import 'package:flutter/material.dart';
import 'package:logging/logging.dart';
import 'package:provider/provider.dart';
import 'package:scrollable_positioned_list/scrollable_positioned_list.dart';

import '../../models/entry_tree_item.dart';
import '../../models/flattened_tree_item.dart';
import '../../models/timeline_entry.dart';
import '../../services/timeline_manager.dart';
import '../../utils/entry_tree_item_flattening.dart';
import 'flattened_tree_entry_control.dart';

class PostControl extends StatefulWidget {
  final EntryTreeItem originalItem;
  final String scrollToId;
  final bool openRemote;
  final bool showStatusOpenButton;
  final bool isRoot;

  const PostControl({
    super.key,
    required this.originalItem,
    required this.scrollToId,
    required this.openRemote,
    required this.showStatusOpenButton,
    required this.isRoot,
  });

  @override
  State<PostControl> createState() => _PostControlState();
}

class _PostControlState extends State<PostControl> {
  static final _logger = Logger('$PostControl');

  final ItemScrollController itemScrollController = ItemScrollController();
  final ItemPositionsListener itemPositionsListener =
      ItemPositionsListener.create();

  var showContent = true;

  var showComments = false;

  EntryTreeItem get item => widget.originalItem;

  TimelineEntry get entry => item.entry;

  bool get isPublic => item.entry.isPublic;

  bool get hasComments => entry.engagementSummary.repliesCount > 0;

  @override
  void initState() {
    showContent = entry.spoilerText.isEmpty;
    showComments = widget.scrollToId != item.id;
  }

  @override
  Widget build(BuildContext context) {
    final manager = context.watch<TimelineManager>();
    _logger.finest('Building ${item.entry.toShortString()}');
    final items = widget.originalItem.flatten(topLevelOnly: !showComments);

    if (widget.isRoot) {
      return buildListView(context, items, manager);
    } else {
      return buildColumnView(context, items, manager);
    }
  }

  Widget buildColumnView(
    BuildContext context,
    List<FlattenedTreeItem> items,
    TimelineManager manager,
  ) {
    final widgets = <Widget>[];
    for (var i = 0; i < items.length; i++) {
      final itemWidget = FlattenedTreeEntryControl(
        originalItem: items[i],
        openRemote: widget.openRemote,
        showStatusOpenButton: widget.showStatusOpenButton,
      );

      widgets.add(itemWidget);
      if (i == 0 && hasComments) {
        widgets.add(
          TextButton(
            onPressed: () async {
              setState(() {
                showComments = !showComments;
              });
              if (showComments) {
                await manager.refreshStatusChain(entry.id);
              }
            },
            child:
                Text(showComments ? 'Hide Comments' : 'Load & Show Comments'),
          ),
        );
      }
    }
    return Column(children: widgets);
  }

  Widget buildListView(
    BuildContext context,
    List<FlattenedTreeItem> items,
    TimelineManager manager,
  ) {
    final int count;
    final int offset;
    final int scrollToIndex;
    if (hasComments && showComments) {
      count = items.length + 1;
      offset = 1;
      scrollToIndex = items.indexWhere(
        (e) => e.timelineEntry.id == widget.scrollToId,
      );
    } else if (hasComments) {
      count = 2;
      offset = 0;
      scrollToIndex = 0;
    } else {
      count = 1;
      offset = 0;
      scrollToIndex = 0;
    }
    return ScrollablePositionedList.builder(
        itemCount: count,
        initialScrollIndex: scrollToIndex,
        itemScrollController: itemScrollController,
        itemPositionsListener: itemPositionsListener,
        itemBuilder: (context, index) {
          if (index == 0) {
            return FlattenedTreeEntryControl(
              originalItem: items.first,
              openRemote: widget.openRemote,
              showStatusOpenButton: widget.showStatusOpenButton,
            );
          }
          if (index == 1 && hasComments) {
            return TextButton(
              onPressed: () async {
                setState(() {
                  showComments = !showComments;
                });
                if (showComments) {
                  await manager.refreshStatusChain(entry.id);
                }
              },
              child:
                  Text(showComments ? 'Hide Comments' : 'Load & Show Comments'),
            );
          }
          return FlattenedTreeEntryControl(
            originalItem: items[index - offset],
            openRemote: widget.openRemote,
            showStatusOpenButton: widget.showStatusOpenButton,
          );
        });
  }
}