import 'package:flutter/material.dart';
import 'package:uto_manager/domain/entities/authorized_rank.dart';
import 'package:uto_manager/domain/entities/personnel_record.dart';
import 'package:uto_manager/domain/entities/soldier_position.dart';
import 'package:uto_manager/domain/value_objects/duty_mos.dart';
import 'package:uto_manager/infrastructure/repositories/drift_soldier_positions_repository.dart';
import 'package:uuid/uuid.dart';

/// Dialog for creating or editing a [PersonnelRecord].
///
/// Pass [existing] to edit; leave null to create a new record.
/// [positionsRepository] is used to load and manage the position list.
class AddEditPersonnelDialog extends StatefulWidget {
  const AddEditPersonnelDialog({
    required this.positionsRepository,
    super.key,
    this.existing,
  });

  final DriftSoldierPositionsRepository positionsRepository;
  final PersonnelRecord? existing;

  @override
  State<AddEditPersonnelDialog> createState() => _AddEditPersonnelDialogState();
}

class _AddEditPersonnelDialogState extends State<AddEditPersonnelDialog> {
  final _formKey = GlobalKey<FormState>();

  late final TextEditingController _nameCtrl;
  late final TextEditingController _mosCtrl;

  late AuthorizedRank _payGrade;
  late ReadinessState _readiness;

  /// The currently selected position, or null if none chosen.
  SoldierPosition? _selectedPosition;

  /// All positions loaded from the repository.
  List<SoldierPosition> _positions = [];

  List<String> _mosSuggestions = [];

  bool get _isEditing => widget.existing != null;

  @override
  void initState() {
    super.initState();
    final e = widget.existing;
    _nameCtrl = TextEditingController(text: e?.name ?? '');
    _mosCtrl = TextEditingController(text: e?.primaryMos.code ?? '');
    _payGrade = e?.payGrade ?? AuthorizedRank.e4;
    _readiness = e?.readinessState ?? ReadinessState.fullyMissionCapable;
    _loadPositions(existingTitle: e?.positionTitle);
  }

  @override
  void dispose() {
    _nameCtrl.dispose();
    _mosCtrl.dispose();
    super.dispose();
  }

  Future<void> _loadPositions({String? existingTitle}) async {
    await widget.positionsRepository.seedBuiltIns();
    final positions = await widget.positionsRepository.getAll();
    positions.sort((a, b) => a.title.compareTo(b.title));
    final selected =
        existingTitle != null ? positions.where((p) => p.title == existingTitle).firstOrNull : null;
    if (mounted) {
      setState(() {
        _positions = positions;
        _selectedPosition = selected;
      });
    }
  }

  void _updateMosSuggestions(String query) {
    if (query.isEmpty) {
      setState(() => _mosSuggestions = []);
      return;
    }
    final q = query.toUpperCase();
    final matches =
        DutyMos.allCodes.where((c) => c.startsWith(q) || c.contains(q)).take(12).toList()..sort();
    setState(() => _mosSuggestions = matches);
  }

  void _submit() {
    if (!_formKey.currentState!.validate()) return;

    final mosCode = _mosCtrl.text.trim().toUpperCase();
    DutyMos mos;
    try {
      mos = DutyMos(mosCode);
    } catch (_) {
      mos = DutyMos.unvalidated(mosCode);
    }

    final nameText = _nameCtrl.text.trim();

    final record = PersonnelRecord(
      soldierId: widget.existing?.soldierId ?? const Uuid().v4(),
      name: nameText.isEmpty ? null : nameText,
      positionTitle: _selectedPosition?.title,
      primaryMos: mos,
      payGrade: _payGrade,
      readinessState: _readiness,
      qualifications: widget.existing?.qualifications ?? const [],
      assignedSlotId: widget.existing?.assignedSlotId,
    );

    Navigator.of(context).pop(record);
  }

  // ---------------------------------------------------------------------------
  // Position CRUD helpers
  // ---------------------------------------------------------------------------

  Future<void> _showAddPositionDialog() async {
    final title = await _showPositionTitleDialog(context, initial: '');
    if (title == null || title.isEmpty) return;
    final pos = SoldierPosition(positionId: const Uuid().v4(), title: title);
    await widget.positionsRepository.upsert(pos);
    await _loadPositions();
    if (mounted) {
      setState(() => _selectedPosition = _positions.where((p) => p.title == title).firstOrNull);
    }
  }

  Future<void> _showEditPositionDialog(SoldierPosition pos) async {
    if (pos.isBuiltIn) return; // built-ins cannot be renamed
    final title = await _showPositionTitleDialog(context, initial: pos.title);
    if (title == null || title.isEmpty || title == pos.title) return;
    await widget.positionsRepository.upsert(pos.copyWith(title: title));
    await _loadPositions();
    if (mounted) {
      setState(
        () =>
            _selectedPosition = _positions.where((p) => p.positionId == pos.positionId).firstOrNull,
      );
    }
  }

  Future<void> _confirmDeletePosition(SoldierPosition pos) async {
    if (pos.isBuiltIn) return;
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('Delete Position?'),
        content: Text('Remove the "${pos.title}" position? This cannot be undone.'),
        actions: [
          TextButton(onPressed: () => Navigator.of(ctx).pop(false), child: const Text('Cancel')),
          FilledButton(
            style: FilledButton.styleFrom(backgroundColor: Colors.red.shade700),
            onPressed: () => Navigator.of(ctx).pop(true),
            child: const Text('Delete'),
          ),
        ],
      ),
    );
    if (confirmed ?? false) {
      await widget.positionsRepository.delete(pos.positionId);
      await _loadPositions();
      if (mounted && _selectedPosition?.positionId == pos.positionId) {
        setState(() => _selectedPosition = null);
      }
    }
  }

  /// Shows a simple text-input dialog for a position title.
  Future<String?> _showPositionTitleDialog(BuildContext context, {required String initial}) {
    final ctrl = TextEditingController(text: initial);
    return showDialog<String>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: Text(initial.isEmpty ? 'Add Position' : 'Rename Position'),
        content: TextField(
          controller: ctrl,
          autofocus: true,
          textCapitalization: TextCapitalization.words,
          decoration: const InputDecoration(
            labelText: 'Position Title',
            hintText: 'e.g. Anti-Tank Gunner',
          ),
          onSubmitted: (_) => Navigator.of(ctx).pop(ctrl.text.trim()),
        ),
        actions: [
          TextButton(onPressed: () => Navigator.of(ctx).pop(), child: const Text('Cancel')),
          FilledButton(
            onPressed: () => Navigator.of(ctx).pop(ctrl.text.trim()),
            child: const Text('Save'),
          ),
        ],
      ),
    );
  }

  // ---------------------------------------------------------------------------
  // Build
  // ---------------------------------------------------------------------------

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

    return AlertDialog(
      title: Row(
        children: [
          Icon(_isEditing ? Icons.edit : Icons.person_add, size: 20),
          const SizedBox(width: 8),
          Text(_isEditing ? 'Edit Soldier' : 'Add Soldier'),
        ],
      ),
      content: SizedBox(
        width: 420,
        child: Form(
          key: _formKey,
          child: SingleChildScrollView(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // ── Position ─────────────────────────────────────────────────
                _buildPositionRow(theme),
                const SizedBox(height: 12),

                // ── Name (optional) ──────────────────────────────────────────
                TextFormField(
                  controller: _nameCtrl,
                  decoration: const InputDecoration(
                    labelText: 'Full Name (optional)',
                    hintText: 'e.g. SMITH, John A.',
                    prefixIcon: Icon(Icons.badge_outlined),
                    helperText: 'Leave blank to identify by position only.',
                  ),
                  textCapitalization: TextCapitalization.characters,
                ),
                const SizedBox(height: 12),

                // ── Pay Grade ────────────────────────────────────────────────
                DropdownButtonFormField<AuthorizedRank>(
                  initialValue: _payGrade,
                  isExpanded: true,
                  decoration: const InputDecoration(
                    labelText: 'Pay Grade',
                    prefixIcon: Icon(Icons.military_tech_outlined),
                  ),
                  items: AuthorizedRank.values.map((r) {
                    return DropdownMenuItem(
                      value: r,
                      child: Text('${r.payGrade} — ${r.rankTitle}'),
                    );
                  }).toList(),
                  onChanged: (v) => setState(() => _payGrade = v!),
                ),
                const SizedBox(height: 12),

                // ── MOS with autocomplete ────────────────────────────────────
                TextFormField(
                  controller: _mosCtrl,
                  decoration: const InputDecoration(
                    labelText: 'Primary MOS',
                    hintText: 'e.g. 11B, 68W, 25U',
                    prefixIcon: Icon(Icons.work_outline),
                  ),
                  textCapitalization: TextCapitalization.characters,
                  onChanged: _updateMosSuggestions,
                  validator: (v) {
                    if (v == null || v.trim().isEmpty) return 'MOS is required';
                    final code = v.trim().toUpperCase();
                    if (!DutyMos.isKnown(code)) {
                      return 'Unknown MOS code. Use a valid Army MOS (e.g. 11B, 68W)';
                    }
                    return null;
                  },
                ),
                if (_mosSuggestions.isNotEmpty) ...[
                  const SizedBox(height: 4),
                  Container(
                    padding: const EdgeInsets.all(4),
                    decoration: BoxDecoration(
                      color: theme.colorScheme.surfaceContainerHigh,
                      borderRadius: BorderRadius.circular(6),
                      border: Border.all(color: theme.colorScheme.outlineVariant),
                    ),
                    child: Wrap(
                      spacing: 4,
                      runSpacing: 4,
                      children: _mosSuggestions.map((code) {
                        return ActionChip(
                          label: Text(
                            code,
                            style: theme.textTheme.labelSmall?.copyWith(
                              fontWeight: FontWeight.bold,
                            ),
                          ),
                          onPressed: () {
                            _mosCtrl.text = code;
                            setState(() => _mosSuggestions = []);
                          },
                          padding: const EdgeInsets.symmetric(horizontal: 4),
                          visualDensity: VisualDensity.compact,
                        );
                      }).toList(),
                    ),
                  ),
                ],
                const SizedBox(height: 12),

                // ── Readiness State ──────────────────────────────────────────
                DropdownButtonFormField<ReadinessState>(
                  initialValue: _readiness,
                  isExpanded: true,
                  decoration: const InputDecoration(
                    labelText: 'Readiness State',
                    prefixIcon: Icon(Icons.health_and_safety_outlined),
                  ),
                  items: ReadinessState.values.map((s) {
                    return DropdownMenuItem(
                      value: s,
                      child: Text(s.displayName),
                    );
                  }).toList(),
                  onChanged: (v) => setState(() => _readiness = v!),
                ),
              ],
            ),
          ),
        ),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.of(context).pop(),
          child: const Text('Cancel'),
        ),
        FilledButton.icon(
          icon: Icon(_isEditing ? Icons.save : Icons.add, size: 16),
          label: Text(_isEditing ? 'Save Changes' : 'Add Soldier'),
          onPressed: _submit,
        ),
      ],
    );
  }

  /// Builds the position dropdown row with add / edit / delete action buttons.
  Widget _buildPositionRow(ThemeData theme) {
    return Row(
      crossAxisAlignment: CrossAxisAlignment.end,
      children: [
        Expanded(
          child: _positions.isEmpty
              ? const LinearProgressIndicator()
              : DropdownButtonFormField<SoldierPosition>(
                  initialValue: _selectedPosition,
                  isExpanded: true,
                  decoration: const InputDecoration(
                    labelText: 'Position',
                    prefixIcon: Icon(Icons.work_history_outlined),
                  ),
                  hint: const Text('Select position…'),
                  items: _positions.map((p) {
                    return DropdownMenuItem(
                      value: p,
                      child: Row(
                        children: [
                          Expanded(child: Text(p.title, overflow: TextOverflow.ellipsis)),
                          if (p.isBuiltIn)
                            Icon(
                              Icons.lock_outline,
                              size: 12,
                              color: theme.colorScheme.onSurfaceVariant.withValues(alpha: 0.5),
                            ),
                        ],
                      ),
                    );
                  }).toList(),
                  onChanged: (v) => setState(() => _selectedPosition = v),
                ),
        ),
        // Add custom position
        IconButton(
          icon: const Icon(Icons.add_circle_outline, size: 18),
          tooltip: 'Add custom position',
          onPressed: _showAddPositionDialog,
        ),
        // Edit selected position (only if custom)
        if (_selectedPosition != null && !_selectedPosition!.isBuiltIn)
          IconButton(
            icon: const Icon(Icons.edit_outlined, size: 18),
            tooltip: 'Rename position',
            onPressed: () => _showEditPositionDialog(_selectedPosition!),
          ),
        // Delete selected position (only if custom)
        if (_selectedPosition != null && !_selectedPosition!.isBuiltIn)
          IconButton(
            icon: Icon(Icons.delete_outline, size: 18, color: theme.colorScheme.error),
            tooltip: 'Delete position',
            onPressed: () => _confirmDeletePosition(_selectedPosition!),
          ),
      ],
    );
  }
}