feat: add csv/json format to ls

README.md

@@ -235,6 +235,10 @@ cospend list -p myproject --recent 1m
 
 # Combine multiple filters
 cospend list -p myproject -b alice -c restaurant --amount ">=20"
+
+# Output as CSV or JSON
+cospend list -p myproject --format csv
+cospend list -p myproject --format json
 ```
 
 #### List Command Flags
@@ -253,6 +257,7 @@ cospend list -p myproject -b alice -c restaurant --amount ">=20"
 |       | `--this-month` | Filter bills from the current month                            |
 |       | `--this-week`  | Filter bills from the current calendar week                    |
 |       | `--recent`     | Filter recent bills (e.g., `7d`, `2w`, `1m`)                   |
+|       | `--format`     | Output format: `table` (default), `csv`, `json`                |
 | `-h`  | `--help`       | Display help information                                       |
 
 The output includes the bill ID for each expense, which can be used with the delete command.

cmd/list.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	"encoding/csv"
+	"encoding/json"
 	"fmt"
 	"regexp"
 	"sort"
@@ -27,6 +29,7 @@ var (
 	listThisMonth     bool
 	listThisWeek      bool
 	listRecent        string
+	listFormat        string
 )
 
 // amountFilter holds parsed amount filter criteria
@@ -69,6 +72,7 @@ Examples:
 	cmd.Flags().BoolVar(&listThisMonth, "this-month", false, "Filter bills from the current month")
 	cmd.Flags().BoolVar(&listThisWeek, "this-week", false, "Filter bills from the current calendar week")
 	cmd.Flags().StringVar(&listRecent, "recent", "", "Filter recent bills (e.g., 7d, 2w, 1m)")
+	cmd.Flags().StringVar(&listFormat, "format", "table", "Output format: table, csv, json")
 
 	return cmd
 }
@@ -78,6 +82,12 @@ func runList(cmd *cobra.Command, _ []string) error {
 		return fmt.Errorf("project is required (use -p or --project)")
 	}
 
+	switch listFormat {
+	case "table", "csv", "json":
+	default:
+		return fmt.Errorf("unsupported format: %s (expected table, csv, or json)", listFormat)
+	}
+
 	// Parameters validated, silence usage for subsequent errors
 	cmd.SilenceUsage = true
 
@@ -138,9 +148,18 @@ func runList(cmd *cobra.Command, _ []string) error {
 	// Apply filters
 	filteredBills := applyFilters(bills, filters)
 
-	// Print table
+	// Output results
 	formatter := format.NewAmountFormatter(locale, project.CurrencyName)
-	printBillsTable(cmd, project, filteredBills, formatter)
+	resolved := resolveBillNames(project, filteredBills)
+
+	switch listFormat {
+	case "csv":
+		printBillsCSV(cmd, resolved)
+	case "json":
+		printBillsJSON(cmd, resolved)
+	default:
+		printBillsTable(cmd, resolved, formatter)
+	}
 
 	return nil
 }
@@ -421,12 +440,19 @@ func parseRecent(s string) (time.Time, error) {
 	}
 }
 
-func printBillsTable(cmd *cobra.Command, project *api.Project, bills []api.BillResponse, formatter *format.AmountFormatter) {
-	if len(bills) == 0 {
-		_, _ = fmt.Fprintln(cmd.OutOrStdout(), "No bills found.")
-		return
-	}
+// resolvedBill holds a bill with human-readable names resolved from IDs
+type resolvedBill struct {
+	ID            int      `json:"id"`
+	Date          string   `json:"date"`
+	Name          string   `json:"name"`
+	Amount        float64  `json:"amount"`
+	PaidBy        string   `json:"paid_by"`
+	PaidFor       []string `json:"paid_for"`
+	Category      string   `json:"category"`
+	PaymentMethod string   `json:"payment_method"`
+}
 
+func resolveBillNames(project *api.Project, bills []api.BillResponse) []resolvedBill {
 	// Sort by date (newest first), then by timestamp for same-date entries
 	sort.Slice(bills, func(i, j int) bool {
 		if bills[i].Date != bills[j].Date {
@@ -440,34 +466,27 @@ func printBillsTable(cmd *cobra.Command, project *api.Project, bills []api.BillR
 		bills = bills[:listLimit]
 	}
 
-	// Build lookup maps for names
+	// Build lookup maps
 	memberNames := make(map[int]string)
 	for _, m := range project.Members {
 		memberNames[m.ID] = m.Name
 	}
-
 	categoryNames := make(map[int]string)
 	for _, c := range project.Categories {
 		categoryNames[c.ID] = c.Name
 	}
-
 	paymentModeNames := make(map[int]string)
 	for _, pm := range project.PaymentModes {
 		paymentModeNames[pm.ID] = pm.Name
 	}
 
-	table := NewTable("ID", "DATE", "NAME", "AMOUNT", "PAID BY", "PAID FOR", "CATEGORY", "METHOD")
-
-	var totalAmount float64
+	var result []resolvedBill
 	for _, bill := range bills {
-		totalAmount += bill.Amount
-		// Get payer name
 		payerName := memberNames[bill.PayerID]
 		if payerName == "" {
 			payerName = fmt.Sprintf("#%d", bill.PayerID)
 		}
 
-		// Get owed member names
 		var owerNames []string
 		for _, ower := range bill.Owers {
 			name := memberNames[ower.ID]
@@ -476,33 +495,60 @@ func printBillsTable(cmd *cobra.Command, project *api.Project, bills []api.BillR
 			}
 			owerNames = append(owerNames, name)
 		}
-		owersStr := strings.Join(owerNames, ", ")
 
-		// Get category name
 		catName := categoryNames[bill.CategoryID]
 		if catName == "" && bill.CategoryID != 0 {
 			catName = fmt.Sprintf("#%d", bill.CategoryID)
 		}
-		if catName == "" {
-			catName = "-"
-		}
 
-		// Get payment method name
 		methodName := paymentModeNames[bill.PaymentModeID]
 		if methodName == "" && bill.PaymentModeID != 0 {
 			methodName = fmt.Sprintf("#%d", bill.PaymentModeID)
 		}
-		if methodName == "" {
-			methodName = "-"
-		}
 
-		// Sanitize and truncate name
 		name := strings.Map(func(r rune) rune {
 			if r == '\n' || r == '\r' || r == '\t' {
 				return ' '
 			}
 			return r
 		}, strings.TrimSpace(bill.What))
+
+		result = append(result, resolvedBill{
+			ID:            bill.ID,
+			Date:          bill.Date,
+			Name:          name,
+			Amount:        bill.Amount,
+			PaidBy:        payerName,
+			PaidFor:       owerNames,
+			Category:      catName,
+			PaymentMethod: methodName,
+		})
+	}
+	return result
+}
+
+func printBillsTable(cmd *cobra.Command, bills []resolvedBill, formatter *format.AmountFormatter) {
+	if len(bills) == 0 {
+		_, _ = fmt.Fprintln(cmd.OutOrStdout(), "No bills found.")
+		return
+	}
+
+	table := NewTable("ID", "DATE", "NAME", "AMOUNT", "PAID BY", "PAID FOR", "CATEGORY", "METHOD")
+
+	var totalAmount float64
+	for _, bill := range bills {
+		totalAmount += bill.Amount
+
+		catName := bill.Category
+		if catName == "" {
+			catName = "-"
+		}
+		methodName := bill.PaymentMethod
+		if methodName == "" {
+			methodName = "-"
+		}
+
+		name := bill.Name
 		if len(name) > 30 {
 			name = name[:27] + "..."
 		}
@@ -512,8 +558,8 @@ func printBillsTable(cmd *cobra.Command, project *api.Project, bills []api.BillR
 			bill.Date,
 			name,
 			formatter.Format(bill.Amount),
-			payerName,
-			owersStr,
+			bill.PaidBy,
+			strings.Join(bill.PaidFor, ", "),
 			catName,
 			methodName,
 		)
@@ -523,3 +569,33 @@ func printBillsTable(cmd *cobra.Command, project *api.Project, bills []api.BillR
 	table.Render(out)
 	_, _ = fmt.Fprintf(out, "\nTotal: %d bill(s), %s\n", len(bills), formatter.Format(totalAmount))
 }
+
+func printBillsCSV(cmd *cobra.Command, bills []resolvedBill) {
+	out := cmd.OutOrStdout()
+	w := csv.NewWriter(out)
+
+	_ = w.Write([]string{"ID", "Date", "Name", "Amount", "Paid By", "Paid For", "Category", "Payment Method"})
+	for _, bill := range bills {
+		_ = w.Write([]string{
+			strconv.Itoa(bill.ID),
+			bill.Date,
+			bill.Name,
+			strconv.FormatFloat(bill.Amount, 'f', 2, 64),
+			bill.PaidBy,
+			strings.Join(bill.PaidFor, ", "),
+			bill.Category,
+			bill.PaymentMethod,
+		})
+	}
+	w.Flush()
+}
+
+func printBillsJSON(cmd *cobra.Command, bills []resolvedBill) {
+	out := cmd.OutOrStdout()
+	if bills == nil {
+		bills = []resolvedBill{}
+	}
+	enc := json.NewEncoder(out)
+	enc.SetIndent("", "  ")
+	_ = enc.Encode(bills)
+}

cmd/list_test.go

@@ -2,7 +2,9 @@ package cmd
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
+	"strings"
 	"testing"
 	"time"
 
@@ -162,12 +164,14 @@ func TestPrintBillsTable(t *testing.T) {
 		},
 	}
 
+	resolved := resolveBillNames(project, bills)
+
 	cmd := NewListCommand()
 	buf := new(bytes.Buffer)
 	cmd.SetOut(buf)
 
 	formatter := format.NewAmountFormatter("en_US", "USD")
-	printBillsTable(cmd, project, bills, formatter)
+	printBillsTable(cmd, resolved, formatter)
 
 	output := buf.String()
 
@@ -198,15 +202,12 @@ func TestPrintBillsTable(t *testing.T) {
 func TestPrintBillsTableEmpty(t *testing.T) {
 	resetListFlags()
 
-	project := &api.Project{}
-	bills := []api.BillResponse{}
-
 	cmd := NewListCommand()
 	buf := new(bytes.Buffer)
 	cmd.SetOut(buf)
 
 	formatter := format.NewAmountFormatter("en_US", "")
-	printBillsTable(cmd, project, bills, formatter)
+	printBillsTable(cmd, nil, formatter)
 
 	output := buf.String()
 	if !bytes.Contains([]byte(output), []byte("No bills found")) {
@@ -503,6 +504,147 @@ func TestBuildFiltersRecent(t *testing.T) {
 	}
 }
 
+func TestPrintBillsCSV(t *testing.T) {
+	resetListFlags()
+
+	project := &api.Project{
+		Members: []api.Member{
+			{ID: 1, Name: "Alice", UserID: "alice"},
+			{ID: 2, Name: "Bob", UserID: "bob"},
+		},
+		Categories: []api.Category{
+			{ID: 1, Name: "Food"},
+		},
+		PaymentModes: []api.PaymentMode{
+			{ID: 1, Name: "Cash"},
+		},
+	}
+
+	bills := []api.BillResponse{
+		{
+			ID:            1,
+			What:          "Groceries",
+			Amount:        50.00,
+			Date:          "2026-02-03",
+			PayerID:       1,
+			Owers:         []api.Ower{{ID: 1, Weight: 1}, {ID: 2, Weight: 1}},
+			CategoryID:    1,
+			PaymentModeID: 1,
+		},
+		{
+			ID:      2,
+			What:    "Coffee",
+			Amount:  5.50,
+			Date:    "2026-02-04",
+			PayerID: 2,
+			Owers:   []api.Ower{{ID: 2, Weight: 1}},
+		},
+	}
+
+	resolved := resolveBillNames(project, bills)
+
+	cmd := NewListCommand()
+	buf := new(bytes.Buffer)
+	cmd.SetOut(buf)
+
+	printBillsCSV(cmd, resolved)
+
+	output := buf.String()
+	lines := strings.Split(strings.TrimSpace(output), "\n")
+
+	if len(lines) != 3 {
+		t.Fatalf("Expected 3 lines (header + 2 rows), got %d:\n%s", len(lines), output)
+	}
+	if lines[0] != "ID,Date,Name,Amount,Paid By,Paid For,Category,Payment Method" {
+		t.Errorf("Wrong CSV header: %s", lines[0])
+	}
+	if !strings.Contains(lines[1], "Coffee") {
+		t.Errorf("First data row should contain 'Coffee' (newest first), got: %s", lines[1])
+	}
+	if !strings.Contains(lines[2], "Groceries") {
+		t.Errorf("Second data row should contain 'Groceries', got: %s", lines[2])
+	}
+}
+
+func TestPrintBillsJSON(t *testing.T) {
+	resetListFlags()
+
+	project := &api.Project{
+		Members: []api.Member{
+			{ID: 1, Name: "Alice", UserID: "alice"},
+		},
+		Categories: []api.Category{
+			{ID: 1, Name: "Food"},
+		},
+		PaymentModes: []api.PaymentMode{
+			{ID: 1, Name: "Cash"},
+		},
+	}
+
+	bills := []api.BillResponse{
+		{
+			ID:            1,
+			What:          "Groceries",
+			Amount:        50.00,
+			Date:          "2026-02-03",
+			PayerID:       1,
+			Owers:         []api.Ower{{ID: 1, Weight: 1}},
+			CategoryID:    1,
+			PaymentModeID: 1,
+		},
+	}
+
+	resolved := resolveBillNames(project, bills)
+
+	cmd := NewListCommand()
+	buf := new(bytes.Buffer)
+	cmd.SetOut(buf)
+
+	printBillsJSON(cmd, resolved)
+
+	var result []resolvedBill
+	if err := json.Unmarshal(buf.Bytes(), &result); err != nil {
+		t.Fatalf("Invalid JSON output: %v\n%s", err, buf.String())
+	}
+
+	if len(result) != 1 {
+		t.Fatalf("Expected 1 bill, got %d", len(result))
+	}
+	if result[0].Name != "Groceries" {
+		t.Errorf("Wrong name: %s", result[0].Name)
+	}
+	if result[0].Amount != 50.00 {
+		t.Errorf("Wrong amount: %f", result[0].Amount)
+	}
+	if result[0].PaidBy != "Alice" {
+		t.Errorf("Wrong paid_by: %s", result[0].PaidBy)
+	}
+	if result[0].Category != "Food" {
+		t.Errorf("Wrong category: %s", result[0].Category)
+	}
+	if result[0].PaymentMethod != "Cash" {
+		t.Errorf("Wrong payment_method: %s", result[0].PaymentMethod)
+	}
+}
+
+func TestPrintBillsJSONEmpty(t *testing.T) {
+	resetListFlags()
+
+	cmd := NewListCommand()
+	buf := new(bytes.Buffer)
+	cmd.SetOut(buf)
+
+	printBillsJSON(cmd, nil)
+
+	var result []resolvedBill
+	if err := json.Unmarshal(buf.Bytes(), &result); err != nil {
+		t.Fatalf("Invalid JSON output: %v\n%s", err, buf.String())
+	}
+	if len(result) != 0 {
+		t.Errorf("Expected empty array, got %d items", len(result))
+	}
+}
+
 func resetListFlags() {
 	ProjectID = ""
 	listPaidBy = ""
@@ -516,4 +658,5 @@ func resetListFlags() {
 	listThisMonth = false
 	listThisWeek = false
 	listRecent = ""
+	listFormat = "table"
 }