// In-place help — the "explain it where it happens" pattern
// (usertest: the Add-satellite dialog asked for a name with no hint
// of what a satellite is or what the name does). Two pieces:
//
//   • ChainInlineHelp — a calm intro strip at the top of a dialog
//     or surface: one plain sentence saying what this is and what
//     will happen, with an optional "Learn more" link into the
//     full doc sheet.
//   • ChainFieldHelp — a small "?" affordance to sit next to a
//     single field's label; tap/hover reveals a one-line
//     explanation. Use it only where a field genuinely needs it.
//
// Both are intentionally quiet: help should be present, not loud.

import 'package:flutter/material.dart';

import '../theme/tokens.dart';

/// A one-sentence intro strip for the top of a dialog or panel.
/// [onLearnMore] wires the "Learn more" link to a doc sheet
/// (`showFaiDoc`), shown only when provided.
class ChainInlineHelp extends StatelessWidget {
  final String text;
  final IconData icon;
  final VoidCallback? onLearnMore;
  final String? learnMoreLabel;

  const ChainInlineHelp({
    super.key,
    required this.text,
    this.icon = Icons.info_outline,
    this.onLearnMore,
    this.learnMoreLabel,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Container(
      padding: const EdgeInsets.all(ChainSpace.md),
      decoration: BoxDecoration(
        color: theme.colorScheme.surfaceContainerHigh,
        borderRadius: BorderRadius.circular(ChainRadius.sm),
        border: Border.all(color: theme.colorScheme.outlineVariant),
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Icon(icon, size: 16, color: theme.colorScheme.primary),
          const SizedBox(width: ChainSpace.sm),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  text,
                  style: theme.textTheme.bodySmall?.copyWith(
                    color: theme.colorScheme.onSurface,
                    height: 1.4,
                  ),
                ),
                if (onLearnMore != null) ...[
                  const SizedBox(height: ChainSpace.xs),
                  InkWell(
                    onTap: onLearnMore,
                    borderRadius: BorderRadius.circular(ChainRadius.sm),
                    child: Padding(
                      padding: const EdgeInsets.symmetric(vertical: 2),
                      child: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: [
                          Text(
                            learnMoreLabel ?? 'Learn more',
                            style: theme.textTheme.labelSmall?.copyWith(
                              color: theme.colorScheme.primary,
                              fontWeight: FontWeight.w600,
                            ),
                          ),
                          const SizedBox(width: 2),
                          Icon(
                            Icons.arrow_forward,
                            size: 12,
                            color: theme.colorScheme.primary,
                          ),
                        ],
                      ),
                    ),
                  ),
                ],
              ],
            ),
          ),
        ],
      ),
    );
  }
}

/// A "?" info affordance for a single field. Sit it next to the
/// field's label; hover shows the [message] as a tooltip, and a
/// tap reveals it too (touch / keyboard users who don't hover).
/// Semantics carry [message] for screen readers.
class ChainFieldHelp extends StatefulWidget {
  final String message;

  const ChainFieldHelp({super.key, required this.message});

  @override
  State<ChainFieldHelp> createState() => _ChainFieldHelpState();
}

class _ChainFieldHelpState extends State<ChainFieldHelp> {
  final _tooltipKey = GlobalKey<TooltipState>();

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Tooltip(
      key: _tooltipKey,
      message: widget.message,
      waitDuration: const Duration(milliseconds: 300),
      triggerMode: TooltipTriggerMode.manual,
      preferBelow: false,
      child: Semantics(
        button: true,
        label: widget.message,
        child: InkResponse(
          radius: 14,
          // Manual trigger so a tap (not just hover) reveals it.
          onTap: () => _tooltipKey.currentState?.ensureTooltipVisible(),
          child: Padding(
            padding: const EdgeInsets.all(2),
            child: Icon(
              Icons.help_outline,
              size: 14,
              color: theme.colorScheme.onSurfaceVariant,
            ),
          ),
        ),
      ),
    );
  }
}

/// A field label with a trailing [ChainFieldHelp]. Convenience for
/// the common "label + ?" row above a TextField.
class ChainFieldLabel extends StatelessWidget {
  final String label;
  final String help;

  const ChainFieldLabel({super.key, required this.label, required this.help});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Row(
      children: [
        Text(
          label,
          style: theme.textTheme.labelMedium?.copyWith(
            color: theme.colorScheme.onSurfaceVariant,
          ),
        ),
        const SizedBox(width: 4),
        ChainFieldHelp(message: help),
      ],
    );
  }
}