// Copyright 2022 Go Authors All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package relui

import (
	"archive/tar"
	"archive/zip"
	"bytes"
	"compress/gzip"
	"context"
	"crypto/sha256"
	"fmt"
	"io"
	"io/fs"
	"io/ioutil"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
	"github.com/google/go-github/github"
	"github.com/google/uuid"
	"golang.org/x/build/gerrit"
	"golang.org/x/build/internal"
	"golang.org/x/build/internal/gcsfs"
	"golang.org/x/build/internal/releasetargets"
	"golang.org/x/build/internal/relui/sign"
	"golang.org/x/build/internal/task"
	"golang.org/x/build/internal/workflow"
)

func TestRelease(t *testing.T) {
	t.Run("beta", func(t *testing.T) {
		testRelease(t, "go1.18beta1", task.KindBeta)
	})
	t.Run("rc", func(t *testing.T) {
		testRelease(t, "go1.18rc1", task.KindRC)
	})
	t.Run("major", func(t *testing.T) {
		testRelease(t, "go1.18", task.KindMajor)
	})
}

func TestSecurity(t *testing.T) {
	t.Run("success", func(t *testing.T) {
		testSecurity(t, true)
	})
	t.Run("failure", func(t *testing.T) {
		testSecurity(t, false)
	})
}

const fakeGo = `#!/bin/bash -eu

case "$1" in
"get")
  ls go.mod go.sum >/dev/null
  for i in "${@:2}"; do
    echo -e "// pretend we've upgraded to $i" >> go.mod
    echo "$i h1:asdasd" | tr '@' ' ' >> go.sum
  done
  ;;
"mod")
  ls go.mod go.sum >/dev/null
  echo "tidied!" >> go.mod
  ;;
"generate")
  mkdir -p internal/imports
  cd internal/imports && echo "package imports" >> zstdlib.go
  ;;
*)
  echo unexpected command $@
  exit 1
  ;;
esac
`

type releaseTestDeps struct {
	ctx            context.Context
	cancel         context.CancelFunc
	buildlets      *task.FakeBuildlets
	goRepo         *task.FakeRepo
	gerrit         *reviewerCheckGerrit
	versionTasks   *task.VersionTasks
	buildTasks     *BuildReleaseTasks
	milestoneTasks *task.MilestoneTasks
	publishedFiles map[string]*task.WebsiteFile
}

func newReleaseTestDeps(t *testing.T, wantVersion string) *releaseTestDeps {
	if runtime.GOOS != "linux" && runtime.GOOS != "darwin" {
		t.Skip("Requires bash shell scripting support.")
	}
	task.AwaitDivisor, workflow.MaxRetries = 100, 1
	t.Cleanup(func() { task.AwaitDivisor, workflow.MaxRetries = 1, 3 })
	ctx, cancel := context.WithCancel(context.Background())

	// Set up a server that will be used to serve inputs to the build.
	bootstrapServer := httptest.NewServer(http.HandlerFunc(serveBootstrap))
	t.Cleanup(bootstrapServer.Close)
	fakeBuildlets := task.NewFakeBuildlets(t, bootstrapServer.URL, map[string]string{
		"pkgbuild": `#!/bin/bash -eu
case "$@" in
"--identifier=org.golang.go --version ` + wantVersion + ` --scripts=pkg-scripts --root=pkg-root pkg-intermediate/org.golang.go.pkg")
	# We're doing an intermediate step in building a PKG.
	ls pkg-intermediate >/dev/null
	echo "I'm a intermediate PKG!" > "$6"
	;;
*)
	echo "unexpected command $@"
	exit 1
	;;
esac
`,
		"productbuild": `#!/bin/bash -eu
case "$@" in
"--distribution=pkg-distribution --resources=pkg-resources --package-path=pkg-intermediate pkg-out/` + wantVersion + `.pkg")
	# We're building a PKG.
	ls pkg-distribution pkg-resources/bg-light.png pkg-resources/bg-dark.png >/dev/null
	cat pkg-intermediate/* | sed "s/intermediate //" > "$4"
	;;
*)
	echo "unexpected command $@"
	exit 1
	;;
esac
`,
		"pkgutil": `#!/bin/bash -eu
case "$@" in
"--expand-full go.pkg pkg-expanded")
	# We're expanding a PKG.
	grep "I'm a PKG!" < "$2"
	mkdir -p "$3/org.golang.go.pkg/Payload/usr/local/go"
	;;
*)
	echo "unexpected command $@"
	exit 1
	;;
esac
`,
	})

	// Set up the fake CDN publishing process.
	servingDir := t.TempDir()
	dlDir := t.TempDir()
	dlServer := httptest.NewServer(http.FileServer(http.FS(os.DirFS(dlDir))))
	t.Cleanup(dlServer.Close)
	go fakeCDNLoad(ctx, t, servingDir, dlDir)

	// Set up the fake website to publish to.
	var filesMu sync.Mutex
	files := map[string]*task.WebsiteFile{}
	publishFile := func(f *task.WebsiteFile) error {
		filesMu.Lock()
		defer filesMu.Unlock()
		files[strings.TrimPrefix(f.Filename, wantVersion+".")] = f
		return nil
	}

	goRepo := task.NewFakeRepo(t, "go")
	base := goRepo.Commit(goFiles)
	goRepo.Tag("go1.17", base)
	dlRepo := task.NewFakeRepo(t, "dl")
	toolsRepo := task.NewFakeRepo(t, "tools")
	toolsRepo1 := toolsRepo.Commit(map[string]string{
		"go.mod":                       "module golang.org/x/tools\n",
		"go.sum":                       "\n",
		"internal/imports/mkstdlib.go": "package imports\nconst C=1",
	})
	toolsRepo.Tag("master", toolsRepo1)
	fakeGerrit := task.NewFakeGerrit(t, goRepo, dlRepo, toolsRepo)

	gerrit := &reviewerCheckGerrit{FakeGerrit: fakeGerrit}
	goServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		task.ServeTarball("dl/go1.19.linux-amd64.tar.gz", map[string]string{
			"go/bin/go": fakeGo,
		}, w, r)
	}))
	t.Cleanup(goServer.Close)
	versionTasks := &task.VersionTasks{
		Gerrit:         gerrit,
		GerritURL:      fakeGerrit.GerritURL(),
		GoProject:      "go",
		CreateBuildlet: fakeBuildlets.CreateBuildlet,
		LatestGoBinaries: func(context.Context) (string, error) {
			return goServer.URL + "/dl/go1.19.linux-amd64.tar.gz", nil
		},
	}
	milestoneTasks := &task.MilestoneTasks{
		Client:    fakeGitHub{},
		RepoOwner: "golang",
		RepoName:  "go",
		ApproveAction: func(ctx *workflow.TaskContext) error {
			return fmt.Errorf("unexpected approval request for %q", ctx.TaskName)
		},
	}

	buildTasks := &BuildReleaseTasks{
		GerritClient:     gerrit,
		GerritHTTPClient: http.DefaultClient,
		GerritURL:        fakeGerrit.GerritURL() + "/go",
		GCSClient:        nil,
		ScratchURL:       "file://" + filepath.ToSlash(t.TempDir()),
		ServingURL:       "file://" + filepath.ToSlash(servingDir),
		CreateBuildlet:   fakeBuildlets.CreateBuildlet,
		SignService:      &fakeSignService{t: t, completedJobs: make(map[string][]string)},
		DownloadURL:      dlServer.URL,
		PublishFile:      publishFile,
		ApproveAction: func(ctx *workflow.TaskContext) error {
			if strings.Contains(ctx.TaskName, "Release Coordinator Approval") {
				return nil
			}
			return fmt.Errorf("unexpected approval request for %q", ctx.TaskName)
		},
	}
	// Cleanups are called in reverse order, and we need to cancel the context
	// before the temp dirs are deleted.
	t.Cleanup(cancel)
	return &releaseTestDeps{
		ctx:            ctx,
		cancel:         cancel,
		buildlets:      fakeBuildlets,
		goRepo:         goRepo,
		gerrit:         gerrit,
		versionTasks:   versionTasks,
		buildTasks:     buildTasks,
		milestoneTasks: milestoneTasks,
		publishedFiles: files,
	}
}

func testRelease(t *testing.T, wantVersion string, kind task.ReleaseKind) {
	deps := newReleaseTestDeps(t, wantVersion)
	wd := workflow.New()

	deps.gerrit.wantReviewers = []string{"heschi", "dmitshur"}
	v := addSingleReleaseWorkflow(deps.buildTasks, deps.milestoneTasks, deps.versionTasks, wd, 18, kind, workflow.Const(deps.gerrit.wantReviewers))
	workflow.Output(wd, "Published Go version", v)

	w, err := workflow.Start(wd, map[string]interface{}{
		"Targets to skip testing (or 'all') (optional)":            []string{"js-wasm"},
		"Ref from the private repository to build from (optional)": "",
	})
	if err != nil {
		t.Fatal(err)
	}
	_, err = w.Run(deps.ctx, &verboseListener{t: t, onStall: deps.cancel})
	if err != nil {
		t.Fatal(err)
	}

	// Create a complete list of expected published files.
	wantPublishedFiles := map[string]string{
		wantVersion + ".src.tar.gz": "source",
	}
	for _, t := range releasetargets.TargetsForGo1Point(18) {
		switch t.GOOS {
		case "darwin":
			wantPublishedFiles[wantVersion+"."+t.Name+".tar.gz"] = "archive"
			wantPublishedFiles[wantVersion+"."+t.Name+".pkg"] = "installer"
		case "windows":
			wantPublishedFiles[wantVersion+"."+t.Name+".zip"] = "archive"
			wantPublishedFiles[wantVersion+"."+t.Name+".msi"] = "installer"
		default:
			wantPublishedFiles[wantVersion+"."+t.Name+".tar.gz"] = "archive"
		}
	}

	dlURL, files := deps.buildTasks.DownloadURL, deps.publishedFiles
	for _, f := range deps.publishedFiles {
		wantKind, ok := wantPublishedFiles[f.Filename]
		if !ok {
			t.Errorf("got unexpected published file %q", f.Filename)
		} else if got, want := f.Kind, wantKind; got != want {
			t.Errorf("file %s has unexpected kind: got %q, want %q", f.Filename, got, want)
		}
		delete(wantPublishedFiles, f.Filename)

		checkFile(t, dlURL, files, strings.TrimPrefix(f.Filename, wantVersion+"."), f, func(t *testing.T, b []byte) {
			if got, want := len(b), int(f.Size); got != want {
				t.Errorf("%s size mismatch with metadata: %v != %v", f.Filename, got, want)
			}
			if got, want := fmt.Sprintf("%x", sha256.Sum256(b)), f.ChecksumSHA256; got != want {
				t.Errorf("%s sha256 mismatch with metadata: %q != %q", f.Filename, got, want)
			}
			if got, want := fmt.Sprintf("%x", sha256.Sum256(b)), string(fetch(t, dlURL+"/"+f.Filename+".sha256")); got != want {
				t.Errorf("%s sha256 mismatch with .sha256 file: %q != %q", f.Filename, got, want)
			}
			if strings.HasSuffix(f.Filename, ".tar.gz") {
				if got, want := string(fetch(t, dlURL+"/"+f.Filename+".asc")), fmt.Sprintf("I'm a GPG signature for %x!", sha256.Sum256(b)); got != want {
					t.Errorf("%v doesn't have the expected GPG signature: got %s, want %s", f.Filename, got, want)
				}
			}
		})
	}
	if len(wantPublishedFiles) != 0 {
		t.Errorf("missing %d published files: %v", len(wantPublishedFiles), wantPublishedFiles)
	}
	checkTGZ(t, dlURL, files, "src.tar.gz", &task.WebsiteFile{
		OS:   "",
		Arch: "",
		Kind: "source",
	}, map[string]string{
		"go/VERSION":       wantVersion,
		"go/src/make.bash": makeScript,
	})
	checkContents(t, dlURL, files, "windows-amd64.msi", &task.WebsiteFile{
		OS:   "windows",
		Arch: "amd64",
		Kind: "installer",
	}, "I'm an MSI!\n-signed <Windows>")
	checkTGZ(t, dlURL, files, "linux-amd64.tar.gz", &task.WebsiteFile{
		OS:   "linux",
		Arch: "amd64",
		Kind: "archive",
	}, map[string]string{
		"go/VERSION":                        wantVersion,
		"go/tool/something_orother/compile": "",
		"go/pkg/something_orother/race.a":   "",
	})
	checkZip(t, dlURL, files, "windows-amd64.zip", &task.WebsiteFile{
		OS:   "windows",
		Arch: "amd64",
		Kind: "archive",
	}, map[string]string{
		"go/VERSION":                        wantVersion,
		"go/tool/something_orother/compile": "",
	})
	checkTGZ(t, dlURL, files, "linux-armv6l.tar.gz", &task.WebsiteFile{
		OS:   "linux",
		Arch: "armv6l",
		Kind: "archive",
	}, map[string]string{
		"go/VERSION":                        wantVersion,
		"go/tool/something_orother/compile": "",
	})
	checkContents(t, dlURL, files, "darwin-amd64.pkg", &task.WebsiteFile{
		OS:   "darwin",
		Arch: "amd64",
		Kind: "installer",
	}, "I'm a PKG!\n-signed <macOS>")

	head, err := deps.gerrit.ReadBranchHead(deps.ctx, "dl", "master")
	if err != nil {
		t.Fatal(err)
	}
	content, err := deps.gerrit.ReadFile(deps.ctx, "dl", head, wantVersion+"/main.go")
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(content), fmt.Sprintf("version.Run(%q)", wantVersion)) {
		t.Errorf("unexpected dl content: %v", content)
	}

	tag, err := deps.gerrit.GetTag(deps.ctx, "go", wantVersion)
	if err != nil {
		t.Fatal(err)
	}

	if kind != task.KindBeta {
		version, err := deps.gerrit.ReadFile(deps.ctx, "go", tag.Revision, "VERSION")
		if err != nil {
			t.Fatal(err)
		}
		if string(version) != wantVersion {
			t.Errorf("VERSION file is %q, expected %q", version, wantVersion)
		}
	}
}

func testSecurity(t *testing.T, mergeFixes bool) {
	deps := newReleaseTestDeps(t, "go1.18rc1")

	// Set up the fake merge process. Once we stop to ask for approval, commit
	// the fix to the public server.
	privateRepo := task.NewFakeRepo(t, "go-private")
	privateRepo.Commit(goFiles)
	securityFix := map[string]string{"security.txt": "This file makes us secure"}
	privateRef := privateRepo.Commit(securityFix)
	privateGerrit := task.NewFakeGerrit(t, privateRepo)
	deps.buildTasks.PrivateGerritURL = privateGerrit.GerritURL() + "/go-private"

	defaultApprove := deps.buildTasks.ApproveAction
	deps.buildTasks.ApproveAction = func(tc *workflow.TaskContext) error {
		if mergeFixes {
			deps.goRepo.Commit(securityFix)
		}
		return defaultApprove(tc)
	}

	// Run the release.
	wd := workflow.New()
	v := addSingleReleaseWorkflow(deps.buildTasks, deps.milestoneTasks, deps.versionTasks, wd, 18, task.KindRC, workflow.Slice[string]())
	workflow.Output(wd, "Published Go version", v)

	w, err := workflow.Start(wd, map[string]interface{}{
		"Targets to skip testing (or 'all') (optional)":            []string{"js-wasm"},
		"Ref from the private repository to build from (optional)": privateRef,
	})
	if err != nil {
		t.Fatal(err)
	}

	if mergeFixes {
		_, err = w.Run(deps.ctx, &verboseListener{t: t})
		if err != nil {
			t.Fatal(err)
		}
	} else {
		runToFailure(t, deps.ctx, w, "Check branch state matches source archive", &verboseListener{t: t})
		return
	}
	checkTGZ(t, deps.buildTasks.DownloadURL, deps.publishedFiles, "src.tar.gz", &task.WebsiteFile{
		OS:   "",
		Arch: "",
		Kind: "source",
	}, map[string]string{
		"go/security.txt": "This file makes us secure",
	})
}

func TestAdvisoryTrybotFail(t *testing.T) {
	deps := newReleaseTestDeps(t, "go1.18rc1")
	defaultApprove := deps.buildTasks.ApproveAction
	approvedTrybots := false
	deps.buildTasks.ApproveAction = func(ctx *workflow.TaskContext) error {
		if strings.Contains(ctx.TaskName, "Run advisory TryBot") {
			approvedTrybots = true
			return nil
		}
		return defaultApprove(ctx)
	}

	// Run the release.
	wd := workflow.New()
	v := addSingleReleaseWorkflow(deps.buildTasks, deps.milestoneTasks, deps.versionTasks, wd, 18, task.KindRC, workflow.Slice[string]())
	workflow.Output(wd, "Published Go version", v)

	w, err := workflow.Start(wd, map[string]interface{}{
		"Targets to skip testing (or 'all') (optional)":            []string(nil),
		"Ref from the private repository to build from (optional)": "",
	})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := w.Run(deps.ctx, &verboseListener{t: t}); err != nil {
		t.Fatal(err)
	}
	if !approvedTrybots {
		t.Errorf("advisory trybots didn't need approval")
	}
}

// makeScript pretends to be make.bash. It creates a fake go command that
// knows how to fake the commands the release process runs.
const makeScript = `#!/bin/bash

GO=../
mkdir -p $GO/bin

cat <<'EOF' >$GO/bin/go
#!/bin/bash -eu
case "$1 $2" in
"run releaselet.go")
    # We're building an MSI. The command should be run in the gomote work dir.
	ls go/src/make.bash >/dev/null
	mkdir msi
	echo "I'm an MSI!" > msi/thisisanmsi.msi
	;;
"install -race")
	# Installing the race mode stdlib. Doesn't matter where it's run.
	mkdir -p $(dirname $0)/../pkg/something_orother/
	touch $(dirname $0)/../pkg/something_orother/race.a
	;;
*)
	echo "unexpected command $@"
	exit 1
	;;
esac
EOF
chmod 0755 $GO/bin/go

cp $GO/bin/go $GO/bin/go.exe
# We don't know what GOOS_GOARCH we're "building" for, write some junk for
# versimilitude.
mkdir -p $GO/tool/something_orother/
touch $GO/tool/something_orother/compile
`

// allScript pretends to be all.bash. It is hardcoded to pass.
const allScript = `#!/bin/bash -eu

echo "I'm a test! :D"

if [[ $GO_BUILDER_NAME =~ "js-wasm" ]]; then
  echo "Oh no, WASM is broken"
  exit 1
fi

exit 0
`

var goFiles = map[string]string{
	"src/make.bash": makeScript,
	"src/make.bat":  makeScript,
	"src/all.bash":  allScript,
	"src/all.bat":   allScript,
	"src/race.bash": allScript,
	"src/race.bat":  allScript,
}

func serveBootstrap(w http.ResponseWriter, r *http.Request) {
	task.ServeTarball("go-builder-data/go", map[string]string{
		"bin/go": "I'm a dummy bootstrap go command!",
	}, w, r)
}

func checkFile(t *testing.T, dlURL string, files map[string]*task.WebsiteFile, filename string, meta *task.WebsiteFile, check func(*testing.T, []byte)) {
	t.Run(filename, func(t *testing.T) {
		f, ok := files[filename]
		if !ok {
			t.Fatalf("file %q not published", filename)
		}
		if diff := cmp.Diff(meta, f, cmpopts.IgnoreFields(task.WebsiteFile{}, "Filename", "Version", "ChecksumSHA256", "Size")); diff != "" {
			t.Errorf("file metadata mismatch (-want +got):\n%v", diff)
		}
		body := fetch(t, dlURL+"/"+f.Filename)
		check(t, body)
	})
}
func fetch(t *testing.T, url string) []byte {
	resp, err := http.Get(url)
	if err != nil {
		t.Fatalf("getting %v: %v", url, err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("getting %v: non-200 OK status code %v", url, resp.Status)
	}
	b, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("reading %v: %v", url, err)
	}
	return b
}

func checkContents(t *testing.T, dlURL string, files map[string]*task.WebsiteFile, filename string, meta *task.WebsiteFile, contents string) {
	checkFile(t, dlURL, files, filename, meta, func(t *testing.T, b []byte) {
		if got, want := string(b), contents; got != want {
			t.Errorf("%v contains %q, want %q", filename, got, want)
		}
	})
}

func checkTGZ(t *testing.T, dlURL string, files map[string]*task.WebsiteFile, filename string, meta *task.WebsiteFile, contents map[string]string) {
	checkFile(t, dlURL, files, filename, meta, func(t *testing.T, b []byte) {
		gzr, err := gzip.NewReader(bytes.NewReader(b))
		if err != nil {
			t.Fatal(err)
		}
		tr := tar.NewReader(gzr)
		for {
			h, err := tr.Next()
			if err == io.EOF {
				break
			}
			if err != nil {
				t.Fatal(err)
			}
			want, ok := contents[h.Name]
			if !ok {
				continue
			}
			b, err := ioutil.ReadAll(tr)
			if err != nil {
				t.Fatal(err)
			}
			delete(contents, h.Name)
			if string(b) != want {
				t.Errorf("contents of %v were %q, want %q", h.Name, string(b), want)
			}
		}
		if len(contents) != 0 {
			t.Errorf("not all files were found: missing %v", contents)
		}
	})
}

func checkZip(t *testing.T, dlURL string, files map[string]*task.WebsiteFile, filename string, meta *task.WebsiteFile, contents map[string]string) {
	checkFile(t, dlURL, files, filename, meta, func(t *testing.T, b []byte) {
		zr, err := zip.NewReader(bytes.NewReader(b), int64(len(b)))
		if err != nil {
			t.Fatal(err)
		}
		for _, f := range zr.File {
			want, ok := contents[f.Name]
			if !ok {
				continue
			}
			r, err := zr.Open(f.Name)
			if err != nil {
				t.Fatal(err)
			}
			b, err := ioutil.ReadAll(r)
			if err != nil {
				t.Fatal(err)
			}
			delete(contents, f.Name)
			if string(b) != want {
				t.Errorf("contents of %v were %q, want %q", f.Name, string(b), want)
			}
		}
		if len(contents) != 0 {
			t.Errorf("not all files were found: missing %v", contents)
		}
	})
}

type reviewerCheckGerrit struct {
	wantReviewers []string
	*task.FakeGerrit
}

func (g *reviewerCheckGerrit) CreateAutoSubmitChange(ctx context.Context, input gerrit.ChangeInput, reviewers []string, contents map[string]string) (string, error) {
	if diff := cmp.Diff(g.wantReviewers, reviewers, cmpopts.EquateEmpty()); diff != "" {
		return "", fmt.Errorf("unexpected reviewers for CL: %v", diff)
	}
	return g.FakeGerrit.CreateAutoSubmitChange(ctx, input, reviewers, contents)
}

type fakeGitHub struct{}

func (fakeGitHub) FetchMilestone(_ context.Context, owner, repo, name string, create bool) (int, error) {
	return 0, nil
}

func (fakeGitHub) FetchMilestoneIssues(_ context.Context, owner, repo string, milestoneID int) (map[int]map[string]bool, error) {
	return nil, nil
}

func (fakeGitHub) EditIssue(_ context.Context, owner string, repo string, number int, issue *github.IssueRequest) (*github.Issue, *github.Response, error) {
	return nil, nil, nil
}

func (fakeGitHub) EditMilestone(_ context.Context, owner string, repo string, number int, milestone *github.Milestone) (*github.Milestone, *github.Response, error) {
	return nil, nil, nil
}

type verboseListener struct {
	t       *testing.T
	onStall func()
}

func (l *verboseListener) WorkflowStalled(workflowID uuid.UUID) error {
	l.t.Logf("workflow %q: stalled", workflowID.String())
	if l.onStall != nil {
		l.onStall()
	}
	return nil
}

func (l *verboseListener) TaskStateChanged(_ uuid.UUID, _ string, st *workflow.TaskState) error {
	switch {
	case !st.Finished:
		l.t.Logf("task %-10v: started", st.Name)
	case st.Error != "":
		l.t.Logf("task %-10v: error: %v", st.Name, st.Error)
	default:
		l.t.Logf("task %-10v: done: %v", st.Name, st.Result)
	}
	return nil
}

func (l *verboseListener) Logger(_ uuid.UUID, task string) workflow.Logger {
	return &testLogger{t: l.t, task: task}
}

type testLogger struct {
	t    *testing.T
	task string
}

func (l *testLogger) Printf(format string, v ...interface{}) {
	l.t.Logf("task %-10v: LOG: %s", l.task, fmt.Sprintf(format, v...))
}

func runToFailure(t *testing.T, ctx context.Context, w *workflow.Workflow, task string, wrap workflow.Listener) string {
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()
	t.Helper()
	var message string
	listener := &errorListener{
		taskName: task,
		callback: func(m string) {
			message = m
			cancel()
		},
		Listener: wrap,
	}
	_, err := w.Run(ctx, listener)
	if err == nil {
		t.Fatalf("workflow unexpectedly succeeded")
	}
	return message
}

type errorListener struct {
	taskName string
	callback func(string)
	workflow.Listener
}

func (l *errorListener) TaskStateChanged(id uuid.UUID, taskID string, st *workflow.TaskState) error {
	if st.Name == l.taskName && st.Finished && st.Error != "" {
		l.callback(st.Error)
	}
	l.Listener.TaskStateChanged(id, taskID, st)
	return nil
}

type fakeSignService struct {
	t             *testing.T
	mu            sync.Mutex
	completedJobs map[string][]string // Job ID → output objectURIs.
}

func (s *fakeSignService) SignArtifact(_ context.Context, bt sign.BuildType, in []string) (jobID string, _ error) {
	s.t.Logf("fakeSignService: doing %s signing of %q", bt, in)
	var out []string
	switch bt {
	case sign.BuildMacOS, sign.BuildWindows:
		if len(in) != 1 {
			return "", fmt.Errorf("got %d inputs, want 1", len(in))
		}
		out = []string{fakeSignFile(in[0], fmt.Sprintf("-signed <%s>", bt))}
	case sign.BuildGPG:
		if len(in) == 0 {
			return "", fmt.Errorf("got 0 inputs, want 1 or more")
		}
		for _, f := range in {
			out = append(out, fakeGPGFile(f))
		}
	default:
		return "", fmt.Errorf("SignArtifact: not implemented for %v", bt)
	}
	jobID = uuid.NewString()
	s.mu.Lock()
	s.completedJobs[jobID] = out
	s.mu.Unlock()
	return jobID, nil
}
func (s *fakeSignService) ArtifactSigningStatus(_ context.Context, jobID string) (_ sign.Status, desc string, out []string, _ error) {
	s.mu.Lock()
	out, ok := s.completedJobs[jobID]
	s.mu.Unlock()
	if !ok {
		return sign.StatusNotFound, fmt.Sprintf("job %q not found", jobID), nil, nil
	}
	return sign.StatusCompleted, "", out, nil
}
func (s *fakeSignService) CancelSigning(_ context.Context, jobID string) error {
	s.t.Errorf("CancelSigning was called unexpectedly")
	return fmt.Errorf("intentional fake error")
}
func fakeSignFile(f, msg string) string {
	b, err := os.ReadFile(strings.TrimPrefix(f, "file://"))
	if err != nil {
		panic(fmt.Errorf("fakeSignFile: os.ReadFile: %v", err))
	}
	b = append(b, []byte(msg)...)
	err = os.WriteFile(strings.TrimPrefix(f, "file://")+".signed", b, 0600)
	if err != nil {
		panic(fmt.Errorf("fakeSignFile: os.WriteFile: %v", err))
	}
	return f + ".signed"
}
func fakeGPGFile(f string) string {
	b, err := os.ReadFile(strings.TrimPrefix(f, "file://"))
	if err != nil {
		panic(fmt.Errorf("fakeGPGFile: os.ReadFile: %v", err))
	}
	gpg := fmt.Sprintf("I'm a GPG signature for %x!", sha256.Sum256(b))
	err = os.WriteFile(strings.TrimPrefix(f, "file://")+".asc", []byte(gpg), 0600)
	if err != nil {
		panic(fmt.Errorf("fakeGPGFile: os.WriteFile: %v", err))
	}
	return f + ".asc"
}

func fakeCDNLoad(ctx context.Context, t *testing.T, from, to string) {
	fromFS, toFS := gcsfs.DirFS(from), gcsfs.DirFS(to)
	seen := map[string]bool{}
	periodicallyDo(ctx, t, 100*time.Millisecond, func() error {
		files, err := fs.ReadDir(fromFS, ".")
		if err != nil {
			return err
		}
		for _, f := range files {
			if seen[f.Name()] {
				continue
			}
			seen[f.Name()] = true
			contents, err := fs.ReadFile(fromFS, f.Name())
			if err != nil {
				return err
			}
			if err := gcsfs.WriteFile(toFS, f.Name(), contents); err != nil {
				return err
			}
		}
		return nil
	})
}

func periodicallyDo(ctx context.Context, t *testing.T, period time.Duration, f func() error) {
	var err error
	childCtx, cancel := context.WithCancel(ctx)
	internal.PeriodicallyDo(childCtx, period, func(_ context.Context, _ time.Time) {
		err = f()
		if err != nil {
			cancel()
		}
	})
	// Suppress errors caused by the test finishing before we notice.
	if err != nil && ctx.Err() == nil {
		t.Fatal(err)
	}
}