package prdcthsomod

import (
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
)

// VIPExperimentGoldOrderStat contains successful VIP card purchases paid with coins.
type VIPExperimentGoldOrderStat struct {
	Variant        string             `json:"variant" bson:"variant"`
	ProductID      primitive.ObjectID `json:"productId" bson:"productId"`
	GoldPaidOrders int                `json:"goldPaidOrders" bson:"goldPaidOrders"`
	GoldPaidAmount int64              `json:"goldPaidAmount" bson:"goldPaidAmount"`
}

func VIPExperimentGoldOrderStatistics(experimentID string) ([]VIPExperimentGoldOrderStat, error) {
	var raw []struct {
		ID struct {
			Variant   string             `bson:"variant"`
			ProductID primitive.ObjectID `bson:"productId"`
		} `bson:"_id"`
		GoldPaidOrders int   `bson:"goldPaidOrders"`
		GoldPaidAmount int64 `bson:"goldPaidAmount"`
	}
	err := coll(nil).Aggregate(&raw, []bson.M{
		{"$match": bson.M{"experimentId": experimentID}},
		{"$group": bson.M{
			"_id": bson.M{
				"variant":   "$experimentVariant",
				"productId": "$productID",
			},
			"goldPaidOrders": bson.M{"$sum": 1},
			"goldPaidAmount": bson.M{"$sum": bson.M{"$add": bson.A{
				bson.M{"$ifNull": bson.A{"$amount", 0}},
				bson.M{"$ifNull": bson.A{"$income", 0}},
			}}},
		}},
		{"$sort": bson.D{{Key: "_id.variant", Value: 1}, {Key: "goldPaidOrders", Value: -1}}},
	})
	if err != nil {
		return nil, err
	}
	result := make([]VIPExperimentGoldOrderStat, 0, len(raw))
	for _, item := range raw {
		result = append(result, VIPExperimentGoldOrderStat{
			Variant:        item.ID.Variant,
			ProductID:      item.ID.ProductID,
			GoldPaidOrders: item.GoldPaidOrders,
			GoldPaidAmount: item.GoldPaidAmount,
		})
	}
	return result, nil
}