package bill

import (
	"context"
	"time"
)

type billService struct {
	billRepository BillRepository
}

func NewBillService(r BillRepository) BillService {
	return &billService{
		billRepository: r,
	}
}

// FetchBills
// - date is {year, month, day} when return a day bills
// - date is {year, month} when return a month bills
// - date is {year} when return a year bills
// - date is {} when return all bills
func (b *billService) FetchBills(ctx context.Context, date BDate) (*[]Bill, error) {
	if date.Year == 0 && (date.Month != 0 || date.Day != 0) {
		date.Year = time.Now().Year()
	} else if date.Month == 0 && date.Day != 0 {
		date.Month = int(time.Now().Month())
	}
	switch {
	case date.Year == 0:
		return b.billRepository.GetBills(ctx)
	case date.Month == 0:
		return b.billRepository.GetBillByYear(ctx, date.Year)
	case date.Day == 0:
		return b.billRepository.GetBillByMonth(ctx, date.Year, date.Month)
	default:
		return b.billRepository.GetBillByDate(ctx, date.Year, date.Month, date.Day)
	}
}

func (b *billService) FetchBillByID(ctx context.Context, id int) (*Bill, error) {
	return b.billRepository.GetBillByID(ctx, id)
}

func (b *billService) BuildBill(ctx context.Context, bill *Bill) error {
	return b.billRepository.CreateBill(ctx, bill)
}

func (b *billService) ModifyBill(ctx context.Context, bill *Bill) error {
	return b.billRepository.UpdateBill(ctx, bill)
}

func (b *billService) DestroyBill(ctx context.Context, id int) error {
	return b.billRepository.DeleteBill(ctx, id)
}