Permissions.dib

#!csharp

[Flags]
public enum Permissions
{
    None = 0,     // 00000  
    A    = 1,     // 00001
    B    = 2,     // 00010
    C    = 4,     // 00100
    D    = 8,     // 01000
    E    = 16,    // 10000
    All  = ~None  // 11111
}
// Permissions are stored using a C# flags enum
// Applying the attribute indicates the enum can be treated as a bit field, i.e. a set of flags.
// Note: Values are powers of 2, e.g. 2, 4, 8, 16, ... 

// ~None - The operator ~ produces a complement of its operand by reversing each bit,
//         So ~00000 = 11111 = A, B, C, D, E 

var userPermissions = Permissions.A | Permissions.C;     // 00001 + 00100 = 00101 = 5
var requiredPermissions = Permissions.A | Permissions.B; // 00001 + 00010 = 00011 = 3

#!csharp

// Output permissions (as string)
Console.WriteLine($"User Permissions: {userPermissions}");

#!csharp

Console.WriteLine($"Required Permissions: {requiredPermissions}");

#!csharp

// Output permissions (as int)
Console.WriteLine($"User Permissions: {(int)userPermissions}");
Console.WriteLine($"Required Permissions: {(int)requiredPermissions}");

#!csharp

// Check permissions
Console.WriteLine($"User Permissions: {userPermissions}");
Console.WriteLine($"Required Permissions: {requiredPermissions}");
Console.WriteLine($"Authorised: {((requiredPermissions & userPermissions) != 0)}");

#!csharp

// Add permission (with logical OR operator)
userPermissions |= Permissions.B;

// Output permissions (as string)
Console.WriteLine($"User Permissions: {userPermissions}");

#!csharp

// Remove permission (with logical XOR operator)
userPermissions ^= Permissions.B;

// Output permissions (as string)
Console.WriteLine($"User Permissions: {userPermissions}");

#!csharp

requiredPermissions = Permissions.A | Permissions.B;

// Create a policy name
// [Authorize(Permissions.A | Permission.B)]
private const string PolicyPrefix = "Permissions";

var policyName = $"{PolicyPrefix}{(int)requiredPermissions}";

// Output policy name
Console.WriteLine($"Required Permissions: {requiredPermissions} ({(int)requiredPermissions})");
Console.WriteLine($"Policy Name: '{policyName}'");

#!csharp

// Update required permissions and policy name
requiredPermissions = Permissions.A | Permissions.B | Permissions.C;

policyName = $"{PolicyPrefix}{(int)requiredPermissions}";

// Output policy name
Console.WriteLine($"Required Permissions: {requiredPermissions} ({(int)requiredPermissions})");
Console.WriteLine($"Policy Name: '{policyName}'");

#!csharp

// Get permissions based on policy name
var permissionsValue = int.Parse(policyName[PolicyPrefix.Length..]);

Console.WriteLine($"Policy Name: {policyName}");
Console.WriteLine($"Required Permissions: {(Permissions)permissionsValue}");