import 'package:flutter/material.dart';
import 'dart:typed_data';
import '../../core/service_locator.dart';
import '../navigation/main_navigation_scaffold.dart';

/// Primary AppBar widget with user icon for all main screens.
class PrimaryAppBar extends StatefulWidget implements PreferredSizeWidget {
  final String title;

  const PrimaryAppBar({
    super.key,
    required this.title,
  });

  @override
  State<PrimaryAppBar> createState() => _PrimaryAppBarState();

  @override
  Size get preferredSize => const Size.fromHeight(kToolbarHeight);
}

class _PrimaryAppBarState extends State<PrimaryAppBar> {
  Uint8List? _avatarBytes;
  bool _isLoadingAvatar = false;
  String? _lastProfilePictureUrl; // Track URL to avoid reloading

  @override
  void initState() {
    super.initState();
    _loadAvatar();
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    // Only reload if the profile picture URL has changed
    final sessionService = ServiceLocator.instance.sessionService;
    if (sessionService != null && sessionService.isLoggedIn) {
      final currentUser = sessionService.currentUser;
      final profilePictureUrl = currentUser?.nostrProfile?.picture;
      if (profilePictureUrl != _lastProfilePictureUrl) {
        _lastProfilePictureUrl = profilePictureUrl;
        _loadAvatar();
      }
    }
  }

  Future<void> _loadAvatar() async {
    final sessionService = ServiceLocator.instance.sessionService;
    if (sessionService == null || !sessionService.isLoggedIn) {
      // Clear avatar when logged out
      if (mounted) {
        setState(() {
          _avatarBytes = null;
          _isLoadingAvatar = false;
          _lastProfilePictureUrl = null;
        });
      }
      return;
    }

    final currentUser = sessionService.currentUser;
    if (currentUser == null) {
      if (mounted) {
        setState(() {
          _avatarBytes = null;
          _isLoadingAvatar = false;
          _lastProfilePictureUrl = null;
        });
      }
      return;
    }

    final profilePictureUrl = currentUser.nostrProfile?.picture;
    if (profilePictureUrl == null || profilePictureUrl.isEmpty) {
      // Clear avatar if no profile picture
      if (mounted) {
        setState(() {
          _avatarBytes = null;
          _isLoadingAvatar = false;
          _lastProfilePictureUrl = null;
        });
      }
      return;
    }

    // Don't reload if it's the same URL
    if (profilePictureUrl == _lastProfilePictureUrl && _avatarBytes != null) {
      return;
    }

    _lastProfilePictureUrl = profilePictureUrl;

    setState(() {
      _isLoadingAvatar = true;
    });

    try {
      // Extract asset ID from Immich URL using regex (same as SessionScreen)
      final mediaService = ServiceLocator.instance.mediaService;
      if (mediaService != null) {
        // Try to extract asset ID from URL (format: .../api/assets/{id}/original or .../share/{shareId})
        final assetIdMatch = RegExp(r'/api/assets/([^/]+)/').firstMatch(profilePictureUrl);
        String? assetId;
        
        if (assetIdMatch != null) {
          assetId = assetIdMatch.group(1);
        } else {
          // For Blossom URLs, use the full URL
          assetId = profilePictureUrl;
        }
        
        if (assetId != null) {
          final bytes = await mediaService.fetchImageBytes(assetId, isThumbnail: true);
          if (mounted) {
            setState(() {
              _avatarBytes = bytes;
              _isLoadingAvatar = false;
            });
          }
          return;
        }
      }

      // Fallback: try to fetch as regular image (for non-Immich URLs or shared links)
      // For now, we'll just set loading to false
      if (mounted) {
        setState(() {
          _isLoadingAvatar = false;
        });
      }
    } catch (e) {
      // Log error for debugging
      debugPrint('Failed to load avatar: $e');
      if (mounted) {
        setState(() {
          _isLoadingAvatar = false;
          _avatarBytes = null; // Clear on error
        });
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return AppBar(
      title: Text(widget.title),
      actions: [
        // Only show user icon on Home screen (title == 'Home')
        if (widget.title == 'Home')
          IconButton(
            icon: _buildUserIcon(),
            tooltip: 'User',
            onPressed: () {
              // Navigate to User screen by finding the MainNavigationScaffold
              final scaffold = context.findAncestorStateOfType<MainNavigationScaffoldState>();
              scaffold?.navigateToUser();
            },
          ),
      ],
    );
  }

  Widget _buildUserIcon() {
    if (_isLoadingAvatar) {
      return const CircleAvatar(
        radius: 12,
        backgroundColor: Colors.transparent,
        child: SizedBox(
          width: 16,
          height: 16,
          child: CircularProgressIndicator(strokeWidth: 2),
        ),
      );
    }

    if (_avatarBytes != null) {
      return CircleAvatar(
        radius: 12,
        backgroundImage: MemoryImage(_avatarBytes!),
        onBackgroundImageError: (_, __) {
          // Clear avatar on error
          if (mounted) {
            setState(() {
              _avatarBytes = null;
            });
          }
        },
      );
    }

    return const CircleAvatar(
      radius: 12,
      child: Icon(Icons.person, size: 16),
    );
  }
}