Add repository file browser

ios/Sources/DetailScreens.swift

@@ -1,4 +1,7 @@
+import Highlighter
+import QuickLook
 import UIKit
+import UniformTypeIdentifiers
 
 @MainActor
 class MarkdownPageViewController: UIViewController {
@@ -259,6 +262,192 @@ final class FilesViewController: RefreshingTableViewController {
     }
 }
 
+@MainActor
+final class RepositoryDirectoryViewController: RefreshingTableViewController {
+    private let context: AppContext
+    private let owner: String
+    private let repository: String
+    private let path: String
+    private var rows: [RepositoryContentRow] = []
+
+    init(context: AppContext, owner: String, repository: String, path: String) {
+        self.context = context
+        self.owner = owner
+        self.repository = repository
+        self.path = path
+        super.init()
+        title = path.split(separator: "/").last.map(String.init) ?? repository
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) { fatalError("init(coder:) is not supported") }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        loadContent(refreshing: false)
+    }
+
+    override func loadContent(refreshing: Bool) {
+        beginLoading(refreshing: refreshing)
+        loadingTask?.cancel()
+        loadingTask = Task {
+            do {
+                rows = try await context.core.repositoryContents(
+                    owner: owner,
+                    repository: repository,
+                    path: path
+                )
+                tableView.reloadData()
+                tableView.backgroundView = rows.isEmpty
+                    ? EmptyBackgroundView(title: "Empty folder", detail: "This folder does not contain any files.")
+                    : nil
+            } catch {
+                if !Task.isCancelled { show(error: error) }
+            }
+            endLoading()
+        }
+    }
+
+    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        rows.count
+    }
+
+    override func tableView(
+        _ tableView: UITableView,
+        cellForRowAt indexPath: IndexPath
+    ) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: "repository-content")
+            ?? UITableViewCell(style: .subtitle, reuseIdentifier: "repository-content")
+        configureRepositoryContentCell(cell, row: rows[indexPath.row])
+        return cell
+    }
+
+    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
+        tableView.deselectRow(at: indexPath, animated: true)
+        showRepositoryContent(
+            rows[indexPath.row],
+            context: context,
+            owner: owner,
+            repository: repository,
+            navigationController: navigationController
+        )
+    }
+}
+
+@MainActor
+final class RepositoryFileViewController: UIViewController, QLPreviewControllerDataSource {
+    private let context: AppContext
+    private let owner: String
+    private let repository: String
+    private let path: String
+    private let spinner = UIActivityIndicatorView(style: .medium)
+    private var loadingTask: Task<Void, Never>?
+    private var previewURL: URL?
+
+    init(context: AppContext, owner: String, repository: String, path: String) {
+        self.context = context
+        self.owner = owner
+        self.repository = repository
+        self.path = path
+        super.init(nibName: nil, bundle: nil)
+        title = path.split(separator: "/").last.map(String.init)
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) { fatalError("init(coder:) is not supported") }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        view.backgroundColor = .systemBackground
+        beginNavigationLoading(spinner)
+        loadingTask = Task {
+            do {
+                let data = try await context.core.repositoryFile(
+                    owner: owner,
+                    repository: repository,
+                    path: path
+                )
+                if !isMediaFile(path), let source = String(data: data, encoding: .utf8) {
+                    showSource(source)
+                } else {
+                    try showQuickLook(data)
+                }
+            } catch {
+                if !Task.isCancelled { show(error: error) }
+            }
+            endNavigationLoading(spinner)
+        }
+    }
+
+    private func isMediaFile(_ path: String) -> Bool {
+        guard let type = UTType(filenameExtension: (path as NSString).pathExtension) else {
+            return false
+        }
+        return type.conforms(to: .image)
+            || type.conforms(to: .audio)
+            || type.conforms(to: .audiovisualContent)
+            || type.conforms(to: .pdf)
+    }
+
+    deinit {
+        loadingTask?.cancel()
+        if let previewURL { try? FileManager.default.removeItem(at: previewURL) }
+    }
+
+    func numberOfPreviewItems(in controller: QLPreviewController) -> Int {
+        previewURL == nil ? 0 : 1
+    }
+
+    func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
+        previewURL! as NSURL
+    }
+
+    private func showSource(_ source: String) {
+        let textView = UITextView(frame: view.bounds)
+        textView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        textView.isEditable = false
+        textView.isSelectable = true
+        textView.alwaysBounceHorizontal = true
+        textView.isDirectionalLockEnabled = true
+        textView.showsHorizontalScrollIndicator = true
+        textView.textContainer.widthTracksTextView = false
+        textView.textContainer.size = CGSize(
+            width: CGFloat.greatestFiniteMagnitude,
+            height: CGFloat.greatestFiniteMagnitude
+        )
+        let highlighter = Highlighter()
+        highlighter?.setTheme(
+            traitCollection.userInterfaceStyle == .dark ? "atom-one-dark" : "atom-one-light"
+        )
+        highlighter?.theme.setCodeFont(.monospacedSystemFont(ofSize: 13, weight: .regular))
+        textView.attributedText = highlighter?.highlight(source, as: sourceLanguage(path))
+            ?? NSAttributedString(string: source, attributes: [
+                .font: UIFont.monospacedSystemFont(ofSize: 13, weight: .regular),
+                .foregroundColor: UIColor.label,
+            ])
+        textView.layoutManager.ensureLayout(for: textView.textContainer)
+        textView.contentSize.width = textView.layoutManager.usedRect(for: textView.textContainer).width
+            + textView.textContainerInset.left
+            + textView.textContainerInset.right
+        view.addSubview(textView)
+    }
+
+    private func showQuickLook(_ data: Data) throws {
+        let name = path.split(separator: "/").last.map(String.init) ?? "Preview"
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("\(UUID().uuidString)-\(name)")
+        try data.write(to: url, options: .atomic)
+        previewURL = url
+        let preview = QLPreviewController()
+        preview.dataSource = self
+        addChild(preview)
+        preview.view.frame = view.bounds
+        preview.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        view.addSubview(preview.view)
+        preview.didMove(toParent: self)
+    }
+}
+
 enum DiffSource {
     case commit(owner: String, repository: String, sha: String, path: String)
     case pull(owner: String, repository: String, number: Int64, path: String)