import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

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

  @override
  State<AnimatedBackground> createState() => _AnimatedBackgroundState();
}

class _AnimatedBackgroundState extends State<AnimatedBackground> with SingleTickerProviderStateMixin {

  late AnimationController _controller;
  late Animation<Alignment> _topAnimationAlignment;
  late Animation<Alignment> _bottomAnimationAlignment;

  @override
  void initState(){
    super.initState();
    SystemChrome.setSystemUIOverlayStyle(const SystemUiOverlayStyle(statusBarColor: Colors.transparent,statusBarIconBrightness: Brightness.dark,));
    _controller= AnimationController(vsync: this, duration: Duration(seconds: 5));

    _topAnimationAlignment =TweenSequence<Alignment>(
      [
        TweenSequenceItem<Alignment>
          (tween: Tween<Alignment>(begin: Alignment.topLeft,end: Alignment.topRight),
            weight: 1),
        TweenSequenceItem<Alignment>
          (tween: Tween<Alignment>(begin: Alignment.topRight,end: Alignment.bottomRight),
            weight: 2),
        TweenSequenceItem<Alignment>
          (tween: Tween<Alignment>(begin: Alignment.bottomRight,end: Alignment.bottomLeft),
            weight: 1),
        TweenSequenceItem<Alignment>
          (tween: Tween<Alignment>(begin: Alignment.bottomLeft,end: Alignment.topLeft),
            weight: 2),
      ]
    ).animate(_controller);

    _bottomAnimationAlignment =TweenSequence<Alignment>(
        [
          TweenSequenceItem<Alignment>
            (tween: Tween<Alignment>(begin: Alignment.bottomRight,end: Alignment.bottomLeft),
              weight: 1),
          TweenSequenceItem<Alignment>
            (tween: Tween<Alignment>(begin: Alignment.bottomLeft,end: Alignment.topLeft),
              weight: 2),
          TweenSequenceItem<Alignment>
            (tween: Tween<Alignment>(begin: Alignment.topLeft,end: Alignment.topRight),
              weight: 1),
          TweenSequenceItem<Alignment>
            (tween: Tween<Alignment>(begin: Alignment.topRight,end: Alignment.bottomRight),
              weight: 2),
        ]
    ).animate(_controller);

    _controller.repeat();
  }


  @override
  Widget build(BuildContext context) {
    Size screenSize =MediaQuery.of(context).size;
    return Scaffold(

      body: AnimatedBuilder(
        animation: _controller,
        builder: (context,widget){
          return Container(
            height: screenSize.height,
            width: screenSize.width,
            decoration: BoxDecoration(
                gradient: LinearGradient(
                    begin: _topAnimationAlignment.value,
                    end: _bottomAnimationAlignment.value,
                    colors:  [
                      Colors.cyan.shade300,
                      Colors.cyan.shade800,
                    ]
                )
            ),
          );
        },


      )

    );
  }
}