export comic as pdf

lib/utils/pdf.dart

@@ -0,0 +1,92 @@
+import 'dart:isolate';
+
+import 'package:pdf/widgets.dart';
+import 'package:venera/foundation/local.dart';
+import 'package:venera/utils/io.dart';
+
+Future<void> _createPdfFromComic({
+  required LocalComic comic,
+  required String savePath,
+  required String localPath,
+}) async {
+  final pdf = Document(
+    title: comic.title,
+    author: comic.subTitle ?? "",
+    producer: "Venera",
+  );
+
+  pdf.document.outline;
+
+  var baseDir = comic.directory.contains('/') || comic.directory.contains('\\')
+      ? comic.directory
+      : FilePath.join(localPath, comic.directory);
+
+  // add cover
+  var imageData = File(FilePath.join(baseDir, comic.cover)).readAsBytesSync();
+  pdf.addPage(Page(
+    build: (Context context) {
+      return Image(MemoryImage(imageData), fit: BoxFit.contain);
+    },
+  ));
+
+  bool multiChapters = comic.chapters != null;
+
+  void reorderFiles(List<FileSystemEntity> files) {
+    files.removeWhere(
+        (element) => element is! File || element.path.startsWith('cover'));
+    files.sort((a, b) {
+      var aName = (a as File).name;
+      var bName = (b as File).name;
+      var aNumber = int.tryParse(aName);
+      var bNumber = int.tryParse(bName);
+      if (aNumber != null && bNumber != null) {
+        return aNumber.compareTo(bNumber);
+      }
+      return aName.compareTo(bName);
+    });
+  }
+
+  if (!multiChapters) {
+    var files = Directory(baseDir).listSync();
+    reorderFiles(files);
+
+    for (var file in files) {
+      var imageData = (file as File).readAsBytesSync();
+      pdf.addPage(Page(
+        build: (Context context) {
+          return Image(MemoryImage(imageData), fit: BoxFit.contain);
+        },
+      ));
+    }
+  } else {
+    for (var chapter in comic.chapters!.keys) {
+      var files = Directory(FilePath.join(baseDir, chapter)).listSync();
+      reorderFiles(files);
+      for (var file in files) {
+        var imageData = (file as File).readAsBytesSync();
+        pdf.addPage(Page(
+          build: (Context context) {
+            return Image(MemoryImage(imageData), fit: BoxFit.contain);
+          },
+        ));
+      }
+    }
+  }
+
+  final file = File(savePath);
+  file.writeAsBytesSync(await pdf.save());
+}
+
+Future<void> createPdfFromComicIsolate({
+  required LocalComic comic,
+  required String savePath,
+}) async {
+  var localPath = LocalManager().path;
+  return Isolate.run(() => overrideIO(() async {
+        return await _createPdfFromComic(
+          comic: comic,
+          savePath: savePath,
+          localPath: localPath,
+        );
+      }));
+}