package install

import (
	"archive/zip"
	"crypto/sha256"
	"encoding/hex"
	"errors"
	"os"
	"path/filepath"
	"testing"

	"softbox.local/core/catalog"
	"softbox.local/core/installer"
	"softbox.local/core/storage"
)

func TestInstallServiceInstallsVerifiedPackageAndRecordsPayloadFiles(t *testing.T) {
	archivePath, publishedPackage := writeInstallPackage(t, "1.2.3", "new executable")
	appsRoot := filepath.Join(t.TempDir(), "apps")
	store := storage.NewInstalledAppStore(appsRoot)
	service := newInstallService(t, store, func(currentPath string) error {
		_, err := os.Stat(filepath.Join(currentPath, "bin", "App.exe"))
		return err
	})

	result, err := service.Install(InstallRequest{
		Entry:        installEntry(publishedPackage, "1.2.3"),
		Architecture: catalog.ArchitectureAMD64,
		DownloadPath: archivePath,
	})
	if err != nil {
		t.Fatalf("Install() error = %v", err)
	}
	if result.AppID != "test-app" || result.Version != "1.2.3" || result.Recovery.Action != installer.RecoveryNone {
		t.Fatalf("result = %#v", result)
	}
	if got := mustReadFile(t, filepath.Join(appsRoot, "test-app", "current", "bin", "App.exe")); got != "new executable" {
		t.Fatalf("current entrypoint = %q", got)
	}
	record, found, err := store.Read("test-app")
	if err != nil || !found {
		t.Fatalf("Read() found=%t err=%v", found, err)
	}
	if record.Version != "1.2.3" || len(record.Files) != 2 {
		t.Fatalf("record = %#v", record)
	}
	if record.Files[0].Path != "bin/App.exe" || record.Files[0].Size != int64(len("new executable")) {
		t.Fatalf("record first file = %#v", record.Files[0])
	}
	hash := sha256.Sum256([]byte("new executable"))
	if record.Files[0].SHA256 != hex.EncodeToString(hash[:]) {
		t.Fatalf("record first hash = %q", record.Files[0].SHA256)
	}
}

func TestInstallServiceRejectsCatalogSelectionAndHashBeforeStaging(t *testing.T) {
	archivePath, publishedPackage := writeInstallPackage(t, "1.2.3", "new executable")
	tests := []struct {
		name    string
		entry   catalog.Entry
		wantErr error
	}{
		{
			name: "selected package differs from architecture package",
			entry: func() catalog.Entry {
				entry := installEntry(publishedPackage, "1.2.3")
				forged := publishedPackage
				forged.SHA256 = "0000000000000000000000000000000000000000000000000000000000000000"
				entry.Package = &forged
				return entry
			}(),
			wantErr: ErrInstallRequestInvalid,
		},
		{
			name: "download hash differs from Catalog",
			entry: func() catalog.Entry {
				entry := installEntry(publishedPackage, "1.2.3")
				entry.App.Packages[catalog.ArchitectureAMD64] = catalog.Package{
					Size:      publishedPackage.Size,
					SHA256:    "0000000000000000000000000000000000000000000000000000000000000000",
					Signature: publishedPackage.Signature,
					URL:       publishedPackage.URL,
				}
				*entry.Package = entry.App.Packages[catalog.ArchitectureAMD64]
				return entry
			}(),
			wantErr: installer.ErrPackageHashMismatch,
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			appsRoot := filepath.Join(t.TempDir(), "apps")
			store := storage.NewInstalledAppStore(appsRoot)
			service := newInstallService(t, store, func(string) error { return nil })

			_, err := service.Install(InstallRequest{
				Entry:        test.entry,
				Architecture: catalog.ArchitectureAMD64,
				DownloadPath: archivePath,
			})
			if !errors.Is(err, test.wantErr) {
				t.Fatalf("Install() error = %v, want %v", err, test.wantErr)
			}
			if stage := installErrorStage(t, err); stage != InstallStageVerify {
				t.Fatalf("stage = %q, want %q", stage, InstallStageVerify)
			}
			if _, statErr := os.Stat(filepath.Join(appsRoot, "test-app", "staging")); !os.IsNotExist(statErr) {
				t.Fatalf("rejected install left staging, stat error = %v", statErr)
			}
		})
	}
}

func TestInstallServiceRollsBackHealthAndRecordWriteFailure(t *testing.T) {
	appsRoot := filepath.Join(t.TempDir(), "apps")
	store := storage.NewInstalledAppStore(appsRoot)
	oldArchive, oldPackage := writeInstallPackage(t, "1.0.0", "old executable")
	initial := newInstallService(t, store, func(string) error { return nil })
	if _, err := initial.Install(InstallRequest{
		Entry:        installEntry(oldPackage, "1.0.0"),
		Architecture: catalog.ArchitectureAMD64,
		DownloadPath: oldArchive,
	}); err != nil {
		t.Fatalf("initial Install() error = %v", err)
	}

	tests := []struct {
		name      string
		service   func(t *testing.T) *InstallService
		wantStage InstallStage
		wantErr   error
	}{
		{
			name: "health failure",
			service: func(t *testing.T) *InstallService {
				return newInstallService(t, store, func(string) error { return errors.New("health failed") })
			},
			wantStage: InstallStageHealth,
			wantErr:   installer.ErrHealthCheckFailed,
		},
		{
			name: "record write failure",
			service: func(t *testing.T) *InstallService {
				return newInstallService(t, &failingRecordStore{
					InstalledAppStore: store,
					writeErr:          errors.New("record disk error"),
				}, func(string) error { return nil })
			},
			wantStage: InstallStageRecord,
			wantErr:   ErrInstallRecordWrite,
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			archivePath, publishedPackage := writeInstallPackage(t, "1.1.0", "new executable")
			_, err := test.service(t).Install(InstallRequest{
				Entry:        installEntry(publishedPackage, "1.1.0"),
				Architecture: catalog.ArchitectureAMD64,
				DownloadPath: archivePath,
			})
			if !errors.Is(err, test.wantErr) {
				t.Fatalf("Install() error = %v, want %v", err, test.wantErr)
			}
			if stage := installErrorStage(t, err); stage != test.wantStage {
				t.Fatalf("stage = %q, want %q", stage, test.wantStage)
			}
			if got := mustReadFile(t, filepath.Join(appsRoot, "test-app", "current", "bin", "App.exe")); got != "old executable" {
				t.Fatalf("current entrypoint after failure = %q", got)
			}
			record, found, readErr := store.Read("test-app")
			if readErr != nil || !found || record.Version != "1.0.0" {
				t.Fatalf("record after failure found=%t record=%#v err=%v", found, record, readErr)
			}
		})
	}
}

func TestInstallServiceRecoversPreparedTransactionBeforeExtracting(t *testing.T) {
	appsRoot := filepath.Join(t.TempDir(), "apps")
	store := storage.NewInstalledAppStore(appsRoot)
	appRoot, err := store.EnsureAppRoot("test-app")
	if err != nil {
		t.Fatalf("EnsureAppRoot() error = %v", err)
	}
	if err := os.MkdirAll(filepath.Join(appRoot, "current"), 0o700); err != nil {
		t.Fatalf("create current: %v", err)
	}
	if err := os.MkdirAll(filepath.Join(appRoot, "staging"), 0o700); err != nil {
		t.Fatalf("create stale staging: %v", err)
	}
	if err := os.WriteFile(
		filepath.Join(appRoot, "install-transaction.json"),
		[]byte(`{"schema_version":1,"phase":"prepared","had_current":true}`),
		0o600,
	); err != nil {
		t.Fatalf("write transaction: %v", err)
	}

	archivePath, publishedPackage := writeInstallPackage(t, "1.2.3", "new executable")
	service := newInstallService(t, store, func(string) error { return nil })
	result, err := service.Install(InstallRequest{
		Entry:        installEntry(publishedPackage, "1.2.3"),
		Architecture: catalog.ArchitectureAMD64,
		DownloadPath: archivePath,
	})
	if err != nil {
		t.Fatalf("Install() error = %v", err)
	}
	if result.Recovery.Action != installer.RecoveryAborted {
		t.Fatalf("recovery action = %q, want %q", result.Recovery.Action, installer.RecoveryAborted)
	}
	if got := mustReadFile(t, filepath.Join(appRoot, "current", "bin", "App.exe")); got != "new executable" {
		t.Fatalf("current entrypoint = %q", got)
	}
	if _, statErr := os.Stat(filepath.Join(appRoot, "staging")); !os.IsNotExist(statErr) {
		t.Fatalf("staging remains, stat error = %v", statErr)
	}
	if _, statErr := os.Stat(filepath.Join(appRoot, "install-transaction.json")); !os.IsNotExist(statErr) {
		t.Fatalf("transaction remains, stat error = %v", statErr)
	}
}

type failingRecordStore struct {
	*storage.InstalledAppStore
	writeErr error
}

func (store *failingRecordStore) Write(storage.InstalledApp) error {
	return store.writeErr
}

func newInstallService(
	t *testing.T,
	store InstallRecordStore,
	health installer.HealthCheck,
) *InstallService {
	t.Helper()
	extractor, err := installer.NewExtractor(installTestLimits())
	if err != nil {
		t.Fatalf("NewExtractor() error = %v", err)
	}
	service, err := NewInstallService(extractor, store, health)
	if err != nil {
		t.Fatalf("NewInstallService() error = %v", err)
	}
	return service
}

func installTestLimits() installer.Limits {
	return installer.Limits{
		MaxEntries:               20,
		MaxArchiveBytes:          64 * 1024,
		MaxCentralDirectoryBytes: 4 * 1024,
		MaxUncompressedBytes:     64 * 1024,
		MaxCompressionRatio:      100,
	}
}

func installEntry(publishedPackage catalog.Package, version string) catalog.Entry {
	selectedPackage := publishedPackage
	return catalog.Entry{
		App: catalog.App{
			ID:            "test-app",
			Version:       version,
			Channel:       catalog.ReleaseStable,
			Status:        catalog.CatalogStatusActive,
			MinOS:         catalog.Windows10,
			Architectures: []catalog.Architecture{catalog.ArchitectureAMD64},
			EntryEXE:      "bin/App.exe",
			Packages: map[catalog.Architecture]catalog.Package{
				catalog.ArchitectureAMD64: publishedPackage,
			},
		},
		Package:     &selectedPackage,
		Installable: true,
	}
}

func writeInstallPackage(t *testing.T, version, executable string) (string, catalog.Package) {
	t.Helper()
	path := filepath.Join(t.TempDir(), "package.download")
	file, err := os.Create(path)
	if err != nil {
		t.Fatalf("create package: %v", err)
	}
	writer := zip.NewWriter(file)
	entries := []struct {
		name string
		body []byte
		mode os.FileMode
	}{
		{name: "app.json", body: installManifest(version)},
		{name: "payload/bin/App.exe", body: []byte(executable), mode: 0o755},
		{name: "payload/readme.txt", body: []byte("readme")},
	}
	for _, entry := range entries {
		header := &zip.FileHeader{Name: entry.name}
		mode := entry.mode
		if mode == 0 {
			mode = 0o600
		}
		header.SetMode(mode)
		part, err := writer.CreateHeader(header)
		if err != nil {
			t.Fatalf("create ZIP entry: %v", err)
		}
		if _, err := part.Write(entry.body); err != nil {
			t.Fatalf("write ZIP entry: %v", err)
		}
	}
	if err := writer.Close(); err != nil {
		file.Close()
		t.Fatalf("close ZIP writer: %v", err)
	}
	if err := file.Close(); err != nil {
		t.Fatalf("close package: %v", err)
	}
	document, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("read package: %v", err)
	}
	hash := sha256.Sum256(document)
	return path, catalog.Package{
		URL:       "https://download.invalid/test-app.zip",
		Size:      int64(len(document)),
		SHA256:    hex.EncodeToString(hash[:]),
		Signature: "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA==",
	}
}

func installManifest(version string) []byte {
	return []byte(`{"schema_version":1,"id":"test-app","name":"Test App","vendor":"SoftBox","version":"` + version + `","channel":"stable","min_os":"windows-10","architecture":"amd64","entrypoint":"bin/App.exe","working_directory":".","product_id":"test-product","supports_trial":false,"requires_admin":false,"data_policy":"local-app-data","update_policy":"managed-by-softbox"}`)
}

func installErrorStage(t *testing.T, err error) InstallStage {
	t.Helper()
	var installErr *InstallError
	if !errors.As(err, &installErr) {
		t.Fatalf("error %v is not InstallError", err)
	}
	return installErr.Stage
}

func mustReadFile(t *testing.T, path string) string {
	t.Helper()
	document, err := os.ReadFile(path)
	if err != nil {
		t.Fatalf("read %s: %v", path, err)
	}
	return string(document)
}