import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../services/odoo_service.dart';
import '../utils/theme.dart';
import 'pos_list_screen.dart';

class HomeScreen extends StatefulWidget {
  const HomeScreen({super.key});

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  List<dynamic> _menuItems = [];
  bool _isLoading = true;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => _fetchMenus());
  }

  Future<void> _fetchMenus() async {
    final odoo = Provider.of<OdooService>(context, listen: false);
    try {
      // Fetch top-level menus (Apps)
      final result = await odoo.callKw(
        model: 'ir.ui.menu',
        method: 'search_read',
        args: [
          [['parent_id', '=', false]] // Top level only
        ],
        kwargs: {
          'fields': ['name', 'web_icon_data', 'action', 'id'],
          'order': 'sequence,id',
        },
      );
      
      if (mounted) {
        setState(() {
          _menuItems = result;
          _isLoading = false;
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() { _isLoading = false; });
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Error fetching apps: $e')),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Dashboard', style: TextStyle(fontWeight: FontWeight.bold)),
        backgroundColor: Colors.white,
        foregroundColor: AppTheme.secondaryColor,
        elevation: 1,
        actions: [
          IconButton(
            icon: const Icon(Icons.logout),
            onPressed: () {
              Provider.of<OdooService>(context, listen: false).logout();
            },
          ),
        ],
      ),
      body: Container(
        decoration: const BoxDecoration(
          gradient: LinearGradient(
              begin: Alignment.topCenter,
              end: Alignment.bottomCenter,
              colors: [Color(0xFFfdfdfd), Color(0xFFf4f6f8)],
          ),
        ),
        child: _isLoading
            ? const Center(child: CircularProgressIndicator())
            : RefreshIndicator(
                onRefresh: _fetchMenus,
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: GridView.builder(
                    gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                      crossAxisCount: 3,
                      crossAxisSpacing: 16,
                      mainAxisSpacing: 16,
                      childAspectRatio: 0.85,
                    ),
                    itemCount: _menuItems.length,
                    itemBuilder: (context, index) {
                      final item = _menuItems[index];
                      return _buildAppIcon(item);
                    },
                  ),
                ),
              ),
      ),
    );
  }

  Widget _buildAppIcon(Map<String, dynamic> item) {
    String name = item['name'] ?? 'App';
    String? iconData = item['web_icon_data']; // Base64 png usually

    // Clean base64 string if necessary (sometimes Odoo sends headers)
    if (iconData != null) {
      iconData = iconData.replaceAll(RegExp(r'\s'), '');
    }

    return Card(
      elevation: 4,
      shadowColor: Colors.black12,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
      child: InkWell(
        onTap: () {
          if (name.toLowerCase().contains('point of sale')) {
            Navigator.push(
              context,
              MaterialPageRoute(builder: (context) => const PosListScreen()),
            );
          } else {
            ScaffoldMessenger.of(context).showSnackBar(
               SnackBar(content: Text('Opening $name... (Not implemented in demo)')),
            );
          }
        },
        borderRadius: BorderRadius.circular(16),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Container(
              height: 50,
              width: 50,
              padding: const EdgeInsets.all(8),
              decoration: BoxDecoration(
                color: Colors.white,
                borderRadius: BorderRadius.circular(12),
              ),
              child: iconData != null 
                  ? Image.memory(
                      const Base64Decoder().convert(iconData),
                      errorBuilder: (context, error, stackTrace) => const Icon(Icons.apps, size: 30, color: AppTheme.secondaryColor),
                    )
                  : const Icon(Icons.apps, size: 30, color: AppTheme.secondaryColor),
            ),
            const SizedBox(height: 12),
            Text(
              name,
              textAlign: TextAlign.center,
              maxLines: 2,
              overflow: TextOverflow.ellipsis,
              style: const TextStyle(
                fontSize: 13,
                fontWeight: FontWeight.w600,
                color: Color(0xFF4a5568),
              ),
            ),
          ],
        ),
      ),
    );
  }
}