tm_app/lib/views/tenders/widgets/main_tenders_slider.dart

import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';
import 'package:provider/provider.dart';
import 'package:tm_app/core/theme/colors.dart';
import 'package:tm_app/data/services/model/tender_data/tender_data.dart';
import 'package:tm_app/view_models/tenders_view_model.dart';

import '../../../core/constants/assets.dart';
import '../../../core/utils/size_config.dart';
import 'tender_card.dart';

class MainTendersSlider extends StatefulWidget {
  const MainTendersSlider({
    required this.tenders,
    super.key,
    this.isDesktop = false,
  });
  final bool isDesktop;
  final List<TenderData> tenders;

  @override
  State<MainTendersSlider> createState() => _MainTendersSliderState();
}

class _MainTendersSliderState extends State<MainTendersSlider> {
  final PageController pageController = PageController(initialPage: 0);

  int currentPage = 1;

  void _goToPreviousPage() {
    if (currentPage == 1) {
      return;
    }

    pageController.previousPage(
      duration: const Duration(milliseconds: 300),
      curve: Curves.easeInOutCubic,
    );
    setState(() {
      currentPage = currentPage - 1;
    });

    // Fetch feedback and approvals for the previous tender if not already loaded
    final viewModel = context.read<TendersViewModel>();
    final previousTenderId = widget.tenders[currentPage - 2].id!;
    if (!viewModel.hasFeedbackForTender(previousTenderId)) {
      viewModel.getTenderFeedback(previousTenderId);
    }
    if (!viewModel.hasTenderApprovalForTender(previousTenderId)) {
      viewModel.getTenderApprovals(previousTenderId);
    }
  }

  void _goToNextPage() {
    if (currentPage == widget.tenders.length) {
      return;
    }

    pageController.nextPage(
      duration: const Duration(milliseconds: 300),
      curve: Curves.easeInOutCubic,
    );
    setState(() {
      currentPage = currentPage + 1;
    });

    // Fetch feedback and approvals for the next tender if not already loaded
    final viewModel = context.read<TendersViewModel>();
    final nextTenderId = widget.tenders[currentPage].id!;
    if (!viewModel.hasFeedbackForTender(nextTenderId)) {
      viewModel.getTenderFeedback(nextTenderId);
    }
    if (!viewModel.hasTenderApprovalForTender(nextTenderId)) {
      viewModel.getTenderApprovals(nextTenderId);
    }
  }

  @override
  void dispose() {
    pageController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      child: Stack(children: [_tendersPageView(), _nextPreviousArrows()]),
    );
  }

  Widget _tendersPageView() {
    return SizedBox(
      width: double.infinity,
      height: 722.0.h(),
      child: PageView.builder(
        controller: pageController,
        scrollDirection: Axis.horizontal,
        itemCount: widget.tenders.length,
        onPageChanged: (index) {
          setState(() {
            currentPage = index + 1;
          });

          // Fetch feedback and approvals for the new tender if not already loaded
          final viewModel = context.read<TendersViewModel>();
          if (!viewModel.hasFeedbackForTender(widget.tenders[index].id!)) {
            viewModel.getTenderFeedback(widget.tenders[index].id!);
          }
          if (!viewModel.hasTenderApprovalForTender(
            widget.tenders[index].id!,
          )) {
            viewModel.getTenderApprovals(widget.tenders[index].id!);
          }

          // Check if we need to load more tenders (when user reaches near the end)
          if (index >= widget.tenders.length - 1 &&
              viewModel.hasMoreData &&
              !viewModel.isLoadingMore) {
            viewModel.loadMoreTenders();
          }
        },
        itemBuilder: (context, index) {
          final tender = widget.tenders[index];
          return TenderCard(tender: tender, isDesktop: widget.isDesktop);
        },
      ),
    );
  }

  Widget _nextPreviousArrows() {
    return Positioned(
      top: 607.0.h(),
      bottom: 52.0.h(),
      left: 9.0.w(),
      right: 9.0.w(),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [_leftArrowButton(), _pageNumberText(), _rightArrowButton()],
      ),
    );
  }

  Widget _leftArrowButton() {
    return Visibility(
      visible: currentPage != 1,
      child: InkWell(
        borderRadius: BorderRadius.circular(100),
        onTap: _goToPreviousPage,
        child: Container(
          width: 32.0.h(),
          height: 32.0.h(),
          decoration: BoxDecoration(
            shape: BoxShape.circle,
            border: Border.all(color: AppColors.iconColor, width: 1.5),
          ),
          alignment: Alignment.center,
          child: SvgPicture.asset(
            AssetsManager.arrowLeftSmall,
            colorFilter: ColorFilter.mode(
              AppColors.iconColor,
              BlendMode.srcATop,
            ),
          ),
        ),
      ),
    );
  }

  Widget _pageNumberText() {
    final viewModel = context.watch<TendersViewModel>();
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        viewModel.isLoadingMore
            ? Padding(
              padding: EdgeInsets.only(top: 4.0.h()),
              child: SizedBox(
                width: 16.0.w(),
                height: 16.0.w(),
                child: const CircularProgressIndicator(
                  strokeWidth: 2.0,
                  color: AppColors.jellyBean,
                ),
              ),
            )
            : Text(
              '$currentPage/${widget.tenders.length}',
              style: TextStyle(
                fontSize: 14.0.sp(),
                fontWeight: FontWeight.w500,
                color: AppColors.grey,
              ),
            ),
      ],
    );
  }

  Widget _rightArrowButton() {
    return Visibility(
      visible: currentPage != widget.tenders.length,
      child: InkWell(
        borderRadius: BorderRadius.circular(100),
        onTap: _goToNextPage,
        child: Container(
          width: 32.0.h(),
          height: 32.0.h(),
          decoration: BoxDecoration(
            shape: BoxShape.circle,
            border: Border.all(color: AppColors.iconColor, width: 1.5),
          ),
          alignment: Alignment.center,
          child: SvgPicture.asset(
            AssetsManager.arrowRightSmall,
            colorFilter: ColorFilter.mode(
              AppColors.iconColor,
              BlendMode.srcATop,
            ),
          ),
        ),
      ),
    );
  }
}