improvathon: add GetDraftInvoice command + MCP tool

internal/tiger/cmd/billing.go

@@ -0,0 +1,147 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/olekukonko/tablewriter"
+	"github.com/spf13/cobra"
+
+	"github.com/timescale/tiger-cli/internal/tiger/api"
+	"github.com/timescale/tiger-cli/internal/tiger/common"
+	"github.com/timescale/tiger-cli/internal/tiger/util"
+)
+
+// buildBillingCmd creates the main billing command with all subcommands
+func buildBillingCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:     "billing",
+		Aliases: []string{"invoice"},
+		Short:   "View billing information",
+		Long:    `View billing information for the current Tiger Cloud project.`,
+	}
+
+	cmd.AddCommand(buildBillingDraftInvoiceCmd())
+
+	return cmd
+}
+
+// buildBillingDraftInvoiceCmd represents the draft-invoice command under billing
+func buildBillingDraftInvoiceCmd() *cobra.Command {
+	var output string
+
+	cmd := &cobra.Command{
+		Use:     "draft-invoice",
+		Aliases: []string{"current-invoice"},
+		Short:   "Show the current draft invoice",
+		Long: `Show the current draft (upcoming) invoice for the current project,
+including a per-service cost breakdown.
+
+Examples:
+  # Show the current draft invoice
+  tiger billing draft-invoice
+
+  # Show the draft invoice in JSON format
+  tiger billing draft-invoice --output json
+
+  # Show the draft invoice in YAML format
+  tiger billing draft-invoice --output yaml`,
+		Args:    cobra.NoArgs,
+		PreRunE: bindFlags("output"),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cmd.SilenceUsage = true
+
+			// Load config and API client
+			cfg, err := common.LoadConfig(cmd.Context())
+			if err != nil {
+				return err
+			}
+
+			// Make API call to get the draft invoice
+			ctx, cancel := context.WithTimeout(cmd.Context(), 30*time.Second)
+			defer cancel()
+
+			resp, err := cfg.Client.GetDraftInvoiceWithResponse(ctx, cfg.ProjectID)
+			if err != nil {
+				return fmt.Errorf("failed to get draft invoice: %w", err)
+			}
+
+			// Handle API response
+			if resp.StatusCode() != http.StatusOK {
+				return common.ExitWithErrorFromStatusCode(resp.StatusCode(), resp.JSON4XX)
+			}
+
+			if resp.JSON200 == nil {
+				return fmt.Errorf("empty response from API")
+			}
+
+			// Output draft invoice in requested format
+			return outputDraftInvoice(cmd, *resp.JSON200, cfg.Output)
+		},
+	}
+
+	cmd.Flags().VarP((*outputFlag)(&output), "output", "o", "Output format (json, yaml, table)")
+
+	return cmd
+}
+
+// outputDraftInvoice formats and outputs the draft invoice based on the specified format
+func outputDraftInvoice(cmd *cobra.Command, invoice api.DraftInvoice, format string) error {
+	outputWriter := cmd.OutOrStdout()
+
+	switch strings.ToLower(format) {
+	case "json":
+		return util.SerializeToJSON(outputWriter, invoice)
+	case "yaml":
+		return util.SerializeToYAML(outputWriter, invoice)
+	default: // table format (default)
+		return outputDraftInvoiceTable(invoice, outputWriter)
+	}
+}
+
+// outputDraftInvoiceTable outputs detailed draft invoice information in formatted tables
+func outputDraftInvoiceTable(invoice api.DraftInvoice, output io.Writer) error {
+	// Summary table
+	summary := tablewriter.NewWriter(output)
+	summary.Header("PROPERTY", "VALUE")
+
+	summary.Append("Status", util.Deref(invoice.Status))
+	summary.Append("Currency", util.Deref(invoice.Currency))
+	if invoice.BillingPeriodStart != nil {
+		summary.Append("Period Start", invoice.BillingPeriodStart.Format("2006-01-02"))
+	}
+	if invoice.BillingPeriodEnd != nil {
+		summary.Append("Period End", invoice.BillingPeriodEnd.Format("2006-01-02"))
+	}
+	summary.Append("Subtotal", util.Deref(invoice.Subtotal))
+	summary.Append("Total", util.Deref(invoice.Total))
+	summary.Append("Amount Due", util.Deref(invoice.AmountDue))
+
+	if err := summary.Render(); err != nil {
+		return err
+	}
+
+	// Per-service line items table
+	if invoice.LineItems != nil && len(*invoice.LineItems) > 0 {
+		items := tablewriter.NewWriter(output)
+		items.Header("SERVICE ID", "PRODUCT", "AMOUNT")
+
+		for _, item := range *invoice.LineItems {
+			items.Append(
+				util.Deref(item.ServiceId),
+				util.Deref(item.Label),
+				util.Deref(item.Amount),
+			)
+		}
+
+		if err := items.Render(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}