package programs

import (
	"Yimaru-Backend/internal/domain"
	"Yimaru-Backend/internal/ports"
	"context"
	"errors"

	"github.com/jackc/pgx/v5"
)

var ErrProgramNotFound = errors.New("program not found")

type Service struct {
	store ports.ProgramStore
}

func NewService(store ports.ProgramStore) *Service {
	return &Service{store: store}
}

func (s *Service) Create(ctx context.Context, input domain.CreateProgramInput) (domain.Program, error) {
	return s.store.CreateProgram(ctx, input)
}

func (s *Service) GetByID(ctx context.Context, id int64) (domain.Program, error) {
	p, err := s.store.GetProgramByID(ctx, id)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return domain.Program{}, ErrProgramNotFound
		}
		return domain.Program{}, err
	}
	return p, nil
}

func (s *Service) List(ctx context.Context, limit, offset int32) ([]domain.Program, int64, error) {
	if limit <= 0 {
		limit = 20
	}
	if limit > 200 {
		limit = 200
	}
	if offset < 0 {
		offset = 0
	}
	return s.store.ListPrograms(ctx, limit, offset)
}

func (s *Service) Update(ctx context.Context, id int64, input domain.UpdateProgramInput) (domain.Program, error) {
	p, err := s.store.UpdateProgram(ctx, id, input)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return domain.Program{}, ErrProgramNotFound
		}
		return domain.Program{}, err
	}
	return p, nil
}

func (s *Service) Delete(ctx context.Context, id int64) error {
	if _, err := s.store.GetProgramByID(ctx, id); err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return ErrProgramNotFound
		}
		return err
	}
	return s.store.DeleteProgram(ctx, id)
}