import 'dart:io';
import 'dart:typed_data';

import 'package:flutter/widgets.dart';
import 'package:wechat_assets_picker/wechat_assets_picker.dart';

import 'video_batch_upload_config.dart';
import 'video_batch_upload_task.dart';

class VideoBatchUploadPicker {
  const VideoBatchUploadPicker._();

  static Future<List<VideoBatchUploadTask>> pickVideos(
    BuildContext context, {
    int maxAssets = VideoBatchUploadConfig.maxAssets,
  }) async {
    return pickMedia(
      context,
      maxAssets: maxAssets,
      assetType: VideoBatchUploadAssetType.video,
    );
  }

  static Future<List<VideoBatchUploadTask>> pickImages(
    BuildContext context, {
    int maxAssets = VideoBatchUploadConfig.maxAssets,
  }) async {
    return pickMedia(
      context,
      maxAssets: maxAssets,
      assetType: VideoBatchUploadAssetType.image,
    );
  }

  static Future<List<VideoBatchUploadTask>> pickMedia(
    BuildContext context, {
    int maxAssets = VideoBatchUploadConfig.maxAssets,
    VideoBatchUploadAssetType assetType = VideoBatchUploadAssetType.video,
  }) async {
    final List<AssetEntity>? assets = await AssetPicker.pickAssets(
      context,
      pickerConfig: AssetPickerConfig(
        maxAssets: maxAssets,
        requestType: _requestType(assetType),
      ),
    );
    if (assets == null || assets.isEmpty) {
      return <VideoBatchUploadTask>[];
    }

    final List<VideoBatchUploadTask> tasks = <VideoBatchUploadTask>[];
    for (final AssetEntity asset in assets) {
      final File? file = await asset.file;
      if (file == null) {
        continue;
      }
      final Uint8List? thumbnail = await asset.thumbnailDataWithSize(
        const ThumbnailSize.square(220),
        quality: 72,
      );
      final int fileSize = await file.length();
      tasks.add(
        VideoBatchUploadTask(
          id: '${asset.id}_${DateTime.now().microsecondsSinceEpoch}',
          assetType: assetType,
          file: file,
          fileName: _normalizeFileName(asset.title, file.path, assetType),
          fileSize: fileSize,
          duration:
              assetType == VideoBatchUploadAssetType.video ? asset.duration : 0,
          thumbnail: thumbnail,
        ),
      );
    }
    return tasks;
  }

  static RequestType _requestType(VideoBatchUploadAssetType assetType) {
    switch (assetType) {
      case VideoBatchUploadAssetType.image:
        return RequestType.image;
      case VideoBatchUploadAssetType.video:
        return RequestType.video;
    }
  }

  static String _normalizeFileName(
    String? assetTitle,
    String path,
    VideoBatchUploadAssetType assetType,
  ) {
    final String title = (assetTitle ?? '').trim();
    if (title.isNotEmpty) {
      return title;
    }
    final List<String> segments = path.split(Platform.pathSeparator);
    final String fileName = segments.isEmpty ? '' : segments.last.trim();
    return fileName.isEmpty ? assetType.defaultFileName : fileName;
  }
}