budgit/internal/service/recurring_expense.go

304 lines
8.6 KiB
Go

package service
import (
"fmt"
"log/slog"
"time"
"git.juancwu.dev/juancwu/budgit/internal/model"
"git.juancwu.dev/juancwu/budgit/internal/repository"
"github.com/google/uuid"
"github.com/shopspring/decimal"
)
type CreateRecurringExpenseDTO struct {
SpaceID string
UserID string
Description string
Amount decimal.Decimal
Type model.ExpenseType
PaymentMethodID *string
Frequency model.Frequency
StartDate time.Time
EndDate *time.Time
TagIDs []string
}
type UpdateRecurringExpenseDTO struct {
ID string
Description string
Amount decimal.Decimal
Type model.ExpenseType
PaymentMethodID *string
Frequency model.Frequency
StartDate time.Time
EndDate *time.Time
TagIDs []string
}
type RecurringExpenseService struct {
recurringRepo repository.RecurringExpenseRepository
expenseRepo repository.ExpenseRepository
profileRepo repository.ProfileRepository
spaceRepo repository.SpaceRepository
}
func NewRecurringExpenseService(recurringRepo repository.RecurringExpenseRepository, expenseRepo repository.ExpenseRepository, profileRepo repository.ProfileRepository, spaceRepo repository.SpaceRepository) *RecurringExpenseService {
return &RecurringExpenseService{
recurringRepo: recurringRepo,
expenseRepo: expenseRepo,
profileRepo: profileRepo,
spaceRepo: spaceRepo,
}
}
func (s *RecurringExpenseService) CreateRecurringExpense(dto CreateRecurringExpenseDTO) (*model.RecurringExpense, error) {
if dto.Description == "" {
return nil, fmt.Errorf("description cannot be empty")
}
if dto.Amount.LessThanOrEqual(decimal.Zero) {
return nil, fmt.Errorf("amount must be positive")
}
now := time.Now()
re := &model.RecurringExpense{
ID: uuid.NewString(),
SpaceID: dto.SpaceID,
CreatedBy: dto.UserID,
Description: dto.Description,
Amount: dto.Amount,
Type: dto.Type,
PaymentMethodID: dto.PaymentMethodID,
Frequency: dto.Frequency,
StartDate: dto.StartDate,
EndDate: dto.EndDate,
NextOccurrence: dto.StartDate,
IsActive: true,
CreatedAt: now,
UpdatedAt: now,
}
if err := s.recurringRepo.Create(re, dto.TagIDs); err != nil {
return nil, err
}
return re, nil
}
func (s *RecurringExpenseService) GetRecurringExpense(id string) (*model.RecurringExpense, error) {
return s.recurringRepo.GetByID(id)
}
func (s *RecurringExpenseService) GetRecurringExpensesForSpace(spaceID string) ([]*model.RecurringExpense, error) {
return s.recurringRepo.GetBySpaceID(spaceID)
}
func (s *RecurringExpenseService) GetRecurringExpensesWithTagsAndMethodsForSpace(spaceID string) ([]*model.RecurringExpenseWithTagsAndMethod, error) {
recs, err := s.recurringRepo.GetBySpaceID(spaceID)
if err != nil {
return nil, err
}
ids := make([]string, len(recs))
for i, re := range recs {
ids[i] = re.ID
}
tagsMap, err := s.recurringRepo.GetTagsByRecurringExpenseIDs(ids)
if err != nil {
return nil, err
}
methodsMap, err := s.recurringRepo.GetPaymentMethodsByRecurringExpenseIDs(ids)
if err != nil {
return nil, err
}
result := make([]*model.RecurringExpenseWithTagsAndMethod, len(recs))
for i, re := range recs {
result[i] = &model.RecurringExpenseWithTagsAndMethod{
RecurringExpense: *re,
Tags: tagsMap[re.ID],
PaymentMethod: methodsMap[re.ID],
}
}
return result, nil
}
func (s *RecurringExpenseService) UpdateRecurringExpense(dto UpdateRecurringExpenseDTO) (*model.RecurringExpense, error) {
if dto.Description == "" {
return nil, fmt.Errorf("description cannot be empty")
}
if dto.Amount.LessThanOrEqual(decimal.Zero) {
return nil, fmt.Errorf("amount must be positive")
}
existing, err := s.recurringRepo.GetByID(dto.ID)
if err != nil {
return nil, err
}
existing.Description = dto.Description
existing.Amount = dto.Amount
existing.Type = dto.Type
existing.PaymentMethodID = dto.PaymentMethodID
existing.Frequency = dto.Frequency
existing.StartDate = dto.StartDate
existing.EndDate = dto.EndDate
existing.UpdatedAt = time.Now()
// Recalculate next occurrence if frequency or start changed
if existing.NextOccurrence.Before(dto.StartDate) {
existing.NextOccurrence = dto.StartDate
}
if err := s.recurringRepo.Update(existing, dto.TagIDs); err != nil {
return nil, err
}
return existing, nil
}
func (s *RecurringExpenseService) DeleteRecurringExpense(id string) error {
return s.recurringRepo.Delete(id)
}
func (s *RecurringExpenseService) ToggleRecurringExpense(id string) (*model.RecurringExpense, error) {
re, err := s.recurringRepo.GetByID(id)
if err != nil {
return nil, err
}
newActive := !re.IsActive
if err := s.recurringRepo.SetActive(id, newActive); err != nil {
return nil, err
}
re.IsActive = newActive
return re, nil
}
func (s *RecurringExpenseService) ProcessDueRecurrences(now time.Time) error {
dues, err := s.recurringRepo.GetDueRecurrences(now)
if err != nil {
return fmt.Errorf("failed to get due recurrences: %w", err)
}
tzCache := make(map[string]*time.Location)
for _, re := range dues {
localNow := s.getLocalNow(re.SpaceID, re.CreatedBy, now, tzCache)
if err := s.processRecurrence(re, localNow); err != nil {
slog.Error("failed to process recurring expense", "id", re.ID, "error", err)
}
}
return nil
}
func (s *RecurringExpenseService) ProcessDueRecurrencesForSpace(spaceID string, now time.Time) error {
dues, err := s.recurringRepo.GetDueRecurrencesForSpace(spaceID, now)
if err != nil {
return fmt.Errorf("failed to get due recurrences for space: %w", err)
}
tzCache := make(map[string]*time.Location)
for _, re := range dues {
localNow := s.getLocalNow(re.SpaceID, re.CreatedBy, now, tzCache)
if err := s.processRecurrence(re, localNow); err != nil {
slog.Error("failed to process recurring expense", "id", re.ID, "error", err)
}
}
return nil
}
func (s *RecurringExpenseService) processRecurrence(re *model.RecurringExpense, now time.Time) error {
// Get tag IDs for this recurring expense
tagsMap, err := s.recurringRepo.GetTagsByRecurringExpenseIDs([]string{re.ID})
if err != nil {
return err
}
var tagIDs []string
for _, t := range tagsMap[re.ID] {
tagIDs = append(tagIDs, t.ID)
}
// Generate expenses for each missed occurrence up to now
for !re.NextOccurrence.After(now) {
// Check if end_date has been passed
if re.EndDate != nil && re.NextOccurrence.After(*re.EndDate) {
return s.recurringRepo.Deactivate(re.ID)
}
expense := &model.Expense{
ID: uuid.NewString(),
SpaceID: re.SpaceID,
CreatedBy: re.CreatedBy,
Description: re.Description,
Amount: re.Amount,
Type: re.Type,
Date: re.NextOccurrence,
PaymentMethodID: re.PaymentMethodID,
RecurringExpenseID: &re.ID,
CreatedAt: time.Now(),
UpdatedAt: time.Now(),
}
if err := s.expenseRepo.Create(expense, tagIDs, nil); err != nil {
return fmt.Errorf("failed to create expense from recurring: %w", err)
}
re.NextOccurrence = AdvanceDate(re.NextOccurrence, re.Frequency)
}
// Check if the new next occurrence exceeds end date
if re.EndDate != nil && re.NextOccurrence.After(*re.EndDate) {
if err := s.recurringRepo.Deactivate(re.ID); err != nil {
return err
}
}
return s.recurringRepo.UpdateNextOccurrence(re.ID, re.NextOccurrence)
}
// getLocalNow resolves the effective timezone for a recurring expense.
// Resolution order: space timezone → user profile timezone → UTC.
func (s *RecurringExpenseService) getLocalNow(spaceID, userID string, now time.Time, cache map[string]*time.Location) time.Time {
spaceKey := "space:" + spaceID
if loc, ok := cache[spaceKey]; ok {
return now.In(loc)
}
space, err := s.spaceRepo.ByID(spaceID)
if err == nil && space != nil {
if loc := space.Location(); loc != nil {
cache[spaceKey] = loc
return now.In(loc)
}
}
userKey := "user:" + userID
if loc, ok := cache[userKey]; ok {
return now.In(loc)
}
loc := time.UTC
profile, err := s.profileRepo.ByUserID(userID)
if err == nil && profile != nil {
loc = profile.Location()
}
cache[userKey] = loc
return now.In(loc)
}
func AdvanceDate(date time.Time, freq model.Frequency) time.Time {
switch freq {
case model.FrequencyDaily:
return date.AddDate(0, 0, 1)
case model.FrequencyWeekly:
return date.AddDate(0, 0, 7)
case model.FrequencyBiweekly:
return date.AddDate(0, 0, 14)
case model.FrequencyMonthly:
return date.AddDate(0, 1, 0)
case model.FrequencyYearly:
return date.AddDate(1, 0, 0)
default:
return date.AddDate(0, 1, 0)
}
}