package rechargeser

import (
	"fmt"
	"strings"
	"unicode/utf8"

	"91porn-server/models/commod"
	"91porn-server/models/v/vipcardexperimentmod"

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

const maxAttributionValueLength = 128

func (r *RechargeRequest) normalizeAttribution() {
	r.SourcePage = NormalizeOrderSourcePage(r.SourcePage)
	r.SourceRef = strings.TrimSpace(r.SourceRef)
	r.VideoID = strings.TrimSpace(r.VideoID)
	r.ActivityID = strings.TrimSpace(r.ActivityID)
	r.ExperimentID = strings.TrimSpace(r.ExperimentID)
	r.ExperimentVariant = strings.ToUpper(strings.TrimSpace(r.ExperimentVariant))
	r.SessionID = strings.TrimSpace(r.SessionID)
	r.CheckoutContextID = strings.TrimSpace(r.CheckoutContextID)
}

func (r *RechargeRequest) validateAttribution(uid uint64) error {
	r.normalizeAttribution()
	if utf8.RuneCountInString(r.SourcePage) > maxAttributionValueLength {
		return fmt.Errorf("sourcePage must not exceed %d characters", maxAttributionValueLength)
	}
	if r.SourcePage == OrderSourcePageDramaPaywall {
		if r.BuyType != commod.BuyGold && r.BuyType != commod.BuyProduct {
			return fmt.Errorf("buyType must be 1 or 4 for DRAMA_PAYWALL")
		}
		// sourceRef is the generic order attribution field. For drama paywall
		// orders, derive it from the backend-issued checkout context instead of
		// requiring clients to submit the same identifier twice. The remaining
		// drama fields are attribution-only and must not block a real payment.
		if len(r.CheckoutContextID) > maxAttributionValueLength {
			r.CheckoutContextID = ""
		}
		r.SourceRef = r.CheckoutContextID
	}
	values := map[string]string{
		"sourceRef":         r.SourceRef,
		"videoId":           r.VideoID,
		"activityId":        r.ActivityID,
		"experimentId":      r.ExperimentID,
		"experimentVariant": r.ExperimentVariant,
		"sessionId":         r.SessionID,
		"checkoutContextId": r.CheckoutContextID,
	}
	for name, value := range values {
		if len(value) > maxAttributionValueLength {
			return fmt.Errorf("%s must not exceed %d characters", name, maxAttributionValueLength)
		}
	}
	if r.ExperimentID == "" {
		r.ExperimentVariant = ""
		return nil
	}
	if r.ExperimentVariant == "" || r.SessionID == "" {
		return fmt.Errorf("experimentVariant and sessionId are required with experimentId")
	}
	experiment, err := vipcardexperimentmod.FindByExperimentID(r.ExperimentID)
	if err != nil {
		return err
	}
	if experiment == nil {
		return fmt.Errorf("experiment does not exist")
	}
	config, ok := experiment.ConfigFor(r.ExperimentVariant)
	if !ok {
		return fmt.Errorf("experimentVariant must be A or B")
	}
	if assigned := experiment.Assign(uid); assigned != r.ExperimentVariant {
		return fmt.Errorf("experimentVariant does not match user assignment")
	}
	if !containsObjectID(config.ProductIDs, r.ProductID) {
		return fmt.Errorf("productID does not belong to experiment variant")
	}
	return nil
}

func containsObjectID(ids []primitive.ObjectID, target primitive.ObjectID) bool {
	for _, id := range ids {
		if id == target {
			return true
		}
	}
	return false
}