package service

import (
	"context"
	"math/rand"
	"time"

	"git.techease.ru/Smart-search/smart-search-back/internal/model"
	"git.techease.ru/Smart-search/smart-search-back/internal/repository"
	"git.techease.ru/Smart-search/smart-search-back/pkg/errors"
	"github.com/jackc/pgx/v5"
)

type inviteService struct {
	inviteRepo repository.InviteRepository
	userRepo   repository.UserRepository
	txManager  *repository.TxManager
}

func NewInviteService(inviteRepo repository.InviteRepository, userRepo repository.UserRepository, txManager *repository.TxManager) InviteService {
	return &inviteService{
		inviteRepo: inviteRepo,
		userRepo:   userRepo,
		txManager:  txManager,
	}
}

func (s *inviteService) Generate(ctx context.Context, userID, maxUses, ttlDays int) (*model.InviteCode, error) {
	code := rand.Int63n(90000000) + 10000000

	invite := &model.InviteCode{
		UserID:         userID,
		Code:           code,
		CanBeUsedCount: maxUses,
		ExpiresAt:      time.Now().Add(time.Duration(ttlDays) * 24 * time.Hour),
	}

	err := s.txManager.WithTx(ctx, func(tx pgx.Tx) error {
		canIssue, err := s.userRepo.CheckInviteLimitTx(ctx, tx, userID)
		if err != nil {
			return err
		}

		if !canIssue {
			return errors.NewBusinessError(errors.InviteLimitReached, "User reached maximum invite codes limit")
		}

		if err := s.inviteRepo.CreateTx(ctx, tx, invite); err != nil {
			return err
		}

		if err := s.userRepo.IncrementInvitesIssuedTx(ctx, tx, userID); err != nil {
			return err
		}

		return nil
	})

	if err != nil {
		return nil, err
	}

	return invite, nil
}

func (s *inviteService) GetInfo(ctx context.Context, code int64) (*model.InviteCode, error) {
	return s.inviteRepo.FindByCode(ctx, code)
}