import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../../../core/utils/media_url.dart';
import '../../../../core/utils/validators.dart';
import '../../../../shared/models/user_management_models.dart';
import '../../../../shared/providers/auth_provider.dart';
import '../../../../shared/widgets/app_button.dart';
import '../../../../shared/widgets/app_text_field.dart';
import '../../../../shared/widgets/app_toast.dart';
import '../../../../shared/widgets/user_avatar.dart';
import '../../../auth/data/repositories/auth_repository_impl.dart';

class UserProfileScreen extends ConsumerStatefulWidget {
  const UserProfileScreen({super.key});

  @override
  ConsumerState<UserProfileScreen> createState() => _UserProfileScreenState();
}

class _UserProfileScreenState extends ConsumerState<UserProfileScreen> {
  final _formKey = GlobalKey<FormState>();
  final _fullNameController = TextEditingController();
  final _nameController = TextEditingController();
  final _emailController = TextEditingController();
  final _mobileController = TextEditingController();
  bool _isUpdatingProfile = false;
  bool _isUploadingAvatar = false;

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

  void _loadUser() {
    final user = ref.read(authStateProvider).user;
    if (user == null) return;
    _fullNameController.text = user.name;
    _nameController.text = user.name;
    _emailController.text = user.email;
    _mobileController.text = user.mobile;
  }

  @override
  void dispose() {
    _fullNameController.dispose();
    _nameController.dispose();
    _emailController.dispose();
    _mobileController.dispose();
    super.dispose();
  }

  Future<void> _pickAndUploadAvatar() async {
    final result = await FilePicker.pickFiles(
      type: FileType.custom,
      allowedExtensions: const ['jpg', 'jpeg', 'png', 'webp'],
      withData: true,
    );
    if (result == null || result.files.isEmpty) return;

    final file = result.files.first;
    final bytes = file.bytes;
    if (bytes == null || bytes.isEmpty) {
      if (!mounted) return;
      showAppToastFromSnackBar(
        context,
        const SnackBar(content: Text('Could not read the selected image.')),
      );
      return;
    }

    setState(() => _isUploadingAvatar = true);
    final repository = ref.read(authRepositoryProvider);
    final uploadResult = await repository.uploadProfileAvatar(
      bytes: bytes,
      filename: file.name.isNotEmpty ? file.name : 'avatar.png',
    );

    if (!mounted) return;

    if (uploadResult.failure != null) {
      setState(() => _isUploadingAvatar = false);
      showAppToastFromSnackBar(
        context,
        SnackBar(
          content: Text(
            uploadResult.failure?.message ?? 'Unable to upload profile picture.',
          ),
        ),
      );
      return;
    }

    final current = ref.read(authStateProvider).user;
    if (current != null) {
      ref.read(authStateProvider.notifier).setUser(
            current.copyWith(avatarUrl: uploadResult.data),
          );
    }
    // Sync role/department/avatar from /auth/me when available.
    await ref.read(authStateProvider.notifier).refreshCurrentUser();

    if (!mounted) return;
    setState(() => _isUploadingAvatar = false);
    showAppToastFromSnackBar(
      context,
      const SnackBar(content: Text('Profile picture updated')),
    );
  }

  Future<void> _updateProfile() async {
    if (!_formKey.currentState!.validate()) return;
    setState(() => _isUpdatingProfile = true);

    final repository = ref.read(authRepositoryProvider);
    final result = await repository.updateProfile(
      UpdateProfileRequest(
        fullName: _fullNameController.text.trim(),
        name: _nameController.text.trim(),
        email: _emailController.text.trim(),
        mobile: _mobileController.text.trim(),
      ),
    );

    if (!mounted) return;
    setState(() => _isUpdatingProfile = false);

    if (result.failure != null) {
      showAppToastFromSnackBar(
        context,
        SnackBar(
          content: Text(
            result.failure?.message ?? 'Unable to update profile.',
          ),
        ),
      );
      return;
    }

    if (result.data != null) {
      ref.read(authStateProvider.notifier).setUser(result.data!);
      _fullNameController.text = result.data!.name;
      _nameController.text = result.data!.name;
      _emailController.text = result.data!.email;
      _mobileController.text = result.data!.mobile;
    }

    showAppToastFromSnackBar(
      context,
      const SnackBar(content: Text('Profile updated')),
    );
  }

  @override
  Widget build(BuildContext context) {
    final user = ref.watch(authStateProvider).user;
    final theme = Theme.of(context);

    if (user == null) {
      return const Center(child: Text('Not signed in'));
    }

    final avatarUrl = resolveMediaUrl(user.avatarUrl);

    return SingleChildScrollView(
      padding: const EdgeInsets.all(24),
      child: Center(
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 640),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              Text(
                'User Profile',
                style: theme.textTheme.headlineSmall,
              ),
              const SizedBox(height: 24),
              Center(
                child: Stack(
                  clipBehavior: Clip.none,
                  children: [
                    UserAvatar(
                      name: user.name,
                      avatarUrl: avatarUrl,
                      radius: 48,
                    ),
                    Positioned(
                      bottom: 0,
                      right: 0,
                      child: IconButton.filled(
                        onPressed:
                            _isUploadingAvatar ? null : _pickAndUploadAvatar,
                        icon: _isUploadingAvatar
                            ? const SizedBox(
                                width: 18,
                                height: 18,
                                child: CircularProgressIndicator(
                                  strokeWidth: 2,
                                  color: Colors.white,
                                ),
                              )
                            : const Icon(Icons.camera_alt, size: 18),
                      ),
                    ),
                  ],
                ),
              ),
              const SizedBox(height: 24),
              Form(
                key: _formKey,
                child: Column(
                  children: [
                    AppTextField(
                      controller: _fullNameController,
                      label: 'Full Name',
                      validator: (v) =>
                          Validators.required(v, fieldName: 'Full Name'),
                    ),
                    const SizedBox(height: 16),
                    AppTextField(
                      controller: _nameController,
                      label: 'Name',
                      validator: (v) =>
                          Validators.required(v, fieldName: 'Name'),
                    ),
                    const SizedBox(height: 16),
                    AppTextField(
                      controller: _emailController,
                      label: 'Email',
                      keyboardType: TextInputType.emailAddress,
                      validator: Validators.email,
                    ),
                    const SizedBox(height: 16),
                    AppTextField(
                      controller: _mobileController,
                      label: 'Mobile',
                      keyboardType: TextInputType.phone,
                      validator: Validators.mobile,
                      inputFormatters: Validators.mobileInput,
                    ),
                    const SizedBox(height: 8),
                    Align(
                      alignment: Alignment.centerLeft,
                      child: Text('Department: ${user.department ?? '—'}'),
                    ),
                    const SizedBox(height: 4),
                    Align(
                      alignment: Alignment.centerLeft,
                      child: Text('Role: ${user.role}'),
                    ),
                    const SizedBox(height: 24),
                    AppButton(
                      label: 'Update Profile',
                      isLoading: _isUpdatingProfile,
                      onPressed: _updateProfile,
                    ),
                  ],
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}