package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// The guard exists because the build tag is invisible in the binary's name and
// in its version stamp: a wrong one is otherwise only discovered in production.
// These cases pin the two directions that matter — shipping billing to a
// deployment that runs without it, and shipping a stub to one that expects it.
func TestVerifyAppviewBilling(t *testing.T) {
	t.Parallel()

	for _, tc := range []struct {
		name    string
		content string
		want    bool
		wantErr bool
	}{
		{"billing build, billing wanted", "...github.com/stripe/stripe-go/v79...", true, false},
		{"stub build, no billing wanted", "...Billing is not enabled on this deployment...", false, false},
		{"billing build leaking into a no-billing deploy", "...stripe-go...", false, true},
		{"stub build where billing was asked for", "...no payment code here...", true, true},
	} {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			path := filepath.Join(t.TempDir(), "atcr-appview")
			if err := os.WriteFile(path, []byte(tc.content), 0o600); err != nil {
				t.Fatalf("write fixture: %v", err)
			}
			err := verifyAppviewBilling(path, tc.want)
			if tc.wantErr && err == nil {
				t.Fatalf("want=%v: expected a mismatch error, got nil", tc.want)
			}
			if !tc.wantErr && err != nil {
				t.Fatalf("want=%v: unexpected error: %v", tc.want, err)
			}
			// The message has to say which way round the mismatch is, or the
			// operator cannot tell whether to add or drop the flag.
			if tc.wantErr && !strings.Contains(err.Error(), "billing mismatch") {
				t.Errorf("error should name the mismatch, got: %v", err)
			}
		})
	}
}

// A missing binary must fail loudly rather than be read as "no stripe symbols,
// therefore billing is off" — which would let a deploy proceed on a file that
// was never built.
func TestVerifyAppviewBillingMissingBinary(t *testing.T) {
	t.Parallel()
	err := verifyAppviewBilling(filepath.Join(t.TempDir(), "does-not-exist"), false)
	if err == nil {
		t.Fatal("expected an error for a missing binary, got nil")
	}
}