feat: add AI retouch before-after comparison

suixinkanTests/TravelAlbumAPITests.swift

@@ -162,7 +162,7 @@ final class TravelAlbumAPITests: XCTestCase {
 
     func testAIRetouchTemplatesBuildsQueryAndDecodesGroups() async throws {
         let data = envelopeJSON(
-            #"{"refined_templates":[{"id":1,"name":"清透","preview_url":"https://cdn/refined.jpg"}],"atmosphere_templates":[{"id":2,"name":"暖阳","preview_url":"https://cdn/atmosphere.jpg"}],"cover_templates":[{"id":3,"name":"杂志","preview_url":"https://cdn/cover.jpg"}],"remaining_quota":12}"#
+            #"{"refined_templates":[{"id":1,"name":"清透","preview_url":"https://cdn/refined.jpg","before_url":"https://cdn/refined-before.jpg","after_url":"https://cdn/refined-after.jpg"}],"atmosphere_templates":[{"id":2,"name":"暖阳","preview_url":"https://cdn/atmosphere.jpg","before_url":"https://cdn/atmosphere-before.jpg","after_url":"https://cdn/atmosphere-after.jpg"}],"cover_templates":[{"id":3,"name":"杂志","preview_url":"https://cdn/cover.jpg","before_url":"https://cdn/cover-before.jpg","after_url":"https://cdn/cover-after.jpg"}],"remaining_quota":12}"#
         )
         let session = MockURLSession(responses: [data])
         let api = TravelAlbumAPI(client: APIClient(environment: .testing, session: session))
@@ -170,6 +170,8 @@ final class TravelAlbumAPITests: XCTestCase {
         let response = try await api.aiRetouchTemplates(scenicId: 18)
 
         XCTAssertEqual(response.refinedTemplates.first?.name, "清透")
+        XCTAssertEqual(response.refinedTemplates.first?.beforeURL, "https://cdn/refined-before.jpg")
+        XCTAssertEqual(response.refinedTemplates.first?.afterURL, "https://cdn/refined-after.jpg")
         XCTAssertEqual(response.atmosphereTemplates.first?.id, 2)
         XCTAssertEqual(response.coverTemplates.first?.previewURL, "https://cdn/cover.jpg")
         XCTAssertEqual(response.remainingQuota, 12)

suixinkanTests/TravelAlbumDetailViewControllerTests.swift

@@ -637,35 +637,96 @@ final class TravelAlbumDetailViewControllerTests: XCTestCase {
         XCTAssertEqual(cell.accessibilityValue, "未选择")
     }
 
-    func testAIRetouchTemplatePreviewUsesImmersiveZoomableLayout() throws {
-        let template = TravelAlbumAIRetouchTemplate(
-            id: 2,
-            name: "简约留白",
-            previewURL: ""
+    func testBeforeAfterComparisonUsesImmersiveAccessibleLayout() throws {
+        let controller = BeforeAfterComparisonViewController(
+            viewModel: BeforeAfterComparisonViewModel(
+                content: BeforeAfterComparisonContent(
+                    beforeURL: "https://cdn.example.com/before.jpg",
+                    afterURL: "https://cdn.example.com/after.jpg"
+                )
+            )
         )
-        let controller = TravelAlbumAIRetouchTemplatePreviewViewController(template: template)
         controller.loadViewIfNeeded()
         controller.view.frame = CGRect(x: 0, y: 0, width: 390, height: 844)
         controller.view.layoutIfNeeded()
 
-        let scrollView = try XCTUnwrap(
+        let imageContainer = try XCTUnwrap(
             controller.view.findSubview {
-                $0.accessibilityIdentifier == "travelAlbum.aiRetouchTemplatePreviewScrollView"
-            } as? UIScrollView
+                $0.accessibilityIdentifier == "travelAlbum.beforeAfterImageContainer"
+            }
         )
         let backButton = try XCTUnwrap(
             controller.view.findSubview {
-                $0.accessibilityIdentifier == "travelAlbum.aiRetouchTemplatePreviewBackButton"
+                $0.accessibilityIdentifier == "travelAlbum.beforeAfterBackButton"
+            } as? UIButton
+        )
+        let divider = try XCTUnwrap(
+            controller.view.findSubview {
+                $0.accessibilityIdentifier == "travelAlbum.beforeAfterDivider"
+            }
+        )
+
+        XCTAssertEqual(controller.view.backgroundColor, UIColor(hex: 0x05070D))
+        XCTAssertTrue(controller.view.allLabels().contains { $0.text == "原图" })
+        XCTAssertTrue(controller.view.allLabels().contains { $0.text == "效果图" })
+        XCTAssertEqual(imageContainer.layer.cornerRadius, 0)
+        XCTAssertTrue(divider.accessibilityTraits.contains(.adjustable))
+        XCTAssertEqual(divider.accessibilityValue, "原图占比 50%")
+        XCTAssertGreaterThanOrEqual(backButton.bounds.width, 44)
+        XCTAssertGreaterThanOrEqual(backButton.bounds.height, 44)
+    }
+
+    func testPreviewComparisonButtonOnlyShowsForSelectedAIResult() throws {
+        UIView.setAnimationsEnabled(false)
+        defer { UIView.setAnimationsEnabled(true) }
+        let project = TravelAlbumPreviewProject(
+            originalMaterialId: 7,
+            assets: [
+                TravelAlbumPreviewAsset(
+                    id: "original-7",
+                    kind: .original,
+                    fileURL: "https://cdn.example.com/original.jpg",
+                    coverURL: "",
+                    fileName: "原图.jpg",
+                    fileSize: 10
+                ),
+                TravelAlbumPreviewAsset(
+                    id: "retouched-7",
+                    kind: .retouched,
+                    fileURL: "https://cdn.example.com/retouched.jpg",
+                    coverURL: "",
+                    fileName: "精修.jpg",
+                    fileSize: 10
+                ),
+            ]
+        )
+        let controller = TravelAlbumPhotoPreviewViewController(
+            projects: [project],
+            totalCount: 1,
+            startProjectIndex: 0
+        )
+        controller.loadViewIfNeeded()
+        controller.view.frame = CGRect(x: 0, y: 0, width: 390, height: 844)
+        controller.view.layoutIfNeeded()
+        let segmentedControl = try XCTUnwrap(
+            controller.view.findSubview {
+                $0.accessibilityIdentifier == "travelAlbum.previewVariantSegmentedControl"
+            } as? UISegmentedControl
+        )
+        let comparisonButton = try XCTUnwrap(
+            controller.view.findSubview {
+                $0.accessibilityIdentifier == "travelAlbum.previewComparisonButton"
             } as? UIButton
         )
 
-        XCTAssertEqual(controller.view.backgroundColor, .black)
-        XCTAssertTrue(controller.view.allLabels().contains { $0.text == "简约留白" })
-        XCTAssertTrue(controller.view.allLabels().contains { $0.text == "双指缩放查看细节" })
-        XCTAssertEqual(scrollView.minimumZoomScale, 1)
-        XCTAssertEqual(scrollView.maximumZoomScale, 4)
-        XCTAssertGreaterThanOrEqual(backButton.bounds.width, 44)
-        XCTAssertGreaterThanOrEqual(backButton.bounds.height, 44)
+        XCTAssertTrue(comparisonButton.isHidden)
+        segmentedControl.selectedSegmentIndex = 1
+        segmentedControl.sendActions(for: .valueChanged)
+
+        XCTAssertFalse(comparisonButton.isHidden)
+        XCTAssertNil(comparisonButton.configuration?.title)
+        XCTAssertNotNil(comparisonButton.configuration?.image)
+        XCTAssertEqual(comparisonButton.bounds.size, CGSize(width: 48, height: 48))
     }
 
     func testPreviewAIRetouchUsesSelectedRetouchedTabWorkflowAndStaysPresented() async throws {

suixinkanTests/TravelAlbumModelsTests.swift

@@ -8,6 +8,40 @@ import XCTest
 
 /// 旅拍相册模型与展示工具测试。
 final class TravelAlbumModelsTests: XCTestCase {
+    func testBeforeAfterComparisonMotionMatchesShipSwiftInteractionRange() {
+        XCTAssertEqual(BeforeAfterComparisonMotion.automaticFraction(elapsed: 0), 0.5, accuracy: 0.001)
+        XCTAssertEqual(
+            BeforeAfterComparisonMotion.automaticFraction(
+                elapsed: .pi / (2 * BeforeAfterComparisonMotion.automaticSpeed)
+            ),
+            0.8,
+            accuracy: 0.001
+        )
+        XCTAssertEqual(BeforeAfterComparisonMotion.clampedManualFraction(0), 0.05)
+        XCTAssertEqual(BeforeAfterComparisonMotion.clampedManualFraction(1), 0.95)
+        XCTAssertEqual(BeforeAfterComparisonMotion.clampedManualFraction(0.42), 0.42)
+    }
+
+    func testBeforeAfterComparisonLayoutFitsVariableRatiosWithoutCropping() {
+        let landscape = BeforeAfterComparisonLayout.fittedSize(
+            aspectRatio: 16.0 / 9.0,
+            maximumSize: CGSize(width: 358, height: 580)
+        )
+        let portrait = BeforeAfterComparisonLayout.fittedSize(
+            aspectRatio: 2.0 / 3.0,
+            maximumSize: CGSize(width: 358, height: 580)
+        )
+
+        XCTAssertEqual(landscape.width, 358, accuracy: 0.001)
+        XCTAssertEqual(landscape.height, 201.375, accuracy: 0.001)
+        XCTAssertEqual(portrait.width, 358, accuracy: 0.001)
+        XCTAssertEqual(portrait.height, 537, accuracy: 0.001)
+        XCTAssertEqual(
+            BeforeAfterComparisonLayout.aspectRatio(for: CGSize(width: 4000, height: 3000)),
+            4.0 / 3.0
+        )
+    }
+
     func testPreviewProjectMapsMaterialToOriginalAsset() {
         let material = TravelAlbumMaterial(
             id: 8,
@@ -68,6 +102,77 @@ final class TravelAlbumModelsTests: XCTestCase {
         )
     }
 
+    func testPreviewProjectBuildsComparisonOnlyForValidAIResults() {
+        let project = makePreviewProject(id: 8, kinds: [.original, .retouched, .atmosphere, .cover])
+
+        XCTAssertEqual(
+            project.comparisonContent(for: .retouched),
+            BeforeAfterComparisonContent(
+                beforeURL: "https://cdn.example.com/8-0.jpg",
+                afterURL: "https://cdn.example.com/8-1.jpg"
+            )
+        )
+        XCTAssertNotNil(project.comparisonContent(for: .atmosphere))
+        XCTAssertNil(project.comparisonContent(for: .original))
+        XCTAssertNil(project.comparisonContent(for: .cover))
+
+        let missingResultURL = TravelAlbumPreviewProject(
+            originalMaterialId: 9,
+            assets: [
+                TravelAlbumPreviewAsset(
+                    id: "original-9",
+                    kind: .original,
+                    fileURL: "https://cdn.example.com/original.jpg",
+                    coverURL: "",
+                    fileName: "原图.jpg",
+                    fileSize: 1
+                ),
+                TravelAlbumPreviewAsset(
+                    id: "retouched-9",
+                    kind: .retouched,
+                    fileURL: " ",
+                    coverURL: "",
+                    fileName: "精修.jpg",
+                    fileSize: 1
+                ),
+            ]
+        )
+        XCTAssertNil(missingResultURL.comparisonContent(for: .retouched))
+    }
+
+    func testTemplateComparisonContentRequiresBothURLs() {
+        let valid = TravelAlbumAIRetouchTemplate(
+            id: 1,
+            name: "清透",
+            previewURL: "https://cdn.example.com/preview.jpg",
+            beforeURL: " https://cdn.example.com/before.jpg ",
+            afterURL: "https://cdn.example.com/after.jpg"
+        )
+        let missingAfter = TravelAlbumAIRetouchTemplate(
+            id: 2,
+            name: "暖阳",
+            previewURL: "https://cdn.example.com/preview.jpg",
+            beforeURL: "https://cdn.example.com/before.jpg"
+        )
+
+        XCTAssertEqual(valid.comparisonContent?.beforeURL, "https://cdn.example.com/before.jpg")
+        XCTAssertEqual(valid.comparisonContent?.afterLabel, "效果图")
+        XCTAssertNil(missingAfter.comparisonContent)
+    }
+
+    func testTemplateDecodingDefaultsMissingComparisonURLsToEmptyStrings() throws {
+        let data = Data(
+            #"{"id":3,"name":"旧模板","preview_url":"https://cdn.example.com/preview.jpg"}"#.utf8
+        )
+
+        let template = try JSONDecoder().decode(TravelAlbumAIRetouchTemplate.self, from: data)
+
+        XCTAssertEqual(template.previewURL, "https://cdn.example.com/preview.jpg")
+        XCTAssertEqual(template.beforeURL, "")
+        XCTAssertEqual(template.afterURL, "")
+        XCTAssertNil(template.comparisonContent)
+    }
+
     func testPreviewAssetFallsBackToAvailableURLForBothQualityLevels() {
         let missingOriginal = TravelAlbumPreviewAsset(
             id: "cover-only",