// lib/screens/contribute_screen.dart
// Contributor Module v3 — matches web at app.eventifyplus.com/contribute
// 3 tabs: My Events · Submit Event · Reward Shop

import 'dart:io';
import 'package:flutter/foundation.dart' show kIsWeb;
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:image_picker/image_picker.dart';
import 'package:intl/intl.dart';
import 'package:provider/provider.dart';
import 'package:share_plus/share_plus.dart';

import '../core/utils/error_utils.dart';
import '../features/gamification/models/gamification_models.dart';
import '../features/gamification/providers/gamification_provider.dart';
import '../widgets/bouncing_loader.dart';
import '../core/analytics/posthog_service.dart';

// ─────────────────────────────────────────────────────────────────────────────
// Constants
// ─────────────────────────────────────────────────────────────────────────────
const _tierColors = <ContributorTier, Color>{
  ContributorTier.BRONZE:   Color(0xFFCD7F32),
  ContributorTier.SILVER:   Color(0xFFA8A9AD),
  ContributorTier.GOLD:     Color(0xFFFFD700),
  ContributorTier.PLATINUM: Color(0xFFE5E4E2),
  ContributorTier.DIAMOND:  Color(0xFF67E8F9),
};

const _tierIcons = <ContributorTier, IconData>{
  ContributorTier.BRONZE:   Icons.shield_outlined,
  ContributorTier.SILVER:   Icons.shield_outlined,
  ContributorTier.GOLD:     Icons.workspace_premium_outlined,
  ContributorTier.PLATINUM: Icons.diamond_outlined,
  ContributorTier.DIAMOND:  Icons.diamond_outlined,
};

const _tierThresholds = [0, 100, 500, 1500, 5000];

const _districts = [
  'Thiruvananthapuram', 'Kollam', 'Pathanamthitta', 'Alappuzha',
  'Kottayam', 'Idukki', 'Ernakulam', 'Thrissur', 'Palakkad',
  'Malappuram', 'Kozhikode', 'Wayanad', 'Kannur', 'Kasaragod', 'Other',
];

const _categories = [
  'Music', 'Food', 'Arts', 'Sports', 'Tech', 'Community',
  'Dance', 'Film', 'Business', 'Health', 'Education', 'Other',
];

// Design tokens matching web
const _blue       = Color(0xFF0F45CF);
const _darkText   = Color(0xFF1E293B);
const _subText    = Color(0xFF94A3B8);
const _border     = Color(0xFFE2E8F0);
const _lightBlueBg = Color(0xFFEFF6FF);
const _rpOrange   = Color(0xFFEA580C);
const _greenBg    = Color(0xFFD1FAE5);
const _greenText  = Color(0xFF065F46);
const _yellowBg   = Color(0xFFFEF3C7);
const _yellowText = Color(0xFF92400E);
const _redBg      = Color(0xFFFECDD3);
const _redText    = Color(0xFF9F1239);
const _pageBg     = Color(0xFFF8FAFC);

// ─────────────────────────────────────────────────────────────────────────────
// ContributeScreen
// ─────────────────────────────────────────────────────────────────────────────
class ContributeScreen extends StatefulWidget {
  const ContributeScreen({Key? key}) : super(key: key);
  @override
  State<ContributeScreen> createState() => _ContributeScreenState();
}

class _ContributeScreenState extends State<ContributeScreen>
    with SingleTickerProviderStateMixin {

  int _activeTab = 1; // default to Submit Event

  // Form
  final _formKey       = GlobalKey<FormState>();
  final _titleCtl      = TextEditingController();
  final _descriptionCtl = TextEditingController();
  final _latCtl        = TextEditingController();
  final _lngCtl        = TextEditingController();
  final _mapsLinkCtl   = TextEditingController();

  DateTime? _selectedDate;
  TimeOfDay? _selectedTime;
  String _selectedCategory = _categories.first;
  String _selectedDistrict = _districts.first;
  List<XFile> _images = [];
  bool _submitting = false;
  bool _showSuccess = false;
  bool _useManualCoords = true;
  String? _coordMessage;
  bool _coordSuccess = false;

  final _picker = ImagePicker();

  @override
  void initState() {
    super.initState();
    PostHogService.instance.screen('Contribute');
    WidgetsBinding.instance.addPostFrameCallback((_) {
      context.read<GamificationProvider>().loadAll();
    });
  }

  @override
  void dispose() {
    _titleCtl.dispose();
    _descriptionCtl.dispose();
    _latCtl.dispose();
    _lngCtl.dispose();
    _mapsLinkCtl.dispose();
    super.dispose();
  }

  // ─────────────────────────────────────────────────────────────────────────
  // Build
  // ─────────────────────────────────────────────────────────────────────────
  @override
  Widget build(BuildContext context) {
    return Consumer<GamificationProvider>(
      builder: (context, provider, _) {
        if (provider.isLoading && provider.profile == null) {
          return const Scaffold(
            backgroundColor: _pageBg,
            body: Center(child: BouncingLoader(color: _blue)),
          );
        }
        return Scaffold(
          backgroundColor: _pageBg,
          body: SafeArea(
            child: Column(
              children: [
                _buildStatsBar(provider),
                _buildTierRoadmap(provider),
                _buildTabBar(),
                Expanded(child: _buildTabContent(provider)),
              ],
            ),
          ),
        );
      },
    );
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // 1. COMPACT STATS BAR
  // ═══════════════════════════════════════════════════════════════════════════
  Widget _buildStatsBar(GamificationProvider provider) {
    final profile = provider.profile;
    final tier = profile?.tier ?? ContributorTier.BRONZE;
    final tierColor = _tierColors[tier] ?? const Color(0xFFCD7F32);
    final tierIcon = _tierIcons[tier] ?? Icons.shield_outlined;

    return Padding(
      padding: const EdgeInsets.fromLTRB(16, 12, 16, 8),
      child: Row(
        children: [
          // Tier pill
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
            decoration: BoxDecoration(
              color: _blue,
              borderRadius: BorderRadius.circular(20),
            ),
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Icon(tierIcon, color: tierColor, size: 16),
                const SizedBox(width: 6),
                Text(
                  tierLabel(tier),
                  style: const TextStyle(color: Colors.white, fontWeight: FontWeight.w700, fontSize: 13),
                ),
              ],
            ),
          ),
          const SizedBox(width: 12),

          // Liquid EP
          Icon(Icons.bolt, color: _blue, size: 18),
          const SizedBox(width: 4),
          Text(
            '${profile?.currentEp ?? 0}',
            style: const TextStyle(color: _darkText, fontWeight: FontWeight.w700, fontSize: 15),
          ),
          const SizedBox(width: 4),
          const Text('EP', style: TextStyle(color: _subText, fontSize: 12)),

          const SizedBox(width: 16),

          // RP
          Icon(Icons.card_giftcard, color: _rpOrange, size: 18),
          const SizedBox(width: 4),
          Text(
            '${profile?.currentRp ?? 0}',
            style: TextStyle(color: _rpOrange, fontWeight: FontWeight.w700, fontSize: 15),
          ),
          const SizedBox(width: 4),
          const Text('RP', style: TextStyle(color: _subText, fontSize: 12)),

          const Spacer(),

          // Share button
          GestureDetector(
            onTap: () => _shareRank(provider),
            child: Container(
              padding: const EdgeInsets.all(8),
              decoration: BoxDecoration(
                color: const Color(0xFFF1F5F9),
                borderRadius: BorderRadius.circular(10),
              ),
              child: const Icon(Icons.share_outlined, color: _subText, size: 18),
            ),
          ),
        ],
      ),
    );
  }

  void _shareRank(GamificationProvider provider) {
    final profile = provider.profile;
    if (profile == null) return;
    final text = "I'm a ${tierLabel(profile.tier)} contributor on Eventify with ${profile.lifetimeEp} EP! Join the community.";
    Share.share(text);
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // 2. TIER ROADMAP
  // ═══════════════════════════════════════════════════════════════════════════
  Widget _buildTierRoadmap(GamificationProvider provider) {
    final currentTier = provider.profile?.tier ?? ContributorTier.BRONZE;
    final tiers = ContributorTier.values;

    return Padding(
      padding: const EdgeInsets.fromLTRB(16, 4, 16, 12),
      child: Container(
        padding: const EdgeInsets.symmetric(vertical: 12, horizontal: 8),
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(14),
          border: Border.all(color: _border),
        ),
        child: Row(
          children: List.generate(tiers.length * 2 - 1, (i) {
            if (i.isOdd) {
              // Connector line
              final tierIdx = i ~/ 2;
              final reached = currentTier.index > tierIdx;
              return Expanded(
                child: Container(
                  height: 2,
                  color: reached ? _blue : const Color(0xFFE2E8F0),
                ),
              );
            }
            final tierIdx = i ~/ 2;
            final tier = tiers[tierIdx];
            final isActive = tier == currentTier;
            final reached = currentTier.index >= tierIdx;
            final tierColor = _tierColors[tier]!;
            final thresholdLabel = _tierThresholds[tierIdx] >= 1000
                ? '${(_tierThresholds[tierIdx] / 1000).toStringAsFixed(_tierThresholds[tierIdx] % 1000 == 0 ? 0 : 1)}K'
                : '${_tierThresholds[tierIdx]}';

            return Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                Container(
                  width: 32,
                  height: 32,
                  decoration: BoxDecoration(
                    color: isActive ? _lightBlueBg : (reached ? _blue.withValues(alpha: 0.08) : const Color(0xFFF8FAFC)),
                    shape: BoxShape.circle,
                    border: Border.all(
                      color: isActive ? _blue : (reached ? _blue.withValues(alpha: 0.3) : _border),
                      width: isActive ? 2 : 1,
                    ),
                  ),
                  child: Icon(
                    _tierIcons[tier] ?? Icons.shield_outlined,
                    size: 16,
                    color: reached ? _blue : _subText,
                  ),
                ),
                const SizedBox(height: 4),
                Text(
                  tierLabel(tier),
                  style: TextStyle(
                    fontSize: 9,
                    fontWeight: isActive ? FontWeight.w700 : FontWeight.w500,
                    color: isActive ? _blue : _subText,
                  ),
                ),
                Text(
                  '$thresholdLabel EP',
                  style: TextStyle(fontSize: 8, color: isActive ? _blue : const Color(0xFFCBD5E1)),
                ),
              ],
            );
          }),
        ),
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // 3. TAB BAR WITH ANIMATED GLIDER
  // ═══════════════════════════════════════════════════════════════════════════
  static const _tabLabels = ['My Events', 'Submit Event', 'Reward Shop'];
  static const _tabIcons  = [Icons.list_alt_rounded, Icons.add_circle_outline, Icons.card_giftcard_outlined];

  Widget _buildTabBar() {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Container(
        height: 52,
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(16),
          border: Border.all(color: _border),
        ),
        child: LayoutBuilder(
          builder: (context, constraints) {
            final tabWidth = constraints.maxWidth / 3;
            return Stack(
              children: [
                // Animated glider
                AnimatedPositioned(
                  duration: const Duration(milliseconds: 350),
                  curve: Curves.easeOutBack,
                  left: tabWidth * _activeTab + 4,
                  top: 4,
                  child: Container(
                    width: tabWidth - 8,
                    height: 44,
                    decoration: BoxDecoration(
                      color: _blue,
                      borderRadius: BorderRadius.circular(12),
                      boxShadow: [
                        BoxShadow(color: _blue.withValues(alpha: 0.3), blurRadius: 8, offset: const Offset(0, 2)),
                      ],
                    ),
                  ),
                ),
                // Tab buttons
                Row(
                  children: List.generate(3, (i) {
                    final isActive = i == _activeTab;
                    return Expanded(
                      child: GestureDetector(
                        onTap: () => setState(() => _activeTab = i),
                        behavior: HitTestBehavior.opaque,
                        child: SizedBox(
                          height: 52,
                          child: Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: [
                              Icon(
                                _tabIcons[i],
                                size: 18,
                                color: isActive ? Colors.white : const Color(0xFF64748B),
                              ),
                              const SizedBox(width: 6),
                              Text(
                                _tabLabels[i],
                                style: TextStyle(
                                  fontSize: 13,
                                  fontWeight: FontWeight.w600,
                                  color: isActive ? Colors.white : const Color(0xFF64748B),
                                ),
                              ),
                            ],
                          ),
                        ),
                      ),
                    );
                  }),
                ),
              ],
            );
          },
        ),
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // 4. TAB CONTENT
  // ═══════════════════════════════════════════════════════════════════════════
  Widget _buildTabContent(GamificationProvider provider) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(16, 12, 16, 0),
      child: Container(
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: const BorderRadius.vertical(top: Radius.circular(16)),
          border: Border.all(color: _border),
        ),
        child: ClipRRect(
          borderRadius: const BorderRadius.vertical(top: Radius.circular(16)),
          child: AnimatedSwitcher(
            duration: const Duration(milliseconds: 250),
            child: _activeTab == 0
                ? _buildMyEventsTab(provider)
                : _activeTab == 1
                    ? _buildSubmitEventTab(provider)
                    : _buildRewardShopTab(provider),
          ),
        ),
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // TAB 0: MY EVENTS
  // ═══════════════════════════════════════════════════════════════════════════
  Widget _buildMyEventsTab(GamificationProvider provider) {
    final submissions = provider.submissions;

    if (submissions.isEmpty) {
      return Center(
        key: const ValueKey('empty'),
        child: Padding(
          padding: const EdgeInsets.all(32),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Container(
                width: 64,
                height: 64,
                decoration: BoxDecoration(
                  color: _lightBlueBg,
                  shape: BoxShape.circle,
                ),
                child: const Icon(Icons.star_outline_rounded, color: _blue, size: 32),
              ),
              const SizedBox(height: 16),
              const Text(
                'No events submitted yet',
                style: TextStyle(fontSize: 17, fontWeight: FontWeight.w700, color: _darkText),
              ),
              const SizedBox(height: 8),
              const Text(
                'Head over to the Submit tab to earn your first EP!',
                style: TextStyle(fontSize: 13, color: _subText),
                textAlign: TextAlign.center,
              ),
              const SizedBox(height: 20),
              ElevatedButton(
                onPressed: () => setState(() => _activeTab = 1),
                style: ElevatedButton.styleFrom(
                  backgroundColor: _blue,
                  foregroundColor: Colors.white,
                  shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                  padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 12),
                ),
                child: const Text('Start Contributing', style: TextStyle(fontWeight: FontWeight.w600)),
              ),
            ],
          ),
        ),
      );
    }

    return ListView.separated(
      key: const ValueKey('list'),
      padding: const EdgeInsets.all(16),
      itemCount: submissions.length,
      separatorBuilder: (_, __) => const SizedBox(height: 10),
      itemBuilder: (ctx, i) => _buildSubmissionCard(submissions[i]),
    );
  }

  Widget _buildSubmissionCard(SubmissionModel sub) {
    Color statusBg, statusFg;
    String statusLabel;
    switch (sub.status.toUpperCase()) {
      case 'APPROVED':
        statusBg = _greenBg; statusFg = _greenText; statusLabel = 'Approved';
        break;
      case 'REJECTED':
        statusBg = _redBg; statusFg = _redText; statusLabel = 'Rejected';
        break;
      default:
        statusBg = _yellowBg; statusFg = _yellowText; statusLabel = 'Pending';
    }

    return Container(
      padding: const EdgeInsets.all(14),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: _border),
        boxShadow: [BoxShadow(color: Colors.black.withValues(alpha: 0.03), blurRadius: 6, offset: const Offset(0, 2))],
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              Expanded(
                child: Text(
                  sub.eventName,
                  style: const TextStyle(fontSize: 15, fontWeight: FontWeight.w700, color: _darkText),
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                ),
              ),
              const SizedBox(width: 8),
              if (sub.category.isNotEmpty)
                Container(
                  padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
                  decoration: BoxDecoration(
                    color: _lightBlueBg,
                    borderRadius: BorderRadius.circular(8),
                  ),
                  child: Text(
                    sub.category,
                    style: const TextStyle(fontSize: 11, fontWeight: FontWeight.w600, color: _blue),
                  ),
                ),
            ],
          ),
          const SizedBox(height: 8),
          Row(
            children: [
              Icon(Icons.calendar_today_outlined, size: 14, color: _subText),
              const SizedBox(width: 4),
              Text(
                DateFormat('d MMM yyyy').format(sub.createdAt),
                style: const TextStyle(fontSize: 12, color: _subText),
              ),
              if (sub.district != null && sub.district!.isNotEmpty) ...[
                const SizedBox(width: 12),
                Icon(Icons.location_on_outlined, size: 14, color: _subText),
                const SizedBox(width: 4),
                Text(sub.district!, style: const TextStyle(fontSize: 12, color: _subText)),
              ],
              const Spacer(),
              // Status badge
              Container(
                padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
                decoration: BoxDecoration(
                  color: statusBg,
                  borderRadius: BorderRadius.circular(8),
                ),
                child: Text(statusLabel, style: TextStyle(fontSize: 11, fontWeight: FontWeight.w600, color: statusFg)),
              ),
            ],
          ),
          const SizedBox(height: 6),
          Row(
            children: [
              const Text('EP Earned: ', style: TextStyle(fontSize: 12, color: _subText)),
              Text(
                sub.status.toUpperCase() == 'APPROVED' ? '${sub.epAwarded}' : '-',
                style: TextStyle(
                  fontSize: 13,
                  fontWeight: FontWeight.w700,
                  color: sub.status.toUpperCase() == 'APPROVED' ? _blue : _subText,
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // TAB 1: SUBMIT EVENT
  // ═══════════════════════════════════════════════════════════════════════════
  Widget _buildSubmitEventTab(GamificationProvider provider) {
    if (_showSuccess) return _buildSuccessState();

    return SingleChildScrollView(
      key: const ValueKey('submit'),
      padding: const EdgeInsets.all(20),
      child: Form(
        key: _formKey,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text(
              'Submit a New Event',
              style: TextStyle(fontSize: 20, fontWeight: FontWeight.w800, color: _darkText),
            ),
            const SizedBox(height: 4),
            const Text(
              'Provide accurate details to maximize your evaluated EP points.',
              style: TextStyle(fontSize: 13, color: _subText),
            ),
            const SizedBox(height: 20),

            // Event Name
            _inputLabel('Event Name', required: true),
            const SizedBox(height: 6),
            _textField(_titleCtl, 'e.g. Cochin Carnival 2026',
              validator: (v) => (v == null || v.trim().isEmpty) ? 'Event name is required' : null),
            const SizedBox(height: 16),

            // Category + District row
            Row(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      _inputLabel('Category', required: true),
                      const SizedBox(height: 6),
                      _dropdown(_selectedCategory, _categories, (v) => setState(() => _selectedCategory = v!)),
                    ],
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      _inputLabel('District', required: true),
                      const SizedBox(height: 6),
                      _dropdown(_selectedDistrict, _districts, (v) => setState(() => _selectedDistrict = v!)),
                    ],
                  ),
                ),
              ],
            ),
            const SizedBox(height: 16),

            // Date & Time row
            Row(
              children: [
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      _inputLabel('Date', required: true),
                      const SizedBox(height: 6),
                      _datePicker(),
                    ],
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      _inputLabel('Time'),
                      const SizedBox(height: 6),
                      _timePicker(),
                    ],
                  ),
                ),
              ],
            ),
            const SizedBox(height: 16),

            // Description
            _inputLabel('Description', required: true, hint: '(Required for higher EP)'),
            const SizedBox(height: 6),
            _textField(_descriptionCtl, 'Include agenda, ticket details, organizer contact, etc...',
              maxLines: 4,
              validator: (v) => (v == null || v.trim().isEmpty) ? 'Description is required' : null),
            const SizedBox(height: 16),

            // Location Coordinates
            _inputLabel('Location Coordinates'),
            const SizedBox(height: 6),
            _buildCoordinateInput(),
            const SizedBox(height: 16),

            // Media Upload
            _buildMediaUpload(),
            const SizedBox(height: 24),

            // Submit button
            SizedBox(
              width: double.infinity,
              height: 48,
              child: ElevatedButton(
                onPressed: _submitting ? null : () => _submitForm(provider),
                style: ElevatedButton.styleFrom(
                  backgroundColor: _blue,
                  foregroundColor: Colors.white,
                  disabledBackgroundColor: _blue.withValues(alpha: 0.5),
                  shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                  elevation: 0,
                ),
                child: _submitting
                    ? const SizedBox(width: 22, height: 22, child: CircularProgressIndicator(color: Colors.white, strokeWidth: 2))
                    : const Row(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: [
                          Text('Submit for Review', style: TextStyle(fontSize: 15, fontWeight: FontWeight.w700)),
                          SizedBox(width: 8),
                          Icon(Icons.arrow_forward_rounded, size: 18),
                        ],
                      ),
              ),
            ),
            const SizedBox(height: 24),
          ],
        ),
      ),
    );
  }

  // ── Form helpers ──────────────────────────────────────────────────────────

  Widget _inputLabel(String text, {bool required = false, String? hint}) {
    return Row(
      children: [
        Text(text, style: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600, color: _darkText)),
        if (required) const Text(' *', style: TextStyle(color: Color(0xFFEF4444), fontSize: 13)),
        if (hint != null) ...[
          const SizedBox(width: 4),
          Text(hint, style: const TextStyle(fontSize: 11, color: _subText)),
        ],
      ],
    );
  }

  Widget _textField(TextEditingController ctl, String placeholder, {
    int maxLines = 1,
    String? Function(String?)? validator,
    TextInputType? keyboardType,
    List<TextInputFormatter>? inputFormatters,
  }) {
    return TextFormField(
      controller: ctl,
      maxLines: maxLines,
      keyboardType: keyboardType,
      inputFormatters: inputFormatters,
      validator: validator,
      style: const TextStyle(fontSize: 14, color: _darkText),
      decoration: InputDecoration(
        hintText: placeholder,
        hintStyle: const TextStyle(color: Color(0xFFCBD5E1), fontSize: 14),
        filled: true,
        fillColor: const Color(0xFFF8FAFC),
        contentPadding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
        border: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: const BorderSide(color: _border)),
        enabledBorder: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: const BorderSide(color: _border)),
        focusedBorder: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: const BorderSide(color: _blue, width: 1.5)),
        errorBorder: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: const BorderSide(color: Color(0xFFEF4444))),
      ),
    );
  }

  Widget _dropdown(String value, List<String> items, ValueChanged<String?> onChanged) {
    return DropdownButtonFormField<String>(
      value: value,
      items: items.map((e) => DropdownMenuItem(value: e, child: Text(e, style: const TextStyle(fontSize: 14)))).toList(),
      onChanged: onChanged,
      decoration: InputDecoration(
        filled: true,
        fillColor: const Color(0xFFF8FAFC),
        contentPadding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
        border: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: const BorderSide(color: _border)),
        enabledBorder: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: const BorderSide(color: _border)),
        focusedBorder: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: const BorderSide(color: _blue, width: 1.5)),
      ),
      dropdownColor: Colors.white,
      style: const TextStyle(fontSize: 14, color: _darkText),
      icon: const Icon(Icons.keyboard_arrow_down_rounded, color: _subText),
    );
  }

  Widget _datePicker() {
    return GestureDetector(
      onTap: () async {
        final picked = await showDatePicker(
          context: context,
          initialDate: _selectedDate ?? DateTime.now(),
          firstDate: DateTime(2020),
          lastDate: DateTime(2030),
        );
        if (picked != null) setState(() => _selectedDate = picked);
      },
      child: Container(
        height: 48,
        padding: const EdgeInsets.symmetric(horizontal: 14),
        decoration: BoxDecoration(
          color: const Color(0xFFF8FAFC),
          borderRadius: BorderRadius.circular(12),
          border: Border.all(color: _border),
        ),
        child: Row(
          children: [
            Expanded(
              child: Text(
                _selectedDate != null ? DateFormat('d MMM yyyy').format(_selectedDate!) : 'Select date',
                style: TextStyle(
                  fontSize: 14,
                  color: _selectedDate != null ? _darkText : const Color(0xFFCBD5E1),
                ),
              ),
            ),
            const Icon(Icons.calendar_today_outlined, color: _subText, size: 18),
          ],
        ),
      ),
    );
  }

  Widget _timePicker() {
    return GestureDetector(
      onTap: () async {
        final picked = await showTimePicker(
          context: context,
          initialTime: _selectedTime ?? TimeOfDay.now(),
        );
        if (picked != null) setState(() => _selectedTime = picked);
      },
      child: Container(
        height: 48,
        padding: const EdgeInsets.symmetric(horizontal: 14),
        decoration: BoxDecoration(
          color: const Color(0xFFF8FAFC),
          borderRadius: BorderRadius.circular(12),
          border: Border.all(color: _border),
        ),
        child: Row(
          children: [
            Expanded(
              child: Text(
                _selectedTime != null ? _selectedTime!.format(context) : 'Select time',
                style: TextStyle(
                  fontSize: 14,
                  color: _selectedTime != null ? _darkText : const Color(0xFFCBD5E1),
                ),
              ),
            ),
            const Icon(Icons.access_time_outlined, color: _subText, size: 18),
          ],
        ),
      ),
    );
  }

  // ── Coordinate input (Manual / Google Maps Link toggle) ──────────────────

  Widget _buildCoordinateInput() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        // Toggle tabs
        Row(
          children: [
            _coordToggle('Manual', _useManualCoords, () => setState(() => _useManualCoords = true)),
            const SizedBox(width: 8),
            _coordToggle('Google Maps Link', !_useManualCoords, () => setState(() => _useManualCoords = false)),
          ],
        ),
        const SizedBox(height: 10),

        if (_useManualCoords) ...[
          Row(
            children: [
              Expanded(
                child: _textField(_latCtl, 'Latitude (e.g. 9.93123)',
                  keyboardType: const TextInputType.numberWithOptions(decimal: true, signed: true),
                  inputFormatters: [FilteringTextInputFormatter.allow(RegExp(r'[0-9.\-]'))]),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: _textField(_lngCtl, 'Longitude (e.g. 76.26730)',
                  keyboardType: const TextInputType.numberWithOptions(decimal: true, signed: true),
                  inputFormatters: [FilteringTextInputFormatter.allow(RegExp(r'[0-9.\-]'))]),
              ),
            ],
          ),
        ] else ...[
          Row(
            children: [
              Expanded(
                child: _textField(_mapsLinkCtl, 'Paste Google Maps URL here'),
              ),
              const SizedBox(width: 8),
              SizedBox(
                height: 48,
                child: ElevatedButton(
                  onPressed: _extractCoordinates,
                  style: ElevatedButton.styleFrom(
                    backgroundColor: _blue,
                    foregroundColor: Colors.white,
                    shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                    elevation: 0,
                    padding: const EdgeInsets.symmetric(horizontal: 16),
                  ),
                  child: const Text('Extract', style: TextStyle(fontWeight: FontWeight.w600)),
                ),
              ),
            ],
          ),
          if (_coordMessage != null) ...[
            const SizedBox(height: 8),
            Row(
              children: [
                Icon(
                  _coordSuccess ? Icons.check_circle : Icons.error_outline,
                  size: 16,
                  color: _coordSuccess ? const Color(0xFF22C55E) : const Color(0xFFEF4444),
                ),
                const SizedBox(width: 6),
                Expanded(
                  child: Text(
                    _coordMessage!,
                    style: TextStyle(
                      fontSize: 12,
                      color: _coordSuccess ? const Color(0xFF22C55E) : const Color(0xFFEF4444),
                    ),
                  ),
                ),
              ],
            ),
          ],
        ],
      ],
    );
  }

  Widget _coordToggle(String label, bool active, VoidCallback onTap) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 8),
        decoration: BoxDecoration(
          color: active ? _blue : const Color(0xFFF8FAFC),
          borderRadius: BorderRadius.circular(10),
          border: Border.all(color: active ? _blue : _border),
        ),
        child: Text(
          label,
          style: TextStyle(
            fontSize: 12,
            fontWeight: FontWeight.w600,
            color: active ? Colors.white : _subText,
          ),
        ),
      ),
    );
  }

  void _extractCoordinates() {
    final url = _mapsLinkCtl.text.trim();
    if (url.isEmpty) {
      setState(() { _coordMessage = 'Please paste a Google Maps URL'; _coordSuccess = false; });
      return;
    }

    double? lat, lng;

    // Pattern 1: @lat,lng
    final atMatch = RegExp(r'@(-?\d+\.?\d*),(-?\d+\.?\d*)').firstMatch(url);
    if (atMatch != null) {
      lat = double.tryParse(atMatch.group(1)!);
      lng = double.tryParse(atMatch.group(2)!);
    }

    // Pattern 2: 3dlat!4dlng
    if (lat == null) {
      final dMatch = RegExp(r'3d(-?\d+\.?\d*)!4d(-?\d+\.?\d*)').firstMatch(url);
      if (dMatch != null) {
        lat = double.tryParse(dMatch.group(1)!);
        lng = double.tryParse(dMatch.group(2)!);
      }
    }

    // Pattern 3: q=lat,lng
    if (lat == null) {
      final qMatch = RegExp(r'[?&]q=(-?\d+\.?\d*),(-?\d+\.?\d*)').firstMatch(url);
      if (qMatch != null) {
        lat = double.tryParse(qMatch.group(1)!);
        lng = double.tryParse(qMatch.group(2)!);
      }
    }

    // Pattern 4: ll=lat,lng
    if (lat == null) {
      final llMatch = RegExp(r'[?&]ll=(-?\d+\.?\d*),(-?\d+\.?\d*)').firstMatch(url);
      if (llMatch != null) {
        lat = double.tryParse(llMatch.group(1)!);
        lng = double.tryParse(llMatch.group(2)!);
      }
    }

    if (lat != null && lng != null) {
      _latCtl.text = lat.toStringAsFixed(6);
      _lngCtl.text = lng.toStringAsFixed(6);
      setState(() {
        _coordMessage = 'Coordinates extracted: $lat, $lng';
        _coordSuccess = true;
      });
    } else {
      setState(() {
        _coordMessage = 'Could not extract coordinates from this URL';
        _coordSuccess = false;
      });
    }
  }

  // ── Media upload ──────────────────────────────────────────────────────────

  Widget _buildMediaUpload() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Row(
          children: [
            _inputLabel('Photos'),
            const Spacer(),
            Text('${_images.length}/5', style: const TextStyle(fontSize: 12, color: _subText)),
          ],
        ),
        const SizedBox(height: 4),
        const Text(
          '2 EP per image, max 5 EP',
          style: TextStyle(fontSize: 11, color: _subText),
        ),
        const SizedBox(height: 8),

        // Upload area
        if (_images.length < 5)
          GestureDetector(
            onTap: _pickImages,
            child: Container(
              width: double.infinity,
              padding: const EdgeInsets.symmetric(vertical: 24),
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(12),
                border: Border.all(color: const Color(0xFFCBD5E1), width: 2, strokeAlign: BorderSide.strokeAlignInside),
              ),
              child: Column(
                children: [
                  Icon(Icons.cloud_upload_outlined, color: _blue, size: 28),
                  const SizedBox(height: 6),
                  const Text('Tap to add photos', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w600, color: _darkText)),
                  const SizedBox(height: 2),
                  const Text('JPEG, PNG, WebP', style: TextStyle(fontSize: 11, color: _subText)),
                ],
              ),
            ),
          ),

        // Thumbnail gallery
        if (_images.isNotEmpty) ...[
          const SizedBox(height: 10),
          SizedBox(
            height: 80,
            child: ListView.separated(
              scrollDirection: Axis.horizontal,
              itemCount: _images.length,
              separatorBuilder: (_, __) => const SizedBox(width: 8),
              itemBuilder: (ctx, i) => _buildImageThumb(i),
            ),
          ),
        ],
      ],
    );
  }

  Widget _buildImageThumb(int index) {
    final img = _images[index];
    return Stack(
      clipBehavior: Clip.none,
      children: [
        Container(
          width: 72,
          height: 72,
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(10),
            border: Border.all(color: _border),
          ),
          child: ClipRRect(
            borderRadius: BorderRadius.circular(10),
            child: kIsWeb
                ? const Center(child: Icon(Icons.image, color: _subText, size: 28))
                : Image.file(File(img.path), fit: BoxFit.cover),
          ),
        ),
        Positioned(
          top: -6,
          right: -6,
          child: GestureDetector(
            onTap: () => setState(() => _images.removeAt(index)),
            child: Container(
              width: 22,
              height: 22,
              decoration: const BoxDecoration(
                color: Color(0xFFEF4444),
                shape: BoxShape.circle,
              ),
              child: const Icon(Icons.close, color: Colors.white, size: 14),
            ),
          ),
        ),
      ],
    );
  }

  Future<void> _pickImages() async {
    try {
      final picked = await _picker.pickMultiImage(imageQuality: 80);
      if (picked.isNotEmpty) {
        setState(() {
          final remaining = 5 - _images.length;
          _images.addAll(picked.take(remaining));
        });
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Could not pick images: ${userFriendlyError(e)}')),
        );
      }
    }
  }

  // ── Success state ─────────────────────────────────────────────────────────

  Widget _buildSuccessState() {
    return Center(
      key: const ValueKey('success'),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          TweenAnimationBuilder<double>(
            tween: Tween(begin: 0, end: 1),
            duration: const Duration(milliseconds: 500),
            curve: Curves.elasticOut,
            builder: (_, v, child) => Transform.scale(scale: v, child: child),
            child: Container(
              width: 80,
              height: 80,
              decoration: const BoxDecoration(
                color: _greenBg,
                shape: BoxShape.circle,
              ),
              child: const Icon(Icons.check_rounded, color: Color(0xFF22C55E), size: 44),
            ),
          ),
          const SizedBox(height: 20),
          const Text(
            'Event Submitted!',
            style: TextStyle(fontSize: 20, fontWeight: FontWeight.w800, color: _darkText),
          ),
          const SizedBox(height: 8),
          const Text(
            'Thank you for contributing. It is now pending\nadmin verification. You can earn up to 10 EP!',
            style: TextStyle(fontSize: 13, color: _subText),
            textAlign: TextAlign.center,
          ),
        ],
      ),
    );
  }

  // ── Submit handler ────────────────────────────────────────────────────────

  Future<void> _submitForm(GamificationProvider provider) async {
    if (!(_formKey.currentState?.validate() ?? false)) return;
    if (_selectedDate == null) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Please select a date'), backgroundColor: Color(0xFFEF4444)),
      );
      return;
    }

    setState(() => _submitting = true);

    try {
      final data = <String, dynamic>{
        'title': _titleCtl.text.trim(),
        'category': _selectedCategory,
        'district': _selectedDistrict,
        'date': _selectedDate!.toIso8601String(),
        'time': _selectedTime?.format(context),
        'description': _descriptionCtl.text.trim(),
        'images': _images.map((f) => f.path).toList(),
      };

      // Add coordinates if provided
      final lat = double.tryParse(_latCtl.text.trim());
      final lng = double.tryParse(_lngCtl.text.trim());
      if (lat != null && lng != null) {
        data['location_lat'] = lat;
        data['location_lng'] = lng;
      }

      await provider.submitContribution(data);

      PostHogService.instance.capture('event_contributed', properties: {
        'category': _selectedCategory,
        'district': _selectedDistrict,
        'has_images': _images.isNotEmpty,
        'image_count': _images.length,
        'has_coordinates': lat != null && lng != null,
      });

      // Show success, then reset
      setState(() { _submitting = false; _showSuccess = true; });

      await Future.delayed(const Duration(seconds: 2));
      if (mounted) {
        _clearForm();
        setState(() { _showSuccess = false; _activeTab = 0; });
        provider.loadAll(force: true);
      }
    } catch (e) {
      if (mounted) {
        setState(() => _submitting = false);
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(userFriendlyError(e)), backgroundColor: const Color(0xFFEF4444)),
        );
      }
    }
  }

  void _clearForm() {
    _titleCtl.clear();
    _descriptionCtl.clear();
    _latCtl.clear();
    _lngCtl.clear();
    _mapsLinkCtl.clear();
    _selectedDate = null;
    _selectedTime = null;
    _selectedCategory = _categories.first;
    _selectedDistrict = _districts.first;
    _images.clear();
    _coordMessage = null;
    _useManualCoords = true;
  }

  // ═══════════════════════════════════════════════════════════════════════════
  // TAB 2: REWARD SHOP (Coming Soon)
  // ═══════════════════════════════════════════════════════════════════════════
  Widget _buildRewardShopTab(GamificationProvider provider) {
    final rp = provider.profile?.currentRp ?? 0;

    return SingleChildScrollView(
      key: const ValueKey('shop'),
      padding: const EdgeInsets.all(20),
      child: Column(
        children: [
          const SizedBox(height: 20),

          // RP balance
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
            decoration: BoxDecoration(
              color: const Color(0xFFFFF7ED),
              borderRadius: BorderRadius.circular(12),
              border: Border.all(color: _rpOrange.withValues(alpha: 0.3)),
            ),
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Icon(Icons.card_giftcard, color: _rpOrange, size: 20),
                const SizedBox(width: 8),
                Text(
                  '$rp RP',
                  style: TextStyle(fontSize: 16, fontWeight: FontWeight.w800, color: _rpOrange),
                ),
                const SizedBox(width: 6),
                const Text('available', style: TextStyle(fontSize: 12, color: _subText)),
              ],
            ),
          ),

          const SizedBox(height: 32),

          // Pulsing icon
          TweenAnimationBuilder<double>(
            tween: Tween(begin: 0.95, end: 1.05),
            duration: const Duration(seconds: 2),
            curve: Curves.easeInOut,
            builder: (_, v, child) => Transform.scale(scale: v, child: child),
            onEnd: () {}, // AnimationBuilder loops via repeat — handled below
            child: Container(
              width: 80,
              height: 80,
              decoration: BoxDecoration(
                gradient: LinearGradient(
                  begin: Alignment.topLeft,
                  end: Alignment.bottomRight,
                  colors: [_blue.withValues(alpha: 0.15), _blue.withValues(alpha: 0.05)],
                ),
                shape: BoxShape.circle,
              ),
              child: const Icon(Icons.card_giftcard_rounded, color: _blue, size: 36),
            ),
          ),

          const SizedBox(height: 20),

          // Badge
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 6),
            decoration: BoxDecoration(
              color: _lightBlueBg,
              borderRadius: BorderRadius.circular(20),
              border: Border.all(color: _blue.withValues(alpha: 0.2)),
            ),
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Container(
                  width: 8,
                  height: 8,
                  decoration: const BoxDecoration(color: _blue, shape: BoxShape.circle),
                ),
                const SizedBox(width: 8),
                const Text('Coming Soon', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w700, color: _blue)),
              ],
            ),
          ),

          const SizedBox(height: 16),

          const Text(
            "We're Stocking the Shelves",
            style: TextStyle(fontSize: 20, fontWeight: FontWeight.w800, color: _darkText),
            textAlign: TextAlign.center,
          ),
          const SizedBox(height: 8),
          const Text(
            'Redeem your RP for event vouchers, VIP passes, exclusive merch, and more. Keep contributing to build your balance!',
            style: TextStyle(fontSize: 13, color: _subText, height: 1.5),
            textAlign: TextAlign.center,
          ),

          const SizedBox(height: 28),

          // Ghost teaser cards
          ..._buildGhostCards(),

          const SizedBox(height: 20),
        ],
      ),
    );
  }

  List<Widget> _buildGhostCards() {
    const items = [
      {'name': 'Event Voucher', 'rp': '500', 'icon': Icons.confirmation_number_outlined},
      {'name': 'VIP Access Pass', 'rp': '1,200', 'icon': Icons.verified_outlined},
      {'name': 'Exclusive Merch', 'rp': '2,000', 'icon': Icons.shopping_bag_outlined},
    ];

    return items.map((item) {
      return Padding(
        padding: const EdgeInsets.only(bottom: 10),
        child: Opacity(
          opacity: 0.45,
          child: Container(
            padding: const EdgeInsets.all(16),
            decoration: BoxDecoration(
              color: const Color(0xFFF8FAFC),
              borderRadius: BorderRadius.circular(14),
              border: Border.all(color: _border),
            ),
            child: Row(
              children: [
                Container(
                  width: 44,
                  height: 44,
                  decoration: BoxDecoration(
                    color: _lightBlueBg,
                    borderRadius: BorderRadius.circular(10),
                  ),
                  child: Icon(item['icon'] as IconData, color: _blue, size: 22),
                ),
                const SizedBox(width: 14),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        item['name'] as String,
                        style: const TextStyle(fontSize: 14, fontWeight: FontWeight.w700, color: _darkText),
                      ),
                      const SizedBox(height: 2),
                      Text(
                        '${item['rp']} RP',
                        style: TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: _rpOrange),
                      ),
                    ],
                  ),
                ),
                const Icon(Icons.lock_outline_rounded, color: _subText, size: 20),
              ],
            ),
          ),
        ),
      );
    }).toList();
  }
}