, "查询在线充值账号失败")
		}
		return nil, nil, nil, nil, nil, apperrors.New(apperrors.CodeForbidden, "当前代理账号不可为该店铺充值")
	}
	var shop model.Shop
	if err := s.db.WithContext(ctx).Where("id = ? AND status = ?", command.CurrentShopID, constants.StatusEnabled).First(&shop).Error; err != nil {
		if stderrors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil, nil, nil, nil, apperrors.New(apperrors.CodeForbidden, "无权限操作该资源或资源不存在")
		}
		return nil, nil, nil, nil, nil, apperrors.Wrap(apperrors.CodeDatabaseError, err, "查询当前店铺失败")
	}
	var wallet model.AgentWallet
	if err := s.db.WithContext(ctx).Where("shop_id = ? AND wallet_type = ? AND status = ?", command.CurrentShopID, constants.AgentWalletTypeMain, constants.AgentWalletStatusNormal).First(&wallet).Error; err != nil {
		if stderrors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil, nil, nil, nil, apperrors.New(apperrors.CodeWalletNotFound, "当前店铺主钱包不存在或不可用")
		}
		return nil, nil, nil, nil, nil, apperrors.Wrap(apperrors.CodeDatabaseError, err, "查询当前店铺主钱包失败")
	}
	var config model.WechatConfig
	if err := s.db.WithContext(ctx).Where("is_active = ?", true).First(&config).Error; err != nil {
		if stderrors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil, nil, nil, nil, apperrors.New(apperrors.CodeNoPaymentConfig)
		}
		return nil, nil, nil, nil, nil, apperrors.Wrap(apperrors.CodeDatabaseError, err, "查询生效支付配置失败")
	}
	adapter := s.adapter(command.PaymentMethod)
	if adapter == nil || !adapter.Available(&config) {
		return nil, nil, nil, nil, nil, apperrors.New(apperrors.CodeNoPaymentConfig)
	}
	return &account, &shop, &wallet, &config, adapter, nil
}

func (s *OnlineCreationService) createLocalFacts(
	ctx context.Context,
	command CreateOnlineCommand,
	fingerprint string,
	account *model.Account,
	shop *model.Shop,
	wallet *model.AgentWallet,
	config *model.WechatConfig,
) (*CreateOnlineResult, error) {
	rechargeNo, err := newBusinessNo(constants.AgentRechargeOrderPrefix, time.Now().Format("20060102150405"))
	if err != nil {
		return nil, err
	}
	paymentNo, err := newBusinessNo("PAY", fmt.Sprintf("%d", time.Now().UnixMilli()))
	if err != nil {
		return nil, err
	}
	expireMinutes := config.AliPayExpireMinutes
	if expireMinutes <= 0 {
		expireMinutes = model.DefaultAliPayExpireMinutes
	}
	expireAt := time.Now().Add(time.Duration(expireMinutes) * time.Minute)
	channel, requestID := command.PaymentMethod, command.RequestID
	record := &model.AgentRechargeRecord{
		UserID: account.ID, AgentWalletID: wallet.ID, ShopID: shop.ID, RechargeNo: rechargeNo,
		Amount: command.Amount, PaymentMethod: command.PaymentMethod, PaymentChannel: &channel,
		PaymentConfigID: &config.ID, Status: constants.RechargeStatusPending,
		RequestID: &requestID, RequestFingerprint: &fingerprint,
		ShopIDTag: wallet.ShopIDTag, EnterpriseIDTag: wallet.EnterpriseIDTag,
	}
	payment := &model.Payment{
		PaymentNo: paymentNo, OrderType: model.PaymentOrderTypeAgentRecharge,
		PaymentMethod: command.PaymentMethod, MerchantIdentity: paymentMerchantIdentity(command.PaymentMethod, config),
		Amount: command.Amount, Status: model.PaymentRecordStatusPending,
		PaymentConfigID: &config.ID, ExpireAt: &expireAt,
	}
	err = s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		if err := tx.Create(record).Error; err != nil {
			return err
		}
		payment.OrderID = record.ID
		if err := tx.Create(payment).Error; err != nil {
			return err
		}
		return s.audit.WriteAgentRechargePayment(ctx, tx, PaymentAudit{
			ActionCode: constants.AuditActionPaymentCreated, Summary: "创建代理充值支付记录",
			Payment: payment, Recharge: record, AfterData: map[string]any{"status": payment.Status},
		})
	})
	if err != nil {
		return nil, apperrors.Wrap(apperrors.CodeDatabaseError, err, "创建在线充值本地订单失败")
	}
	return &CreateOnlineResult{Recharge: record, Payment: payment}, nil
}

func paymentMerchantIdentity(paymentMethod string, config *model.WechatConfig) string {
	if config == nil {
		return ""
	}
	if paymentMethod == constants.RechargeMethodWechat {
		return config.WxMchID
	}
	if paymentMethod == constants.RechargeMethodAlipay {
		return config.AliAppID
	}
	return ""
}

func (s *OnlineCreationService) loadReplay(
	ctx context.Context,
	command CreateOnlineCommand,
	fingerprint idempotency.FingerprintValue,
) (*CreateOnlineResult, bool, error) {
	var record model.AgentRechargeRecord
	err := s.db.WithContext(ctx).Where("user_id = ? AND request_id = ?", command.AccountID, command.RequestID).First(&record).Error
	if stderrors.Is(err, gorm.ErrRecordNotFound) {
		return nil, false, nil
	}
	if err != nil {
		return nil, false, apperrors.Wrap(apperrors.CodeDatabaseError, err, "读取在线充值幂等记录失败")
	}
	existingFingerprint := ""
	if record.RequestFingerprint != nil {
		existingFingerprint = *record.RequestFingerprint
	}
	if existingFingerprint != fingerprint.Value {
		return nil, true, apperrors.New(apperrors.CodeConflict, "同一请求标识对应的充值内容不一致")
	}
	var payment model.Payment
	if err := s.db.WithContext(ctx).Where("order_id = ? AND order_type = ?", record.ID, model.PaymentOrderTypeAgentRecharge).First(&payment).Error; err != nil {
		return nil, true, apperrors.Wrap(apperrors.CodeDatabaseError, err, "读取在线充值支付单失败")
	}
	if payment.QRContent == "" {
		if record.Status == constants.RechargeStatusClosed || payment.Status == model.PaymentRecordStatusFailed {
			return nil, true, apperrors.New(apperrors.CodeInvalidStatus, "原在线充值请求支付链接生成失败")
		}
		return nil, true, apperrors.New(apperrors.CodeConflict, "在线充值请求正在处理中，请稍后重试")
	}
	return &CreateOnlineResult{Recharge: &record, Payment: &payment}, true, nil
}

func (s *OnlineCreationService) closeFailedCreation(ctx context.Context, result *CreateOnlineResult) error {
	if result == nil || result.Recharge == nil || result.Payment == nil || !domain.CanCloseAfterPaymentURLFailure(result.Recharge.Status) {
		return nil
	}
	return s.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		paymentUpdate := tx.Model(&model.Payment{}).
			Where("id = ? AND status = ?", result.Payment.ID, model.PaymentRecordStatusPending).
			Update("status", model.PaymentRecordStatusFailed)
		if paymentUpdate.Error != nil {
			return apperrors.Wrap(apperrors.CodeDatabaseError, paymentUpdate.Error, "关闭失败支付单失败")
		}
		rechargeUpdate := tx.Model(&model.AgentRechargeRecord{}).
			Where("id = ? AND status = ?", result.Recharge.ID, constants.RechargeStatusPending).
			Update("status", constants.RechargeStatusClosed)
		if rechargeUpdate.Error != nil {
			return apperrors.Wrap(apperrors.CodeDatabaseError, rechargeUpdate.Error, "关闭失败充值单失败")
		}
		afterPayment := *result.Payment
		afterPayment.Status = model.PaymentRecordStatusFailed
		return s.audit.WriteAgentRechargePayment(ctx, tx, PaymentAudit{
			ActionCode: constants.AuditActionPaymentFailed, Summary: "支付链接生成失败，关闭支付记录",
			Payment: &afterPayment, Recharge: result.Recharge,
			BeforeData: map[string]any{"status": result.Payment.Status}, AfterData: map[string]any{"status": afterPayment.Status},
			RechargeBeforeData: map[string]any{"status": result.Recharge.Status}, RechargeAfterData: map[string]any{"status": constants.RechargeStatusClosed},
		})
	})
}

func (s *OnlineCreationService) adapter(paymentMethod string) OnlinePaymentPort {
	if paymentMethod == constants.RechargeMethodWechat {
		return s.wechat
	}
	if paymentMethod == constants.RechargeMethodAlipay {
		return s.alipay
	}
	return nil
}

func onlineCreationScope(accountID uint) idempotency.Scope {
	return idempotency.Scope{Subject: fmt.Sprintf("account:%d", accountID), Operation: onlineCreationOperation}
}

func newBusinessNo(prefix, timestamp string) (string, error) {
	random, err := cryptorand.Int(cryptorand.Reader, big.NewInt(1000000))
	if err != nil {
		return "", apperrors.Wrap(apperrors.CodeInternalError, err, "生成业务单号失败")
	}
	return fmt.Sprintf("%s%s%06d", prefix, timestamp, random.Int64()), nil
}

func isUnknownPaymentResult(err error) bool {
	var appErr *apperrors.AppError
	return stderrors.As(err, &appErr) && appErr.Code == apperrors.CodeTimeout
}