import 'package:flutter/material.dart';

import '../../core/theme/design_tokens.dart';

enum AppLoadingVariant { surface, inline, button }

class AppLoadingIndicator extends StatelessWidget {
  const AppLoadingIndicator({
    super.key,
    this.variant = AppLoadingVariant.surface,
    this.size,
    this.strokeWidth,
    this.color,
    this.trackColor,
    this.withContainer,
  });

  final AppLoadingVariant variant;
  final double? size;
  final double? strokeWidth;
  final Color? color;
  final Color? trackColor;
  final bool? withContainer;

  double get _resolvedSize {
    return size ??
        switch (variant) {
          AppLoadingVariant.surface => 22,
          AppLoadingVariant.inline => 16,
          AppLoadingVariant.button => 18,
        };
  }

  double get _resolvedStrokeWidth {
    return strokeWidth ??
        switch (variant) {
          AppLoadingVariant.surface => 2.2,
          AppLoadingVariant.inline => 2,
          AppLoadingVariant.button => 2.2,
        };
  }

  Widget _buildSpinner(Color color, Color trackColor) {
    return SizedBox(
      width: _resolvedSize,
      height: _resolvedSize,
      child: CircularProgressIndicator(
        strokeWidth: _resolvedStrokeWidth,
        color: color,
        backgroundColor: trackColor,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;

    final resolvedColor =
        color ??
        switch (variant) {
          AppLoadingVariant.surface => colorScheme.primary,
          AppLoadingVariant.inline => colorScheme.onSurfaceVariant,
          AppLoadingVariant.button => colorScheme.onPrimary,
        };

    final resolvedTrackColor =
        trackColor ??
        switch (variant) {
          AppLoadingVariant.surface => colorScheme.primaryContainer,
          AppLoadingVariant.inline => colorScheme.outlineVariant,
          AppLoadingVariant.button => colorScheme.secondary,
        };

    if (withContainer == false ||
        (withContainer == null &&
            switch (variant) {
              AppLoadingVariant.surface => true,
              AppLoadingVariant.inline => false,
              AppLoadingVariant.button => false,
            })) {
      return _buildSpinner(resolvedColor, resolvedTrackColor);
    }

    return Container(
      width: _resolvedSize + AppSpacing.md,
      height: _resolvedSize + AppSpacing.md,
      padding: const EdgeInsets.all(AppSpacing.xs),
      decoration: BoxDecoration(
        color: colorScheme.surface,
        borderRadius: BorderRadius.circular(AppRadius.full),
        border: Border.all(color: colorScheme.outlineVariant),
        boxShadow: [
          BoxShadow(
            color: colorScheme.outlineVariant.withValues(alpha: 0.55),
            blurRadius: AppRadius.md,
            offset: const Offset(0, AppSpacing.xs),
          ),
        ],
      ),
      child: _buildSpinner(resolvedColor, resolvedTrackColor),
    );
  }
}