import 'package:collection/collection.dart';
import 'package:dropdown_button2/dropdown_button2.dart';
import 'package:easy_localization/easy_localization.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:gap/gap.dart';
import 'package:go_router/go_router.dart';
import 'package:image_picker/image_picker.dart';
import 'package:material_symbols_icons/symbols.dart';
import 'package:pasteboard/pasteboard.dart';
import 'package:styled_widget/styled_widget.dart';
import 'package:surface/controllers/post_write_controller.dart';
import 'package:surface/providers/sn_network.dart';
import 'package:surface/types/post.dart';
import 'package:surface/widgets/account/account_image.dart';
import 'package:surface/widgets/loading_indicator.dart';
import 'package:surface/widgets/post/post_item.dart';
import 'package:surface/widgets/post/post_media_pending_list.dart';
import 'package:surface/widgets/post/post_meta_editor.dart';
import 'package:surface/widgets/dialog.dart';
import 'package:provider/provider.dart';

class PostEditorScreen extends StatefulWidget {
  final String mode;
  final int? postEditId;
  final int? postReplyId;
  final int? postRepostId;

  const PostEditorScreen({
    super.key,
    required this.mode,
    required this.postEditId,
    required this.postReplyId,
    required this.postRepostId,
  });

  @override
  State<PostEditorScreen> createState() => _PostEditorScreenState();
}

class _PostEditorScreenState extends State<PostEditorScreen> {
  final PostWriteController _writeController = PostWriteController();

  bool _isFetching = false;

  bool get _isLoading => _isFetching || _writeController.isLoading;

  List<SnPublisher>? _publishers;

  Future<void> _fetchPublishers() async {
    setState(() => _isFetching = true);

    try {
      final sn = context.read<SnNetworkProvider>();
      final resp = await sn.client.get('/cgi/co/publishers');
      _publishers = List<SnPublisher>.from(
        resp.data?.map((e) => SnPublisher.fromJson(e)) ?? [],
      );
      _writeController.setPublisher(_publishers?.firstOrNull);
    } catch (err) {
      if (!mounted) return;
      context.showErrorDialog(err);
    } finally {
      setState(() => _isFetching = false);
    }
  }

  void _updateMeta() {
    showModalBottomSheet(
      context: context,
      builder: (context) => PostMetaEditor(controller: _writeController),
      useRootNavigator: true,
    );
  }

  final _imagePicker = ImagePicker();

  void _selectMedia() async {
    final result = await _imagePicker.pickMultipleMedia();
    if (result.isEmpty) return;
    _writeController.addAttachments(
      result.map((e) => PostWriteMedia.fromFile(e)),
    );
  }

  void _pasteMedia() async {
    final imageBytes = await Pasteboard.image;
    if (imageBytes == null) return;
    _writeController.addAttachments([
      PostWriteMedia.fromBytes(
        imageBytes,
        'attachmentPastedImage'.tr(),
        PostWriteMediaType.image,
      ),
    ]);
  }

  @override
  void dispose() {
    _writeController.dispose();
    super.dispose();
  }

  @override
  void initState() {
    super.initState();
    if (!PostWriteController.kTitleMap.keys.contains(widget.mode)) {
      context.showErrorDialog('Unknown post type');
      Navigator.pop(context);
    } else {
      _writeController.setMode(widget.mode);
    }
    _fetchPublishers();
    _writeController.fetchRelatedPost(
      context,
      editing: widget.postEditId,
      replying: widget.postReplyId,
      reposting: widget.postRepostId,
    );
  }

  @override
  Widget build(BuildContext context) {
    return ListenableBuilder(
      listenable: _writeController,
      builder: (context, _) {
        return Scaffold(
          appBar: AppBar(
            leading: BackButton(
              onPressed: () {
                Navigator.pop(context);
              },
            ),
            title: RichText(
              textAlign: TextAlign.center,
              text: TextSpan(children: [
                TextSpan(
                  text: _writeController.title.isNotEmpty ? _writeController.title : 'untitled'.tr(),
                  style: Theme.of(context).textTheme.titleLarge!.copyWith(color: Colors.white),
                ),
                const TextSpan(text: '\n'),
                TextSpan(
                  text: PostWriteController.kTitleMap[widget.mode]!.tr(),
                  style: Theme.of(context).textTheme.bodySmall!.copyWith(color: Colors.white),
                ),
              ]),
            ),
            actions: [
              IconButton(
                icon: const Icon(Symbols.tune),
                onPressed: _writeController.isBusy ? null : _updateMeta,
              ),
              const Gap(8),
            ],
          ),
          body: Column(
            children: [
              DropdownButtonHideUnderline(
                child: DropdownButton2<SnPublisher>(
                  isExpanded: true,
                  hint: Text(
                    'fieldPostPublisher',
                    style: TextStyle(
                      fontSize: 14,
                      color: Theme.of(context).hintColor,
                    ),
                  ).tr(),
                  items: <DropdownMenuItem<SnPublisher>>[
                    ...(_publishers?.map(
                          (item) => DropdownMenuItem<SnPublisher>(
                            enabled: _writeController.editingPost == null,
                            value: item,
                            child: Row(
                              children: [
                                AccountImage(content: item.avatar, radius: 16),
                                const Gap(8),
                                Expanded(
                                  child: Column(
                                    mainAxisSize: MainAxisSize.min,
                                    crossAxisAlignment: CrossAxisAlignment.start,
                                    children: [
                                      Text(item.nick).textStyle(Theme.of(context).textTheme.bodyMedium!),
                                      Text('@${item.name}')
                                          .textStyle(Theme.of(context).textTheme.bodySmall!)
                                          .fontSize(12),
                                    ],
                                  ),
                                ),
                              ],
                            ),
                          ),
                        ) ??
                        []),
                    DropdownMenuItem<SnPublisher>(
                      value: null,
                      child: Row(
                        children: [
                          CircleAvatar(
                            radius: 16,
                            backgroundColor: Colors.transparent,
                            foregroundColor: Theme.of(context).colorScheme.onSurface,
                            child: const Icon(Symbols.add),
                          ),
                          const Gap(8),
                          Expanded(
                            child: Column(
                              mainAxisSize: MainAxisSize.min,
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                Text('publishersNew').tr().textStyle(Theme.of(context).textTheme.bodyMedium!),
                              ],
                            ),
                          ),
                        ],
                      ),
                    ),
                  ],
                  value: _writeController.publisher,
                  onChanged: (SnPublisher? value) {
                    if (value == null) {
                      GoRouter.of(context).pushNamed('accountPublisherNew').then((value) {
                        if (value == true) {
                          _publishers = null;
                          _fetchPublishers();
                        }
                      });
                    } else {
                      _writeController.setPublisher(value);
                    }
                  },
                  buttonStyleData: const ButtonStyleData(
                    padding: EdgeInsets.only(right: 16),
                    height: 48,
                  ),
                  menuItemStyleData: const MenuItemStyleData(
                    height: 48,
                  ),
                ),
              ),
              const Divider(height: 1),
              Expanded(
                child: SingleChildScrollView(
                  padding: EdgeInsets.only(bottom: 8),
                  child: Column(
                    children: [
                      // Replying Notice
                      if (_writeController.replyingPost != null)
                        Column(
                          children: [
                            Theme(
                              data: Theme.of(context).copyWith(
                                dividerColor: Colors.transparent,
                              ),
                              child: ExpansionTile(
                                minTileHeight: 48,
                                leading: const Icon(Symbols.reply).padding(left: 4),
                                title: Text('postReplyingNotice')
                                    .fontSize(15)
                                    .tr(args: ['@${_writeController.replyingPost!.publisher.name}']),
                                children: <Widget>[PostItem(data: _writeController.replyingPost!)],
                              ),
                            ),
                            const Divider(height: 1),
                          ],
                        ),
                      // Reposting Notice
                      if (_writeController.repostingPost != null)
                        Column(
                          children: [
                            Theme(
                              data: Theme.of(context).copyWith(
                                dividerColor: Colors.transparent,
                              ),
                              child: ExpansionTile(
                                minTileHeight: 48,
                                leading: const Icon(Symbols.forward).padding(left: 4),
                                title: Text('postRepostingNotice')
                                    .fontSize(15)
                                    .tr(args: ['@${_writeController.repostingPost!.publisher.name}']),
                                children: <Widget>[
                                  PostItem(
                                    data: _writeController.repostingPost!,
                                  )
                                ],
                              ),
                            ),
                            const Divider(height: 1),
                          ],
                        ),
                      // Editing Notice
                      if (_writeController.editingPost != null)
                        Column(
                          children: [
                            Theme(
                              data: Theme.of(context).copyWith(
                                dividerColor: Colors.transparent,
                              ),
                              child: ExpansionTile(
                                minTileHeight: 48,
                                leading: const Icon(Symbols.edit_note).padding(left: 4),
                                title: Text('postEditingNotice')
                                    .fontSize(15)
                                    .tr(args: ['@${_writeController.editingPost!.publisher.name}']),
                                children: <Widget>[PostItem(data: _writeController.editingPost!)],
                              ),
                            ),
                            const Divider(height: 1),
                          ],
                        ),
                      // Content Input Area
                      TextField(
                        controller: _writeController.contentController,
                        maxLines: null,
                        decoration: InputDecoration(
                          hintText: 'fieldPostContent'.tr(),
                          hintStyle: TextStyle(fontSize: 14),
                          isCollapsed: true,
                          contentPadding: const EdgeInsets.symmetric(
                            horizontal: 16,
                          ),
                          border: InputBorder.none,
                        ),
                        onTapOutside: (_) => FocusManager.instance.primaryFocus?.unfocus(),
                      ),
                    ]
                        .expandIndexed(
                          (idx, ele) => [
                            if (idx != 0 || _writeController.isRelatedNull) const Gap(8),
                            ele,
                          ],
                        )
                        .toList(),
                  ),
                ),
              ),
              if (_writeController.attachments.isNotEmpty || _writeController.thumbnail != null)
                PostMediaPendingList(
                  thumbnail: _writeController.thumbnail,
                  attachments: _writeController.attachments,
                  isBusy: _writeController.isBusy,
                  onUpload: (int idx) async {
                    await _writeController.uploadSingleAttachment(context, idx);
                  },
                  onPostSetThumbnail: (int? idx) {
                    _writeController.setThumbnail(idx);
                  },
                  onInsertLink: (int idx) async {
                    _writeController.contentController.text +=
                        '\n![](solink://attachments/${_writeController.attachments[idx].attachment!.rid})';
                  },
                  onUpdate: (int idx, PostWriteMedia updatedMedia) async {
                    _writeController.setIsBusy(true);
                    try {
                      _writeController.setAttachmentAt(idx, updatedMedia);
                    } finally {
                      _writeController.setIsBusy(false);
                    }
                  },
                  onRemove: (int idx) async {
                    _writeController.setIsBusy(true);
                    try {
                      _writeController.removeAttachmentAt(idx);
                    } finally {
                      _writeController.setIsBusy(false);
                    }
                  },
                  onUpdateBusy: (state) => _writeController.setIsBusy(state),
                ).padding(bottom: 8),
              Material(
                elevation: 2,
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    LoadingIndicator(isActive: _isLoading),
                    if (_writeController.isBusy && _writeController.progress != null)
                      TweenAnimationBuilder<double>(
                        tween: Tween(begin: 0, end: _writeController.progress),
                        duration: Duration(milliseconds: 300),
                        builder: (context, value, _) => LinearProgressIndicator(value: value, minHeight: 2),
                      )
                    else if (_writeController.isBusy)
                      const LinearProgressIndicator(value: null, minHeight: 2),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        Expanded(
                          child: ScrollConfiguration(
                            behavior: _PostEditorActionScrollBehavior(),
                            child: SingleChildScrollView(
                              scrollDirection: Axis.vertical,
                              child: Row(
                                children: [
                                  PopupMenuButton(
                                    icon: Icon(
                                      Symbols.add_photo_alternate,
                                      color: Theme.of(context).colorScheme.primary,
                                    ),
                                    itemBuilder: (context) => [
                                      PopupMenuItem(
                                        child: Row(
                                          children: [
                                            const Icon(Symbols.photo_library),
                                            const Gap(16),
                                            Text('addAttachmentFromAlbum').tr(),
                                          ],
                                        ),
                                        onTap: () {
                                          _selectMedia();
                                        },
                                      ),
                                      PopupMenuItem(
                                        child: Row(
                                          children: [
                                            const Icon(Symbols.content_paste),
                                            const Gap(16),
                                            Text('addAttachmentFromClipboard').tr(),
                                          ],
                                        ),
                                        onTap: () {
                                          _pasteMedia();
                                        },
                                      ),
                                    ],
                                  ),
                                ],
                              ),
                            ),
                          ),
                        ),
                        TextButton.icon(
                          onPressed: (_writeController.isBusy || _writeController.publisher == null)
                              ? null
                              : () {
                                  _writeController.post(context).then((_) {
                                    if (!context.mounted) return;
                                    Navigator.pop(context, true);
                                  });
                                },
                          icon: const Icon(Symbols.send),
                          label: Text('postPublish').tr(),
                        ),
                      ],
                    ).padding(horizontal: 16),
                  ],
                ).padding(
                  bottom: MediaQuery.of(context).padding.bottom,
                  top: 4,
                ),
              ),
            ],
          ),
        );
      },
    );
  }
}

class _PostEditorActionScrollBehavior extends MaterialScrollBehavior {
  @override
  Set<PointerDeviceKind> get dragDevices => {
        PointerDeviceKind.touch,
        PointerDeviceKind.mouse,
      };
}