import 'package:fl_query/models/query_job.dart';
import 'package:fl_query/query.dart';
import 'package:fl_query/query_bowl.dart';
import 'package:fl_query/utils.dart';
import 'package:flutter/widgets.dart';

class QueryBuilder<T extends Object, Outside> extends StatefulWidget {
  final Function(BuildContext, Query<T, Outside>) builder;
  final QueryJob<T, Outside> job;
  final Outside externalData;

  /// Called when the query returns new data, on query
  /// refetch or query gets expired
  final QueryListener<T>? onData;

  /// Called when the query returns error
  final QueryListener<dynamic>? onError;

  const QueryBuilder({
    required this.job,
    required this.externalData,
    required this.builder,
    this.onData,
    this.onError,
    Key? key,
  }) : super(key: key);

  @override
  State<QueryBuilder<T, Outside>> createState() =>
      _QueryBuilderState<T, Outside>();
}

class _QueryBuilderState<T extends Object, Outside>
    extends State<QueryBuilder<T, Outside>> {
  late QueryBowl queryBowl;
  late final ValueKey<String> uKey;
  late Query<T, Outside> query;

  @override
  void initState() {
    super.initState();
    uKey = ValueKey<String>(uuid.v4());
    query = Query<T, Outside>.fromOptions(
      widget.job,
      externalData: widget.externalData,
    );
    WidgetsBinding.instance.addPostFrameCallback((_) async {
      query = QueryBowl.of(context).addQuery<T, Outside>(
        query,
        key: uKey,
        onData: widget.onData,
        onError: widget.onError,
      );
      await query.fetch();
    });
  }

  @override
  void didUpdateWidget(covariant oldWidget) {
    if (oldWidget.externalData != widget.externalData) {
      QueryBowl.of(context).fetchQuery(
        widget.job,
        externalData: widget.externalData,
        onData: widget.onData,
        onError: widget.onError,
        key: uKey,
      );
    } else {
      if (oldWidget.onData != widget.onData && oldWidget.onData != null) {
        query.onDataListeners.remove(oldWidget.onData);
        if (widget.onData != null) query.onDataListeners.add(widget.onData!);
      }
      if (oldWidget.onError != widget.onError && oldWidget.onError != null) {
        query.onErrorListeners.remove(oldWidget.onError);
        if (widget.onError != null) query.onErrorListeners.add(widget.onError!);
      }
    }
    super.didUpdateWidget(oldWidget);
  }

  @override
  void dispose() {
    query.unmount(uKey);
    if (widget.onData != null) query.onDataListeners.remove(widget.onData);
    if (widget.onError != null) query.onErrorListeners.remove(widget.onError);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    queryBowl = QueryBowl.of(context);
    final latestQuery = queryBowl.getQuery<T, Outside>(query.queryKey) ?? query;
    return widget.builder(context, latestQuery);
  }
}