import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:manager_app/l10n/app_localizations.dart';
import 'package:manager_app/Models/managerContext.dart';
import 'package:manager_app/app_context.dart';
import 'package:manager_app/Components/common_loader.dart';
import 'package:manager_app/constants.dart';
import 'package:provider/provider.dart';

class UsersScreen extends StatefulWidget {
  const UsersScreen({Key? key}) : super(key: key);

  @override
  _UsersScreenState createState() => _UsersScreenState();
}

class _UsersScreenState extends State<UsersScreen> {
  List<Map<String, dynamic>> _users = [];
  bool _loading = true;

  static const _roleNames = ['SuperAdmin', 'InstanceAdmin', 'ContentEditor', 'Viewer'];

  static String _roleName(dynamic v) {
    if (v is String) return v;
    final i = v as int?;
    if (i != null && i >= 0 && i < _roleNames.length) return _roleNames[i];
    return '—';
  }

  static int _roleToInt(dynamic v) {
    if (v is int) return v;
    if (v is String) {
      final i = _roleNames.indexOf(v);
      return i >= 0 ? i : 3;
    }
    return 3;
  }

  List<int> _allowedRoles(int callerRoleValue) =>
      [0, 1, 2, 3].where((r) => r >= callerRoleValue).toList();

  Future<void> _loadUsers(ManagerAppContext ctx) async {
    try {
      final response = await ctx.clientAPI!.userApi!.userGetWithHttpInfo();
      if (response.statusCode == 200) {
        final List<dynamic> json = jsonDecode(utf8.decode(response.bodyBytes));
        setState(() {
          _users = json.cast<Map<String, dynamic>>();
          _loading = false;
        });
      }
    } catch (e) {
      setState(() => _loading = false);
    }
  }

  Future<void> _createUser(ManagerAppContext ctx, String email,
      String firstName, String lastName, String password, int roleValue) async {
    final body = {
      'email': email,
      'firstName': firstName,
      'lastName': lastName,
      'password': password,
      'role': roleValue,
    };
    await ctx.clientAPI!.apiApi!.invokeAPI(
      '/api/User', 'POST', [], body, {}, {}, 'application/json');
    await _loadUsers(ctx);
  }

  Future<void> _updateUser(ManagerAppContext ctx, String id, String firstName,
      String lastName, int roleValue) async {
    final body = {
      'id': id,
      'firstName': firstName,
      'lastName': lastName,
      'role': roleValue,
    };
    await ctx.clientAPI!.apiApi!.invokeAPI(
      '/api/User', 'PUT', [], body, {}, {}, 'application/json');
    await _loadUsers(ctx);
  }

  Future<void> _deleteUser(ManagerAppContext ctx, String id) async {
    await ctx.clientAPI!.userApi!.userDeleteUser(id);
    await _loadUsers(ctx);
  }

  void _showCreateDialog(BuildContext context, ManagerAppContext ctx) {
    final l = AppLocalizations.of(context)!;
    final callerRole = _roleToInt(ctx.role?.value);
    final emailCtrl = TextEditingController();
    final firstCtrl = TextEditingController();
    final lastCtrl = TextEditingController();
    final passCtrl = TextEditingController();
    int selectedRole = callerRole;

    showDialog(
      context: context,
      builder: (_) => StatefulBuilder(builder: (ctx2, setLocal) {
        return AlertDialog(
          title: Text(l.createUserTitle),
          content: SingleChildScrollView(
            child: Column(mainAxisSize: MainAxisSize.min, children: [
              TextField(controller: emailCtrl, decoration: InputDecoration(labelText: l.email)),
              TextField(controller: firstCtrl, decoration: InputDecoration(labelText: l.firstName)),
              TextField(controller: lastCtrl, decoration: InputDecoration(labelText: l.lastName)),
              TextField(controller: passCtrl, obscureText: true, decoration: InputDecoration(labelText: l.password)),
              const SizedBox(height: 8),
              Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(l.role, style: const TextStyle(fontSize: 12, color: Colors.grey)),
                  DropdownButton<int>(
                    value: selectedRole,
                    isExpanded: true,
                    items: _allowedRoles(callerRole)
                        .map((r) => DropdownMenuItem(value: r, child: Text(_roleName(r))))
                        .toList(),
                    onChanged: (v) => setLocal(() => selectedRole = v!),
                  ),
                ],
              ),
            ]),
          ),
          actions: [
            TextButton(onPressed: () => Navigator.pop(ctx2), child: Text(l.cancel)),
            ElevatedButton(
              onPressed: () async {
                Navigator.pop(ctx2);
                await _createUser(ctx, emailCtrl.text, firstCtrl.text,
                    lastCtrl.text, passCtrl.text, selectedRole);
              },
              child: Text(l.create),
            ),
          ],
        );
      }),
    );
  }

  void _showEditDialog(BuildContext context, ManagerAppContext ctx, Map<String, dynamic> user) {
    final l = AppLocalizations.of(context)!;
    final callerRole = _roleToInt(ctx.role?.value);
    final firstCtrl = TextEditingController(text: user['firstName'] as String? ?? '');
    final lastCtrl = TextEditingController(text: user['lastName'] as String? ?? '');
    int selectedRole = _roleToInt(user['role']);

    showDialog(
      context: context,
      builder: (_) => StatefulBuilder(builder: (ctx2, setLocal) {
        return AlertDialog(
          title: Text(l.editUserTitle),
          content: SingleChildScrollView(
            child: Column(mainAxisSize: MainAxisSize.min, children: [
              TextField(controller: firstCtrl, decoration: InputDecoration(labelText: l.firstName)),
              TextField(controller: lastCtrl, decoration: InputDecoration(labelText: l.lastName)),
              const SizedBox(height: 8),
              Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(l.role, style: const TextStyle(fontSize: 12, color: Colors.grey)),
                  DropdownButton<int>(
                    value: selectedRole,
                    isExpanded: true,
                    items: _allowedRoles(callerRole)
                        .map((r) => DropdownMenuItem(value: r, child: Text(_roleName(r))))
                        .toList(),
                    onChanged: (v) => setLocal(() => selectedRole = v!),
                  ),
                ],
              ),
            ]),
          ),
          actions: [
            TextButton(onPressed: () => Navigator.pop(ctx2), child: Text(l.cancel)),
            ElevatedButton(
              onPressed: () async {
                Navigator.pop(ctx2);
                await _updateUser(ctx, user['id'] as String, firstCtrl.text,
                    lastCtrl.text, selectedRole);
              },
              child: Text(l.save),
            ),
          ],
        );
      }),
    );
  }

  void _confirmDelete(BuildContext context, ManagerAppContext ctx, Map<String, dynamic> user) {
    final l = AppLocalizations.of(context)!;
    showDialog(
      context: context,
      builder: (_) => AlertDialog(
        title: Text(l.deleteUserTitle),
        content: Text(l.deleteUserConfirm(user['email'] as String? ?? '')),
        actions: [
          TextButton(onPressed: () => Navigator.pop(context), child: Text(l.cancel)),
          ElevatedButton(
            style: ElevatedButton.styleFrom(backgroundColor: Colors.red),
            onPressed: () async {
              Navigator.pop(context);
              await _deleteUser(ctx, user['id'] as String);
            },
            child: Text(l.delete, style: const TextStyle(color: Colors.white)),
          ),
        ],
      ),
    );
  }

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final ctx = Provider.of<AppContext>(context, listen: false).getContext() as ManagerAppContext;
      _loadUsers(ctx);
    });
  }

  static Color _roleColor(dynamic v) {
    switch (_roleToInt(v)) {
      case 0: return Colors.purple;
      case 1: return Colors.blue;
      case 2: return Colors.teal;
      default: return Colors.grey;
    }
  }

  @override
  Widget build(BuildContext context) {
    final l = AppLocalizations.of(context)!;
    final appContext = Provider.of<AppContext>(context);
    final managerCtx = appContext.getContext() as ManagerAppContext;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Text(l.usersTitle, style: TextStyle(fontSize: 24, fontWeight: FontWeight.w600, color: kPrimaryColor)),
            ElevatedButton.icon(
              onPressed: () => _showCreateDialog(context, managerCtx),
              icon: const Icon(Icons.add),
              label: Text(l.createUserBtn),
            ),
          ],
        ),
        const SizedBox(height: 16),
        if (_loading)
          const CommonLoader()
        else if (_users.isEmpty)
          Center(child: Text(l.noUsers))
        else
          Expanded(
            child: Card(
              elevation: 0,
              color: Colors.white,
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(8),
                side: BorderSide(color: Colors.grey.shade200),
              ),
              clipBehavior: Clip.antiAlias,
              child: SingleChildScrollView(
                child: SizedBox(
                  width: double.infinity,
                  child: DataTable(
                  horizontalMargin: 16,
                  columnSpacing: 24,
                  headingRowColor: WidgetStateProperty.all(Colors.grey.shade50),
                  dividerThickness: 1,
                  columns: [
                    DataColumn(label: Text(l.email, style: const TextStyle(fontWeight: FontWeight.w600))),
                    DataColumn(label: Text(l.firstName, style: const TextStyle(fontWeight: FontWeight.w600))),
                    DataColumn(label: Text(l.lastName, style: const TextStyle(fontWeight: FontWeight.w600))),
                    DataColumn(label: Text(l.role, style: const TextStyle(fontWeight: FontWeight.w600))),
                    DataColumn(label: Text(l.actions, style: const TextStyle(fontWeight: FontWeight.w600))),
                  ],
                  rows: _users.map((user) {
                    final roleColor = _roleColor(user['role']);
                    return DataRow(cells: [
                      DataCell(Text(user['email'] as String? ?? '')),
                      DataCell(Text(user['firstName'] as String? ?? '')),
                      DataCell(Text(user['lastName'] as String? ?? '')),
                      DataCell(Chip(
                        label: Text(
                          _roleName(user['role']),
                          style: TextStyle(color: roleColor, fontSize: 12),
                        ),
                        backgroundColor: roleColor.withValues(alpha: 0.08),
                        side: BorderSide(color: roleColor.withValues(alpha: 0.3)),
                        padding: const EdgeInsets.symmetric(horizontal: 4),
                        visualDensity: VisualDensity.compact,
                      )),
                      DataCell(Row(children: [
                        IconButton(
                          icon: Icon(Icons.edit, color: kPrimaryColor, size: 20),
                          tooltip: l.tooltipEdit,
                          onPressed: () => _showEditDialog(context, managerCtx, user),
                        ),
                        IconButton(
                          icon: const Icon(Icons.delete_outline, color: Colors.red, size: 20),
                          tooltip: l.tooltipDelete,
                          onPressed: () => _confirmDelete(context, managerCtx, user),
                        ),
                      ])),
                    ]);
                  }).toList(),
                ),
              ),
            ),
          ),
        ),
      ],
    );
  }
}