Add a Save to Mac button for files in the Files tab

mac/Sources/Byre/Files.swift

@@ -1,5 +1,6 @@
 import ByreAPI
 import SwiftUI
+import UniformTypeIdentifiers
 
 typealias DirListing = Components.Schemas.DirListing
 typealias DirEntry = Components.Schemas.DirEntry
@@ -95,6 +96,8 @@ private final class FilesModel {
     private(set) var error = ""
     private(set) var generation = 0
     private(set) var loads = 0
+    var saving: FileCopy?
+    var saveError = ""
     @ObservationIgnored private var target = 0
     @ObservationIgnored private var timer: Task<Void, Never>?
 
@@ -113,12 +116,21 @@ private final class FilesModel {
         store.filePlaces[root] = p
     }
 
+    func save(_ path: String) {
+        guard let root else {
+            return
+        }
+        saveError = ""
+        saving = FileCopy(api: store.api, root: root, path: path)
+    }
+
     func reset() {
         target += 1
         timer?.cancel()
         listing = nil
         content = nil
         error = ""
+        saveError = ""
         generation += 1
         Task {
             await load()
@@ -206,6 +218,12 @@ struct FilesView: View {
             if let model {
                 FilesHead(model: model)
                 FilesBody(model: model)
+                    .fileExporter(isPresented: Binding { model.saving != nil } set: { if !$0 { model.saving = nil } }, item: model.saving, contentTypes: [.data], defaultFilename: model.saving.map { ($0.path as NSString).lastPathComponent }) { result in
+                        model.saving = nil
+                        if case .failure(let error) = result {
+                            model.saveError = errorText(error)
+                        }
+                    }
             }
         }
         .frame(maxHeight: .infinity, alignment: .top)
@@ -236,6 +254,37 @@ struct FilesView: View {
     }
 }
 
+private struct FileCopy: Transferable, Sendable {
+    let api: API
+    let root: FileRoot
+    let path: String
+
+    static var transferRepresentation: some TransferRepresentation {
+        FileRepresentation(exportedContentType: .data) { copy in
+            SentTransferredFile(try await copy.download())
+        }
+    }
+
+    private func download() async throws -> URL {
+        let body = switch root {
+        case .task(let id): try await api.client.getTaskRaw(path: .init(taskId: id), query: .init(path: path)).ok.body.any
+        case .project(let id): try await api.client.getProjectRaw(path: .init(projectId: id), query: .init(path: path)).ok.body.any
+        }
+        let dir = FileManager.default.temporaryDirectory.appending(path: UUID().uuidString)
+        try FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+        let dest = dir.appending(path: (path as NSString).lastPathComponent)
+        FileManager.default.createFile(atPath: dest.path, contents: nil)
+        let h = try FileHandle(forWritingTo: dest)
+        defer {
+            try? h.close()
+        }
+        for try await chunk in body {
+            try h.write(contentsOf: chunk)
+        }
+        return dest
+    }
+}
+
 private struct FilesHead: View {
     let model: FilesModel
 
@@ -257,11 +306,18 @@ private struct FilesHead: View {
                 }
             }
             Spacer(minLength: 0)
-            Text(model.summary)
+            Text(model.saveError.isEmpty ? model.summary : model.saveError)
                 .font(Fonts.font(11))
-                .foregroundStyle(Palette.muted)
+                .foregroundStyle(model.saveError.isEmpty ? Palette.muted : Palette.danger)
                 .lineLimit(1)
                 .fixedSize()
+            if let file = p.file, model.content != nil {
+                Button("Save Copy…") {
+                    model.save(file)
+                }
+                .buttonStyle(WebButtonStyle())
+                .help("Save a copy of this file on this device")
+            }
         }
         .modifier(HeaderBar())
     }
@@ -307,13 +363,13 @@ private struct FilesBody: View {
             ScrollView {
                 VStack(alignment: .leading, spacing: 0) {
                     if !l.path.isEmpty && l.path != "/" {
-                        EntryRow(label: "../", kind: .dir, ignored: false, meta: "", symlink: false) {
+                        EntryRow(label: "../", kind: .dir, ignored: false, meta: "", symlink: false, save: nil) {
                             model.go(FilePlace(dir: parent(l.path)))
                         }
                     }
                     ForEach(l.entries, id: \.name) { e in
                         let meta = [e.ignored ? "ignored" : nil, e._type == .file ? bytes(e.size) : nil].compactMap { $0 }.joined(separator: " · ")
-                        EntryRow(label: e._type == .dir ? "\(e.name)/" : e.name, kind: e._type, ignored: e.ignored, meta: meta, symlink: e.symlink) {
+                        EntryRow(label: e._type == .dir ? "\(e.name)/" : e.name, kind: e._type, ignored: e.ignored, meta: meta, symlink: e.symlink, save: e._type == .file ? { model.save(join(l.path, e.name)) } : nil) {
                             if e._type == .dir {
                                 model.go(FilePlace(dir: join(l.path, e.name)))
                             } else if e._type == .file && isPage(e.name), case .task(let taskId) = model.root {
@@ -349,6 +405,7 @@ private struct EntryRow: View {
     let ignored: Bool
     let meta: String
     let symlink: Bool
+    let save: (() -> Void)?
     let action: () -> Void
     @ViewState private var hover = false
 
@@ -380,6 +437,11 @@ private struct EntryRow: View {
             }
             .buttonStyle(.plain)
             .onHover { hover = $0 }
+            .contextMenu {
+                if let save {
+                    Button("Save Copy…", action: save)
+                }
+            }
         }
     }
 }