package wallet

import (
	"context"

	"github.com/bytedance/sonic"
	"gorm.io/gorm"

	walletapp "github.com/break/junhong_cmp_fiber/internal/application/wallet"
	"github.com/break/junhong_cmp_fiber/internal/infrastructure/messaging/outbox"
	"github.com/break/junhong_cmp_fiber/internal/model"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
)

// DebitEventConsumer 校验已投递的代理主钱包扣款事件具有对应权威资金流水。
// 后续余额预警等消费者在此稳定接缝上扩展，不需要回读或改写订单扣款事务。
type DebitEventConsumer struct {
	db *gorm.DB
}

// NewDebitEventConsumer 创建代理主钱包扣款事件消费者。
func NewDebitEventConsumer(db *gorm.DB) *DebitEventConsumer {
	return &DebitEventConsumer{db: db}
}

// Consume 校验事件载荷及不可变流水，保证未知或损坏事件不会被静默确认。
func (c *DebitEventConsumer) Consume(ctx context.Context, envelope outbox.DeliveryEnvelope) error {
	if c == nil || c.db == nil {
		return errors.New(errors.CodeInternalError, "代理主钱包扣款事件消费者未配置")
	}
	if envelope.EventType != constants.OutboxEventTypeAgentMainWalletDebited ||
		envelope.PayloadVersion != constants.AgentMainWalletDebitedPayloadVersionV1 {
		return errors.New(errors.CodeInvalidParam, "代理主钱包扣款事件类型或版本不受支持")
	}
	var event walletapp.DebitedEvent
	if err := sonic.Unmarshal(envelope.Payload, &event); err != nil {
		return errors.Wrap(errors.CodeInvalidParam, err, "代理主钱包扣款事件载荷无法解析")
	}
	if event.EventID != envelope.EventID || event.WalletID == 0 || event.ReferenceID == 0 ||
		event.ReferenceType != constants.ReferenceTypeOrder || event.TransactionType != constants.AgentTransactionTypeDeduct ||
		event.Amount <= 0 {
		return errors.New(errors.CodeInvalidParam, "代理主钱包扣款事件载荷不完整")
	}

	var transaction model.AgentWalletTransaction
	err := c.db.WithContext(ctx).Unscoped().
		Where("agent_wallet_id = ? AND reference_type = ? AND reference_id = ? AND transaction_type = ? AND status = ?",
			event.WalletID, event.ReferenceType, event.ReferenceID, constants.AgentTransactionTypeDeduct, constants.TransactionStatusSuccess).
		First(&transaction).Error
	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return errors.New(errors.CodeInternalError, "代理主钱包扣款事件缺少权威资金流水")
		}
		return errors.Wrap(errors.CodeDatabaseError, err, "查询代理主钱包扣款流水失败")
	}
	if transaction.Amount != -event.Amount || transaction.BalanceBefore != event.BalanceBefore ||
		transaction.BalanceAfter != event.BalanceAfter {
		return errors.New(errors.CodeInternalError, "代理主钱包扣款事件与权威资金流水不一致")
	}
	return nil
}