feat(i18n): Add runtime language packs and language switching (#1)

2026-10-20 09:46:47 +08:00
parent 39ed6d7bba
commit 6d48d7f852
52 changed files with 3119 additions and 968 deletions
@@ -1,5 +1,4 @@
-// 三點對齊剛體變換數學驗證：
-// (1) 已知變換還原 (2) Matrix3D ↔ ModOp 兩種表示一致 (3) 共線拒絕
+// Three-point alignment checks: known transform, Matrix3D/ModOp agreement, and collinear rejection.
 using System.Windows.Media.Media3D;
 using STPViewer.Services;

@@ -11,29 +10,29 @@ internal static class AlignTest
    {
        int failures = 0;

-        // ── (1) 已知剛體變換：繞 Z 軸 90° + 平移 (5,-3,2)，三點求解後應還原同一變換 ──
+        // Recover a known 90-degree Z rotation followed by translation (5,-3,2).
        var truth = Matrix3D.Identity;
        truth.RotateAt(new Quaternion(new Vector3D(0, 0, 1), 90), new Point3D(2, 1, 0));
        truth.Translate(new Vector3D(5, -3, 2));

        var p1 = new Point3D(0, 0, 0);
        var p2 = new Point3D(10, 0, 0);
-        var p3 = new Point3D(0, 7, 3);  // 不共線、不在同平面軸上
+        var p3 = new Point3D(0, 7, 3);  // Not collinear with the first two points.
        Point3D q1 = truth.Transform(p1), q2 = truth.Transform(p2), q3 = truth.Transform(p3);

        bool ok = RigidAlign.TryRigidTransform(p1, p2, p3, q1, q2, q3, out Matrix3D m);
-        failures += Check("三點求解成功", ok, true);
+        failures += Check("three-point transform solved", ok, true);

-        // 三個對應點要精確貼合
+        // Corresponding points must coincide.
        failures += CheckPoint("p1→q1", m.Transform(p1), q1);
        failures += CheckPoint("p2→q2", m.Transform(p2), q2);
        failures += CheckPoint("p3→q3", m.Transform(p3), q3);

-        // 剛體變換唯一性：任意第 4 點也應該跟著正確變換
+        // An independent fourth point checks the full rigid transform.
        var r = new Point3D(-4, 12, 8);
-        failures += CheckPoint("任意第4點", m.Transform(r), truth.Transform(r));
+        failures += CheckPoint("fourth point", m.Transform(r), truth.Transform(r));

-        // ── (2) ToModOp：CADability ModOp 與 WPF Matrix3D 對同一點要算出同樣結果 ──
+        // CADability ModOp and WPF Matrix3D must transform points identically.
        CADability.ModOp op = RigidAlign.ToModOp(m);
        foreach (Point3D p in new[] { p1, p2, p3, r, new Point3D(1.5, -2.25, 9) })
        {
@@ -42,28 +41,28 @@ internal static class AlignTest
            bool same = Dist(new Point3D(gp.x, gp.y, gp.z), wpf) < 1e-9;
            if (!same)
            {
-                System.Console.WriteLine($"  FAIL: ModOp/Matrix3D 不一致 @ ({p.X},{p.Y},{p.Z})");
+                System.Console.WriteLine($"  FAIL: ModOp/Matrix3D mismatch at ({p.X},{p.Y},{p.Z})");
                failures++;
            }
        }
-        System.Console.WriteLine($"  {(failures == 0 ? "PASS" : "----")}: ModOp ↔ Matrix3D 一致（5 個測試點）");
+        System.Console.WriteLine($"  {(failures == 0 ? "PASS" : "----")}: ModOp/Matrix3D agree at five points");

-        // ── (3) 共線拒絕 ──
+        // Collinear source points must be rejected.
        bool collinearRejected = !RigidAlign.TryRigidTransform(
-            new Point3D(0, 0, 0), new Point3D(1, 0, 0), new Point3D(2, 0, 0), // 共線
+            new Point3D(0, 0, 0), new Point3D(1, 0, 0), new Point3D(2, 0, 0), // Collinear.
            q1, q2, q3, out _);
-        failures += Check("來源共線 → 拒絕", collinearRejected, true);
-        failures += Check("Collinear 判定", RigidAlign.Collinear(
+        failures += Check("collinear source rejected", collinearRejected, true);
+        failures += Check("collinearity detection", RigidAlign.Collinear(
            new Point3D(0, 0, 0), new Point3D(1, 1, 1), new Point3D(3, 3, 3)), true);

-        System.Console.WriteLine(failures == 0 ? "AlignTest: 全部通過" : $"AlignTest: {failures} 項失敗");
+        System.Console.WriteLine(failures == 0 ? "AlignTest: all passed" : $"AlignTest: {failures} failed");
        return failures;
    }

    private static int Check(string name, bool actual, bool expected)
    {
        bool ok = actual == expected;
-        System.Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name}（{actual}）");
+        System.Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name} ({actual})");
        return ok ? 0 : 1;
    }

@@ -71,7 +70,7 @@ internal static class AlignTest
    {
        double d = Dist(actual, expected);
        bool ok = d < 1e-9;
-        System.Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name} 誤差 {d:E2}");
+        System.Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name} error {d:E2}");
        return ok ? 0 : 1;
    }

@@ -1,4 +1,4 @@
-// 剖面裁切數學驗證：對單位幾何裁切，檢查保留側與面積守恆
+// Section clipping checks the retained side and triangle area.
 using System.Windows.Media;
 using System.Windows.Media.Media3D;
 using STPViewer.Services;
@@ -11,7 +11,7 @@ internal static class ClipTest
    {
        int failures = 0;

-        // 單一三角形 (0,0,0)(10,0,0)(0,10,0)，面積 50
+        // A single triangle with area 50.
        var mesh = new MeshGeometry3D
        {
            Positions = new Point3DCollection
@@ -22,38 +22,38 @@ internal static class ClipTest
        };
        mesh.Freeze();

-        // case 1: 平面 x=20，全保留
+        // A plane at x=20 retains the full triangle.
        var m1 = SectionService.ClipMesh(mesh, new Point3D(20, 0, 0), new Vector3D(1, 0, 0));
-        failures += Check("全保留", Area(m1), 50.0);
+        failures += Check("fully retained", Area(m1), 50.0);

-        // case 2: 平面 x=-1，全裁掉
+        // A plane at x=-1 removes the full triangle.
        var m2 = SectionService.ClipMesh(mesh, new Point3D(-1, 0, 0), new Vector3D(1, 0, 0));
-        failures += Check("全裁掉", Area(m2), 0.0);
+        failures += Check("fully removed", Area(m2), 0.0);

-        // case 3: 平面 x=5 → 保留 x≤5：梯形面積 = 50 - 右側小三角形(底5高5)/2 = 50 - 12.5 = 37.5
+        // At x=5, the retained trapezoid has area 50 - 12.5 = 37.5.
        var m3 = SectionService.ClipMesh(mesh, new Point3D(5, 0, 0), new Vector3D(1, 0, 0));
-        failures += Check("半裁(x≤5)", Area(m3), 37.5);
+        failures += Check("half clipped (x<=5)", Area(m3), 37.5);
        foreach (Point3D p in m3.Positions)
-            if (p.X > 5 + 1e-9) { Console.WriteLine($"  FAIL: 頂點 x={p.X} 超出保留側"); failures++; }
+            if (p.X > 5 + 1e-9) { Console.WriteLine($"  FAIL: vertex x={p.X} is outside retained side"); failures++; }

-        // case 4: 反向（保留 x≥5）→ 12.5
+        // Reverse the plane normal to retain the smaller triangle.
        var m4 = SectionService.ClipMesh(mesh, new Point3D(5, 0, 0), new Vector3D(-1, 0, 0));
-        failures += Check("半裁(x≥5)", Area(m4), 12.5);
+        failures += Check("half clipped (x>=5)", Area(m4), 12.5);

-        // case 5: 線段裁切
+        // Clip a line segment.
        var segs = new Point3DCollection { new(0, 0, 0), new(10, 0, 0) };
        Point3DCollection s1 = SectionService.ClipSegments(segs, new Point3D(4, 0, 0), new Vector3D(1, 0, 0));
        double segLen = s1.Count == 2 ? (s1[1] - s1[0]).Length : -1;
-        failures += Check("線段裁切長度", segLen, 4.0);
+        failures += Check("clipped segment length", segLen, 4.0);

-        Console.WriteLine(failures == 0 ? "ClipTest: 全部通過" : $"ClipTest: {failures} 項失敗");
+        Console.WriteLine(failures == 0 ? "ClipTest: all passed" : $"ClipTest: {failures} failed");
        return failures;
    }

    private static int Check(string name, double actual, double expected)
    {
        bool ok = Math.Abs(actual - expected) < 1e-9;
-        Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name} = {actual}（期望 {expected}）");
+        Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name} = {actual} (expected {expected})");
        return ok ? 0 : 1;
    }

@@ -5,13 +5,13 @@ using System.Linq;
 using CADability;
 using CADability.GeoObject;
 using STPViewer.Services;
-using IOPath = System.IO.Path; // CADability.GeoObject.Path（曲線）撞名
+using IOPath = System.IO.Path; // Avoid the CADability.GeoObject.Path name collision.

 namespace SmokeTest;

 /// <summary>
-/// STEP 匯出往返驗證（v0.5.0 匯出 STEP 功能的無 UI 驗證）：
-/// 匯入來源 STEP → 走與 MainViewModel.ExportStepFile 相同路徑寫出新檔 → 重新匯入比對實體數。
+/// Headless STEP export round trip: import, export through the same CADability path,
+/// then import the result and compare solid counts.
 /// </summary>
 public static class ExportTest
 {
@@ -20,26 +20,26 @@ public static class ExportTest
        Console.WriteLine($"=== ExportTest: {IOPath.GetFileName(sourcePath)} → {IOPath.GetFileName(outPath)} ===");
        ImportedFileData data = new StepImportService().Import(sourcePath);
        var geos = Collect(data.Root).Where(g => g is Solid or Shell).ToList();
-        Console.WriteLine($"  來源 Solid/Shell 物件 = {geos.Count}（Solids = {data.Root.SolidCount}）");
+        Console.WriteLine($"  Source Solid/Shell objects = {geos.Count} (solids = {data.Root.SolidCount})");

        Project project = Project.CreateSimpleProject();
        Model model = project.GetActiveModel();
        foreach (IGeoObject g in geos) model.Add(g);
        new ExportStep().WriteToFile(outPath, project);
        var fi = new FileInfo(outPath);
-        Console.WriteLine($"  已寫出（{fi.Length:N0} bytes）");
+        Console.WriteLine($"  Written ({fi.Length:N0} bytes)");
        if (fi.Length < 100)
        {
-            Console.WriteLine("ExportTest: FAIL（輸出檔近乎空白）");
+            Console.WriteLine("ExportTest: FAIL (output is nearly empty)");
            return 1;
        }

        ImportedFileData back = new StepImportService().Import(outPath);
-        Console.WriteLine($"  回讀 Solids = {back.Root.SolidCount}, Faces = {back.Root.FaceCount}");
+        Console.WriteLine($"  Reimported solids = {back.Root.SolidCount}, faces = {back.Root.FaceCount}");
        bool ok = back.Root.SolidCount == data.Root.SolidCount && back.Root.FaceCount > 0;
        Console.WriteLine(ok
-            ? "ExportTest: PASS（實體數一致）"
-            : $"ExportTest: FAIL（來源 Solids {data.Root.SolidCount} ↔ 回讀 {back.Root.SolidCount}）");
+            ? "ExportTest: PASS (solid counts match)"
+            : $"ExportTest: FAIL (source solids {data.Root.SolidCount} vs reimported {back.Root.SolidCount})");
        return ok ? 0 : 1;
    }

@@ -1,4 +1,4 @@
-// 干涉檢查數學驗證：相交 / 分離 / 貼合三種情境
+// Interference checks for intersecting, separated, and touching meshes.
 using System.Windows.Media;
 using System.Windows.Media.Media3D;
 using STPViewer.Services;
@@ -11,41 +11,41 @@ internal static class InterferenceTest
    {
        int failures = 0;

-        // 兩個互穿的四面體（B 比 A 平移 +5，邊長 10 → 必相交）
+        // Two tetrahedra overlap when B is offset by 5 along X.
        MeshGeometry3D a = Tetra(new Vector3D(0, 0, 0));
        MeshGeometry3D b = Tetra(new Vector3D(5, 0, 0));
        InterferenceResult r1 = InterferenceService.Check(new[] { a }, new[] { b });
-        failures += Check("互穿 → 相交", r1.Intersects, true);
-        failures += Check("互穿 → 有交線段", r1.Segments.Count > 0, true);
+        failures += Check("overlap intersects", r1.Intersects, true);
+        failures += Check("overlap has intersection segments", r1.Segments.Count > 0, true);

-        // 分離（B 平移 +30，gap 應 ≈ 30 - 10 = 20）
+        // B at X=30 leaves a gap of about 20.
        MeshGeometry3D c = Tetra(new Vector3D(30, 0, 0));
        InterferenceResult r2 = InterferenceService.Check(new[] { a }, new[] { c });
-        failures += Check("分離 → 不相交", r2.Intersects, false);
+        failures += Check("separated meshes do not intersect", r2.Intersects, false);
        bool gapOk = Math.Abs(r2.GapDistance - 20.0) < 0.01;
-        Console.WriteLine($"  {(gapOk ? "PASS" : "FAIL")}: 分離 gap = {r2.GapDistance:F4}（期望 ≈ 20）");
+        Console.WriteLine($"  {(gapOk ? "PASS" : "FAIL")}: separated gap = {r2.GapDistance:F4} (expected ~20)");
        if (!gapOk) failures++;

-        // 貼合（B 平移 +10，頂點剛好接觸 → 不算穿透、gap ≈ 0）
+        // B at X=10 touches a vertex without penetrating A.
        MeshGeometry3D d = Tetra(new Vector3D(10, 0, 0));
        InterferenceResult r3 = InterferenceService.Check(new[] { a }, new[] { d });
-        failures += Check("貼合 → 不算穿透", r3.Intersects, false);
+        failures += Check("touching is not penetration", r3.Intersects, false);
        bool touchOk = r3.GapDistance < 0.01;
-        Console.WriteLine($"  {(touchOk ? "PASS" : "FAIL")}: 貼合 gap = {r3.GapDistance:F6}（期望 ≈ 0）");
+        Console.WriteLine($"  {(touchOk ? "PASS" : "FAIL")}: touching gap = {r3.GapDistance:F6} (expected ~0)");
        if (!touchOk) failures++;

-        Console.WriteLine(failures == 0 ? "InterferenceTest: 全部通過" : $"InterferenceTest: {failures} 項失敗");
+        Console.WriteLine(failures == 0 ? "InterferenceTest: all passed" : $"InterferenceTest: {failures} failed");
        return failures;
    }

    private static int Check(string name, bool actual, bool expected)
    {
        bool ok = actual == expected;
-        Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name}（{actual}）");
+        Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name} ({actual})");
        return ok ? 0 : 1;
    }

-    /// <summary>邊長 10 的四面體，offset 平移</summary>
+    /// <summary>A tetrahedron with side length 10, translated by offset.</summary>
    private static MeshGeometry3D Tetra(Vector3D offset)
    {
        Point3D P(double x, double y, double z) => new Point3D(x, y, z) + offset;
@@ -0,0 +1,313 @@
+using System.ComponentModel;
+using System.Globalization;
+using System.IO;
+using System.Reflection;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+using System.Windows.Media.Media3D;
+using CADability.GeoObject;
+using STPViewer.Models;
+using STPViewer.Services;
+using STPViewer.ViewModels;
+using IOPath = System.IO.Path;
+
+namespace SmokeTest;
+
+internal static class LocalizationTest
+{
+    private static readonly Regex FormatIndex = new(@"(?<!\{)\{(\d+)(?:[^{}]*)\}(?!\})", RegexOptions.Compiled);
+
+    public static int Run()
+    {
+        int failures = 0;
+        Exception? error = null;
+        var thread = new Thread(() =>
+        {
+            try { failures = RunCore(); }
+            catch (Exception ex) { error = ex; }
+        });
+        thread.SetApartmentState(ApartmentState.STA);
+        thread.Start();
+        thread.Join();
+        if (error is not null)
+        {
+            Console.WriteLine($"LocalizationTest: {error}");
+            return 1;
+        }
+        return failures;
+    }
+
+    private static int RunCore()
+    {
+        int failures = CheckTemporaryPacks() + CheckBundledPacks() + CheckViewModel() + CheckSettings();
+        Console.WriteLine(failures == 0 ? "LocalizationTest: all passed" : $"LocalizationTest: {failures} failed");
+        return failures;
+    }
+
+    private static int CheckTemporaryPacks()
+    {
+        int failures = 0;
+        string directory = IOPath.Combine(IOPath.GetTempPath(), "stpviewer_i18n_" + Guid.NewGuid().ToString("N"));
+        try
+        {
+            failures += Check("missing directory loads without languages", new LocalizationService(directory).Languages.Count == 0);
+            Directory.CreateDirectory(directory);
+            failures += Check("empty directory loads without languages", new LocalizationService(directory).Languages.Count == 0);
+            WritePack(directory, "en", "English", new()
+            {
+                ["Ui.Sample"] = "View", ["Ui.Fallback"] = "Fallback {0}",
+                ["Ui.BadBrace"] = "English {0}", ["Ui.BadIndex"] = "English {0}",
+                ["Ui.BothBad"] = "English {"
+            });
+            WritePack(directory, "zh_cn", "Simplified", new()
+            {
+                ["Ui.Sample"] = "CN_VIEW", ["Ui.BadBrace"] = "Chinese {",
+                ["Ui.BadIndex"] = "Chinese {1}", ["Ui.BothBad"] = "Chinese {"
+            });
+            WritePack(directory, "zh_tw", "Traditional", new() { ["Ui.Sample"] = "TW_VIEW" });
+            WritePack(directory, "pirate_dialect", "Pirate", new() { ["Ui.Sample"] = "ARR_VIEW" });
+            File.WriteAllText(IOPath.Combine(directory, "broken.json"), "{invalid json");
+            File.WriteAllText(IOPath.Combine(directory, "no_key.json"), "{\"data\":{\"Ui.Sample\":\"unused\"}}");
+            File.WriteAllText(IOPath.Combine(directory, "no_data.json"), "{\"key\":\"Missing data\"}");
+            File.WriteAllText(IOPath.Combine(directory, "non_string.json"), "{\"key\":\"Invalid\",\"data\":{\"Ui.Sample\":42}}");
+
+            CultureInfo oldUi = CultureInfo.CurrentUICulture;
+            LocalizationService service;
+            try
+            {
+                CultureInfo.CurrentUICulture = CultureInfo.GetCultureInfo("en-US");
+                service = new LocalizationService(directory);
+            }
+            finally { CultureInfo.CurrentUICulture = oldUi; }
+
+            failures += Check("valid packs isolated from malformed files", service.Languages.Count == 4 &&
+                service.Languages.Select(l => l.Id).Order().SequenceEqual(new[] { "en", "pirate_dialect", "zh_cn", "zh_tw" }));
+            failures += Check("display names and data loaded", service.Languages.Any(l =>
+                l.Id == "pirate_dialect" && l.Key == "Pirate" && l.Data["Ui.Sample"] == "ARR_VIEW"));
+            failures += Check("English selected from system culture", service.Language == "en");
+            failures += Check("legacy Chinese IDs resolved", service.ResolveLanguage("zh-CN") == "zh_cn" &&
+                service.ResolveLanguage("zh-TW") == "zh_tw");
+            failures += Check("Chinese script and region aliases resolved", service.ResolveLanguage("zh-Hans") == "zh_cn" &&
+                service.ResolveLanguage("zh-SG") == "zh_cn" && service.ResolveLanguage("zh-Hant") == "zh_tw" &&
+                service.ResolveLanguage("zh-HK") == "zh_tw" && service.ResolveLanguage("zh-MO") == "zh_tw");
+            failures += Check("custom language ID resolved", service.ResolveLanguage("pirate-dialect") == "pirate_dialect");
+            failures += Check("unknown language falls back", service.ResolveLanguage("unknown") == "en");
+            failures += Check("invalid custom ID falls back", service.ResolveLanguage("pirate_other") == "en");
+
+            CultureInfo beforeNull = CultureInfo.CurrentUICulture;
+            try
+            {
+                CultureInfo.CurrentUICulture = CultureInfo.GetCultureInfo("zh-HK");
+                failures += Check("null language uses system UI culture", service.ResolveLanguage(null) == "zh_tw");
+            }
+            finally { CultureInfo.CurrentUICulture = beforeNull; }
+
+            LanguageDefinition chinese = service.Languages.Single(l => l.Id == "zh_cn");
+            bool selectedNotified = false, indexerNotified = false;
+            chinese.PropertyChanged += (_, e) => selectedNotified |= e.PropertyName == nameof(LanguageDefinition.IsSelected);
+            ((INotifyPropertyChanged)service).PropertyChanged += (_, e) => indexerNotified |= e.PropertyName == "Item[]";
+            service.SetLanguage("zh-CN");
+            failures += Check("selection and indexer notify", service.Language == "zh_cn" &&
+                chinese.IsSelected && selectedNotified && indexerNotified);
+            failures += Check("selected data and fallback", service["Ui.Sample"] == "CN_VIEW" &&
+                service["Ui.Fallback"] == "Fallback {0}" && service["Ui.Missing"] == "Ui.Missing");
+            failures += Check("malformed brace uses English format", service.FormatText("Ui.BadBrace", "value") == "English value");
+            failures += Check("missing format argument uses English format", service.FormatText("Ui.BadIndex", "value") == "English value");
+            failures += Check("invalid English format returns key", service.FormatText("Ui.BothBad", "value") == "Ui.BothBad");
+            service.SetLanguage("pirate_dialect");
+            failures += Check("custom language selected", service.Language == "pirate_dialect" &&
+                service["Ui.Sample"] == "ARR_VIEW");
+
+            WritePack(directory, "new_language", "New language", new() { ["Ui.Sample"] = "NEW_VIEW" });
+            WritePack(directory, "en", "English", new() { ["Ui.Sample"] = "Updated view", ["Ui.Fallback"] = "Fallback {0}" });
+            failures += Check("existing instance does not hot reload", service.Languages.Count == 4 &&
+                service.Languages.Single(l => l.Id == "en").Data["Ui.Sample"] == "View");
+            var reloaded = new LocalizationService(directory);
+            failures += Check("new instance rescans files and values", reloaded.Languages.Count == 5 &&
+                reloaded.Languages.Single(l => l.Id == "en").Data["Ui.Sample"] == "Updated view");
+
+            File.Delete(IOPath.Combine(directory, "zh_tw.json"));
+            var withoutTraditional = new LocalizationService(directory);
+            failures += Check("missing language not listed", withoutTraditional.Languages.All(l => l.Id != "zh_tw"));
+            failures += Check("missing legacy ID falls back", withoutTraditional.ResolveLanguage("zh-TW") == "en");
+        }
+        finally
+        {
+            if (Directory.Exists(directory)) Directory.Delete(directory, recursive: true);
+        }
+        return failures;
+    }
+
+    private static void WritePack(string directory, string id, string name, Dictionary<string, string> data) =>
+        File.WriteAllText(IOPath.Combine(directory, id + ".json"), JsonSerializer.Serialize(new { key = name, data }));
+
+    private static int CheckBundledPacks()
+    {
+        int failures = 0;
+        LocalizationService service = LocalizationService.Instance;
+        failures += Check("bundled languages available", new[] { "en", "zh_cn", "zh_tw" }
+            .All(id => service.Languages.Any(l => l.Id == id)));
+        LanguageDefinition? english = service.Languages.FirstOrDefault(l => l.Id == "en");
+        if (english is null) return failures;
+        failures += Check("bundled English data nonempty", english.Data.Count > 0 &&
+            english.Data.Values.All(v => !string.IsNullOrWhiteSpace(v)));
+        int formatFailures = 0;
+        foreach (LanguageDefinition language in service.Languages)
+            foreach ((string key, string value) in language.Data)
+            {
+                if (string.IsNullOrWhiteSpace(value)) formatFailures++;
+                int[] indices = Indices(value);
+                if (english.Data.TryGetValue(key, out string? fallback) && !Indices(fallback).SequenceEqual(indices))
+                {
+                    Console.WriteLine($"  FAIL: {language.Id} format arguments differ for {key}");
+                    formatFailures++;
+                }
+                object[] args = Enumerable.Range(0, indices.DefaultIfEmpty(-1).Max() + 1)
+                    .Select(i => (object)i).ToArray();
+                try { _ = string.Format(CultureInfo.InvariantCulture, value, args); }
+                catch (FormatException)
+                {
+                    Console.WriteLine($"  FAIL: {language.Id} format syntax for {key}");
+                    formatFailures++;
+                }
+            }
+        failures += Check("bundled data and format strings valid", formatFailures == 0);
+        failures += Check("missing key returns key", service["__missing_localization_key__"] == "__missing_localization_key__");
+        return failures;
+    }
+
+    private static int CheckViewModel()
+    {
+        int failures = 0;
+        LocalizationService service = LocalizationService.Instance;
+        string originalLanguage = service.Language;
+        CultureInfo numericCulture = CultureInfo.CurrentCulture;
+        try
+        {
+            service.SetLanguage("en");
+            var vm = new MainViewModel();
+            vm.InitializeLocalization();
+            try
+            {
+                string oldLabel = vm.QuickBar["Import"].Label;
+                bool labelChanged = false;
+                vm.QuickBar["Import"].PropertyChanged += (_, e) =>
+                    labelChanged |= e.PropertyName == nameof(QuickBarItemViewModel.Label);
+
+                MeasurementResult result = new MeasurementService().MeasureDistance(
+                    new Point3D(0, 0, 0), new Point3D(25.4, 0, 0), "D1", 0.2);
+                vm.Measurements.Add(result);
+                vm.UseInch = true;
+                string oneInch = 1d.ToString("F4", numericCulture) + " in";
+                string beforeTitle = result.Title, beforeDetail = result.Detail;
+                string beforeLabel = result.DynamicLabels.Single().Label.Text;
+                var (distanceLabel, distanceTextFor) = result.DynamicLabels.Single();
+                int labelRefreshes = 0;
+                result.DynamicLabels[0] = (distanceLabel, u =>
+                {
+                    labelRefreshes++;
+                    return distanceTextFor(u);
+                });
+                bool titleChanged = false, detailChanged = false;
+                result.PropertyChanged += (_, e) =>
+                {
+                    titleChanged |= e.PropertyName == nameof(MeasurementResult.Title);
+                    detailChanged |= e.PropertyName == nameof(MeasurementResult.Detail);
+                };
+
+                vm.ChangeLanguageCommand.Execute("zh_tw");
+                failures += Check("VM selects language", service.Language == "zh_tw" &&
+                    service.Languages.Single(l => l.Id == "zh_tw").IsSelected);
+                failures += Check("existing distance detail translated", beforeDetail != result.Detail &&
+                    titleChanged && detailChanged && result.Detail.Contains(oneInch, StringComparison.Ordinal));
+                failures += Check("distance and number culture preserved", vm.UseInch &&
+                    CultureInfo.CurrentCulture.Equals(numericCulture) && beforeTitle == result.Title &&
+                    result.Title.Contains(oneInch, StringComparison.Ordinal));
+                failures += Check("3D distance label refreshed", labelRefreshes == 1 &&
+                    beforeLabel == oneInch && result.DynamicLabels.Single().Label.Text == beforeLabel);
+                failures += Check("quick bar label refreshed", labelChanged && vm.QuickBar["Import"].Label != oldLabel);
+
+                LanguageDefinition selected = service.Languages.Single(l => l.Id == "zh_tw");
+                bool reselected = false;
+                selected.PropertyChanged += (_, e) => reselected |= e.PropertyName == nameof(LanguageDefinition.IsSelected);
+                vm.ChangeLanguageCommand.Execute("zh_tw");
+                failures += Check("reselecting current language restores check", reselected && selected.IsSelected);
+            }
+            finally { vm.DisposeLocalization(); }
+            failures += CheckImportedNames(service);
+        }
+        finally { service.SetLanguage(originalLanguage); }
+        return failures;
+    }
+
+    private static int CheckImportedNames(LocalizationService service)
+    {
+        int failures = 0;
+        MethodInfo blockNode = typeof(StepImportService).GetMethod("BlockNode", BindingFlags.NonPublic | BindingFlags.Instance)!;
+        var importer = new StepImportService();
+        service.SetLanguage("en");
+
+        ImportedNode Import(Block block) => (ImportedNode)blockNode.Invoke(importer, [block])!;
+        var namedSolidBlock = Block.Construct();
+        namedSolidBlock.Name = "Solid";
+        namedSolidBlock.Add(Solid.Construct());
+        ImportedNode namedSolid = Import(namedSolidBlock);
+        var namedShellBlock = Block.Construct();
+        namedShellBlock.Name = "Shell";
+        namedShellBlock.Add(Shell.Construct());
+        ImportedNode namedShell = Import(namedShellBlock);
+        var defaultSolidBlock = Block.Construct();
+        defaultSolidBlock.Add(Solid.Construct());
+        ImportedNode defaultSolid = Import(defaultSolidBlock);
+        var defaultShellBlock = Block.Construct();
+        defaultShellBlock.Add(Shell.Construct());
+        ImportedNode defaultShellLeaf = Import(defaultShellBlock).Children.Single();
+        var collisionBlock = Block.Construct();
+        var realComponentShell = Shell.Construct();
+        realComponentShell.Name = "Component";
+        collisionBlock.Add(realComponentShell);
+        ImportedNode collision = Import(collisionBlock);
+
+        ModelNodeViewModel ViewModel(ImportedNode node) => new(0)
+        {
+            Name = node.Name,
+            NameKey = node.NameKey,
+            NameNumber = node.NameNumber
+        };
+        var namedSolidVm = ViewModel(namedSolid);
+        var namedShellVm = ViewModel(namedShell);
+        var defaultSolidVm = ViewModel(defaultSolid);
+        var defaultShellVm = ViewModel(defaultShellLeaf);
+        var collisionVm = ViewModel(collision);
+        service.SetLanguage("zh_cn");
+        failures += Check("explicit solid name retained", namedSolid.NameKey is null && namedSolidVm.Name == "Solid");
+        failures += Check("real block name retained", namedShell.NameKey is null && namedShellVm.Name == "Shell");
+        failures += Check("default solid name translated", defaultSolid.NameKey == "Runtime.SolidName" &&
+            defaultSolidVm.Name == service["Runtime.SolidName"]);
+        failures += Check("default shell name translated", defaultShellLeaf.NameKey == "Runtime.ShellName" &&
+            defaultShellVm.Name == service["Runtime.ShellName"]);
+        failures += Check("real child name wins collision", collision.NameKey is null && collisionVm.Name == "Component");
+        return failures;
+    }
+
+    private static int CheckSettings()
+    {
+        var settings = new AppSettings
+        {
+            Language = "zh-CN", WindowWidth = 1200, WindowHeight = 800, WindowLeft = 100, WindowTop = 100
+        };
+        AppSettings? restored = JsonSerializer.Deserialize<AppSettings>(JsonSerializer.Serialize(settings));
+        return Check("legacy ID round trips through settings JSON", restored?.Language == "zh-CN" &&
+            LocalizationService.Instance.ResolveLanguage(restored.Language) == "zh_cn");
+    }
+
+    private static int[] Indices(string format) => FormatIndex.Matches(format)
+        .Select(m => int.Parse(m.Groups[1].Value, CultureInfo.InvariantCulture))
+        .Distinct().Order().ToArray();
+
+    private static int Check(string name, bool ok)
+    {
+        Console.WriteLine($"  {(ok ? "PASS" : "FAIL")}: {name}");
+        return ok ? 0 : 1;
+    }
+}
@@ -1,4 +1,4 @@
-// 測試輔助：用 CADability 內嵌的 netDxf 產生標準 DXF 測試檔
+// Generate a small standard DXF test file with the bundled netDxf library.
 using netDxf;
 using netDxf.Entities;

@@ -12,6 +12,6 @@ internal static class MakeDxf
        doc.Entities.Add(new Line(new Vector3(0, 0, 0), new Vector3(100, 50, 0)));
        doc.Entities.Add(new Circle(new Vector3(50, 25, 0), 10));
        doc.Save(path);
-        Console.WriteLine($"已產生 {path}");
+        Console.WriteLine($"Generated {path}");
    }
 }
@@ -2,12 +2,12 @@ using System.IO;

 namespace SmokeTest;

-/// <summary>產生測試用 binary STL：一片 gridN×gridN 的網格，每格 2 個三角形（波浪起伏，避免全共面）。</summary>
+/// <summary>Generate a binary STL grid with two triangles per cell and noncoplanar vertices.</summary>
 internal static class MakeStl
 {
    public static void Run(string path, int triCount)
    {
-        // 每格 2 三角，格數 = triCount/2；邊長 grid = ceil(sqrt(cells))
+        // Two triangles per cell; use a square grid large enough for the requested count.
        int cells = System.Math.Max(1, triCount / 2);
        int grid = (int)System.Math.Ceiling(System.Math.Sqrt(cells));
        int tris = grid * grid * 2;
@@ -36,6 +36,6 @@ internal static class MakeStl
                WriteTri(bw, x0, y0, Z(x, y), x1, y1, Z(x + 1, y + 1), x0, y1, Z(x, y + 1));
            }

-        Console.WriteLine($"寫出 {tris:N0} 三角形 → {path} ({new FileInfo(path).Length:N0} bytes)");
+        Console.WriteLine($"Wrote {tris:N0} triangles to {path} ({new FileInfo(path).Length:N0} bytes)");
    }
 }
@@ -1,4 +1,4 @@
-// 無 UI smoke test：驗證 CAD 檔解析 → 三角化 → 裝配樹 整條匯入管線
+// Headless smoke tests for CAD import, triangulation, and the assembly tree.
 using System.Diagnostics;
 using System.IO;
 using STPViewer.Services;
@@ -7,7 +7,7 @@ Console.OutputEncoding = System.Text.Encoding.UTF8;

 if (args.Length == 0)
 {
-    Console.WriteLine("用法: SmokeTest [--tree] <file.stp|.stl|.dxf> [...]");
+    Console.WriteLine("Usage: SmokeTest [--tree] <file.stp|.stl|.dxf> [...]");
    return 1;
 }

@@ -38,6 +38,9 @@ if (args[0] == "--interference-test")
 if (args[0] == "--align-test")
    return SmokeTest.AlignTest.Run() == 0 ? 0 : 2;

+if (args[0] == "--localization-test")
+    return SmokeTest.LocalizationTest.Run() == 0 ? 0 : 2;
+
 if (args[0] == "--bbox")
    return SmokeTest.BBoxDump.Run(args[1]);

@@ -47,7 +50,7 @@ if (args[0] == "--export-test")
 if (args[0] == "--stl-export-test")
    return SmokeTest.StlExportTest.Run(args.Length > 1 ? args[1] : null) == 0 ? 0 : 2;

-var service = new StepImportService { Progress = s => Console.WriteLine($"  [階段] {s}") };
+var service = new StepImportService { Progress = s => Console.WriteLine($"  [stage] {s}") };
 int failed = 0;

 foreach (string path in args)
@@ -64,7 +67,7 @@ foreach (string path in args)
        Console.WriteLine($"  Triangles : {r.TriangleCount:N0}");
        Console.WriteLine($"  Bounds    : {r.Bounds.SizeX:F2} x {r.Bounds.SizeY:F2} x {r.Bounds.SizeZ:F2} mm");
        Console.WriteLine($"  Time      : {sw.ElapsedMilliseconds} ms");
-        Console.WriteLine("  --- 裝配樹 ---");
+        Console.WriteLine("  --- assembly tree ---");
        PrintNode(r, 1);
    }
    catch (Exception ex)
@@ -81,6 +84,6 @@ static void PrintNode(ImportedNode n, int indent)
 {
    string seg = n.EdgeSegments is null ? "" : $", edgeSegs={n.EdgeSegments.Count / 2:N0}";
    Console.WriteLine($"{new string(' ', indent * 2)}{n.Name}  " +
-        $"[solids={n.SolidCount}, faces={n.FaceCount}, tris={n.TriangleCount:N0}{seg}{(n.HasBrep ? "" : ", 無B-rep")}]");
+        $"[solids={n.SolidCount}, faces={n.FaceCount}, tris={n.TriangleCount:N0}{seg}{(n.HasBrep ? "" : ", no B-rep")}]");
    foreach (ImportedNode c in n.Children) PrintNode(c, indent + 1);
 }
@@ -5,15 +5,13 @@ using System.Text;
 using System.Windows.Media;
 using System.Windows.Media.Media3D;
 using STPViewer.Services;
-using IOPath = System.IO.Path; // CADability.GeoObject.Path（曲線）撞名
+using IOPath = System.IO.Path; // Avoid the CADability.GeoObject.Path name collision.

 namespace SmokeTest;

 /// <summary>
-/// STL 匯出驗證（無 UI）：
-/// 1) binary — 已知立方體網格寫出 → 解析 header/三角形數/座標範圍比對（含縮放）
-/// 2) ASCII — facet 數與 solid/endsolid 結構
-/// 3) 退化三角形（零面積）自動濾除
+/// Headless STL export checks:
+/// binary round trip, ASCII facet structure, and degenerate triangle filtering.
 /// </summary>
 public static class StlExportTest
 {
@@ -24,20 +22,20 @@ public static class StlExportTest
        string dir = IOPath.Combine(IOPath.GetTempPath(), "stpviewer_stl_test");
        Directory.CreateDirectory(dir);

-        MeshGeometry3D cube = BuildCube(10); // 10×10×10 mm、12 三角形
+        MeshGeometry3D cube = BuildCube(10); // 10x10x10 mm, 12 triangles.

-        // 1) binary：三角形數 + 縮放後座標範圍
+        // Binary triangle count and scaled coordinate range.
        {
            string f = IOPath.Combine(dir, "cube_bin.stl");
-            double scale = 1.0 / 25.4; // mm → inch
+            double scale = 1.0 / 25.4; // mm to inches.
            int written = StlExportService.Write(f, new[] { cube }, ascii: false, scale);
            (uint count, float min, float max) = ReadBinary(f);
            bool ok = written == 12 && count == 12
                      && Math.Abs(min - 0f) < 1e-5 && Math.Abs(max - 10f / 25.4f) < 1e-4;
-            Report(ref failed, ok, $"binary 寫出/回讀 12 三角形、inch 縮放範圍 [{min:F4}, {max:F4}]");
+            Report(ref failed, ok, $"binary round trip: 12 triangles, inch range [{min:F4}, {max:F4}]");
        }

-        // 2) ASCII：facet 數 + 結構
+        // ASCII facet count and structure.
        {
            string f = IOPath.Combine(dir, "cube_ascii.stl");
            int written = StlExportService.Write(f, new[] { cube }, ascii: true, scale: 1.0);
@@ -46,15 +44,15 @@ public static class StlExportTest
            bool ok = written == 12 && facets == 12
                      && text.StartsWith("solid ", StringComparison.Ordinal)
                      && text.Contains("endsolid");
-            Report(ref failed, ok, $"ASCII 結構完整、facet = {facets}");
+            Report(ref failed, ok, $"ASCII structure valid, facets = {facets}");
        }

-        // 3) 退化三角形濾除：加一個零面積三角形 → 仍是 12
+        // A zero-area triangle must be filtered from the export.
        {
            var degenerate = new MeshGeometry3D();
            degenerate.Positions.Add(new Point3D(0, 0, 0));
            degenerate.Positions.Add(new Point3D(1, 1, 1));
-            degenerate.Positions.Add(new Point3D(2, 2, 2)); // 共線 → 面積 0
+            degenerate.Positions.Add(new Point3D(2, 2, 2)); // Collinear: zero area.
            degenerate.TriangleIndices.Add(0);
            degenerate.TriangleIndices.Add(1);
            degenerate.TriangleIndices.Add(2);
@@ -64,17 +62,16 @@ public static class StlExportTest
            int written = StlExportService.Write(f, new[] { cube, degenerate }, ascii: false, scale: 1.0);
            (uint count, _, _) = ReadBinary(f);
            bool ok = written == 12 && count == 12;
-            Report(ref failed, ok, $"退化三角形濾除（寫出 {written}）");
+            Report(ref failed, ok, $"degenerate triangle filtered ({written} written)");
        }

-        // 4)（可選）真實 STEP：B-rep 精細重新三角化 → 寫 binary STL 驗證
-        //（不測「較粗」：CADability GetTriangulation 對比快取粗的精度回傳既有快取，粗化無效 → 功能已移除）
+        // Optional real STEP input: retessellate B-rep geometry at fine precision.
        if (stepPath is not null)
        {
            var data = new StepImportService().Import(stepPath);
            var geos = Collect(data.Root).ToList();
            int importTris = data.Root.TriangleCount;
-            Console.WriteLine($"  來源 {IOPath.GetFileName(stepPath)}：{geos.Count} 個 B-rep 物件、匯入網格 {importTris:N0} 三角形");
+            Console.WriteLine($"  Source {IOPath.GetFileName(stepPath)}: {geos.Count} B-rep objects, {importTris:N0} imported triangles");

            var meshes = StlExportService.Tessellate(
                geos, StlExportService.PrecisionFactor(StlMeshQuality.Fine));
@@ -82,13 +79,13 @@ public static class StlExportTest
            int written = StlExportService.Write(f, meshes, ascii: false, scale: 1.0);
            (uint count, _, _) = ReadBinary(f);
            Report(ref failed, meshes.Count > 0 && written > 0 && count == written,
-                $"精細重新三角化 {meshes.Count} 面 → {written:N0} 三角形");
-            // CADability 三角形數對精度非單調（0.4× 反而比 1× 少），Fine=0.15× 實測明顯更細
+                $"fine retessellation: {meshes.Count} faces, {written:N0} triangles");
+            // CADability's triangle count is not monotonic in precision; 0.15x is measurably finer.
            Report(ref failed, written > importTris,
-                $"精細（{written:N0}）> 匯入預設（{importTris:N0}）");
+                $"fine ({written:N0}) > imported default ({importTris:N0})");
        }

-        Console.WriteLine(failed == 0 ? "StlExportTest: PASS" : $"StlExportTest: FAIL（{failed} 項）");
+        Console.WriteLine(failed == 0 ? "StlExportTest: PASS" : $"StlExportTest: FAIL ({failed} checks)");
        return failed;
    }

@@ -106,7 +103,7 @@ public static class StlExportTest
        if (!ok) failed++;
    }

-    /// <summary>0..size 的軸對齊立方體，12 個三角形（法向不講究，STL 寫出時自算）</summary>
+    /// <summary>Axis-aligned cube from 0 to size, with 12 triangles.</summary>
    private static MeshGeometry3D BuildCube(double s)
    {
        var m = new MeshGeometry3D();
@@ -131,7 +128,7 @@ public static class StlExportTest
        using var br = new BinaryReader(File.OpenRead(path));
        byte[] header = br.ReadBytes(80);
        if (Encoding.ASCII.GetString(header, 0, 5) == "solid")
-            throw new InvalidDataException("binary STL header 不可以 solid 開頭");
+            throw new InvalidDataException("Binary STL header must not begin with solid");
        uint count = br.ReadUInt32();
        float min = float.MaxValue, max = float.MinValue;
        for (uint t = 0; t < count; t++)
@@ -1,4 +1,4 @@
-// 實驗工具：印出 STEP 匯入後的物件階層（HierarchyToBlocks=true）
+// Print the STEP object hierarchy after import with HierarchyToBlocks enabled.
 using CADability;
 using CADability.GeoObject;