import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../models/compliance.dart';
import 'seed.dart';

/// The four compliance sections, each a list the worker can act on.
enum ComplianceSection { documents, certificates, taxForms, wardrobe }

extension ComplianceSectionX on ComplianceSection {
  String get title => switch (this) {
    ComplianceSection.documents => 'Documents',
    ComplianceSection.certificates => 'Certificates',
    ComplianceSection.taxForms => 'Tax forms',
    ComplianceSection.wardrobe => 'Attire',
  };

  String get subtitle => switch (this) {
    ComplianceSection.documents => 'ID, SSN, work permit, address',
    ComplianceSection.certificates => 'Food handler, RBS and more',
    ComplianceSection.taxForms => 'Form I-9 and Form W-4',
    ComplianceSection.wardrobe => "Photos of what you'll wear",
  };
}

class ComplianceData {
  const ComplianceData({
    required this.documents,
    required this.certificates,
    required this.taxForms,
    required this.wardrobe,
  });

  final List<ComplianceItem> documents;
  final List<ComplianceItem> certificates;
  final List<ComplianceItem> taxForms;
  final List<ComplianceItem> wardrobe;

  List<ComplianceItem> section(ComplianceSection s) => switch (s) {
    ComplianceSection.documents => documents,
    ComplianceSection.certificates => certificates,
    ComplianceSection.taxForms => taxForms,
    ComplianceSection.wardrobe => wardrobe,
  };

  List<ComplianceItem> get all => [
    ...documents,
    ...certificates,
    ...taxForms,
    ...wardrobe,
  ];

  ComplianceData copyWith({
    List<ComplianceItem>? documents,
    List<ComplianceItem>? certificates,
    List<ComplianceItem>? taxForms,
    List<ComplianceItem>? wardrobe,
  }) => ComplianceData(
    documents: documents ?? this.documents,
    certificates: certificates ?? this.certificates,
    taxForms: taxForms ?? this.taxForms,
    wardrobe: wardrobe ?? this.wardrobe,
  );
}

class ComplianceController extends Notifier<ComplianceData> {
  @override
  ComplianceData build() => ComplianceData(
    documents: Seed.documents(),
    certificates: Seed.certificates(),
    taxForms: Seed.taxForms(),
    wardrobe: Seed.wardrobe(),
  );

  List<ComplianceItem> _apply(
    List<ComplianceItem> list,
    String id,
    ComplianceItem Function(ComplianceItem) f,
  ) => [
    for (final i in list)
      if (i.id == id) f(i) else i,
  ];

  void _update(
    ComplianceSection section,
    String id,
    ComplianceItem Function(ComplianceItem) f,
  ) {
    final s = state;
    state = switch (section) {
      ComplianceSection.documents => s.copyWith(
        documents: _apply(s.documents, id, f),
      ),
      ComplianceSection.certificates => s.copyWith(
        certificates: _apply(s.certificates, id, f),
      ),
      ComplianceSection.taxForms => s.copyWith(
        taxForms: _apply(s.taxForms, id, f),
      ),
      ComplianceSection.wardrobe => s.copyWith(
        wardrobe: _apply(s.wardrobe, id, f),
      ),
    };
  }

  /// Stand-in for the camera / file picker: attaching a file sends the item
  /// back for review.
  void uploadFile(ComplianceSection section, String id, String fileName) {
    _update(
      section,
      id,
      (i) => i.copyWith(
        state: ComplianceState.pending,
        statusLabel: 'In review',
        fileName: fileName,
        fileMeta: 'Uploaded just now',
      ),
    );
  }

  void removeFile(ComplianceSection section, String id) {
    _update(
      section,
      id,
      (i) => ComplianceItem(
        id: i.id,
        title: i.title,
        subtitle: i.subtitle,
        state: ComplianceState.missing,
        statusLabel: 'Not added',
        required_: i.required_,
      ),
    );
  }

  void setExpiry(ComplianceSection section, String id, DateTime date) {
    _update(section, id, (i) => i.copyWith(expires: date));
  }

  ComplianceItem? find(ComplianceSection section, String id) {
    for (final i in state.section(section)) {
      if (i.id == id) return i;
    }
    return null;
  }
}

final complianceProvider =
    NotifierProvider<ComplianceController, ComplianceData>(
      ComplianceController.new,
    );

/// `(verified, total)` across every required item — what the hub reports.
final complianceProgressProvider = Provider<(int, int)>((ref) {
  final items = ref.watch(complianceProvider).all.where((i) => i.required_);
  final total = items.length;
  final done = items.where((i) => i.state == ComplianceState.verified).length;
  return (done, total);
});

/// Whether the worker is cleared to take shifts at all.
final isCompliantProvider = Provider<bool>((ref) {
  final (done, total) = ref.watch(complianceProgressProvider);
  return done == total;
});

final sectionProgressProvider = Provider.family<(int, int), ComplianceSection>((
  ref,
  section,
) {
  final items = ref
      .watch(complianceProvider)
      .section(section)
      .where((i) => i.required_);
  return (
    items.where((i) => i.state == ComplianceState.verified).length,
    items.length,
  );
});