import 'package:flutter/material.dart';

import '../theme/app_theme.dart';

/// Green gradient hero banner background shared by every screen that shows
/// a totals summary (Receipts, Vehicle Detail) — callers supply their own
/// stat row / controls as [child], keeping the container/gradient styling
/// itself in one place.
class HeroBanner extends StatelessWidget {
  final Widget child;

  const HeroBanner({super.key, required this.child});

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.fromLTRB(20, 16, 20, 10),
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(15),
        gradient: LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: AppTheme.heroGradient(context),
        ),
      ),
      child: child,
    );
  }
}

/// A single label/value pair inside a [HeroBanner], e.g. "Total Gallons".
class HeroStat extends StatelessWidget {
  final String label;
  final String value;
  final bool alignEnd;

  const HeroStat({super.key, required this.label, required this.value, required this.alignEnd});

  @override
  Widget build(BuildContext context) {
    final textAlign = alignEnd ? TextAlign.end : TextAlign.start;
    return Column(
      crossAxisAlignment: alignEnd ? CrossAxisAlignment.end : CrossAxisAlignment.start,
      children: [
        Text(
          label,
          textAlign: textAlign,
          style: TextStyle(
            color: AppTheme.heroTextSecondary(context),
            fontSize: 12,
            fontWeight: FontWeight.w600,
          ),
        ),
        const SizedBox(height: 4),
        Text(
          value,
          textAlign: textAlign,
          style: const TextStyle(
            color: AppTheme.heroText,
            fontSize: 28,
            fontWeight: FontWeight.w800,
            letterSpacing: -0.5,
          ),
        ),
      ],
    );
  }
}

/// The icon + two-stat row shared by every hero banner: gallons on the
/// left, the hero icon (or, if [estimatedRefundValue] is given, the
/// estimated fuel refund in its place — see the Receipts tab, the only
/// caller that ever passes it) in the middle, cost on the right.
class HeroStatsRow extends StatelessWidget {
  final String gallonsValue;
  final String costValue;
  final String gallonsLabel;
  final String costLabel;
  final String? estimatedRefundValue;

  const HeroStatsRow({
    super.key,
    required this.gallonsValue,
    required this.costValue,
    this.gallonsLabel = 'Total Gallons',
    this.costLabel = 'Total Fuel Cost',
    this.estimatedRefundValue,
  });

  @override
  Widget build(BuildContext context) {
    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Expanded(child: HeroStat(label: gallonsLabel, value: gallonsValue, alignEnd: false)),
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 8),
          child: estimatedRefundValue == null
              // Tall enough to extend past the bottom of the label+value
              // text next to it, not just match the label's height — width
              // scales automatically from the source's own aspect ratio
              // since only height is given.
              ? Image.asset(
                  'assets/icon/hero_icon.png',
                  height: 58,
                  fit: BoxFit.contain,
                )
              : _EstimatedRefundStat(value: estimatedRefundValue!),
        ),
        Expanded(child: HeroStat(label: costLabel, value: costValue, alignEnd: true)),
      ],
    );
  }
}

/// The estimated-fuel-refund stat that takes the hero icon's place in the
/// middle of [HeroStatsRow] when that's turned on — smaller/more compact
/// than [HeroStat] since it sits in the narrower middle slot rather than
/// an [Expanded] one.
class _EstimatedRefundStat extends StatelessWidget {
  final String value;

  const _EstimatedRefundStat({required this.value});

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Text(
          'Est. Refund',
          textAlign: TextAlign.center,
          style: TextStyle(
            color: AppTheme.heroTextSecondary(context),
            fontSize: 10,
            fontWeight: FontWeight.w600,
          ),
        ),
        const SizedBox(height: 4),
        Text(
          value,
          textAlign: TextAlign.center,
          style: const TextStyle(
            color: AppTheme.heroText,
            fontSize: 30,
            fontWeight: FontWeight.w800,
          ),
        ),
      ],
    );
  }
}