v1.0.1

lib/services/download_task/comic_downloader.dart

@@ -0,0 +1,193 @@
+import 'dart:io';
+import 'dart:typed_data';
+
+import 'package:dio/dio.dart';
+import 'package:extended_image/extended_image.dart';
+import 'package:flutter_dmzj/app/dialog_utils.dart';
+import 'package:flutter_dmzj/app/log.dart';
+import 'package:flutter_dmzj/models/db/comic_download_info.dart';
+import 'package:flutter_dmzj/models/db/download_status.dart';
+import 'package:flutter_dmzj/requests/comic_request.dart';
+import 'package:flutter_dmzj/services/app_settings_service.dart';
+import 'package:flutter_dmzj/services/comic_download_service.dart';
+import 'package:get/get.dart';
+
+// ignore: depend_on_referenced_packages
+import 'package:path/path.dart' as p;
+
+class ComicDownloader {
+  late Rx<ComicDownloadInfo> info;
+  final Function() onUpdateTask;
+  ComicDownloader(ComicDownloadInfo item, {required this.onUpdateTask}) {
+    info = Rx<ComicDownloadInfo>(item);
+  }
+  final ComicRequest request = ComicRequest();
+  DownloadStatus get status => info.value.status;
+  CancelToken? cancelToken;
+  Dio dio = Dio(BaseOptions(
+    headers: {
+      'Referer': "http://www.zaimanhua.com/",
+    },
+  ));
+  void start() {
+    _getPageUrls();
+  }
+
+  void retry() {
+    _getPageUrls();
+  }
+
+  void pause() {
+    stopTask();
+    updateStatus(DownloadStatus.pause);
+  }
+
+  void cancel() async {
+    var result = await DialogUtils.showAlertDialog("确定要取消此任务吗?", title: "取消任务");
+    if (!result) {
+      return;
+    }
+    cancelToken?.cancel();
+    cancelToken = null;
+    await _delete();
+  }
+
+  void resume() {
+    _startDownload();
+  }
+
+  void stopTask() {
+    cancelToken?.cancel();
+    cancelToken = null;
+  }
+
+  void _getPageUrls() async {
+    try {
+      if (info.value.urls.isNotEmpty) {
+        _startDownload();
+        return;
+      }
+      updateStatus(DownloadStatus.loadding);
+      var detail = await request.chapterDetail(
+        comicId: info.value.comicId,
+        chapterId: info.value.chapterId,
+        useHD: AppSettingsService.instance.comicReaderHD.value,
+      );
+      if (detail.pageUrls.isEmpty) {
+        updateStatus(DownloadStatus.errorLoad);
+        return;
+      }
+      info.update((val) {
+        val!.urls = detail.pageUrls;
+        val.total = detail.pageUrls.length;
+      });
+      await _saveInfo();
+      _startDownload();
+    } catch (e) {
+      updateStatus(DownloadStatus.errorLoad);
+    }
+  }
+
+  int retryTime = 0;
+  void _startDownload() async {
+    updateStatus(DownloadStatus.downloading);
+    for (var i = info.value.index; i < info.value.total; i++) {
+      try {
+        if (status != DownloadStatus.downloading) {
+          break;
+        }
+        var url = info.value.urls[i];
+        retryTime = 0;
+        await _downloadImage(url, i);
+      } catch (e) {
+        break;
+      }
+    }
+    if (status == DownloadStatus.downloading &&
+        (info.value.index == info.value.total - 1)) {
+      updateStatus(DownloadStatus.complete);
+    }
+  }
+
+  Future _downloadImage(String url, int index) async {
+    try {
+      //检查本地是否有缓存，有缓存直接复制本地的
+      Uint8List bytes;
+      var localFile = await getCachedImageFile(url);
+      if (localFile != null) {
+        bytes = await localFile.readAsBytes();
+      } else {
+        cancelToken = CancelToken();
+
+        var result = await dio.get(
+          url,
+          options: Options(
+            responseType: ResponseType.bytes,
+          ),
+          cancelToken: cancelToken,
+        );
+        bytes = result.data;
+      }
+      var baseName = Uri.parse(url).path;
+      var fileName = await _saveImage(bytes, index, p.extension(baseName));
+      info.update((val) {
+        val!.index = index;
+        val.files.add(fileName);
+      });
+      await _saveInfo();
+    } catch (e) {
+      Log.logPrint(e);
+      if (e is DioException) {
+        if (e.type == DioExceptionType.cancel) rethrow;
+        if (status == DownloadStatus.waitNetwork ||
+            status == DownloadStatus.pauseCellular) rethrow;
+        if (retryTime < 3) {
+          retryTime++;
+          await Future.delayed(const Duration(seconds: 1));
+          return await _downloadImage(url, index);
+        }
+      }
+      updateStatus(DownloadStatus.error);
+      rethrow;
+    }
+  }
+
+  Future<String> _saveImage(
+      Uint8List bytes, int index, String extension) async {
+    var dir = info.value.savePath;
+    var fileName = "${(index + 1).toString().padLeft(3, "0")}$extension";
+    var file = File(p.join(dir, fileName));
+    if (!await file.exists()) {
+      file = await file.create(recursive: true);
+    }
+    await file.writeAsBytes(bytes);
+    return fileName;
+  }
+
+  void updateStatus(DownloadStatus e, {bool updateTask = true}) async {
+    info.update((val) {
+      val!.status = e;
+    });
+    if (updateTask) {
+      onUpdateTask();
+    }
+
+    await _saveInfo();
+  }
+
+  /// 保存信息
+  Future _saveInfo() async {
+    await ComicDownloadService.instance.box.put(info.value.taskId, info.value);
+  }
+
+  Future _delete() async {
+    try {
+      var dir = Directory(info.value.savePath);
+      await dir.delete(recursive: true);
+    } finally {
+      ComicDownloadService.instance.downloadIds.remove(info.value.taskId);
+      await ComicDownloadService.instance.box.delete(info.value.taskId);
+      updateStatus(DownloadStatus.cancel);
+    }
+  }
+}