import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';
import 'package:provider/provider.dart';
import 'package:tm_app/core/extensions/board_data_extension.dart';
import 'package:tm_app/core/theme/colors.dart';
import 'package:tm_app/core/utils/size_config.dart';
import 'package:tm_app/data/services/model/board_response/board_response.dart';
import 'package:tm_app/views/shared/desktop_navigation_widget.dart';

import '../../../core/constants/assets.dart';
import '../../../core/enums/task_status.dart';
import '../../../core/utils/app_toast.dart';
import '../../../view_models/board_view_model.dart';
import '../strings/board_strings.dart';

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

  @override
  State<BoardScreen> createState() => _BoardScreenState();
}

class _BoardScreenState extends State<BoardScreen> {
  late BoardViewModel _boardViewModel;

  @override
  void initState() {
    super.initState();
    _boardViewModel = context.read<BoardViewModel>();
    WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
      _boardViewModel.getBoard();
    });
  }

  void _updateTaskStatus(BoardData task, TaskStatus newStatus) {
    if (task.statusEnum == newStatus) {
      return;
    }

    final oldStatus = task.statusEnum;

    // update task status in ViewModel
    _boardViewModel.updateTaskStatus(task.id!, newStatus.value);

    _showStatusChangeMessage(context, task, oldStatus, newStatus);
  }

  void _showStatusChangeMessage(
    BuildContext context,
    BoardData task,
    TaskStatus oldStatus,
    TaskStatus newStatus,
  ) {
    final statusNames = {
      TaskStatus.toDo: BoardStrings.toDo,
      TaskStatus.inProgress: BoardStrings.inProgress,
      TaskStatus.done: BoardStrings.done,
    };

    AppToast.success(
      context,
      BoardStrings.taskMovedMessage(
        statusNames[oldStatus]!,
        statusNames[newStatus]!,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    SizeConfig.init(context);
    return Scaffold(
      backgroundColor: AppColors.backgroundColor,
      body: Column(
        children: [
          const DesktopNavigationWidget(
            currentIndex: 2, // Tenders index
          ),
          Consumer<BoardViewModel>(
            builder: (context, viewModel, child) {
              if (viewModel.isLoading) {
                return const Expanded(
                  child: Center(
                    child: CircularProgressIndicator(
                      color: AppColors.secondary50,
                    ),
                  ),
                );
              }
              if (viewModel.errorMessage != null) {
                return Expanded(
                  child: Center(child: Text(viewModel.errorMessage!)),
                );
              }
              if (viewModel.hasData == false) {
                return const Expanded(
                  child: Center(child: Text(BoardStrings.emptyListText)),
                );
              }

              return Expanded(
                child: SingleChildScrollView(
                  child: SizedBox(
                    width: 740,
                    height: 735,
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        const SizedBox(height: 32),
                        Text(
                          BoardStrings.boardTitle,
                          style: TextStyle(
                            fontSize: 20.0.sp(),
                            fontWeight: FontWeight.w600,
                            color: AppColors.titleColor,
                          ),
                        ),
                        const SizedBox(height: 20),
                        Expanded(
                          child: Container(
                            padding: const EdgeInsets.all(16),
                            decoration: BoxDecoration(
                              borderRadius: BorderRadius.circular(12),
                              color: AppColors.primary20,
                            ),
                            child: Row(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                // To Do
                                Expanded(
                                  child: _BoardColumn(
                                    title: BoardStrings.toDo,
                                    color: AppColors.primary20,
                                    textColor: const Color(0xFF1976D2),
                                    tasks: viewModel.getTasksByStatus(
                                      TaskStatus.toDo,
                                    ),
                                    status: TaskStatus.toDo,
                                    onTaskDropped: _updateTaskStatus,
                                    isValidMove: viewModel.isValidMove,
                                  ),
                                ),
                                const SizedBox(width: 12),
                                // In Progress
                                Expanded(
                                  child: _BoardColumn(
                                    title: BoardStrings.inProgress,
                                    color: AppColors.orange20,
                                    textColor: AppColors.orange,
                                    tasks: viewModel.getTasksByStatus(
                                      TaskStatus.inProgress,
                                    ),
                                    status: TaskStatus.inProgress,
                                    onTaskDropped: _updateTaskStatus,
                                    isValidMove: viewModel.isValidMove,
                                  ),
                                ),
                                const SizedBox(width: 12),
                                // Done
                                Expanded(
                                  child: _BoardColumn(
                                    title: BoardStrings.done,
                                    color: AppColors.secondary20,
                                    textColor: AppColors.secondary70,
                                    tasks: viewModel.getTasksByStatus(
                                      TaskStatus.done,
                                    ),
                                    status: TaskStatus.done,
                                    onTaskDropped: _updateTaskStatus,
                                    isValidMove: viewModel.isValidMove,
                                  ),
                                ),
                              ],
                            ),
                          ),
                        ),
                      ],
                    ),
                  ),
                ),
              );
            },
          ),
        ],
      ),
    );
  }
}

class _BoardColumn extends StatelessWidget {
  final String title;
  final Color color;
  final Color textColor;
  final List<BoardData> tasks;
  final TaskStatus status;
  final Function(BoardData, TaskStatus) onTaskDropped;
  final bool Function(TaskStatus, TaskStatus) isValidMove;

  const _BoardColumn({
    required this.title,
    required this.color,
    required this.textColor,
    required this.tasks,
    required this.status,
    required this.onTaskDropped,
    required this.isValidMove,
  });

  @override
  Widget build(BuildContext context) {
    return DragTarget<BoardData>(
      onWillAcceptWithDetails: (details) {
        return isValidMove(details.data.statusEnum, status);
      },
      onAcceptWithDetails: (details) {
        onTaskDropped(details.data, status);
      },
      builder: (context, candidateData, rejectedData) {
        final isHovering = candidateData.isNotEmpty;
        return Container(
          decoration: BoxDecoration(
            color:
                isHovering ? color.withValues(alpha: 0.3) : AppColors.primary0,
            borderRadius: BorderRadius.circular(12),
            border: Border.all(
              color: isHovering ? textColor : AppColors.borderBlue,
              width: isHovering ? 2 : 1,
            ),
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Container(
                width: double.infinity,
                height: 34,
                margin: const EdgeInsets.all(8),
                decoration: BoxDecoration(
                  color: color,
                  borderRadius: BorderRadius.circular(4),
                ),
                alignment: Alignment.center,
                child: Text(
                  title,
                  style: TextStyle(
                    fontSize: 16,
                    fontWeight: FontWeight.w600,
                    color: textColor,
                  ),
                ),
              ),

              Expanded(
                child: ListView.builder(
                  padding: const EdgeInsets.all(12),
                  itemCount: tasks.length,
                  itemBuilder: (context, index) {
                    return _TaskCard(task: tasks[index]);
                  },
                ),
              ),
            ],
          ),
        );
      },
    );
  }
}

class _TaskCard extends StatelessWidget {
  final BoardData task;

  const _TaskCard({required this.task});

  String _formatDate(DateTime date) {
    return '${date.year}-${date.month.toString().padLeft(2, '0')}-${date.day.toString().padLeft(2, '0')}';
  }

  @override
  Widget build(BuildContext context) {
    return Draggable<BoardData>(
      data: task,
      feedback: Material(
        elevation: 8,
        borderRadius: BorderRadius.circular(12),
        child: Container(
          width: 280,
          padding: const EdgeInsets.all(16),
          decoration: BoxDecoration(
            color: AppColors.primary0,
            borderRadius: BorderRadius.circular(12),
            border: Border.all(color: AppColors.borderBlue, width: 2),
          ),
          child: _buildCardContent(context),
        ),
      ),
      childWhenDragging: Opacity(opacity: 0.3, child: _buildCard(context)),
      child: _buildCard(context),
    );
  }

  Widget _buildCard(BuildContext context) {
    return Container(
      margin: const EdgeInsets.only(bottom: 12),
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: AppColors.primary0,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: AppColors.grey30),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withValues(alpha: 0.05),
            blurRadius: 4,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: _buildCardContent(context),
    );
  }

  Widget _buildCardContent(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Container(
          height: 24.0,
          padding: EdgeInsets.symmetric(horizontal: 10.0.w()),
          decoration: BoxDecoration(
            color:
                task.statusEnum == TaskStatus.toDo
                    ? AppColors.primary20
                    : task.statusEnum == TaskStatus.inProgress
                    ? AppColors.orange10
                    : AppColors.secondary10,
            borderRadius: BorderRadius.circular(4),
          ),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Text(
                '${BoardStrings.deadlineLabel} :',
                style: TextStyle(
                  fontSize: 14.0,
                  fontWeight: FontWeight.w500,
                  color: AppColors.textBlue,
                ),
              ),
              Text(
                _formatDate(task.deadline ?? DateTime.now()),
                style: TextStyle(
                  fontSize: 14.0,
                  fontWeight: FontWeight.w500,
                  color: AppColors.grey80,
                ),
              ),
            ],
          ),
        ),
        const SizedBox(height: 12),
        Text(
          task.description!,
          style: TextStyle(fontSize: 14, color: AppColors.grey70),
          maxLines: 3,
          overflow: TextOverflow.ellipsis,
        ),
        const SizedBox(height: 12),

        Container(
          padding: const EdgeInsets.symmetric(horizontal: 8.0, vertical: 4.0),
          decoration: BoxDecoration(
            color: task.isReady ?? false ? AppColors.primary20 : AppColors.red0,
            borderRadius: BorderRadius.circular(8),
          ),
          child: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              Container(
                width: 8,
                height: 8,
                decoration: BoxDecoration(
                  color: task.isReady! ? AppColors.textBlue : AppColors.error,
                  shape: BoxShape.circle,
                ),
              ),
              const SizedBox(width: 6),
              Text(
                task.isReady!
                    ? BoardStrings.readyLabel
                    : BoardStrings.incompleteLabel,
                style: TextStyle(
                  fontSize: 12,
                  color: task.isReady! ? AppColors.textBlue : AppColors.red20,
                  fontWeight: FontWeight.w400,
                ),
              ),
            ],
          ),
        ),
        const SizedBox(height: 12),
        Row(
          children: [
            SvgPicture.asset(AssetsManager.profile),
            const SizedBox(width: 4),
            Text(
              task.assignedTo!,
              style: TextStyle(fontSize: 12, color: AppColors.grey60),
            ),
          ],
        ),
      ],
    );
  }
}