import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:lemmy_api_client/v3.dart';

import '../hooks/delayed_loading.dart';
import '../hooks/logged_in_action.dart';
import '../l10n/l10n.dart';
import 'editor.dart';
import 'markdown_mode_icon.dart';
import 'markdown_text.dart';

/// Modal for writing/editing a comment to a given post/comment (aka reply)
/// on submit pops the navigator stack with a [CommentView]
/// or `null` if cancelled
class WriteComment extends HookWidget {
  final Post post;
  final Comment? comment;
  final bool _isEdit;

  const WriteComment.toPost(this.post)
      : comment = null,
        _isEdit = false;
  const WriteComment.toComment({
    required Comment this.comment,
    required this.post,
  }) : _isEdit = false;
  const WriteComment.edit({
    required Comment this.comment,
    required this.post,
  }) : _isEdit = true;

  @override
  Widget build(BuildContext context) {
    final controller =
        useTextEditingController(text: _isEdit ? comment?.content : null);
    final showFancy = useState(false);
    final delayed = useDelayedLoading();
    final loggedInAction = useLoggedInAction(post.instanceHost);

    final preview = () {
      final body = () {
        final text = comment?.content ?? post.body;
        if (text == null) return const SizedBox.shrink();
        return MarkdownText(
          text,
          instanceHost: post.instanceHost,
          selectable: true,
        );
      }();

      return Column(
        children: [
          SelectableText(
            post.name,
            style: const TextStyle(fontSize: 15, fontWeight: FontWeight.w600),
          ),
          const SizedBox(height: 4),
          body,
        ],
      );
    }();

    handleSubmit(Jwt token) async {
      final api = LemmyApiV3(post.instanceHost);

      delayed.start();
      try {
        final res = await () {
          if (_isEdit) {
            return api.run(EditComment(
              commentId: comment!.id,
              content: controller.text,
              auth: token.raw,
            ));
          } else {
            return api.run(CreateComment(
              content: controller.text,
              postId: post.id,
              parentId: comment?.id,
              auth: token.raw,
            ));
          }
        }();
        Navigator.of(context).pop(res.commentView);
      } catch (e) {
        ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('Failed to post comment')));
      }
      delayed.cancel();
    }

    return Scaffold(
      appBar: AppBar(
        leading: const CloseButton(),
        actions: [
          IconButton(
            icon: markdownModeIcon(fancy: showFancy.value),
            onPressed: () => showFancy.value = !showFancy.value,
          ),
        ],
      ),
      body: ListView(
        children: [
          ConstrainedBox(
            constraints: BoxConstraints(
                maxHeight: MediaQuery.of(context).size.height * .35),
            child: SingleChildScrollView(
              padding: const EdgeInsets.all(8),
              child: preview,
            ),
          ),
          const Divider(),
          Editor(
            instanceHost: post.instanceHost,
            controller: controller,
            autofocus: true,
            fancy: showFancy.value,
          ),
          Row(
            mainAxisAlignment: MainAxisAlignment.end,
            children: [
              TextButton(
                onPressed:
                    delayed.pending ? () {} : loggedInAction(handleSubmit),
                child: delayed.loading
                    ? const CircularProgressIndicator.adaptive()
                    : Text(_isEdit
                        ? L10n.of(context).edit
                        : L10n.of(context).post),
              )
            ],
          ),
        ],
      ),
    );
  }

  static Route<CommentView> toPostRoute(Post post) => MaterialPageRoute(
        builder: (context) => WriteComment.toPost(post),
        fullscreenDialog: true,
      );

  static Route<CommentView> toCommentRoute({
    required Comment comment,
    required Post post,
  }) =>
      MaterialPageRoute(
        builder: (context) =>
            WriteComment.toComment(comment: comment, post: post),
        fullscreenDialog: true,
      );

  static Route<CommentView> editRoute({
    required Comment comment,
    required Post post,
  }) =>
      MaterialPageRoute(
        builder: (context) => WriteComment.edit(comment: comment, post: post),
        fullscreenDialog: true,
      );
}