SolarAgent/lib/screens/publish/attachment_list.dart

import 'dart:convert';
import 'dart:io';
import 'dart:math' as math;

import 'package:crypto/crypto.dart';
import 'package:flutter/material.dart';
import 'package:http/http.dart';
import 'package:image_picker/image_picker.dart';
import 'package:solaragent/auth.dart';
import 'package:solaragent/models/feed.dart';

class AttachmentList extends StatefulWidget {
  final List<Attachment> current;
  final void Function(List<Attachment> data) onUpdate;

  const AttachmentList(
      {super.key, required this.current, required this.onUpdate});

  @override
  State<AttachmentList> createState() => _AttachmentListState();
}

class _AttachmentListState extends State<AttachmentList> {
  final imagePicker = ImagePicker();

  bool isSubmitting = false;

  List<Attachment> attachments = List.empty(growable: true);

  Future<void> pickImageToUpload(BuildContext context) async {
    if (!await authClient.isAuthorized()) return;

    final image = await imagePicker.pickImage(source: ImageSource.gallery);
    if (image == null) return;

    final file = File(image.path);
    final hashcode = await calculateSha256(file);

    try {
      await uploadAttachment(file, hashcode);
    } catch (err) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Something went wrong... $err")),
      );
    }
  }

  Future<void> uploadAttachment(File file, String hashcode) async {
    var req = MultipartRequest(
      'POST',
      Uri.parse('https://co.solsynth.dev/api/attachments'),
    );
    req.files.add(await MultipartFile.fromPath('attachment', file.path));
    req.fields['hashcode'] = hashcode;

    setState(() => isSubmitting = true);
    var res = await authClient.client!.send(req);
    if (res.statusCode == 200) {
      var result = Attachment.fromJson(
        jsonDecode(utf8.decode(await res.stream.toBytes()))["info"],
      );
      setState(() => attachments.add(result));
      widget.onUpdate(attachments);
    } else {
      throw Exception(utf8.decode(await res.stream.toBytes()));
    }
    setState(() => isSubmitting = false);
  }

  Future<void> disposeAttachment(
      BuildContext context, Attachment item, int index) async {
    var req = MultipartRequest(
      'DELETE',
      Uri.parse('https://co.solsynth.dev/api/attachments/${item.id}'),
    );

    setState(() => isSubmitting = true);
    var res = await authClient.client!.send(req);
    if (res.statusCode == 200) {
      setState(() => attachments.removeAt(index));
      widget.onUpdate(attachments);
    } else {
      final err = utf8.decode(await res.stream.toBytes());
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Something went wrong... $err")),
      );
    }
    setState(() => isSubmitting = false);
  }

  Future<String> calculateSha256(File file) async {
    final bytes = await file.readAsBytes();
    final digest = sha256.convert(bytes);
    return digest.toString();
  }

  String getFileName(Attachment item) {
    return item.filename.replaceAll(RegExp(r'\.[^/.]+$'), '');
  }

  String getFileType(Attachment item) {
    switch (item.type) {
      case 1:
        return 'Photo';
      case 2:
        return 'Video';
      case 3:
        return 'Audio';
      default:
        return 'Others';
    }
  }

  String formatBytes(int bytes, {int decimals = 2}) {
    if (bytes == 0) return '0 Bytes';
    const k = 1024;
    final dm = decimals < 0 ? 0 : decimals;
    final sizes = [
      'Bytes',
      'KiB',
      'MiB',
      'GiB',
      'TiB',
      'PiB',
      'EiB',
      'ZiB',
      'YiB'
    ];
    final i = (math.log(bytes) / math.log(k)).floor().toInt();
    return '${(bytes / math.pow(k, i)).toStringAsFixed(dm)} ${sizes[i]}';
  }

  @override
  void initState() {
    attachments = widget.current;
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Container(
          padding: const EdgeInsets.only(left: 10, right: 10, top: 20),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Padding(
                padding: const EdgeInsets.symmetric(
                  horizontal: 8.0,
                  vertical: 12.0,
                ),
                child: Text(
                  'Attachments',
                  style: Theme.of(context).textTheme.headlineSmall,
                ),
              ),
              FutureBuilder(
                future: authClient.isAuthorized(),
                builder: (context, snapshot) {
                  if (snapshot.hasData && snapshot.data == true) {
                    return Tooltip(
                      message: "Add a photo",
                      child: TextButton(
                        onPressed: isSubmitting
                            ? null
                            : () => pickImageToUpload(context),
                        style: TextButton.styleFrom(
                          shape: const CircleBorder(),
                        ),
                        child: const Icon(Icons.add_photo_alternate),
                      ),
                    );
                  } else {
                    return Container();
                  }
                },
              ),
            ],
          ),
        ),
        isSubmitting ? const LinearProgressIndicator() : Container(),
        Expanded(
          child: ListView.separated(
            itemCount: attachments.length,
            itemBuilder: (context, index) {
              var element = attachments[index];
              return Container(
                padding: const EdgeInsets.only(left: 8.0),
                child: ListTile(
                  title: Text(getFileName(element)),
                  subtitle: Text(
                    "${getFileType(element)} · ${formatBytes(element.filesize)}",
                  ),
                  trailing: TextButton(
                    style: TextButton.styleFrom(
                      shape: const CircleBorder(),
                      foregroundColor: Colors.red,
                    ),
                    child: const Icon(Icons.delete),
                    onPressed: () => disposeAttachment(context, element, index),
                  ),
                ),
              );
            },
            separatorBuilder: (context, index) => const Divider(),
          ),
        ),
      ],
    );
  }
}