package service

import (
	"context"
	"database/sql"
	"errors"

	pb "datarush/pkg/api/achievements"
	"google.golang.org/protobuf/types/known/emptypb"
)

type AchievementRepository interface {
	CreateAchievement(ctx context.Context, achievement *pb.Achievement) (*pb.Achievement, error)
	GetAchievement(ctx context.Context, id string) (*pb.Achievement, error)
	EditAchievement(ctx context.Context, achievement *pb.Achievement) (*pb.Achievement, error)
	DeleteAchievement(ctx context.Context, id string) error
	ListAchievements(ctx context.Context) ([]*pb.Achievement, error)
	GetUserAchievements(ctx context.Context, userID string) ([]*pb.AchievementUser, error)
}

type AchievementService struct {
	repo AchievementRepository
}

func NewAchievementService(repo AchievementRepository) *AchievementService {
	return &AchievementService{repo: repo}
}

func (s *AchievementService) CreateAchievement(ctx context.Context, req *pb.Achievement) (*pb.Achievement, error) {
	return s.repo.CreateAchievement(ctx, req)
}

func (s *AchievementService) GetAchievement(ctx context.Context, req *pb.GetAchievementRequest) (*pb.Achievement, error) {
	achievement, err := s.repo.GetAchievement(ctx, req.Id)
	if err != nil {
		if err == sql.ErrNoRows {
			return nil, errors.New("achievement not found")
		}
		return nil, err
	}
	return achievement, nil
}

func (s *AchievementService) EditAchievement(ctx context.Context, req *pb.Achievement) (*pb.Achievement, error) {
	_, err := s.repo.GetAchievement(ctx, req.Id)
	if err != nil {
		if err == sql.ErrNoRows {
			return nil, errors.New("achievement not found")
		}
		return nil, err
	}

	return s.repo.EditAchievement(ctx, req)
}

func (s *AchievementService) DeleteAchievement(ctx context.Context, req *pb.DeleteAchievementRequest) (*emptypb.Empty, error) {
	err := s.repo.DeleteAchievement(ctx, req.AchievementId)
	if err != nil {
		return nil, err
	}
	return &emptypb.Empty{}, nil
}

func (s *AchievementService) ListAchievements(ctx context.Context, req *emptypb.Empty) (*pb.ListAchievementsResponse, error) {
	achievements, err := s.repo.ListAchievements(ctx)
	if err != nil {
		return nil, err
	}
	return &pb.ListAchievementsResponse{Achievements: achievements}, nil
}

func (s *AchievementService) GetUserAchievements(ctx context.Context, req *pb.GetUserAchievementsRequest) (*pb.GetUserAchievementsResponse, error) {
	userAchievements, err := s.repo.GetUserAchievements(ctx, req.UserId)
	if err != nil {
		return nil, err
	}
	return &pb.GetUserAchievementsResponse{UserAchievements: userAchievements}, nil
}