From 047e392ac3bdaaead71cd3e1fe9b6d07405a91ca Mon Sep 17 00:00:00 2001
From: juancwu <git@juancwu.dev>
Date: Tue, 17 Mar 2026 17:04:21 +0000
Subject: [PATCH] feat: show report on payment method

---
 internal/model/report.go                  |  8 ++++++
 internal/repository/expense.go            | 21 ++++++++++++++
 internal/service/report.go                |  6 ++++
 internal/ui/pages/app_space_reports.templ | 35 +++++++++++++++++++++++
 4 files changed, 70 insertions(+)

diff --git a/internal/model/report.go b/internal/model/report.go
index 46945ae..8586c99 100644
--- a/internal/model/report.go
+++ b/internal/model/report.go
@@ -16,8 +16,16 @@ type MonthlySpending struct {
 	Total decimal.Decimal `db:"total"`
 }
 
+type PaymentMethodExpenseSummary struct {
+	PaymentMethodID   string          `db:"payment_method_id"`
+	PaymentMethodName string          `db:"payment_method_name"`
+	PaymentMethodType string          `db:"payment_method_type"`
+	TotalAmount       decimal.Decimal `db:"total_amount"`
+}
+
 type SpendingReport struct {
 	ByTag           []*TagExpenseSummary
+	ByPaymentMethod []*PaymentMethodExpenseSummary
 	DailySpending   []*DailySpending
 	MonthlySpending []*MonthlySpending
 	TopExpenses     []*ExpenseWithTagsAndMethod
diff --git a/internal/repository/expense.go b/internal/repository/expense.go
index 9235630..6d75548 100644
--- a/internal/repository/expense.go
+++ b/internal/repository/expense.go
@@ -30,6 +30,7 @@ type ExpenseRepository interface {
 	GetMonthlySpending(spaceID string, from, to time.Time) ([]*model.MonthlySpending, error)
 	GetTopExpenses(spaceID string, from, to time.Time, limit int) ([]*model.Expense, error)
 	GetIncomeVsExpenseSummary(spaceID string, from, to time.Time) (decimal.Decimal, decimal.Decimal, error)
+	GetExpensesByPaymentMethod(spaceID string, from, to time.Time) ([]*model.PaymentMethodExpenseSummary, error)
 }
 
 type expenseRepository struct {
@@ -324,3 +325,23 @@ func (r *expenseRepository) GetIncomeVsExpenseSummary(spaceID string, from, to t
 	}
 	return income, expenseTotal, nil
 }
+
+func (r *expenseRepository) GetExpensesByPaymentMethod(spaceID string, from, to time.Time) ([]*model.PaymentMethodExpenseSummary, error) {
+	var summaries []*model.PaymentMethodExpenseSummary
+	query := `
+		SELECT COALESCE(pm.id, 'cash') as payment_method_id,
+		       COALESCE(pm.name, 'Cash') as payment_method_name,
+		       COALESCE(pm.type, 'cash') as payment_method_type,
+		       SUM(CAST(e.amount AS DECIMAL)) as total_amount
+		FROM expenses e
+		LEFT JOIN payment_methods pm ON e.payment_method_id = pm.id
+		WHERE e.space_id = $1 AND e.type = 'expense' AND e.date >= $2 AND e.date <= $3
+		GROUP BY pm.id, pm.name, pm.type
+		ORDER BY total_amount DESC;
+	`
+	err := r.db.Select(&summaries, query, spaceID, from, to)
+	if err != nil {
+		return nil, err
+	}
+	return summaries, nil
+}
diff --git a/internal/service/report.go b/internal/service/report.go
index 4de051b..fb6a55c 100644
--- a/internal/service/report.go
+++ b/internal/service/report.go
@@ -61,6 +61,11 @@ func (s *ReportService) GetSpendingReport(spaceID string, from, to time.Time) (*
 		}
 	}
 
+	byPaymentMethod, err := s.expenseRepo.GetExpensesByPaymentMethod(spaceID, from, to)
+	if err != nil {
+		return nil, err
+	}
+
 	totalIncome, totalExpenses, err := s.expenseRepo.GetIncomeVsExpenseSummary(spaceID, from, to)
 	if err != nil {
 		return nil, err
@@ -68,6 +73,7 @@ func (s *ReportService) GetSpendingReport(spaceID string, from, to time.Time) (*
 
 	return &model.SpendingReport{
 		ByTag:           byTag,
+		ByPaymentMethod: byPaymentMethod,
 		DailySpending:   daily,
 		MonthlySpending: monthly,
 		TopExpenses:     topWithTags,
diff --git a/internal/ui/pages/app_space_reports.templ b/internal/ui/pages/app_space_reports.templ
index 82879c9..35e3852 100644
--- a/internal/ui/pages/app_space_reports.templ
+++ b/internal/ui/pages/app_space_reports.templ
@@ -123,6 +123,41 @@ templ ReportCharts(spaceID string, report *model.SpendingReport, from, to time.T
 				<p class="text-sm text-muted-foreground">No tagged expenses in this period.</p>
 			</div>
 		}
+		// Spending by Payment Method (Doughnut chart)
+		if len(report.ByPaymentMethod) > 0 {
+			<div class="border rounded-lg p-4 bg-card text-card-foreground min-w-0 overflow-hidden">
+				<h3 class="font-semibold mb-2">Spending by Payment Method</h3>
+				{{
+					pmLabels := make([]string, len(report.ByPaymentMethod))
+					pmData := make([]float64, len(report.ByPaymentMethod))
+					pmColors := make([]string, len(report.ByPaymentMethod))
+					for i, pm := range report.ByPaymentMethod {
+						pmLabels[i] = pm.PaymentMethodName
+						pmData[i] = pm.TotalAmount.InexactFloat64()
+						pmColors[i] = defaultChartColors[i%len(defaultChartColors)]
+					}
+				}}
+				@chart.Chart(chart.Props{
+					Variant:    chart.VariantDoughnut,
+					ShowLegend: true,
+					Data: chart.Data{
+						Labels: pmLabels,
+						Datasets: []chart.Dataset{
+							{
+								Label:           "Spending",
+								Data:            pmData,
+								BackgroundColor: pmColors,
+							},
+						},
+					},
+				})
+			</div>
+		} else {
+			<div class="border rounded-lg p-4 bg-card text-card-foreground min-w-0">
+				<h3 class="font-semibold mb-2">Spending by Payment Method</h3>
+				<p class="text-sm text-muted-foreground">No payment method data in this period.</p>
+			</div>
+		}
 		// Spending Over Time (Bar chart)
 		if len(report.DailySpending) > 0 || len(report.MonthlySpending) > 0 {
 			<div class="border rounded-lg p-4 bg-card text-card-foreground min-w-0 overflow-hidden">