import 'package:PiliPalaX/http/loading_state.dart';
import 'package:easy_debounce/easy_throttle.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:PiliPalaX/common/widgets/http_error.dart';
import 'package:PiliPalaX/common/widgets/no_data.dart';

import '../../common/constants.dart';
import '../../utils/grid.dart';
import 'controller.dart';
import 'widgets/fan_item.dart';

class FansPage extends StatefulWidget {
  const FansPage({super.key});

  @override
  State<FansPage> createState() => _FansPageState();
}

class _FansPageState extends State<FansPage> {
  late String mid;
  late FansController _fansController;

  @override
  void initState() {
    super.initState();
    mid = Get.parameters['mid']!;
    _fansController = Get.put(FansController(), tag: mid);
    _fansController.scrollController.addListener(
      () async {
        if (_fansController.scrollController.position.pixels >=
            _fansController.scrollController.position.maxScrollExtent - 200) {
          EasyThrottle.throttle('follow', const Duration(seconds: 1), () {
            _fansController.onLoadMore();
          });
        }
      },
    );
  }

  @override
  void dispose() {
    _fansController.scrollController.removeListener(() {});
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        elevation: 0,
        scrolledUnderElevation: 0,
        centerTitle: false,
        titleSpacing: 0,
        title: Text(
          _fansController.isOwner.value ? '我的粉丝' : '${_fansController.name}的粉丝',
          style: Theme.of(context).textTheme.titleMedium,
        ),
      ),
      body: RefreshIndicator(
        onRefresh: () async => await _fansController.onRefresh(),
        child: CustomScrollView(
          physics: const AlwaysScrollableScrollPhysics(),
          controller: _fansController.scrollController,
          slivers: [
            Obx(() => _buildBody(_fansController.loadingState.value)),
          ],
        ),
      ),
    );
  }

  Widget _buildBody(LoadingState loadingState) {
    return loadingState is Success
        ? loadingState.response.isNotEmpty
            ? SliverGrid(
                gridDelegate: SliverGridDelegateWithMaxCrossAxisExtent(
                    mainAxisSpacing: StyleString.cardSpace,
                    crossAxisSpacing: StyleString.safeSpace,
                    maxCrossAxisExtent: Grid.maxRowWidth * 2,
                    mainAxisExtent: 56),
                delegate: SliverChildBuilderDelegate(
                  (BuildContext context, int index) {
                    return fanItem(item: loadingState.response[index]);
                  },
                  childCount: loadingState.response.length,
                ))
            : const NoData()
        : loadingState is Error
            ? HttpError(
                errMsg: loadingState.errMsg,
                fn: _fansController.onReload,
              )
            : const SliverToBoxAdapter(
                child: SizedBox(
                  height: 200,
                  child: Center(
                    child: CircularProgressIndicator(),
                  ),
                ),
              );
  }
}