// No [IniSection] needed — section name is "AppSettings", description from [Description]
using System.ComponentModel;

[Description("Application settings")]
public interface IAppSettings : IIniSection
{
    [DefaultValue("MyApp")]
    string? AppName { get; set; }
}

// Use [IniSection] only when you need a custom section name
[IniSection("app")]
public interface IAppSettings : IIniSection { /* … */ }

using System.ComponentModel;
using System.Runtime.Serialization;

// No [IniSection] — section name = "UserProfileSettings"
[Description("User profile settings")]          // sets the section comment
public interface IUserProfileSettings : IIniSection
{
    [DataMember(Name = "display_name")]          // INI key → "display_name"
    [DefaultValue("Anonymous")]                  // default value
    [Description("The user's display name")]     // key comment
    string? DisplayName { get; set; }

    [DefaultValue(3)]                            // numeric default — no string quoting needed
    int LoginAttempts { get; set; }

    [IgnoreDataMember]                           // never read from or written to the file
    string? CachedToken { get; set; }

    [DefaultValue("1.0.0")]
    string? AppVersion { get; }                  // getter-only: loaded but never saved
}

[IniSection("AppState")]
public interface IAppStateSettings : IIniSection, INotifyPropertyChanged
{
    // Raises PropertyChanged (enabled by INotifyPropertyChanged on the interface)
    [DefaultValue("MyApp")]
    string? AppName { get; set; }

    // Never persisted — default is reset on every Reload(); use for session-scoped values
    [DefaultValue("unauthenticated")]
    [IniValue(RuntimeOnly = true)]
    string? CurrentUser { get; set; }

    // Custom list delimiter for this property only
    [DefaultValue("alpha|beta|gamma")]
    [IniValue(ListDelimiter = '|')]
    List<string>? Tags { get; set; }
}

// Property level — single property
[IniSection("App")]
public interface IAppSettings : IIniSection
{
    [IniValue(EmptyWhenNull = true)]
    string? Description { get; set; }    // → "" when absent

    [IniValue(EmptyWhenNull = true)]
    List<string>? Tags { get; set; }     // → [] when absent

    string? OptionalNote { get; set; }   // → null when absent (unchanged)
}

// Section level — applies to all non-value-type properties in the section
[IniSection("App", EmptyWhenNull = true)]
public interface IAppSettings : IIniSection
{
    string? Description { get; set; }    // → "" when absent
    List<string>? Tags { get; set; }     // → [] when absent
    int Counter { get; set; }            // value type — unaffected
}

[IniSection("AppInfo")]
public interface IAppInfo : IIniSection
{
    // Getter-only: loaded from INI, never written back.
    [DefaultValue("1.0.0")]
    string? Version { get; }

    // Regular read-write property — written to disk when saved.
    [DefaultValue("MyApp")]
    string? Name { get; set; }
}

IAppInfo settings = new AppInfoImpl();   // concrete type from source generator

// ✓ Reading always works through the interface:
Console.WriteLine(settings.Version);

// ✗ Compile error — interface does not expose a setter:
// settings.Version = "2.0.0";

// ✓ Setting is still possible via the concrete class:
var impl = (AppInfoImpl)settings;
impl.Version = "2.0.0";

[IniSection("AppInfo")]
public interface IAppInfo : IIniSection
{
    // Interface setter is present, but the value is never written to disk.
    [DefaultValue("1.0.0")]
    [IniValue(ReadOnly = true)]
    string? Version { get; set; }
}

[IniSection("Session")]
public interface ISessionSettings : IIniSection
{
    // Persisted normally
    [DefaultValue("DefaultUser")]
    string? LastUser { get; set; }

    // Runtime-only: default is restored on Reload(); never touches the file
    [DefaultValue("unauthenticated")]
    [IniValue(RuntimeOnly = true)]
    string? CurrentUser { get; set; }

    [DefaultValue("0")]
    [IniValue(RuntimeOnly = true)]
    int FailedAttempts { get; set; }
}

if (section.IsConstant("AdminValue"))
    adminValueInput.IsEnabled = false;  // disable the control in the UI

// Throws AccessViolationException:
section.AdminValue = "override";

// Entire section: never touched by the defaults file
[IniSection("UserPreferences", IgnoreDefaults = true)]
public interface IUserPreferences : IIniSection
{
    [DefaultValue("Light")]
    string? Theme { get; set; }
}

// Single property: user-owned value; admin constants file cannot lock it
[IniSection("App")]
public interface IAppSettings : IIniSection
{
    [DefaultValue("5")]
    int MaxRetries { get; set; }

    [DefaultValue("Light")]
    [IniValue(IgnoreConstants = true)]
    string? Theme { get; set; }
}

[IniSection("App")]
public interface IAppSettings : IIniSection
{
    [Required]
    string? Name { get; set; }

    [Range(1024, 65535, ErrorMessage = "Port must be between 1024 and 65535.")]
    int Port { get; set; }

    [MaxLength(100)]
    string? Description { get; set; }

    [RegularExpression(@"^[a-z0-9_-]+$", ErrorMessage = "Slug must be lowercase alphanumeric.")]
    string? Slug { get; set; }
}