MerchantSliverAppbar

import 'package:app/router.dart';
import 'package:app/src/components/buttons/about_merchant_button.dart';
import 'package:app/src/components/buttons/back_button.dart';
import 'package:app/src/components/buttons/follow_button.dart';
import 'package:app/src/components/buttons/search_button.dart';
import 'package:app/src/components/cards/merchant_thumbnail_card.dart';
import 'package:app/src/components/icons/follower_count_icon.dart';
import 'package:app/src/constants/custom_colors.dart';
import 'package:app/src/models/merchant_model.dart';
import 'package:flutter/material.dart';

class MerchantSliverAppbar extends StatefulWidget {
  final Merchant merchant;
  const MerchantSliverAppbar({
    Key? key,
    required this.merchant,
  }) : super(key: key);

  @override
  _MerchantSliverAppbarState createState() => _MerchantSliverAppbarState();
}

class _MerchantSliverAppbarState extends State<MerchantSliverAppbar> {
  @override
  Widget build(BuildContext context) {
    final size = MediaQuery.of(context).size;
    // final maxHeightAppbar = 80;
    return SliverAppBar(
      expandedHeight: 200.0,
      pinned: true,
      floating: false,
      snap: false,
      backgroundColor: CustomColors.white,
      leading: CustomBackButton(greyBackground: false),
      flexibleSpace: merchantExpandedView(size),
      actions: [
        CustomSearchButton(
          greyBackground: false,
          onPressed: () {
            openSearchPage(context);
          },
        ),
      ],
    );
  }

  Widget merchantExpandedView(size) {
    return Container(
      child: LayoutBuilder(
        builder: (BuildContext context, BoxConstraints constraints) {
          double scrollPosition = constraints.biggest.height;
          return FlexibleSpaceBar(
            centerTitle: true,
            title: scrollPosition < 80
                ? buildTitle(scrollPosition, CustomColors.primary)
                : null,
            background: Stack(
              children: <Widget>[
                _buildBackgroundImage(),
                Positioned(
                  bottom: 30.0,
                  left: 15.0,
                  child: _buildMerchantInfo(scrollPosition),
                ),
              ],
            ),
          );
        },
      ),
    );
  }

  Widget _buildBackgroundImage() {
    return ClipRRect(
      borderRadius: BorderRadius.only(
        bottomLeft: Radius.circular(20),
        bottomRight: Radius.circular(20),
      ),
      child: Container(
        decoration: BoxDecoration(
          borderRadius: BorderRadius.only(
            bottomRight: Radius.circular(20.0),
            bottomLeft: Radius.circular(20.0),
          ),
          image: DecorationImage(
            image: AssetImage('assets/images/mock_background.png'),
            fit: BoxFit.cover,
          ),
        ),
      ),
    );
  }

  Widget _buildMerchantInfo(double scrollPosition) {
    return Container(
      padding: EdgeInsets.all(20),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              MerchantThumbnailCard(
                imageUrl: "assets/images/aarong_logo_small.png",
              ),
              SizedBox(width: 15),
              Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(
                    children: [
                      buildTitle(scrollPosition, CustomColors.white),
                      SizedBox(width: 40),
                      _buildRadting(),
                    ],
                  ),
                  SizedBox(
                    height: 15,
                  ),
                  _buildButtonRow(),
                ],
              ),
            ],
          ),
        ],
      ),
    );
  }

  Widget buildTitle(double scrollPosition, Color color) {
    return Text(
      widget.merchant.merchantName!.toUpperCase(),
      maxLines: 1,
      style: TextStyle(
        color: color,
        fontSize: 20.0,
        fontWeight: FontWeight.w500,
      ),
    );
  }

  Widget _buildRadting() {
    return Container(
      child: Row(
        children: [
          Icon(
            Icons.star,
            color: Colors.amber,
            size: 18,
          ),
          Text(
            "4.5",
            style: TextStyle(
              color: CustomColors.primary,
              fontSize: 18,
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildButtonRow() {
    return Row(
      children: [
        FollowButton(
          isFollowing: false,
          blackBackground: false,
          onPressed: () {},
        ),
        SizedBox(width: 20),
        FollowerCountIcon(
          followerCount: widget.merchant.merchantFollowers!.toInt(),
        ),
        SizedBox(width: 20),
        AboutMerchantButton(
          onPressed: () {
            openMerchantProfilePage(context);
          },
        ),
      ],
    );
  }
}