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

import 'package:crypto/crypto.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:http/http.dart';
import 'package:image_picker/image_picker.dart';
import 'package:provider/provider.dart';
import 'package:solian/models/post.dart';
import 'package:solian/providers/auth.dart';
import 'package:solian/utils/service_url.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';

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

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

  @override
  State<AttachmentEditor> createState() => _AttachmentEditorState();
}

class _AttachmentEditorState extends State<AttachmentEditor> {
  final _imagePicker = ImagePicker();

  bool isSubmitting = false;

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

  void viewAttachMethods(BuildContext context) {
    showModalBottomSheet(
      context: context,
      builder: (context) => AttachmentEditorMethodPopup(
        pickImage: () => pickImageToUpload(context),
      ),
    );
  }

  Future<void> pickImageToUpload(BuildContext context) async {
    final auth = context.read<AuthProvider>();
    if (!await auth.isAuthorized()) return;

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

    setState(() => isSubmitting = true);

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

    if (Navigator.canPop(context)) {
      Navigator.pop(context);
    }

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

  Future<void> uploadAttachment(File file, String hashcode) async {
    final auth = context.read<AuthProvider>();
    final req = MultipartRequest(
      'POST',
      getRequestUri('interactive', '/api/attachments'),
    );
    req.files.add(await MultipartFile.fromPath('attachment', file.path));
    req.fields['hashcode'] = hashcode;

    var res = await auth.client!.send(req);
    print(res);
    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()));
    }
  }

  Future<void> disposeAttachment(
      BuildContext context, Attachment item, int index) async {
    final auth = context.read<AuthProvider>();

    final req = MultipartRequest(
      'DELETE',
      getRequestUri('interactive', '/api/attachments/${item.id}'),
    );

    setState(() => isSubmitting = true);
    var res = await auth.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) {
    final auth = context.read<AuthProvider>();

    return Column(
      children: [
        Container(
          padding: const EdgeInsets.only(left: 8, right: 8, top: 20),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Padding(
                padding: const EdgeInsets.symmetric(
                  horizontal: 8.0,
                  vertical: 12.0,
                ),
                child: Text(
                  AppLocalizations.of(context)!.attachment,
                  style: Theme.of(context).textTheme.headlineSmall,
                ),
              ),
              FutureBuilder(
                future: auth.isAuthorized(),
                builder: (context, snapshot) {
                  if (snapshot.hasData && snapshot.data == true) {
                    return TextButton(
                      onPressed: isSubmitting
                          ? null
                          : () => viewAttachMethods(context),
                      style: TextButton.styleFrom(shape: const CircleBorder()),
                      child: const Icon(Icons.add_circle),
                    );
                  } 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: 16, right: 8),
                child: Row(
                  children: [
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            getFileName(element),
                            overflow: TextOverflow.ellipsis,
                            maxLines: 1,
                            style: Theme.of(context).textTheme.titleMedium,
                          ),
                          Text(
                            "${getFileType(element)} · ${formatBytes(element.filesize)}",
                          ),
                        ],
                      ),
                    ),
                    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(),
          ),
        ),
      ],
    );
  }
}

class AttachmentEditorMethodPopup extends StatelessWidget {
  final Function pickImage;

  const AttachmentEditorMethodPopup({super.key, required this.pickImage});

  @override
  Widget build(BuildContext context) {
    return Container(
      height: 320,
      padding: const EdgeInsets.only(left: 8, right: 8, top: 20),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Padding(
            padding: const EdgeInsets.symmetric(
              horizontal: 8.0,
              vertical: 12.0,
            ),
            child: Text(
              AppLocalizations.of(context)!.attachmentAdd,
              style: Theme.of(context).textTheme.headlineSmall,
            ),
          ),
          Expanded(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: [
                InkWell(
                  borderRadius: BorderRadius.circular(8),
                  onTap: () => pickImage(),
                  child: Padding(
                    padding: const EdgeInsets.all(8),
                    child: Column(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        const Icon(Icons.add_photo_alternate,
                            color: Colors.indigo),
                        const SizedBox(height: 8),
                        Text(AppLocalizations.of(context)!.pickPhoto),
                      ],
                    ),
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}