import 'package:flutter/material.dart';
import 'package:lucide_icons/lucide_icons.dart';
import 'package:flutter_markdown_plus/flutter_markdown_plus.dart';

import '../data/models/message.dart';

class JournalPrepCard extends StatefulWidget {
  /// The first assistant message from today's journal — the daily prep
  /// (LLM-generated briefing-style opener), or null if not yet generated.
  final Message? message;

  /// Called when the user taps "Generate now".
  final VoidCallback? onGenerateNow;

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

  @override
  State<JournalPrepCard> createState() => _JournalPrepCardState();
}

class _JournalPrepCardState extends State<JournalPrepCard> {
  bool _expanded = false;

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

    return Card(
      margin: const EdgeInsets.fromLTRB(12, 8, 12, 4),
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(14),
        side: BorderSide(
          color: scheme.outlineVariant.withValues(alpha: 0.5),
          width: 1,
        ),
      ),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Icon(LucideIcons.bookOpen, size: 18, color: scheme.primary),
                const SizedBox(width: 8),
                Text(
                  _todayLabel(),
                  style: textTheme.labelMedium?.copyWith(
                    color: scheme.onSurfaceVariant,
                  ),
                ),
              ],
            ),
            const SizedBox(height: 10),
            if (widget.message == null) ...[
              Text(
                'No prep yet today.',
                style: textTheme.bodyMedium?.copyWith(
                  color: scheme.onSurfaceVariant,
                ),
              ),
              const SizedBox(height: 12),
              if (widget.onGenerateNow != null)
                FilledButton.tonal(
                  onPressed: widget.onGenerateNow,
                  child: const Text('Generate now'),
                ),
            ] else ...[
              AnimatedSize(
                duration: const Duration(milliseconds: 250),
                curve: Curves.easeInOut,
                alignment: Alignment.topCenter,
                child: _expanded
                    ? MarkdownBody(data: widget.message!.content)
                    : _TruncatedMarkdown(
                        data: widget.message!.content,
                        maxLines: 5,
                      ),
              ),
              const SizedBox(height: 8),
              GestureDetector(
                onTap: () => setState(() => _expanded = !_expanded),
                child: Text(
                  _expanded ? 'Show less ↑' : 'Show more ↓',
                  style: TextStyle(
                    color: scheme.primary,
                    fontSize: 13,
                    fontWeight: FontWeight.w500,
                  ),
                ),
              ),
            ],
          ],
        ),
      ),
    );
  }

  String _todayLabel() {
    final now = DateTime.now();
    const days = [
      'Monday', 'Tuesday', 'Wednesday', 'Thursday',
      'Friday', 'Saturday', 'Sunday'
    ];
    const months = [
      'January', 'February', 'March', 'April', 'May', 'June',
      'July', 'August', 'September', 'October', 'November', 'December'
    ];
    return '${days[now.weekday - 1]}, ${months[now.month - 1]} ${now.day}';
  }
}

/// Renders Markdown truncated to [maxLines] visible lines.
class _TruncatedMarkdown extends StatelessWidget {
  final String data;
  final int maxLines;
  const _TruncatedMarkdown({required this.data, required this.maxLines});

  @override
  Widget build(BuildContext context) {
    return ConstrainedBox(
      constraints: BoxConstraints(maxHeight: maxLines * 20.0),
      child: ClipRect(child: MarkdownBody(data: data)),
    );
  }
}