update at 2026-03-15 15:58:14

calendar/scripts/export-kindle-background.swift

@@ -0,0 +1,186 @@
+#!/usr/bin/env swift
+
+import AppKit
+import Foundation
+import WebKit
+
+enum ExportError: Error, CustomStringConvertible {
+  case invalidArguments
+  case snapshotFailed
+  case pngEncodingFailed(String)
+  case clockRegionMissing
+
+  var description: String {
+    switch self {
+    case .invalidArguments:
+      return "用法：export-kindle-background.swift <url> <png-output> <region-output>"
+    case .snapshotFailed:
+      return "网页截图失败"
+    case let .pngEncodingFailed(path):
+      return "PNG 编码失败：\(path)"
+    case .clockRegionMissing:
+      return "页面里没有找到 data-clock-region 标记"
+    }
+  }
+}
+
+final class SnapshotExporter: NSObject, WKNavigationDelegate {
+  private let url: URL
+  private let pngOutputURL: URL
+  private let regionOutputURL: URL
+  private let completion: (Result<Void, Error>) -> Void
+  private let targetSize = CGSize(width: 1024, height: 600)
+
+  private lazy var window: NSWindow = {
+    let window = NSWindow(
+      contentRect: CGRect(origin: .zero, size: targetSize),
+      styleMask: [.borderless],
+      backing: .buffered,
+      defer: false
+    )
+    window.isReleasedWhenClosed = false
+    window.backgroundColor = .white
+    return window
+  }()
+
+  private lazy var webView: WKWebView = {
+    let config = WKWebViewConfiguration()
+    let view = WKWebView(frame: CGRect(origin: .zero, size: targetSize), configuration: config)
+    view.navigationDelegate = self
+    return view
+  }()
+
+  init(url: URL, pngOutputURL: URL, regionOutputURL: URL, completion: @escaping (Result<Void, Error>) -> Void) {
+    self.url = url
+    self.pngOutputURL = pngOutputURL
+    self.regionOutputURL = regionOutputURL
+    self.completion = completion
+    super.init()
+  }
+
+  func start() {
+    window.contentView = webView
+    window.orderBack(nil)
+    webView.load(URLRequest(url: url))
+  }
+
+  func webView(_ webView: WKWebView, didFinish _: WKNavigation!) {
+    // 等页面数据与图片稳定下来，避免只截到骨架。
+    DispatchQueue.main.asyncAfter(deadline: .now() + 4) {
+      self.capture()
+    }
+  }
+
+  private func capture() {
+    let regionScript = """
+      (() => {
+        const node = document.querySelector('[data-clock-region="true"]');
+        if (!node) return null;
+        const rect = node.getBoundingClientRect();
+        return {
+          x: Math.round(rect.left),
+          y: Math.round(rect.top),
+          width: Math.round(rect.width),
+          height: Math.round(rect.height)
+        };
+      })();
+      """
+
+    webView.evaluateJavaScript(regionScript) { value, error in
+      if let error {
+        self.finish(.failure(error))
+        return
+      }
+
+      guard let region = value as? [String: NSNumber] else {
+        self.finish(.failure(ExportError.clockRegionMissing))
+        return
+      }
+
+      let snapshotConfig = WKSnapshotConfiguration()
+      snapshotConfig.rect = CGRect(origin: .zero, size: self.targetSize)
+      snapshotConfig.snapshotWidth = NSNumber(value: Float(self.targetSize.width))
+
+      self.webView.takeSnapshot(with: snapshotConfig) { image, snapshotError in
+        if let snapshotError {
+          self.finish(.failure(snapshotError))
+          return
+        }
+
+        guard let image else {
+          self.finish(.failure(ExportError.snapshotFailed))
+          return
+        }
+
+        do {
+          try self.savePNG(image: image, to: self.pngOutputURL)
+          try self.saveRegion(region: region)
+          self.finish(.success(()))
+        } catch {
+          self.finish(.failure(error))
+        }
+      }
+    }
+  }
+
+  private func savePNG(image: NSImage, to url: URL) throws {
+    let normalizedImage = NSImage(size: NSSize(width: targetSize.width, height: targetSize.height))
+    normalizedImage.lockFocus()
+    image.draw(in: NSRect(origin: .zero, size: targetSize))
+    normalizedImage.unlockFocus()
+
+    guard
+      let tiffRepresentation = normalizedImage.tiffRepresentation,
+      let bitmap = NSBitmapImageRep(data: tiffRepresentation),
+      let pngData = bitmap.representation(using: .png, properties: [:])
+    else {
+      throw ExportError.pngEncodingFailed(url.path)
+    }
+
+    try FileManager.default.createDirectory(at: url.deletingLastPathComponent(), withIntermediateDirectories: true)
+    try pngData.write(to: url)
+  }
+
+  private func saveRegion(region: [String: NSNumber]) throws {
+    let jsonObject: [String: Int] = [
+      "x": region["x"]?.intValue ?? 0,
+      "y": region["y"]?.intValue ?? 0,
+      "width": region["width"]?.intValue ?? 0,
+      "height": region["height"]?.intValue ?? 0,
+    ]
+    let data = try JSONSerialization.data(withJSONObject: jsonObject, options: [.prettyPrinted, .sortedKeys])
+    try FileManager.default.createDirectory(at: regionOutputURL.deletingLastPathComponent(), withIntermediateDirectories: true)
+    try data.write(to: regionOutputURL)
+  }
+
+  private func finish(_ result: Result<Void, Error>) {
+    completion(result)
+    NSApplication.shared.terminate(nil)
+  }
+}
+
+guard CommandLine.arguments.count >= 4 else {
+  fputs("\(ExportError.invalidArguments)\n", stderr)
+  exit(1)
+}
+
+let url = URL(string: CommandLine.arguments[1])!
+let pngOutputURL = URL(fileURLWithPath: CommandLine.arguments[2])
+let regionOutputURL = URL(fileURLWithPath: CommandLine.arguments[3])
+
+let app = NSApplication.shared
+app.setActivationPolicy(.prohibited)
+
+let exporter = SnapshotExporter(url: url, pngOutputURL: pngOutputURL, regionOutputURL: regionOutputURL) { result in
+  switch result {
+  case .success:
+    print("Exported \(pngOutputURL.path)")
+    print("Region saved to \(regionOutputURL.path)")
+  case let .failure(error):
+    fputs("\(error)\n", stderr)
+    exit(1)
+  }
+}
+
+exporter.start()
+app.run()