package installer

import (
	"bytes"
	"crypto/sha256"
	"encoding/hex"
	"errors"
	"os"
	"path/filepath"
	"testing"
)

func TestExtractorExtractVerifiedFile(t *testing.T) {
	archivePath := writeTestZIP(t, []testZIPEntry{
		{name: "app.json", body: validAppManifest("1.2.3", "bin/App.exe")},
		{name: "payload/bin/App.exe", body: []byte("executable"), mode: 0o755},
		{name: "payload/readme.txt", body: []byte("hello")},
	})
	destination := filepath.Join(t.TempDir(), "staging")
	extractor := mustExtractor(t, testLimits())

	result, err := extractor.ExtractVerifiedFile(
		archivePath,
		destination,
		verifiedExpectation(t, archivePath, "1.2.3", "bin/App.exe"),
	)
	if err != nil {
		t.Fatalf("ExtractVerifiedFile() error = %v", err)
	}
	if result.Files != 2 || len(result.PayloadFiles) != 2 {
		t.Fatalf("files = %d, payload files = %d, want 2", result.Files, len(result.PayloadFiles))
	}
	if result.PayloadFiles[0].Path != "bin/App.exe" || result.PayloadFiles[0].Size != int64(len("executable")) {
		t.Fatalf("first payload file = %#v", result.PayloadFiles[0])
	}
	wantHash := sha256.Sum256([]byte("executable"))
	if result.PayloadFiles[0].SHA256 != hex.EncodeToString(wantHash[:]) {
		t.Fatalf("first payload hash = %q", result.PayloadFiles[0].SHA256)
	}
	if _, err := os.Stat(result.EntrypointPath); err != nil {
		t.Fatalf("entrypoint stat error = %v", err)
	}
}

func TestExtractorExtractVerifiedFileWithCheckPreflightsBeforeStaging(t *testing.T) {
	archivePath := writeTestZIP(t, []testZIPEntry{
		{name: "app.json", body: validAppManifest("1.2.3", "bin/App.exe")},
		{name: "payload/bin/App.exe", body: []byte("executable"), mode: 0o755},
		{name: "payload/readme.txt", body: []byte("hello")},
	})
	destination := filepath.Join(t.TempDir(), "staging")
	extractor := mustExtractor(t, testLimits())
	stop := errors.New("pre-extract check stopped")

	_, err := extractor.ExtractVerifiedFileWithCheck(
		archivePath,
		destination,
		verifiedExpectation(t, archivePath, "1.2.3", "bin/App.exe"),
		func(verified VerifiedPackage) error {
			if verified.Entrypoint != "bin/App.exe" {
				t.Fatalf("entrypoint = %q", verified.Entrypoint)
			}
			if verified.PayloadFiles != 2 {
				t.Fatalf("payload files = %d, want 2", verified.PayloadFiles)
			}
			if verified.PayloadBytes != int64(len("executable")+len("hello")) {
				t.Fatalf("payload bytes = %d", verified.PayloadBytes)
			}
			return stop
		},
	)
	if !errors.Is(err, stop) {
		t.Fatalf("ExtractVerifiedFileWithCheck() error = %v, want %v", err, stop)
	}
	var packageErr *PackageError
	if !errors.As(err, &packageErr) || packageErr.Stage != PackageStagePreflight {
		t.Fatalf("package error = %#v, want preflight stage", packageErr)
	}
	if _, statErr := os.Stat(destination); !os.IsNotExist(statErr) {
		t.Fatalf("preflight failure left staging, stat error = %v", statErr)
	}
}

func TestExtractorExtractVerifiedFileRejectsBeforeStaging(t *testing.T) {
	archivePath := writeTestZIP(t, []testZIPEntry{
		{name: "app.json", body: validAppManifest("1.2.3", "App.exe")},
		{name: "payload/App.exe", body: []byte("executable"), mode: 0o755},
	})

	tests := []struct {
		name    string
		modify  func(PackageExpectation) PackageExpectation
		wantErr error
		stage   PackageStage
	}{
		{
			name: "hash mismatch",
			modify: func(expectation PackageExpectation) PackageExpectation {
				expectation.SHA256 = "0000000000000000000000000000000000000000000000000000000000000000"
				return expectation
			},
			wantErr: ErrPackageHashMismatch,
			stage:   PackageStageVerify,
		},
		{
			name: "app manifest identity mismatch",
			modify: func(expectation PackageExpectation) PackageExpectation {
				expectation.App.Version = "9.9.9"
				return expectation
			},
			wantErr: ErrPackageIdentityMismatch,
			stage:   PackageStageManifest,
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			destination := filepath.Join(t.TempDir(), "staging")
			extractor := mustExtractor(t, testLimits())
			expectation := test.modify(verifiedExpectation(t, archivePath, "1.2.3", "App.exe"))

			_, err := extractor.ExtractVerifiedFile(archivePath, destination, expectation)
			if !errors.Is(err, test.wantErr) {
				t.Fatalf("ExtractVerifiedFile() error = %v, want %v", err, test.wantErr)
			}
			var packageErr *PackageError
			if !errors.As(err, &packageErr) || packageErr.Stage != test.stage {
				t.Fatalf("package error = %#v, want stage %q", packageErr, test.stage)
			}
			if _, statErr := os.Stat(destination); !os.IsNotExist(statErr) {
				t.Fatalf("rejected package left staging, stat error = %v", statErr)
			}
		})
	}
}

func TestExtractorExtractVerifiedFileRejectsStrictAppManifest(t *testing.T) {
	manifest := validAppManifest("1.2.3", "App.exe")
	archivePath := writeTestZIP(t, []testZIPEntry{
		{name: "app.json", body: append(manifest[:len(manifest)-1], []byte(`,"unexpected":true}`)...)},
		{name: "payload/App.exe", body: []byte("executable"), mode: 0o755},
	})
	destination := filepath.Join(t.TempDir(), "staging")
	extractor := mustExtractor(t, testLimits())

	_, err := extractor.ExtractVerifiedFile(
		archivePath,
		destination,
		verifiedExpectation(t, archivePath, "1.2.3", "App.exe"),
	)
	if !errors.Is(err, ErrAppManifestInvalid) {
		t.Fatalf("ExtractVerifiedFile() error = %v, want %v", err, ErrAppManifestInvalid)
	}
	if _, statErr := os.Stat(destination); !os.IsNotExist(statErr) {
		t.Fatalf("invalid manifest left staging, stat error = %v", statErr)
	}
}

func TestExtractorExtractVerifiedFileRejectsNonRegularDownload(t *testing.T) {
	destination := filepath.Join(t.TempDir(), "staging")
	extractor := mustExtractor(t, testLimits())
	_, err := extractor.ExtractVerifiedFile(
		t.TempDir(),
		destination,
		PackageExpectation{
			Size:   1,
			SHA256: "0000000000000000000000000000000000000000000000000000000000000000",
			App: AppExpectation{
				ID:           "test-app",
				Version:      "1.2.3",
				Channel:      "stable",
				MinOS:        "windows-10",
				Architecture: "amd64",
				Entrypoint:   "App.exe",
			},
		},
	)
	if !errors.Is(err, ErrInvalidArchive) {
		t.Fatalf("ExtractVerifiedFile() error = %v, want %v", err, ErrInvalidArchive)
	}
	if _, statErr := os.Stat(destination); !os.IsNotExist(statErr) {
		t.Fatalf("non-regular download left staging, stat error = %v", statErr)
	}
}

func TestExtractorExtractVerifiedFileBoundsAppManifest(t *testing.T) {
	manifest := append(validAppManifest("1.2.3", "App.exe"), bytes.Repeat([]byte(" "), MaxAppManifestBytes)...)
	archivePath := writeTestZIP(t, []testZIPEntry{
		{name: "app.json", body: manifest},
		{name: "payload/App.exe", body: []byte("executable"), mode: 0o755},
	})
	destination := filepath.Join(t.TempDir(), "staging")
	extractor := mustExtractor(t, Limits{
		MaxEntries:               20,
		MaxArchiveBytes:          2 * MaxAppManifestBytes,
		MaxCentralDirectoryBytes: 4 * 1024,
		MaxUncompressedBytes:     2 * MaxAppManifestBytes,
		MaxCompressionRatio:      100,
	})

	_, err := extractor.ExtractVerifiedFile(
		archivePath,
		destination,
		verifiedExpectation(t, archivePath, "1.2.3", "App.exe"),
	)
	if !errors.Is(err, ErrAppManifestTooLarge) {
		t.Fatalf("ExtractVerifiedFile() error = %v, want %v", err, ErrAppManifestTooLarge)
	}
	var packageErr *PackageError
	if !errors.As(err, &packageErr) || packageErr.Stage != PackageStageManifest {
		t.Fatalf("package error = %#v, want manifest stage", packageErr)
	}
	if _, statErr := os.Stat(destination); !os.IsNotExist(statErr) {
		t.Fatalf("oversized manifest left staging, stat error = %v", statErr)
	}
}

func verifiedExpectation(t *testing.T, archivePath, version, entrypoint string) PackageExpectation {
	t.Helper()
	document, err := os.ReadFile(archivePath)
	if err != nil {
		t.Fatalf("read archive: %v", err)
	}
	hash := sha256.Sum256(document)
	return PackageExpectation{
		Size:   int64(len(document)),
		SHA256: hex.EncodeToString(hash[:]),
		App: AppExpectation{
			ID:            "test-app",
			Version:       version,
			Channel:       "stable",
			MinOS:         "windows-10",
			Architecture:  "amd64",
			Entrypoint:    entrypoint,
			RequiresAdmin: false,
		},
	}
}

func validAppManifest(version, entrypoint 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":"` + entrypoint + `","working_directory":".","product_id":"test-product","supports_trial":false,"requires_admin":false,"data_policy":"local-app-data","update_policy":"managed-by-softbox"}`)
}