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

import '../../../core/theme/app_colors.dart';
import '../../../core/theme/app_dimens.dart';
import '../../../core/utils/formatters.dart';
import '../../../core/widgets/primary_button.dart';
import '../../../domain/entities/cart.dart';
import '../providers/cart_controller.dart';

Future<void> showLineDiscountSheet(
  BuildContext context,
  WidgetRef ref,
  CartLine line,
) {
  return _show(
    context: context,
    title: line.product.name,
    subtitle: 'Line value ${Formatters.money(line.grossAmount)}',
    current: line.discount,
    onApply: (d) => ref
        .read(cartControllerProvider.notifier)
        .applyLineDiscount(line.product.id, d),
  );
}

Future<void> showBillDiscountSheet(BuildContext context, WidgetRef ref) {
  final cart = ref.read(cartControllerProvider);
  return _show(
    context: context,
    title: 'Bill discount',
    subtitle: 'Subtotal ${Formatters.money(cart.subtotal)}',
    current: cart.billDiscount,
    onApply: (d) =>
        ref.read(cartControllerProvider.notifier).applyBillDiscount(d),
  );
}

Future<void> _show({
  required BuildContext context,
  required String title,
  required String subtitle,
  required Discount current,
  required ValueChanged<Discount> onApply,
}) {
  return showModalBottomSheet<void>(
    context: context,
    isScrollControlled: true,
    backgroundColor: Colors.transparent,
    builder: (_) => _DiscountSheet(
      title: title,
      subtitle: subtitle,
      current: current,
      onApply: onApply,
    ),
  );
}

class _DiscountSheet extends StatefulWidget {
  const _DiscountSheet({
    required this.title,
    required this.subtitle,
    required this.current,
    required this.onApply,
  });

  final String title;
  final String subtitle;
  final Discount current;
  final ValueChanged<Discount> onApply;

  @override
  State<_DiscountSheet> createState() => _DiscountSheetState();
}

class _DiscountSheetState extends State<_DiscountSheet> {
  late DiscountType _type =
      widget.current.type == DiscountType.none
          ? DiscountType.percentage
          : widget.current.type;
  late final TextEditingController _value = TextEditingController(
    text: widget.current.isActive
        ? widget.current.value.toStringAsFixed(0)
        : '',
  );

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

  void _apply() {
    final v = double.tryParse(_value.text.trim()) ?? 0;
    widget.onApply(
      v <= 0 ? Discount.none : Discount(type: _type, value: v),
    );
    Navigator.of(context).pop();
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.only(
        bottom: MediaQuery.viewInsetsOf(context).bottom,
      ),
      child: Container(
        padding: const EdgeInsets.all(AppSpacing.xxl),
        decoration: const BoxDecoration(
          color: AppColors.surface,
          borderRadius:
              BorderRadius.vertical(top: Radius.circular(AppRadius.xxl)),
        ),
        child: Column(mainAxisSize: MainAxisSize.min, children: [
          Container(
            width: 40,
            height: 4,
            decoration: const BoxDecoration(
              color: AppColors.border,
              borderRadius: AppRadius.brPill,
            ),
          ),
          const SizedBox(height: AppSpacing.xl),

          Text(widget.title,
              style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w700),),
          const SizedBox(height: 2),
          Text(widget.subtitle,
              style: const TextStyle(
                fontSize: 13,
                color: AppColors.textSecondary,
              ),),
          const SizedBox(height: AppSpacing.xxl),

          SegmentedButton<DiscountType>(
            segments: const [
              ButtonSegment(
                value: DiscountType.percentage,
                label: Text('Percent'),
                icon: Icon(Icons.percent_rounded, size: 17),
              ),
              ButtonSegment(
                value: DiscountType.flat,
                label: Text('Flat'),
                icon: Icon(Icons.currency_rupee_rounded, size: 17),
              ),
            ],
            selected: {_type},
            onSelectionChanged: (s) => setState(() => _type = s.first),
          ),
          const SizedBox(height: AppSpacing.xl),

          TextField(
            controller: _value,
            autofocus: true,
            keyboardType: const TextInputType.numberWithOptions(decimal: true),
            inputFormatters: [
              FilteringTextInputFormatter.allow(RegExp(r'^\d*\.?\d{0,2}')),
            ],
            style: const TextStyle(fontSize: 24, fontWeight: FontWeight.w700),
            textAlign: TextAlign.center,
            decoration: InputDecoration(
              hintText: '0',
              prefixText: _type == DiscountType.flat ? '₹ ' : null,
              suffixText: _type == DiscountType.percentage ? '%' : null,
            ),
            onSubmitted: (_) => _apply(),
          ),
          const SizedBox(height: AppSpacing.lg),

          Wrap(
            spacing: AppSpacing.sm,
            children: (_type == DiscountType.percentage
                    ? const [5, 10, 15, 20, 25]
                    : const [10, 20, 50, 100, 200])
                .map((v) => ActionChip(
                      label: Text(_type == DiscountType.percentage
                          ? '$v%'
                          : '₹$v',),
                      onPressed: () =>
                          setState(() => _value.text = v.toString()),
                    ),)
                .toList(),
          ),
          const SizedBox(height: AppSpacing.xxl),

          Row(children: [
            Expanded(
              child: PrimaryButton(
                label: 'Remove',
                tone: ButtonTone.neutral,
                onPressed: () {
                  widget.onApply(Discount.none);
                  Navigator.of(context).pop();
                },
              ),
            ),
            const SizedBox(width: AppSpacing.md),
            Expanded(
              flex: 2,
              child: PrimaryButton(
                label: 'Apply discount',
                icon: Icons.check_rounded,
                onPressed: _apply,
              ),
            ),
          ],),
        ],),
      ),
    );
  }
}