package main

import (
	"strings"
	"testing"
)

func TestPrintBackhaulReport(t *testing.T) {
	var b strings.Builder
	printBackhaulReport(&b, backhaulReport{
		Period: "mtd", CoveredDays: 3, PeriodDays: 10, EgressGB: 14, BackhaulGB: 5, BackhaulReq1k: 7,
		ShareOfEgress: 5.0 / 14, InterRegionGBUSD: 0.02, AbsorbedUSD: 0.10,
		Accounts: []backhaulAccount{
			{Account: "bab", Name: "ops", EgressGB: 10, BackhaulGB: 2.5, BackhaulReq1k: 7, ShareOfEgress: 0.25, AbsorbedUSD: 0.225},
		},
	})
	out := b.String()
	for _, want := range []string{"backhaul mtd (3/10 days covered): 5.00 GB of 14.00 GB egress (35.7%)", "inter-region leg ≈ $0.10 at $0.020/GB, absorbed", "bab", "ops", "25.0%"} {
		if !strings.Contains(out, want) {
			t.Errorf("missing %q in:\n%s", want, out)
		}
	}
	var empty strings.Builder
	printBackhaulReport(&empty, backhaulReport{Period: "7d", PeriodDays: 7})
	if !strings.Contains(empty.String(), "no account backhauled anything") {
		t.Errorf("empty report printed a bare header:\n%s", empty.String())
	}
}