import 'package:flutter/material.dart';

import '../../../core/theme/app_colors.dart';
import '../../../core/theme/app_dimens.dart';
import '../../../core/theme/app_typography.dart';

/// Scrollable page body shared by every module screen.
///
/// Always scrolls vertically, so no module can overflow no matter how short
/// the viewport gets.
class ModulePage extends StatelessWidget {
  const ModulePage({
    super.key,
    required this.children,
    this.padding = AppSpacing.xxl,
  });

  final List<Widget> children;
  final double padding;

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      padding: EdgeInsets.all(padding),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: children,
      ),
    );
  }
}

/// KPI card. Designed to sit inside a [Wrap] so it reflows instead of
/// overflowing when the window narrows.
class StatTile extends StatelessWidget {
  const StatTile({
    super.key,
    required this.label,
    required this.value,
    required this.icon,
    this.color = AppColors.primary,
    this.delta,
    this.deltaPositive = true,
    this.caption,
    this.width = 232,
  });

  final String label;
  final String value;
  final IconData icon;
  final Color color;
  final String? delta;
  final bool deltaPositive;
  final String? caption;
  final double width;

  @override
  Widget build(BuildContext context) {
    return Container(
      width: width,
      padding: const EdgeInsets.all(AppSpacing.lg),
      decoration: BoxDecoration(
        color: AppColors.surface,
        borderRadius: AppRadius.brLg,
        border: Border.all(color: AppColors.border),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        mainAxisSize: MainAxisSize.min,
        children: [
          Row(
            children: [
              Container(
                width: 34,
                height: 34,
                decoration: BoxDecoration(
                  color: color.withValues(alpha: 0.12),
                  borderRadius: AppRadius.brSm,
                ),
                child: Icon(icon, size: 17, color: color),
              ),
              const SizedBox(width: AppSpacing.sm),
              Expanded(
                child: Text(
                  label,
                  overflow: TextOverflow.ellipsis,
                  style: const TextStyle(
                    fontSize: 12.5,
                    fontWeight: FontWeight.w500,
                    color: AppColors.textSecondary,
                  ),
                ),
              ),
            ],
          ),
          const SizedBox(height: AppSpacing.md),
          FittedBox(
            fit: BoxFit.scaleDown,
            alignment: Alignment.centerLeft,
            child: Text(value, style: AppTypography.money(24)),
          ),
          if (delta != null || caption != null) ...[
            const SizedBox(height: AppSpacing.xs),
            Row(
              children: [
                if (delta != null) ...[
                  Icon(
                    deltaPositive
                        ? Icons.trending_up_rounded
                        : Icons.trending_down_rounded,
                    size: 14,
                    color:
                        deltaPositive ? AppColors.success : AppColors.danger,
                  ),
                  const SizedBox(width: 3),
                  Text(
                    delta!,
                    style: TextStyle(
                      fontSize: 12,
                      fontWeight: FontWeight.w600,
                      color:
                          deltaPositive ? AppColors.success : AppColors.danger,
                    ),
                  ),
                  const SizedBox(width: AppSpacing.xs),
                ],
                if (caption != null)
                  Expanded(
                    child: Text(
                      caption!,
                      overflow: TextOverflow.ellipsis,
                      style: const TextStyle(
                        fontSize: 11.5,
                        color: AppColors.textTertiary,
                      ),
                    ),
                  ),
              ],
            ),
          ],
        ],
      ),
    );
  }
}

/// Titled container for a block of module content.
class PanelCard extends StatelessWidget {
  const PanelCard({
    super.key,
    required this.title,
    required this.child,
    this.subtitle,
    this.action,
    this.padding = AppSpacing.lg,
  });

  final String title;
  final Widget child;
  final String? subtitle;
  final Widget? action;
  final double padding;

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
        color: AppColors.surface,
        borderRadius: AppRadius.brLg,
        border: Border.all(color: AppColors.border),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        mainAxisSize: MainAxisSize.min,
        children: [
          Padding(
            padding: EdgeInsets.fromLTRB(padding, padding, padding, AppSpacing.md),
            // Wrap so a long title plus an action never collide.
            child: Wrap(
              alignment: WrapAlignment.spaceBetween,
              crossAxisAlignment: WrapCrossAlignment.center,
              spacing: AppSpacing.md,
              runSpacing: AppSpacing.sm,
              children: [
                Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text(
                      title,
                      style: const TextStyle(
                        fontSize: 15.5,
                        fontWeight: FontWeight.w600,
                        color: AppColors.textPrimary,
                      ),
                    ),
                    if (subtitle != null)
                      Text(
                        subtitle!,
                        style: const TextStyle(
                          fontSize: 12.5,
                          color: AppColors.textTertiary,
                        ),
                      ),
                  ],
                ),
                if (action != null) action!,
              ],
            ),
          ),
          const Divider(height: 1),
          Padding(padding: EdgeInsets.all(padding), child: child),
        ],
      ),
    );
  }
}

/// One column of a [ResponsiveTable].
class TableCol {
  const TableCol(
    this.label, {
    this.flex = 2,
    this.numeric = false,
    this.priority = 0,
  });

  final String label;
  final int flex;
  final bool numeric;

  /// Higher numbers are dropped first as the table narrows.
  final int priority;
}

/// Table that degrades into stacked cards rather than overflowing.
///
/// Above [stackBelow] it renders as aligned columns; below, each row becomes a
/// label/value card. Low-priority columns are hidden at intermediate widths.
class ResponsiveTable extends StatelessWidget {
  const ResponsiveTable({
    super.key,
    required this.columns,
    required this.rows,
    this.stackBelow = 620,
    this.hideSecondaryBelow = 900,
    this.onRowTap,
  });

  final List<TableCol> columns;

  /// Each row must supply exactly one cell per column.
  final List<List<Widget>> rows;

  final double stackBelow;
  final double hideSecondaryBelow;
  final void Function(int index)? onRowTap;

  @override
  Widget build(BuildContext context) {
    if (rows.isEmpty) {
      return const Padding(
        padding: EdgeInsets.symmetric(vertical: AppSpacing.xxl),
        child: Center(
          child: Text(
            'Nothing to show yet.',
            style: TextStyle(color: AppColors.textTertiary),
          ),
        ),
      );
    }

    return LayoutBuilder(
      builder: (context, constraints) {
        final w = constraints.maxWidth;

        if (w < stackBelow) return _stacked();

        final visible = <int>[
          for (var i = 0; i < columns.length; i++)
            if (w >= hideSecondaryBelow || columns[i].priority == 0) i,
        ];

        return Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Padding(
              padding: const EdgeInsets.only(bottom: AppSpacing.sm),
              child: Row(
                children: [
                  for (final i in visible)
                    Expanded(
                      flex: columns[i].flex,
                      child: Text(
                        columns[i].label.toUpperCase(),
                        textAlign:
                            columns[i].numeric ? TextAlign.right : TextAlign.left,
                        overflow: TextOverflow.ellipsis,
                        style: AppTypography.sectionLabel(),
                      ),
                    ),
                ],
              ),
            ),
            const Divider(height: 1),
            for (var r = 0; r < rows.length; r++)
              InkWell(
                onTap: onRowTap == null ? null : () => onRowTap!(r),
                borderRadius: AppRadius.brXs,
                child: Container(
                  padding:
                      const EdgeInsets.symmetric(vertical: AppSpacing.md),
                  decoration: const BoxDecoration(
                    border:
                        Border(bottom: BorderSide(color: AppColors.divider)),
                  ),
                  child: Row(
                    children: [
                      for (final i in visible)
                        Expanded(
                          flex: columns[i].flex,
                          child: Align(
                            alignment: columns[i].numeric
                                ? Alignment.centerRight
                                : Alignment.centerLeft,
                            child: rows[r][i],
                          ),
                        ),
                    ],
                  ),
                ),
              ),
          ],
        );
      },
    );
  }

  Widget _stacked() {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        for (var r = 0; r < rows.length; r++)
          Container(
            margin: const EdgeInsets.only(bottom: AppSpacing.sm),
            padding: const EdgeInsets.all(AppSpacing.md),
            decoration: BoxDecoration(
              color: AppColors.surfaceAlt,
              borderRadius: AppRadius.brSm,
              border: Border.all(color: AppColors.border),
            ),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                for (var c = 0; c < columns.length; c++)
                  Padding(
                    padding: const EdgeInsets.symmetric(vertical: 3),
                    child: Row(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        SizedBox(
                          width: 104,
                          child: Text(
                            columns[c].label,
                            style: const TextStyle(
                              fontSize: 12,
                              color: AppColors.textTertiary,
                            ),
                          ),
                        ),
                        Expanded(
                          child: Align(
                            alignment: Alignment.centerLeft,
                            child: rows[r][c],
                          ),
                        ),
                      ],
                    ),
                  ),
              ],
            ),
          ),
      ],
    );
  }
}

/// Plain text cell.
class Cell extends StatelessWidget {
  const Cell(
    this.text, {
    super.key,
    this.bold = false,
    this.color,
    this.mono = false,
  });

  final String text;
  final bool bold;
  final Color? color;
  final bool mono;

  @override
  Widget build(BuildContext context) {
    return Text(
      text,
      overflow: TextOverflow.ellipsis,
      style: mono
          ? AppTypography.money(13.5,
              weight: bold ? FontWeight.w700 : FontWeight.w500, color: color,)
          : TextStyle(
              fontSize: 13.5,
              fontWeight: bold ? FontWeight.w600 : FontWeight.w400,
              color: color ?? AppColors.textPrimary,
            ),
    );
  }
}

/// Small coloured status label.
class TagChip extends StatelessWidget {
  const TagChip(this.label, {super.key, this.color = AppColors.primary});

  final String label;
  final Color color;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: AppSpacing.sm, vertical: 3),
      decoration: BoxDecoration(
        color: color.withValues(alpha: 0.12),
        borderRadius: AppRadius.brPill,
      ),
      child: Text(
        label,
        overflow: TextOverflow.ellipsis,
        style: TextStyle(
          fontSize: 11,
          fontWeight: FontWeight.w600,
          color: color,
        ),
      ),
    );
  }
}

/// Lightweight bar chart painted in code, so no charting dependency is needed.
class MiniBarChart extends StatelessWidget {
  const MiniBarChart({
    super.key,
    required this.values,
    required this.labels,
    this.height = 180,
    this.color = AppColors.primary,
  });

  final List<double> values;
  final List<String> labels;
  final double height;
  final Color color;

  @override
  Widget build(BuildContext context) {
    if (values.isEmpty) return SizedBox(height: height);
    final max = values.reduce((a, b) => a > b ? a : b);

    return SizedBox(
      height: height,
      child: LayoutBuilder(
        builder: (context, constraints) {
          // Labels are dropped rather than squeezed when space is tight.
          final showLabels = constraints.maxWidth / values.length >= 28;

          return Row(
            crossAxisAlignment: CrossAxisAlignment.end,
            children: [
              for (var i = 0; i < values.length; i++)
                Expanded(
                  child: Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 3),
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.end,
                      children: [
                        Expanded(
                          child: FractionallySizedBox(
                            alignment: Alignment.bottomCenter,
                            heightFactor:
                                max <= 0 ? 0 : (values[i] / max).clamp(0.03, 1),
                            child: Container(
                              decoration: BoxDecoration(
                                gradient: LinearGradient(
                                  begin: Alignment.topCenter,
                                  end: Alignment.bottomCenter,
                                  colors: [
                                    color,
                                    color.withValues(alpha: 0.45),
                                  ],
                                ),
                                borderRadius: const BorderRadius.vertical(
                                  top: Radius.circular(5),
                                ),
                              ),
                            ),
                          ),
                        ),
                        if (showLabels) ...[
                          const SizedBox(height: AppSpacing.sm),
                          Text(
                            labels[i],
                            maxLines: 1,
                            overflow: TextOverflow.clip,
                            style: const TextStyle(
                              fontSize: 10.5,
                              color: AppColors.textTertiary,
                            ),
                          ),
                        ],
                      ],
                    ),
                  ),
                ),
            ],
          );
        },
      ),
    );
  }
}

/// Horizontal proportion bar used for breakdowns.
class ProgressRow extends StatelessWidget {
  const ProgressRow({
    super.key,
    required this.label,
    required this.value,
    required this.fraction,
    this.color = AppColors.primary,
  });

  final String label;
  final String value;
  final double fraction;
  final Color color;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: AppSpacing.sm),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Row(
            children: [
              Expanded(
                child: Text(
                  label,
                  overflow: TextOverflow.ellipsis,
                  style: const TextStyle(fontSize: 13),
                ),
              ),
              const SizedBox(width: AppSpacing.sm),
              Text(value, style: AppTypography.money(13)),
            ],
          ),
          const SizedBox(height: AppSpacing.sm),
          ClipRRect(
            borderRadius: AppRadius.brPill,
            child: LinearProgressIndicator(
              value: fraction.clamp(0, 1),
              minHeight: 6,
              backgroundColor: AppColors.divider,
              valueColor: AlwaysStoppedAnimation(color),
            ),
          ),
        ],
      ),
    );
  }
}