package releasekit_test

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"testing"

	releasekit "gitea.maximumdirect.net/eric/ReleaseKit"
)

func TestDeliverManagedBuildUploadsArtifactsAndCleansTemporaryOutput(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	temporaryRoot := t.TempDir()
	t.Setenv("TMPDIR", temporaryRoot)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	var progress strings.Builder

	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		Output: &progress,
	})
	if err != nil {
		t.Fatalf("Deliver() error = %v; result = %#v", err, result)
	}
	if result.State != releasekit.DeliveryComplete || result.CandidateCommit != remote.commit {
		t.Fatalf("delivery result = %#v", result)
	}
	if len(result.Uploaded) != 2 || len(remote.assets) != 2 {
		t.Fatalf("uploaded = %#v; hosted assets = %v", result.Uploaded, mapKeys(remote.assets))
	}
	if !strings.Contains(progress.String(), "checking fixture version output") {
		t.Fatalf("build progress = %q", progress.String())
	}
	if entries, err := os.ReadDir(temporaryRoot); err != nil || len(entries) != 0 {
		t.Fatalf("managed build output remains: entries=%v error=%v", entries, err)
	}
}

func TestDeliverBinaryConsumerWithBuildinfoAndSelectedTargets(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	var progress strings.Builder

	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets: []releasekit.Target{
				{OS: "linux", Arch: "amd64"},
				{OS: "linux", Arch: "arm64"},
			},
		},
		Output: &progress,
	})
	if err != nil {
		t.Fatalf("Deliver() error = %v; result = %#v", err, result)
	}
	if result.State != releasekit.DeliveryComplete || result.CandidateCommit != remote.commit {
		t.Fatalf("delivery result = %#v", result)
	}
	wantAssets := []string{
		"fixture-v1.2.3-linux-amd64",
		"fixture-v1.2.3-linux-arm64",
		"SHA256SUMS",
	}
	if len(result.Uploaded) != len(wantAssets) || len(remote.assets) != len(wantAssets) {
		t.Fatalf("uploaded = %#v; hosted assets = %v", result.Uploaded, mapKeys(remote.assets))
	}
	for _, name := range wantAssets {
		if _, ok := remote.assets[name]; !ok {
			t.Errorf("hosted assets omit %q: %v", name, mapKeys(remote.assets))
		}
	}
	if !strings.Contains(progress.String(), "checking fixture version output") {
		t.Fatalf("build progress = %q", progress.String())
	}
}

func TestDeliverPrebuiltArtifactsRemainCallerOwned(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	outputDir := filepath.Join(t.TempDir(), "caller-owned-assets")
	prebuilt, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v1.2.3",
		Spec: releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		OutputDir: outputDir,
	})
	if err != nil {
		t.Fatalf("Build() error = %v", err)
	}
	server, _ := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Prebuilt:      &prebuilt,
	})
	if err != nil || result.State != releasekit.DeliveryComplete {
		t.Fatalf("Deliver() = %#v, %v", result, err)
	}
	for _, artifact := range prebuilt.Artifacts {
		if _, err := os.Stat(artifact.Path); err != nil {
			t.Errorf("caller-owned artifact %q was removed: %v", artifact.Path, err)
		}
	}
}

func TestDeliverRejectsSameSizePrebuiltTamperingBeforeHostedWrites(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	prebuilt, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v1.2.3",
		Spec: releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		OutputDir: filepath.Join(t.TempDir(), "caller-owned-assets"),
	})
	if err != nil {
		t.Fatalf("Build() error = %v", err)
	}
	contents, err := os.ReadFile(prebuilt.Artifacts[0].Path)
	if err != nil {
		t.Fatal(err)
	}
	if len(contents) == 0 {
		t.Fatal("built artifact is empty")
	}
	contents[0] ^= 0xff
	if err := os.WriteFile(prebuilt.Artifacts[0].Path, contents, 0o600); err != nil {
		t.Fatal(err)
	}

	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Prebuilt:      &prebuilt,
	})
	if err == nil || !strings.Contains(err.Error(), "verify build assets") || result.State != releasekit.DeliveryNotAttempted {
		t.Fatalf("Deliver() = %#v, %v; want local asset verification failure", result, err)
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests = %d, want none before local verification", remote.requests)
	}
}

func TestDeliverPageOnlySkipsBuildAndHostedAssets(t *testing.T) {
	for _, test := range []struct {
		name     string
		build    *releasekit.BuildSpec
		prebuilt *releasekit.BuildResult
	}{
		{name: "no build"},
		{name: "empty target set", build: &releasekit.BuildSpec{}},
		{name: "empty prebuilt result", prebuilt: &releasekit.BuildResult{}},
	} {
		t.Run(test.name, func(t *testing.T) {
			repository := newTaggedDeliveryConsumer(t)
			prebuilt := test.prebuilt
			if prebuilt != nil {
				built, err := releasekit.Build(context.Background(), releasekit.BuildRequest{RepositoryDir: repository, Version: "v1.2.3"})
				if err != nil {
					t.Fatalf("Build() for page-only prebuilt identity = %#v, %v", built, err)
				}
				prebuilt = &built
			}
			temporaryRoot := t.TempDir()
			t.Setenv("TMPDIR", temporaryRoot)
			server, remote := newFacadeDeliveryServer(t, repository)
			defer server.Close()
			var progress strings.Builder

			result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
				RepositoryDir: repository,
				Product:       "Fixture",
				Version:       "v1.2.3",
				Destination:   facadeDeliveryDestination(server.URL),
				Build:         test.build,
				Prebuilt:      prebuilt,
				Output:        &progress,
			})
			if err != nil || result.State != releasekit.DeliveryComplete {
				t.Fatalf("Deliver() = %#v, %v", result, err)
			}
			if len(remote.assets) != 0 || len(result.Uploaded) != 0 || len(result.Pending) != 0 {
				t.Fatalf("page-only delivery included assets: result=%#v assets=%v", result, mapKeys(remote.assets))
			}
			if progress.Len() != 0 {
				t.Fatalf("page-only delivery emitted build progress: %q", progress.String())
			}
			if entries, err := os.ReadDir(temporaryRoot); err != nil || len(entries) != 0 {
				t.Fatalf("page-only delivery allocated temporary output: entries=%v error=%v", entries, err)
			}
		})
	}
}

func TestDeliverUsesCommittedModuleIdentityForSeparatePages(t *testing.T) {
	repository := newTwoModuleDeliveryConsumer(t)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()

	wrongTag, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		ExpectedTag:   "integrations/wrong/v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
	})
	if err == nil || wrongTag.Tag != "v1.2.3" || remote.requests != 0 {
		t.Fatalf("delivery with inconsistent expected tag = %#v, %v; hosted requests %d", wrongTag, err, remote.requests)
	}

	rootResult, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		ExpectedTag:   "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
	})
	if err != nil || rootResult.State != releasekit.DeliveryComplete || rootResult.Tag != "v1.2.3" {
		t.Fatalf("root delivery = %#v, %v", rootResult, err)
	}

	nestedTag := "integrations/ckconfig/v1.2.3"
	remote.tag = nestedTag
	remote.noteBody = "# Fixture v1.2.3\n\nNested delivery fixture.\n"
	nestedResult, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		ModuleDir:     "integrations/ckconfig",
		Product:       "Fixture",
		Version:       "v1.2.3",
		ExpectedTag:   nestedTag,
		Destination:   facadeDeliveryDestination(server.URL),
	})
	if err != nil || nestedResult.State != releasekit.DeliveryComplete || nestedResult.Tag != nestedTag || nestedResult.ModulePath != "example.com/ckconfig" {
		t.Fatalf("nested delivery = %#v, %v", nestedResult, err)
	}
	if len(remote.pages) != 2 || !remote.pages["v1.2.3"] || !remote.pages[nestedTag] {
		t.Fatalf("created hosted pages = %#v", remote.pages)
	}
}

func TestDeliverRejectsPrebuiltArtifactsForAnotherModuleBeforeHostedRequests(t *testing.T) {
	repository := newTwoModuleDeliveryConsumer(t)
	prebuilt, err := releasekit.Build(context.Background(), releasekit.BuildRequest{
		RepositoryDir: repository,
		Version:       "v1.2.3",
		Spec: releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		OutputDir: filepath.Join(t.TempDir(), "root-artifacts"),
	})
	if err != nil || !prebuilt.SourceVerified {
		t.Fatalf("root Build() = %#v, %v", prebuilt, err)
	}
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	remote.tag = "integrations/ckconfig/v1.2.3"
	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		ModuleDir:     "integrations/ckconfig",
		Product:       "Fixture",
		Version:       "v1.2.3",
		ExpectedTag:   remote.tag,
		Destination:   facadeDeliveryDestination(server.URL),
		Prebuilt:      &prebuilt,
	})
	if err == nil || !strings.Contains(err.Error(), "selected tagged module") || result.Tag != remote.tag {
		t.Fatalf("nested delivery with root artifacts = %#v, %v", result, err)
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests before prebuilt identity rejection = %d", remote.requests)
	}
}

func newTwoModuleDeliveryConsumer(t *testing.T) string {
	t.Helper()
	repository := newTaggedDeliveryConsumer(t)
	writeNestedBuildConsumer(t, repository, "integrations/ckconfig", "example.com/ckconfig", `package main
import (
	"fmt"
	"os"
	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
)
func main() { if len(os.Args) == 2 && os.Args[1] == "version" { fmt.Println("fixture", buildinfo.Version()) } }
`)
	writeBuildFixture(t, repository, "integrations/ckconfig/docs/releases/v1.2.3.md", "# Fixture v1.2.3\n\nNested delivery fixture.\n")
	buildGit(t, repository, "add", "--all")
	buildGit(t, repository, "commit", "-m", "add nested release module")
	buildGit(t, repository, "tag", "-f", "v1.2.3")
	buildGit(t, repository, "tag", "integrations/ckconfig/v1.2.3")
	return repository
}

func TestDeliverRejectsDirtyTaggedSourceBeforeBuildOrHostedWrites(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	writeBuildFixture(t, repository, "local-change.txt", "dirty source")
	temporaryRoot := t.TempDir()
	t.Setenv("TMPDIR", temporaryRoot)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	var progress strings.Builder

	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		Output: &progress,
	})
	if err == nil || result.State != releasekit.DeliveryNotAttempted || result.CandidateCommit != remote.commit {
		t.Fatalf("Deliver() = %#v, %v; want preflight failure for known commit", result, err)
	}
	if progress.Len() != 0 {
		t.Fatalf("build started before source eligibility passed: %q", progress.String())
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests = %d, want none", remote.requests)
	}
}

func TestDeliverRejectsCheckoutAwayFromTagBeforeBuildOrHostedWrites(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	tagCommit := buildGit(t, repository, "rev-parse", "HEAD")
	writeBuildFixture(t, repository, "later-change.txt", "new commit")
	buildGit(t, repository, "add", "--all")
	buildGit(t, repository, "commit", "-m", "advance checkout after release tag")
	temporaryRoot := t.TempDir()
	t.Setenv("TMPDIR", temporaryRoot)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	var progress strings.Builder

	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		Output: &progress,
	})
	if err == nil || result.State != releasekit.DeliveryNotAttempted || result.CandidateCommit == tagCommit {
		t.Fatalf("Deliver() = %#v, %v; want tag/HEAD mismatch", result, err)
	}
	if progress.Len() != 0 {
		t.Fatalf("build started before tag/HEAD agreement: %q", progress.String())
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests = %d, want none", remote.requests)
	}
}

func TestDeliverRejectsInvalidCommittedNoteBeforeBuildOrHostedWrites(t *testing.T) {
	repository := newTaggedDeliveryConsumerWithNote(t, "# Different Product v1.2.3\n\nWrong product.\n")
	temporaryRoot := t.TempDir()
	t.Setenv("TMPDIR", temporaryRoot)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	var progress strings.Builder

	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		Output: &progress,
	})
	if err == nil || result.State != releasekit.DeliveryNotAttempted || result.CandidateCommit != remote.commit {
		t.Fatalf("Deliver() = %#v, %v; want committed-note preflight failure", result, err)
	}
	if progress.Len() != 0 {
		t.Fatalf("build started before committed-note validation: %q", progress.String())
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests = %d, want none", remote.requests)
	}
}

func TestDeliverManagedBuildRejectsCheckoutMutationBeforeHostedWrites(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	temporaryRoot := t.TempDir()
	t.Setenv("TMPDIR", temporaryRoot)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	writer := &sourceChangeWriter{change: func() {
		source, err := os.ReadFile(filepath.Join(repository, "cmd/app/main.go"))
		if err != nil {
			t.Errorf("read application source: %v", err)
			return
		}
		writeBuildFixture(t, repository, "cmd/app/main.go", string(source)+"\n// changed during delivery build\n")
	}}

	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		Output: writer,
	})
	if err == nil || !strings.Contains(err.Error(), "build source") || result.State != releasekit.DeliveryNotAttempted {
		t.Fatalf("Deliver() = %#v, %v; want build-source eligibility failure", result, err)
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests = %d, want none", remote.requests)
	}
	if entries, err := os.ReadDir(temporaryRoot); err != nil || len(entries) != 0 {
		t.Fatalf("ineligible managed build output remains: entries=%v error=%v", entries, err)
	}
}

func TestDeliverManagedBuildFailureCleansTemporaryOutputBeforeHostedWrites(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	temporaryRoot := t.TempDir()
	t.Setenv("TMPDIR", temporaryRoot)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()

	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/missing",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
	})
	if err == nil || result.State != releasekit.DeliveryNotAttempted || result.CandidateCommit != remote.commit {
		t.Fatalf("Deliver() = %#v, %v; want managed build failure before hosted writes", result, err)
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests = %d, want none", remote.requests)
	}
	if entries, err := os.ReadDir(temporaryRoot); err != nil || len(entries) != 0 {
		t.Fatalf("failed managed build output remains: entries=%v error=%v", entries, err)
	}
}

func TestDeliverManagedBuildCancellationCleansTemporaryOutput(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	temporaryRoot := t.TempDir()
	t.Setenv("TMPDIR", temporaryRoot)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	writer := deliveryCancelWriter{cancel: cancel}

	result, err := releasekit.Deliver(ctx, releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build: &releasekit.BuildSpec{
			MainPackage: "./cmd/app",
			BinaryName:  "fixture",
			Targets:     []releasekit.Target{{OS: runtime.GOOS, Arch: runtime.GOARCH}},
		},
		Output: writer,
	})
	if !errors.Is(err, context.Canceled) || result.State != releasekit.DeliveryNotAttempted {
		t.Fatalf("Deliver() = %#v, %v; want cancellation before hosted writes", result, err)
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests = %d, want none", remote.requests)
	}
	if entries, err := os.ReadDir(temporaryRoot); err != nil || len(entries) != 0 {
		t.Fatalf("canceled managed build output remains: entries=%v error=%v", entries, err)
	}
}

func TestDeliverRejectsBothBuildSourcesBeforeHostedWrites(t *testing.T) {
	repository := newTaggedDeliveryConsumer(t)
	server, remote := newFacadeDeliveryServer(t, repository)
	defer server.Close()

	result, err := releasekit.Deliver(context.Background(), releasekit.DeliveryRequest{
		RepositoryDir: repository,
		Product:       "Fixture",
		Version:       "v1.2.3",
		Destination:   facadeDeliveryDestination(server.URL),
		Build:         &releasekit.BuildSpec{},
		Prebuilt:      &releasekit.BuildResult{},
	})
	if err == nil || result.State != releasekit.DeliveryNotAttempted || !strings.Contains(err.Error(), "both") {
		t.Fatalf("Deliver() = %#v, %v; want invalid build-source combination", result, err)
	}
	if remote.requests != 0 {
		t.Fatalf("hosted requests = %d, want none", remote.requests)
	}
}

func newTaggedDeliveryConsumer(t *testing.T) string {
	return newTaggedDeliveryConsumerWithNote(t, "# Fixture v1.2.3\n\nDelivery fixture.\n")
}

func newTaggedDeliveryConsumerWithNote(t *testing.T, note string) string {
	t.Helper()
	repository := newBuildConsumer(t, `package main
import (
	"fmt"
	"os"
	"gitea.maximumdirect.net/eric/ReleaseKit/buildinfo"
)
func main() { if len(os.Args) == 2 && os.Args[1] == "version" { fmt.Println("fixture", buildinfo.Version()) } }
`)
	writeBuildFixture(t, repository, "docs/releases/v1.2.3.md", note)
	buildGit(t, repository, "add", "--all")
	buildGit(t, repository, "commit", "-m", "add release note")
	buildGit(t, repository, "tag", "v1.2.3")
	return repository
}

func facadeDeliveryDestination(baseURL string) releasekit.GiteaDestination {
	return releasekit.GiteaDestination{BaseURL: baseURL, Owner: "owner", Repository: "example", Token: "fixture-token"}
}

type deliveryCancelWriter struct{ cancel context.CancelFunc }

func (writer deliveryCancelWriter) Write(content []byte) (int, error) {
	writer.cancel()
	return len(content), nil
}

type facadeDeliveryServer struct {
	t        *testing.T
	commit   string
	tag      string
	version  string
	noteBody string
	pages    map[string]bool
	requests int
	assets   map[string][]byte
	url      string
}

func newFacadeDeliveryServer(t *testing.T, repository string) (*httptest.Server, *facadeDeliveryServer) {
	t.Helper()
	state := &facadeDeliveryServer{t: t, commit: buildGit(t, repository, "rev-parse", "HEAD"), tag: "v1.2.3", version: "v1.2.3", noteBody: "# Fixture v1.2.3\n\nDelivery fixture.\n", pages: make(map[string]bool), assets: make(map[string][]byte)}
	server := httptest.NewServer(http.HandlerFunc(state.serveHTTP))
	state.url = server.URL
	return server, state
}

func (state *facadeDeliveryServer) serveHTTP(w http.ResponseWriter, r *http.Request) {
	if strings.HasPrefix(r.URL.Path, "/api/") {
		state.requests++
		if r.Header.Get("Authorization") != "token fixture-token" {
			state.t.Errorf("authorization = %q", r.Header.Get("Authorization"))
		}
	}
	switch r.URL.EscapedPath() {
	case "/api/v1/repos/owner/example/tags/" + url.PathEscape(state.tag):
		_, _ = fmt.Fprintf(w, `{"name":%q,"commit":{"sha":%q}}`, state.tag, state.commit)
	case "/api/v1/repos/owner/example/releases/tags/" + url.PathEscape(state.tag):
		if !state.pages[state.tag] {
			http.NotFound(w, r)
			return
		}
		state.writeRelease(w)
	case "/api/v1/repos/owner/example/releases":
		var payload struct {
			Tag    string `json:"tag_name"`
			Target string `json:"target_commitish"`
			Name   string `json:"name"`
			Body   string `json:"body"`
		}
		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
			state.t.Errorf("decode release payload: %v", err)
			http.Error(w, "invalid payload", http.StatusBadRequest)
			return
		}
		if payload.Tag != state.tag || payload.Target != state.commit || payload.Name != "Fixture "+state.version {
			state.t.Errorf("release payload = %#v", payload)
		}
		state.pages[state.tag] = true
		state.writeRelease(w)
	case "/api/v1/repos/owner/example/releases/10/assets":
		if r.Method == http.MethodGet {
			list := make([]map[string]any, 0, len(state.assets))
			for name, content := range state.assets {
				list = append(list, map[string]any{"id": len(list) + 1, "name": name, "size": len(content), "browser_download_url": state.url + "/files/" + name})
			}
			_ = json.NewEncoder(w).Encode(list)
			return
		}
		name := r.URL.Query().Get("name")
		file, _, err := r.FormFile("attachment")
		if err != nil {
			state.t.Errorf("read upload %q: %v", name, err)
			http.Error(w, "invalid multipart upload", http.StatusBadRequest)
			return
		}
		content, err := io.ReadAll(file)
		_ = file.Close()
		if err != nil {
			state.t.Errorf("read upload %q: %v", name, err)
		}
		state.assets[name] = content
		w.WriteHeader(http.StatusCreated)
		_ = json.NewEncoder(w).Encode(map[string]any{"id": len(state.assets), "name": name, "size": len(content)})
	default:
		if strings.HasPrefix(r.URL.Path, "/files/") {
			name := strings.TrimPrefix(r.URL.Path, "/files/")
			content, ok := state.assets[name]
			if !ok {
				http.NotFound(w, r)
				return
			}
			_, _ = w.Write(content)
			return
		}
		state.t.Errorf("unexpected delivery request %s %s", r.Method, r.URL)
		http.NotFound(w, r)
	}
}

func (state *facadeDeliveryServer) writeRelease(w http.ResponseWriter) {
	w.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(w).Encode(map[string]any{
		"id": 10, "html_url": state.url + "/releases/10", "tag_name": state.tag,
		"target_commitish": state.commit, "name": "Fixture " + state.version,
		"body": state.noteBody, "draft": false, "prerelease": false,
	})
}

func mapKeys(values map[string][]byte) []string {
	keys := make([]string, 0, len(values))
	for key := range values {
		keys = append(keys, key)
	}
	return keys
}