import 'package:flutter/material.dart';
import 'package:get/get.dart';
import '../../dashboard/views/dashboard_view.dart';
import '../../invoices/views/invoices_list_view.dart';
import '../../notifications/views/notifications_view.dart';
import '../../settings/views/settings_view.dart';
import '../controllers/main_shell_controller.dart';
import '../../../app/routes/app_pages.dart';
import '../../../core/services/upload_progress_service.dart';

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

  @override
  State<MainShellView> createState() => _MainShellViewState();
}

class _MainShellViewState extends State<MainShellView> {
  final MainShellController _shellController = Get.find<MainShellController>();
  // Must be find(), not put(): main.dart already registers the permanent
  // instance. Re-putting it here swapped in a second, empty instance that other
  // controllers were no longer holding, so progress updates went nowhere.
  final UploadProgressService _progressService =
      Get.find<UploadProgressService>();

  // 5 pages: Home(0), Invoices(1), [Scanner FAB](2), Notifications(3), Settings(4)
  final List<Widget> _pages = const [
    DashboardView(), // 0
    InvoicesListView(), // 1
    SizedBox(), // 2 - Scanner (FAB placeholder)
    NotificationsView(), // 3
    SettingsView(), // 4
  ];

  @override
  Widget build(BuildContext context) {
    final isDark = Theme.of(context).brightness == Brightness.dark;
    final navBg = isDark ? const Color(0xFF1A1A2E) : Colors.white;
    const activeColor = Color(0xFF0F4C81);
    final inactiveColor = isDark ? Colors.white38 : const Color(0xFF94A3B8);

    return Scaffold(
      backgroundColor:
          isDark ? const Color(0xFF121212) : const Color(0xFFF5F7FA),
      body: Stack(
        children: [
          Obx(
            () => IndexedStack(
              index: _getPageIndex(_shellController.currentIndex.value),
              children: [
                _pages[0], // Dashboard
                _pages[1], // Invoices
                _pages[3], // Notifications
                _pages[4], // Settings
              ],
            ),
          ),

          // Global Upload Progress Overlay
          Obx(() => _progressService.isUploading.value
              ? Positioned(
                  bottom: 80,
                  left: 16,
                  right: 16,
                  child: _buildUploadOverlay(isDark),
                )
              : const SizedBox.shrink()),
        ],
      ),
      floatingActionButton: _buildScannerFAB(),
      floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
      bottomNavigationBar: BottomAppBar(
        shape: const CircularNotchedRectangle(),
        notchMargin: 8,
        color: navBg,
        elevation: 16,
        child: SizedBox(
          height: 60,
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceAround,
            children: [
              // Left side (2 items)
              _buildNavItem(0, Icons.home_rounded, 'الرئيسية', activeColor,
                  inactiveColor),
              _buildNavItem(1, Icons.receipt_long_rounded, 'الفواتير',
                  activeColor, inactiveColor),
              // Center gap for FAB
              const SizedBox(width: 48),
              // Right side (2 items)
              _buildNavItem(3, Icons.notifications_rounded, 'الإشعارات',
                  activeColor, inactiveColor),
              _buildNavItem(4, Icons.settings_rounded, 'الإعدادات', activeColor,
                  inactiveColor),
            ],
          ),
        ),
      ),
    );
  }

  int _getPageIndex(int navIndex) {
    // Map nav index to page index (skip scanner placeholder at 2)
    if (navIndex <= 1) return navIndex;
    if (navIndex == 3) return 2; // Notifications
    if (navIndex == 4) return 3; // Settings
    return 0;
  }

  Widget _buildNavItem(
      int index, IconData icon, String label, Color active, Color inactive) {
    return Expanded(
      child: Obx(() {
        final isSelected = _shellController.currentIndex.value == index;

        return InkWell(
          onTap: () => _shellController.selectTab(index),
          borderRadius: BorderRadius.circular(12),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              AnimatedContainer(
                duration: const Duration(milliseconds: 200),
                padding:
                    const EdgeInsets.symmetric(horizontal: 12, vertical: 2),
                decoration: isSelected
                    ? BoxDecoration(
                        color: active.withValues(alpha: 0.1),
                        borderRadius: BorderRadius.circular(16),
                      )
                    : null,
                child:
                    Icon(icon, color: isSelected ? active : inactive, size: 22),
              ),
              const SizedBox(height: 2),
              Text(
                label,
                style: TextStyle(
                  fontSize: 10,
                  fontWeight: isSelected ? FontWeight.w700 : FontWeight.w400,
                  color: isSelected ? active : inactive,
                ),
              ),
            ],
          ),
        );
      }),
    );
  }

  Widget _buildScannerFAB() {
    return Container(
      width: 56,
      height: 56,
      decoration: BoxDecoration(
        shape: BoxShape.circle,
        gradient: const LinearGradient(
          colors: [Color(0xFFD4AF37), Color(0xFFF0D060)],
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
        ),
        boxShadow: [
          BoxShadow(
            color: const Color(0xFFD4AF37).withValues(alpha: 0.4),
            blurRadius: 12,
            offset: const Offset(0, 4),
          ),
        ],
      ),
      child: FloatingActionButton(
        onPressed: () => Get.toNamed(AppRoutes.SCANNER),
        backgroundColor: Colors.transparent,
        elevation: 0,
        heroTag: 'scanner_fab',
        child: const Icon(Icons.document_scanner_rounded,
            color: Colors.white, size: 26),
      ),
    );
  }

  Widget _buildUploadOverlay(bool isDark) {
    final status = _progressService.status.value;
    final progress = _progressService.progress.value;

    // Terminal states must look different from in-progress ones, otherwise a
    // failed or partially failed batch is indistinguishable from a success.
    final bool isTerminal =
        status == 'done' || status == 'partial' || status == 'failed';

    final Color accentColor = switch (status) {
      'done' => const Color(0xFF10B981),
      'partial' => const Color(0xFFF59E0B),
      'failed' => const Color(0xFFEF4444),
      _ => const Color(0xFF0F4C81),
    };

    final String statusText = switch (status) {
      'uploading' => 'جاري رفع الصور...',
      'processing' => 'جاري استخراج البيانات...',
      'done' => 'اكتملت المعالجة ✓',
      'partial' => 'اكتملت المعالجة مع أخطاء',
      'failed' => 'فشلت العملية',
      _ => 'جاري المعالجة...',
    };

    final IconData? terminalIcon = switch (status) {
      'done' => Icons.check_circle,
      'partial' => Icons.warning_amber_rounded,
      'failed' => Icons.error_outline,
      _ => null,
    };

    final String detailText = _progressService.errorMessage.value.isNotEmpty
        ? _progressService.errorMessage.value
        : '${_progressService.companyName.value} • ${_progressService.currentImageIndex.value}/${_progressService.totalImages.value}';

    return Card(
      elevation: 8,
      shadowColor: Colors.black26,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
      color: isDark ? const Color(0xFF1E1E2E) : Colors.white,
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Row(
              children: [
                terminalIcon != null
                    ? Icon(terminalIcon, color: accentColor, size: 24)
                    : const SizedBox(
                        width: 24,
                        height: 24,
                        child: CircularProgressIndicator(
                            strokeWidth: 2, color: Color(0xFF0F4C81))),
                const SizedBox(width: 12),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(statusText,
                          style: TextStyle(
                              fontWeight: FontWeight.bold,
                              fontSize: 13,
                              color: status == 'failed' ? accentColor : null)),
                      Text(
                        detailText,
                        maxLines: 2,
                        overflow: TextOverflow.ellipsis,
                        style: TextStyle(
                            fontSize: 11,
                            color: isDark ? Colors.white38 : Colors.grey),
                      ),
                    ],
                  ),
                ),
                if (isTerminal)
                  // A terminal card no longer moves on its own, so give the user
                  // a way to clear it instead of waiting out a timer.
                  IconButton(
                    icon: const Icon(Icons.close, size: 18),
                    color: isDark ? Colors.white38 : Colors.grey,
                    onPressed: _progressService.dismiss,
                    tooltip: 'إخفاء',
                  )
                else
                  Text(
                    '${(progress * 100).toInt()}%',
                    style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 14,
                        color: accentColor),
                  ),
              ],
            ),
            const SizedBox(height: 10),
            ClipRRect(
              borderRadius: BorderRadius.circular(4),
              child: LinearProgressIndicator(
                value: progress,
                backgroundColor:
                    isDark ? Colors.white10 : const Color(0xFFE2E8F0),
                color: accentColor,
                minHeight: 6,
              ),
            ),
          ],
        ),
      ),
    );
  }
}