namespace Rhea.Nar;

/// <summary>Common strings/flags in NAR archives</summary>
public static class NarConsts
{
    /// <summary>Nix archive header</summary>
    public static readonly byte[] Header = NarWriter.GetLengthPrefixedPadded("nix-archive-1"u8);

    /// <summary>Start of object marker</summary>
    public static readonly byte[] LeftParen = NarWriter.GetLengthPrefixedPadded("("u8);

    /// <summary>End of object marker</summary>
    public static readonly byte[] RightParen = NarWriter.GetLengthPrefixedPadded(")"u8);

    /// <summary>Indicates the node is a regular file</summary>
    public static readonly byte[] Regular = NarWriter.GetLengthPrefixedPadded("regular"u8);

    /// <summary>Indicates the node is a directory</summary>
    public static readonly byte[] Directory = NarWriter.GetLengthPrefixedPadded("directory"u8);

    /// <summary>Indicates the node is a symlink</summary>
    public static readonly byte[] Symlink = NarWriter.GetLengthPrefixedPadded("symlink"u8);

    /// <summary>Indicates a directory entry</summary>
    public static readonly byte[] Entry = NarWriter.GetLengthPrefixedPadded("entry"u8);

    /// <summary>Indicates a directory entry</summary>
    public static readonly byte[] Node = NarWriter.GetLengthPrefixedPadded("node"u8);

    /// <summary>Indicates the name of a directory entry</summary>
    public static readonly byte[] Name = NarWriter.GetLengthPrefixedPadded("name"u8);

    /// <summary>Indicates the target of a symlink</summary>
    public static readonly byte[] Target = NarWriter.GetLengthPrefixedPadded("target"u8);

    /// <summary>Indicates the type of an entry</summary>
    public static readonly byte[] Type = NarWriter.GetLengthPrefixedPadded("type"u8);

    /// <summary>Indicates that a regular file is executable</summary>
    public static readonly byte[] Executable = NarWriter.GetLengthPrefixedPadded("executable"u8);

    /// <summary>Indicates the start of regular file contents</summary>
    public static readonly byte[] Contents = NarWriter.GetLengthPrefixedPadded("contents"u8);
}

/// <summary>Some pre-combined constants</summary>
public static class CombinedNarConsts
{
    /// <summary>Entry of type Regular</summary>
    public static readonly byte[] TypeRegular = [..NarConsts.Type, ..NarConsts.Regular];

    /// <summary>Entry of type Directory</summary>
    public static readonly byte[] TypeDirectory = [..NarConsts.Type, ..NarConsts.Directory];

    /// <summary>Entry of type Symlink</summary>
    public static readonly byte[] TypeSymlink = [..NarConsts.Type, ..NarConsts.Symlink];
    
    /// <summary>Entry with name</summary>
    public static readonly byte[] EntryWithName = [..NarConsts.Entry, ..NarConsts.LeftParen, ..NarConsts.Name];
    
    /// <summary>Symlink with target</summary>
    public static readonly byte[] SymlinkWithTarget = [..NarConsts.Type, ..NarConsts.Symlink, ..NarConsts.Target];
    
    /// <summary>Executable with 8 bytes of padding</summary>
    public static readonly byte[] ExecutableWithPadding = [..NarConsts.Executable, ..new byte[8]];
}