package repository

import (
	"codeword/internal/models"
	"context"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"time"
)

type StatsRepository struct {
	mdb *mongo.Collection
}

func NewStatsRepository(deps Deps) *StatsRepository {

	return &StatsRepository{mdb: deps.Mdb}
}

func (r *StatsRepository) UpdateStatistics(ctx context.Context, req *models.ActivateReq, promoCode *models.PromoCode, userID string) error {
	filter := bson.M{"_id": promoCode.ID, "usageMap." + userID: bson.M{"$exists": true}}
	count, err := r.mdb.CountDocuments(ctx, filter)
	if err != nil {
		return err
	}

	if count >= 1 {
		return ErrPromoCodeAlreadyActivated
	}

	var key string
	if req.FastLink != "" {
		key = req.FastLink
	} else {
		key = req.Codeword
	}

	usage := models.Usage{
		Key:  key,
		Time: time.Now(),
	}

	update := bson.M{
		"$inc": bson.M{"usageCount": 1},
		"$push": bson.M{
			"usageMap." + userID: usage,
		},
	}

	opts := options.Update().SetUpsert(true)
	_, err = r.mdb.UpdateOne(ctx, bson.M{"_id": promoCode.ID}, update, opts)
	return err
}

func (r *StatsRepository) GetStatistics(ctx context.Context, promoCodeID string) (*models.PromoCodeStats, error) {
	objID, err := primitive.ObjectIDFromHex(promoCodeID)
	if err != nil {
		return nil, err
	}

	filter := bson.M{"_id": objID}

	var promoCodeStats models.PromoCodeStats
	err = r.mdb.FindOne(ctx, filter).Decode(&promoCodeStats)
	if err != nil {
		return nil, err
	}

	return &promoCodeStats, nil
}