import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'pages/NewsListPage.dart';
import 'pages/TweetsListPage.dart';
import 'pages/DiscoveryPage.dart';
import 'pages/MyInfoPage.dart';
import './widgets/MyDrawer.dart';

void main() {
  runApp(MyOSCClient());
}

class MyOSCClient extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => MyOSCClientState();
}

class MyOSCClientState extends State<MyOSCClient> {
  int _tabIndex = 0;
  final tabTextStyleNormal = TextStyle(color: const Color(0xff969696));
  final tabTextStyleSelected = TextStyle(color: const Color(0xff63ca6c));

  var tabImages;
  var _body;
  var appBarTitles = ['资讯', '动弹', '发现', '我的'];

  Image getTabImage(path) {
    return Image.asset(path, width: 20.0, height: 20.0);
  }

  void initData() {
    if (tabImages == null) {
      tabImages = [
        [
          getTabImage('images/ic_nav_news_normal.png'),
          getTabImage('images/ic_nav_news_actived.png')
        ],
        [
          getTabImage('images/ic_nav_tweet_normal.png'),
          getTabImage('images/ic_nav_tweet_actived.png')
        ],
        [
          getTabImage('images/ic_nav_discover_normal.png'),
          getTabImage('images/ic_nav_discover_actived.png')
        ],
        [
          getTabImage('images/ic_nav_my_normal.png'),
          getTabImage('images/ic_nav_my_pressed.png')
        ]
      ];
    }
    _body = IndexedStack(
      children: [
        NewsListPage(),
        TweetsListPage(),
        DiscoveryPage(),
        MyInfoPage()
      ],
      index: _tabIndex,
    );
  }

  TextStyle getTabTextStyle(int curIndex) {
    if (curIndex == _tabIndex) {
      return tabTextStyleSelected;
    }
    return tabTextStyleNormal;
  }

  Image getTabIcon(int curIndex) {
    if (curIndex == _tabIndex) {
      return tabImages[curIndex][1];
    }
    return tabImages[curIndex][0];
  }

  String getTabTitle(int curIndex) {
    return appBarTitles[
        curIndex]; //Text(appBarTitles[curIndex], style: getTabTextStyle(curIndex));
  }

  @override
  Widget build(BuildContext context) {
    initData();
    return MaterialApp(
      theme: ThemeData(primaryColor: const Color(0xFF63CA6C)),
      home: Scaffold(
        appBar: AppBar(
            title: Text(appBarTitles[_tabIndex],
                style: TextStyle(color: Colors.white)),
            iconTheme: IconThemeData(color: Colors.white)),
        body: _body,
        bottomNavigationBar: CupertinoTabBar(
          items: <BottomNavigationBarItem>[
            BottomNavigationBarItem(icon: getTabIcon(0), label: getTabTitle(0)),
            BottomNavigationBarItem(icon: getTabIcon(1), label: getTabTitle(1)),
            BottomNavigationBarItem(icon: getTabIcon(2), label: getTabTitle(2)),
            BottomNavigationBarItem(icon: getTabIcon(3), label: getTabTitle(3)),
          ],
          currentIndex: _tabIndex,
          onTap: (index) {
            setState(() {
              _tabIndex = index;
            });
          },
        ),
        drawer: MyDrawer(),
      ),
    );
  }
}