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"
)

// ReservationEventConsumer 校验预占事件与本地权威事实一致。
type ReservationEventConsumer struct {
	db *gorm.DB
}

// NewReservationEventConsumer 创建代理主钱包预占事件消费者。
func NewReservationEventConsumer(db *gorm.DB) *ReservationEventConsumer {
	return &ReservationEventConsumer{db: db}
}

// Consume 只确认具有匹配权威预占事实的事件。
func (c *ReservationEventConsumer) Consume(ctx context.Context, envelope outbox.DeliveryEnvelope) error {
	if c == nil || c.db == nil {
		return errors.New(errors.CodeInternalError, "代理主钱包预占事件消费者未配置")
	}
	if envelope.EventType != constants.OutboxEventTypeAgentMainWalletReservationChanged ||
		envelope.PayloadVersion != constants.AgentMainWalletReservationPayloadVersionV1 {
		return errors.New(errors.CodeInvalidParam, "代理主钱包预占事件类型或版本不受支持")
	}
	var event walletapp.ReservationEvent
	if err := sonic.Unmarshal(envelope.Payload, &event); err != nil {
		return errors.Wrap(errors.CodeInvalidParam, err, "代理主钱包预占事件载荷无法解析")
	}
	if event.EventID != envelope.EventID || event.ReservationID == 0 || event.WalletID == 0 ||
		event.Amount <= 0 || event.ReferenceType == "" || event.ReferenceID == 0 {
		return errors.New(errors.CodeInvalidParam, "代理主钱包预占事件载荷不完整")
	}
	var reservation model.AgentWalletReservation
	if err := c.db.WithContext(ctx).Where("id = ?", event.ReservationID).First(&reservation).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return errors.New(errors.CodeInternalError, "代理主钱包预占事件缺少权威事实")
		}
		return errors.Wrap(errors.CodeDatabaseError, err, "查询代理主钱包预占事实失败")
	}
	if reservation.AgentWalletID != event.WalletID || reservation.Amount != event.Amount ||
		reservation.ReferenceType != event.ReferenceType || reservation.ReferenceID != event.ReferenceID ||
		!reservationStatusContainsEvent(reservation.Status, event.Status) {
		return errors.New(errors.CodeInternalError, "代理主钱包预占事件与权威事实不一致")
	}
	return nil
}

func reservationStatusContainsEvent(current, event int) bool {
	if current == event {
		return true
	}
	return event == constants.AgentWalletReservationStatusFrozen &&
		(current == constants.AgentWalletReservationStatusReleased || current == constants.AgentWalletReservationStatusCompleted)
}