using Microsoft.AspNetCore.Components.Server.ProtectedBrowserStorage;
using Microsoft.EntityFrameworkCore;
using radiuscontroller.Data;
using radiuscontroller.Models;

namespace radiuscontroller.Services;

public class AdminAuthService
{
    private readonly RadiusDbContext _db;
    private readonly ProtectedSessionStorage _sessionStorage;

    private const string SessionKey = "AdminUsername";
    public string? CurrentAdminUsername { get; private set; }
    public bool IsAuthenticated => !string.IsNullOrEmpty(CurrentAdminUsername);

    public event Action? OnAuthStateChanged;

    public AdminAuthService(RadiusDbContext db, ProtectedSessionStorage sessionStorage)
    {
        _db = db;
        _sessionStorage = sessionStorage;
    }

    public async Task InitializeAsync()
    {
        try
        {
            var result = await _sessionStorage.GetAsync<string>(SessionKey);
            if (result.Success && !string.IsNullOrEmpty(result.Value))
            {
                CurrentAdminUsername = result.Value;
                NotifyStateChanged();
            }
        }
        catch
        {
            // Session storage might fail during prerendering or early socket connection
            CurrentAdminUsername = null;
        }
    }

    public async Task<bool> HasAnyAdminAsync()
    {
        return await _db.AdminUsers.AnyAsync();
    }

    public async Task<bool> RegisterInitialAdminAsync(string username, string password)
    {
        if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
            return false;

        // Ensure first-time setup is only allowed if no admin users exist
        if (await _db.AdminUsers.AnyAsync())
            return false;

        string cleanUsername = username.Trim().ToLowerInvariant();
        string hash = BCrypt.Net.BCrypt.HashPassword(password.Trim());

        var admin = new AdminUser
        {
            Username = cleanUsername,
            PasswordHash = hash,
            CreatedAt = DateTime.UtcNow
        };

        _db.AdminUsers.Add(admin);
        await _db.SaveChangesAsync();

        CurrentAdminUsername = admin.Username;
        await _sessionStorage.SetAsync(SessionKey, admin.Username);
        NotifyStateChanged();
        return true;
    }

    public async Task<bool> LoginAsync(string username, string password)
    {
        if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
            return false;

        var admin = await _db.AdminUsers.FirstOrDefaultAsync(u => u.Username == username.Trim().ToLowerInvariant());
        if (admin == null)
            return false;

        bool isValid = BCrypt.Net.BCrypt.Verify(password, admin.PasswordHash);
        if (isValid)
        {
            CurrentAdminUsername = admin.Username;
            await _sessionStorage.SetAsync(SessionKey, admin.Username);
            NotifyStateChanged();
            return true;
        }

        return false;
    }

    public async Task LogoutAsync()
    {
        CurrentAdminUsername = null;
        try
        {
            await _sessionStorage.DeleteAsync(SessionKey);
        }
        catch
        {
            // Ignore storage errors during logout
        }
        NotifyStateChanged();
    }

    private void NotifyStateChanged() => OnAuthStateChanged?.Invoke();
}