package service

import (
	"context"

	"datarush/internal/competition/repository"
	pb "datarush/pkg/api/competition"

	"github.com/google/uuid"
	"google.golang.org/protobuf/types/known/emptypb"
)

type CompetitionService struct {
	repo repository.CompetitionRepository
}

func NewCompetitionService(repo repository.CompetitionRepository) *CompetitionService {
	return &CompetitionService{repo: repo}
}

func (s *CompetitionService) CreateCompetition(ctx context.Context, req *pb.Competition) (*pb.Competition, error) {
	return s.repo.Create(ctx, req)
}

func (s *CompetitionService) GetCompetition(
	ctx context.Context,
	req *pb.GetCompetitionRequest,
) (*pb.Competition, error) {
	id, err := uuid.Parse(req.CompetitionId)
	if err != nil {
		return nil, err
	}
	return s.repo.Get(ctx, id)
}

func (s *CompetitionService) EditCompetition(ctx context.Context, req *pb.Competition) (*pb.Competition, error) {
	return s.repo.Update(ctx, req)
}

func (s *CompetitionService) DeleteCompetition(
	ctx context.Context,
	req *pb.DeleteCompetitionRequest,
) (*emptypb.Empty, error) {
	id, err := uuid.Parse(req.CompetitionId)
	if err != nil {
		return nil, err
	}
	err = s.repo.Delete(ctx, id)
	return &emptypb.Empty{}, err
}

func (s *CompetitionService) ListCompetitions(
	ctx context.Context,
	req *pb.ListCompetitionsRequest,
) (*pb.ListCompetitionsResponse, error) {
	opts := repository.ListCompetitionsOptions{
		Page:            int(req.PageToken),
		PageSize:        int(req.PageSize),
		State:           req.State,
		IsParticipating: req.IsParticipating,
		SearchQuery:     req.SearchQuery,
	}

	competitions, total, err := s.repo.List(ctx, opts)
	if err != nil {
		return nil, err
	}

	var nextPageToken int32
	if (opts.Page+1)*opts.PageSize < total {
		nextPageToken = int32(opts.Page + 1)
	}

	return &pb.ListCompetitionsResponse{
		Competitions:  competitions,
		TotalCount:    int32(total),
		NextPageToken: nextPageToken,
	}, nil
}

func (s *CompetitionService) ChangeCompetitionState(
	ctx context.Context,
	req *pb.ChangeCompetitionStateRequest,
) (*pb.Competition, error) {
	id, err := uuid.Parse(req.CompetitionId)
	if err != nil {
		return nil, err
	}
	return s.repo.ChangeState(ctx, id, req.State)
}