feat: add iOS travel album photo preview

2026-08-10 10:07:19 +08:00
parent dcdab3cff7
commit 99fbad3e97
5 changed files with 1101 additions and 2 deletions
@@ -0,0 +1,174 @@
+//
+//  TravelAlbumPreviewModels.swift
+//  suixinkan
+//
+
+import Foundation
+
+/// 相册预览页横向滑动策略，由调用方通过配置注入。
+enum TravelAlbumPreviewSwipeMode: Sendable, Equatable {
+    /// 横滑只切换原图项目，关联图通过 Tab 切换。
+    case projectsOnly
+    /// 横滑依次切换当前项目的关联图，并在边界进入相邻项目原图。
+    case includeVariants
+}
+
+/// 相册预览页配置。
+struct TravelAlbumPreviewConfiguration: Sendable {
+    let swipeMode: TravelAlbumPreviewSwipeMode
+
+    /// 创建预览配置，默认只按原图项目分页。
+    init(swipeMode: TravelAlbumPreviewSwipeMode = .projectsOnly) {
+        self.swipeMode = swipeMode
+    }
+}
+
+/// 预览图片类型，顺序同时决定 Tab 与关联图浏览顺序。
+enum TravelAlbumPreviewAssetKind: Int, CaseIterable, Sendable, Hashable {
+    case original
+    case retouched
+    case atmosphere
+    case cover
+
+    var title: String {
+        switch self {
+        case .original: "原图"
+        case .retouched: "精修后"
+        case .atmosphere: "氛围感"
+        case .cover: "封面"
+        }
+    }
+}
+
+/// 预览页使用的单张图片信息，与后端关联图字段解耦。
+struct TravelAlbumPreviewAsset: Identifiable, Sendable, Hashable {
+    let id: String
+    let kind: TravelAlbumPreviewAssetKind
+    let fileURL: String
+    let coverURL: String
+    let fileName: String
+    let fileSize: Int
+
+    /// 实际用于展示的地址，优先使用原图地址。
+    var displayURL: String {
+        let trimmedFileURL = fileURL.trimmingCharacters(in: .whitespacesAndNewlines)
+        return trimmedFileURL.isEmpty ? coverURL.trimmingCharacters(in: .whitespacesAndNewlines) : trimmedFileURL
+    }
+
+    /// 横滑预览地址，优先使用体积更小的封面图以降低解码开销。
+    var previewURL: String {
+        let trimmedCoverURL = coverURL.trimmingCharacters(in: .whitespacesAndNewlines)
+        return trimmedCoverURL.isEmpty ? fileURL.trimmingCharacters(in: .whitespacesAndNewlines) : trimmedCoverURL
+    }
+}
+
+/// 一张原图及其所有关联图片组成的预览项目。
+struct TravelAlbumPreviewProject: Identifiable, Sendable, Hashable {
+    let originalMaterialId: Int
+    let assets: [TravelAlbumPreviewAsset]
+
+    var id: Int { originalMaterialId }
+
+    /// 按产品约定顺序返回实际存在的图片。
+    var orderedAssets: [TravelAlbumPreviewAsset] {
+        TravelAlbumPreviewAssetKind.allCases.compactMap(asset(for:))
+    }
+
+    /// 是否存在原图之外的关联图片。
+    var hasVariants: Bool {
+        orderedAssets.contains { $0.kind != .original }
+    }
+
+    /// 返回指定类型的图片。
+    func asset(for kind: TravelAlbumPreviewAssetKind) -> TravelAlbumPreviewAsset? {
+        assets.first { $0.kind == kind }
+    }
+
+    /// 将当前素材映射为仅含原图的预览项目；新接口接入后替换此适配层即可。
+    init(material: TravelAlbumMaterial) {
+        originalMaterialId = material.id
+        assets = [
+            TravelAlbumPreviewAsset(
+                id: "original-\(material.id)",
+                kind: .original,
+                fileURL: material.fileUrl,
+                coverURL: material.coverUrl,
+                fileName: material.fileName,
+                fileSize: material.fileSize
+            ),
+        ]
+    }
+
+    /// 创建包含关联图片的项目，主要供适配器和测试使用。
+    init(originalMaterialId: Int, assets: [TravelAlbumPreviewAsset]) {
+        self.originalMaterialId = originalMaterialId
+        var seenKinds = Set<TravelAlbumPreviewAssetKind>()
+        self.assets = assets.filter { seenKinds.insert($0.kind).inserted }
+    }
+}
+
+/// 预览分页节点，记录当前图片所属项目及类型。
+struct TravelAlbumPreviewNode: Sendable, Hashable {
+    let projectIndex: Int
+    let kind: TravelAlbumPreviewAssetKind
+}
+
+/// 预览页纯状态工具，负责构建节点和处理分组滑动边界。
+enum TravelAlbumPreviewNavigator {
+    /// 根据滑动模式生成页面节点。
+    static func nodes(
+        projects: [TravelAlbumPreviewProject],
+        mode: TravelAlbumPreviewSwipeMode
+    ) -> [TravelAlbumPreviewNode] {
+        projects.enumerated().flatMap { index, project in
+            switch mode {
+            case .projectsOnly:
+                [TravelAlbumPreviewNode(projectIndex: index, kind: .original)]
+            case .includeVariants:
+                project.orderedAssets.map { TravelAlbumPreviewNode(projectIndex: index, kind: $0.kind) }
+            }
+        }
+    }
+
+    /// 处理反向滑动边界：从项目原图向右滑时直接进入上一项目原图。
+    static func backwardTargetIndex(
+        nodes: [TravelAlbumPreviewNode],
+        currentIndex: Int
+    ) -> Int {
+        guard nodes.indices.contains(currentIndex), currentIndex > 0 else { return max(0, currentIndex) }
+        let current = nodes[currentIndex]
+        guard current.kind == .original, current.projectIndex > 0 else { return currentIndex - 1 }
+        return nodes.firstIndex {
+            $0.projectIndex == current.projectIndex - 1 && $0.kind == .original
+        } ?? currentIndex - 1
+    }
+}
+
+/// 预览操作执行结果，便于后续替换真实业务接口。
+enum TravelAlbumPreviewActionResult: Sendable, Equatable {
+    case success(String?)
+    case failure(String)
+    case unavailable(String)
+}
+
+/// 预览页底部操作协议，所有操作均以原素材项目 ID 为目标。
+protocol TravelAlbumPreviewActionHandling: AnyObject {
+    func requestAIRetouch(originalMaterialId: Int) async -> TravelAlbumPreviewActionResult
+    func deleteProject(originalMaterialId: Int) async -> TravelAlbumPreviewActionResult
+    func refreshProject(originalMaterialId: Int) async -> TravelAlbumPreviewActionResult
+}
+
+/// 新接口接入前的占位操作实现，不修改任何业务数据。
+final class PlaceholderTravelAlbumPreviewActionHandler: TravelAlbumPreviewActionHandling {
+    func requestAIRetouch(originalMaterialId: Int) async -> TravelAlbumPreviewActionResult {
+        .unavailable("AI修复功能待接口接入")
+    }
+
+    func deleteProject(originalMaterialId: Int) async -> TravelAlbumPreviewActionResult {
+        .unavailable("项目删除接口待接入")
+    }
+
+    func refreshProject(originalMaterialId: Int) async -> TravelAlbumPreviewActionResult {
+        .unavailable("关联图片刷新接口待接入")
+    }
+}