feat: recurring expenses and reports

internal/service/report.go

@@ -0,0 +1,99 @@
+package service
+
+import (
+	"time"
+
+	"git.juancwu.dev/juancwu/budgit/internal/model"
+	"git.juancwu.dev/juancwu/budgit/internal/repository"
+)
+
+type ReportService struct {
+	expenseRepo repository.ExpenseRepository
+}
+
+func NewReportService(expenseRepo repository.ExpenseRepository) *ReportService {
+	return &ReportService{expenseRepo: expenseRepo}
+}
+
+type DateRange struct {
+	Label string
+	Key   string
+	From  time.Time
+	To    time.Time
+}
+
+func (s *ReportService) GetSpendingReport(spaceID string, from, to time.Time) (*model.SpendingReport, error) {
+	byTag, err := s.expenseRepo.GetExpensesByTag(spaceID, from, to)
+	if err != nil {
+		return nil, err
+	}
+
+	daily, err := s.expenseRepo.GetDailySpending(spaceID, from, to)
+	if err != nil {
+		return nil, err
+	}
+
+	monthly, err := s.expenseRepo.GetMonthlySpending(spaceID, from, to)
+	if err != nil {
+		return nil, err
+	}
+
+	topExpenses, err := s.expenseRepo.GetTopExpenses(spaceID, from, to, 10)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get tags and payment methods for top expenses
+	ids := make([]string, len(topExpenses))
+	for i, e := range topExpenses {
+		ids[i] = e.ID
+	}
+
+	tagsMap, _ := s.expenseRepo.GetTagsByExpenseIDs(ids)
+	methodsMap, _ := s.expenseRepo.GetPaymentMethodsByExpenseIDs(ids)
+
+	topWithTags := make([]*model.ExpenseWithTagsAndMethod, len(topExpenses))
+	for i, e := range topExpenses {
+		topWithTags[i] = &model.ExpenseWithTagsAndMethod{
+			Expense:       *e,
+			Tags:          tagsMap[e.ID],
+			PaymentMethod: methodsMap[e.ID],
+		}
+	}
+
+	totalIncome, totalExpenses, err := s.expenseRepo.GetIncomeVsExpenseSummary(spaceID, from, to)
+	if err != nil {
+		return nil, err
+	}
+
+	return &model.SpendingReport{
+		ByTag:           byTag,
+		DailySpending:   daily,
+		MonthlySpending: monthly,
+		TopExpenses:     topWithTags,
+		TotalIncome:     totalIncome,
+		TotalExpenses:   totalExpenses,
+		NetBalance:      totalIncome - totalExpenses,
+	}, nil
+}
+
+func GetPresetDateRanges(now time.Time) []DateRange {
+	thisMonthStart := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
+	thisMonthEnd := thisMonthStart.AddDate(0, 1, -1)
+	thisMonthEnd = time.Date(thisMonthEnd.Year(), thisMonthEnd.Month(), thisMonthEnd.Day(), 23, 59, 59, 0, now.Location())
+
+	lastMonthStart := thisMonthStart.AddDate(0, -1, 0)
+	lastMonthEnd := thisMonthStart.AddDate(0, 0, -1)
+	lastMonthEnd = time.Date(lastMonthEnd.Year(), lastMonthEnd.Month(), lastMonthEnd.Day(), 23, 59, 59, 0, now.Location())
+
+	last3MonthsStart := thisMonthStart.AddDate(0, -2, 0)
+
+	yearStart := time.Date(now.Year(), 1, 1, 0, 0, 0, 0, now.Location())
+
+	return []DateRange{
+		{Label: "This Month", Key: "this_month", From: thisMonthStart, To: thisMonthEnd},
+		{Label: "Last Month", Key: "last_month", From: lastMonthStart, To: lastMonthEnd},
+		{Label: "Last 3 Months", Key: "last_3_months", From: last3MonthsStart, To: thisMonthEnd},
+		{Label: "This Year", Key: "this_year", From: yearStart, To: thisMonthEnd},
+	}
+}