import 'dart:math' show min;

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

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

class ChatMessageBubble extends StatelessWidget {
  final Message message;
  final String streamingStatus;
  const ChatMessageBubble({
    super.key,
    required this.message,
    this.streamingStatus = '',
  });

  @override
  Widget build(BuildContext context) {
    final isUser = message.role == MessageRole.user;
    final scheme = Theme.of(context).colorScheme;
    final isGenerating = message.status == 'generating';

    return Align(
      alignment: isUser ? Alignment.centerRight : Alignment.centerLeft,
      child: Container(
        constraints: BoxConstraints(
          maxWidth: min(MediaQuery.of(context).size.width * 0.82, 480),
        ),
        margin: const EdgeInsets.symmetric(vertical: 4, horizontal: 4),
        decoration: isUser
            ? BoxDecoration(
                // Ghost style: transparent bg, thin border
                color: Colors.transparent,
                border: Border.all(
                  color: scheme.primary.withValues(alpha: 0.35),
                  width: 1,
                ),
                borderRadius: const BorderRadius.only(
                  topLeft: Radius.circular(16),
                  topRight: Radius.circular(16),
                  bottomLeft: Radius.circular(16),
                  bottomRight: Radius.circular(4),
                ),
              )
            : BoxDecoration(
                // Assistant: elevated surface + left accent border
                color: scheme.surfaceContainerHighest,
                border: Border(
                  left: BorderSide(color: scheme.primary, width: 2),
                ),
                borderRadius: const BorderRadius.only(
                  topLeft: Radius.circular(4),
                  topRight: Radius.circular(16),
                  bottomLeft: Radius.circular(4),
                  bottomRight: Radius.circular(16),
                ),
              ),
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
          child: isGenerating && message.content.isEmpty
              ? Row(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    SizedBox(
                      width: 16,
                      height: 16,
                      child: CircularProgressIndicator(
                        strokeWidth: 2,
                        color: scheme.onSurfaceVariant,
                      ),
                    ),
                    if (streamingStatus.isNotEmpty) ...[
                      const SizedBox(width: 8),
                      Flexible(
                        child: Text(
                          streamingStatus,
                          style: TextStyle(
                            fontSize: 12,
                            color: scheme.onSurfaceVariant,
                            fontStyle: FontStyle.italic,
                          ),
                        ),
                      ),
                    ],
                  ],
                )
              : MarkdownBody(
                  data: message.content.isEmpty ? '…' : message.content,
                  styleSheet: MarkdownStyleSheet(
                    p: TextStyle(
                      color: isUser
                          ? scheme.onSurface.withValues(alpha: 0.75)
                          : scheme.onSurface,
                      fontSize: 14,
                    ),
                  ),
                ),
        ),
      ),
    );
  }
}