FileExtensions.cs

namespace EmptyFiles;

public static class FileExtensions
{
    public static bool IsTextFile(string path) =>
        IsTextExtension(Path.GetExtension(path));

    public static bool IsTextExtension(string extension)
    {
        extension = Guard.ValidExtension(extension);

        return textExtensions.Contains(extension);
    }

    public static bool IsTextExtension(CharSpan extension) =>
        IsTextExtension(extension.ToString());

    public static bool IsTextFile(CharSpan path)
    {
#if NET6_0_OR_GREATER
        var extension = Path.GetExtension(path);
        return IsTextExtension(extension.ToString());
#else
        var extension = Path.GetExtension(path.ToString());
        return IsTextExtension(extension);
#endif
    }

    public static void RemoveTextExtension(string extension)
    {
        extension = Guard.ValidExtension(extension);
        var copy = new HashSet<string>(textExtensions);
        copy.Remove(extension);
        textExtensions = copy.ToFrozenSet();
    }

    public static void RemoveTextExtension(CharSpan extension) =>
        RemoveTextExtension(extension.ToString());

    public static void RemoveTextExtensions(params string[] extensions)
    {
        foreach (var extension in extensions)
        {
            RemoveTextExtension(extension);
        }
    }

    public static void RemoveTextExtensions(IEnumerable<string> extensions)
    {
        foreach (var extension in extensions)
        {
            RemoveTextExtension(extension);
        }
    }

    public static void AddTextExtension(string extension)
    {
        extension = Guard.ValidExtension(extension);
        var copy = new HashSet<string>(textExtensions)
        {
            extension
        };
        textExtensions = copy.ToFrozenSet();
    }

    public static void AddTextExtension(CharSpan extension) =>
        AddTextExtension(extension.ToString());

    public static void AddTextExtensions(params string[] extensions)
    {
        foreach (var extension in extensions)
        {
            AddTextExtension(extension);
        }
    }

    public static void AddTextExtensions(IEnumerable<string> extensions)
    {
        foreach (var extension in extensions)
        {
            AddTextExtension(extension);
        }
    }

    //From https:/sindresorhus/text-extensions/blob/master/text-extensions.json
    static IReadOnlyCollection<string> textExtensions = new HashSet<string>
        {
            ".ada",
            ".adb",
            ".ads",
            ".applescript",
            ".as",
            ".asc",
            ".ascii",
            ".ascx",
            ".asm",
            ".asmx",
            ".asp",
            ".aspx",
            ".atom",
            ".au3",
            ".awk",
            ".bas",
            ".bash",
            ".bashrc",
            ".bat",
            ".bbcolors",
            ".bcp",
            ".bdsgroup",
            ".bdsproj",
            ".bib",
            ".bowerrc",
            ".c",
            ".cbl",
            ".cc",
            ".cfc",
            ".cfg",
            ".cfm",
            ".cfml",
            ".cgi",
            ".cjs",
            ".clj",
            ".cljs",
            ".cls",
            ".cmake",
            ".cmd",
            ".cnf",
            ".cob",
            ".code-snippets",
            ".coffee",
            ".coffeekup",
            ".conf",
            ".config",
            ".cp",
            ".cpp",
            ".cpt",
            ".cpy",
            ".crt",
            ".cs",
            ".csh",
            ".cson",
            ".csproj",
            ".csr",
            ".css",
            ".csslintrc",
            ".csv",
            ".ctl",
            ".curlrc",
            ".cxx",
            ".d",
            ".dart",
            ".dfm",
            ".diff",
            ".dof",
            ".dpk",
            ".dpr",
            ".dproj",
            ".dtd",
            ".eco",
            ".editorconfig",
            ".ejs",
            ".el",
            ".elm",
            ".emacs",
            ".eml",
            ".ent",
            ".erb",
            ".erl",
            ".eslintignore",
            ".eslintrc",
            ".ex",
            ".exs",
            ".f",
            ".f03",
            ".f77",
            ".f90",
            ".f95",
            ".fish",
            ".for",
            ".fpp",
            ".frm",
            ".fs",
            ".fsproj",
            ".fsx",
            ".ftn",
            ".gemrc",
            ".gemspec",
            ".gitattributes",
            ".gitconfig",
            ".gitignore",
            ".gitkeep",
            ".gitmodules",
            ".go",
            ".gpp",
            ".gradle",
            ".graphql",
            ".groovy",
            ".groupproj",
            ".grunit",
            ".gtmpl",
            ".gv",
            ".gvimrc",
            ".h",
            ".haml",
            ".hbs",
            ".hgignore",
            ".hh",
            ".hpp",
            ".hrl",
            ".hs",
            ".hta",
            ".htaccess",
            ".htc",
            ".htm",
            ".html",
            ".htmx",
            ".htpasswd",
            ".hxx",
            ".ics",
            ".iced",
            ".il",
            ".iml",
            ".inc",
            ".inf",
            ".info",
            ".ini",
            ".ino",
            ".int",
            ".irbrc",
            ".itcl",
            ".itermcolors",
            ".itk",
            ".jade",
            ".java",
            ".jhtm",
            ".jhtml",
            ".js",
            ".javascript",
            ".jscsrc",
            ".jshintignore",
            ".jshintrc",
            ".json",
            ".json5",
            ".jsonld",
            ".jsp",
            ".jspx",
            ".jsx",
            ".ksh",
            ".less",
            ".lhs",
            ".lisp",
            ".log",
            ".ls",
            ".lsp",
            ".lua",
            ".m",
            ".m4",
            ".mak",
            ".map",
            ".markdown",
            ".master",
            ".md",
            ".mdown",
            ".mdwn",
            ".mdx",
            ".mermaid",
            ".metadata",
            ".mht",
            ".mhtml",
            ".mjs",
            ".mk",
            ".mkd",
            ".mkdn",
            ".mkdown",
            ".ml",
            ".mli",
            ".mm",
            ".mmd",
            ".mxml",
            ".nfm",
            ".nfo",
            ".noon",
            ".npmignore",
            ".npmrc",
            ".nuspec",
            ".nvmrc",
            ".ops",
            ".pas",
            ".pasm",
            ".patch",
            ".pbxproj",
            ".pch",
            ".pem",
            ".pg",
            ".php",
            ".php3",
            ".php4",
            ".php5",
            ".phpt",
            ".phtml",
            ".pir",
            ".pl",
            ".pm",
            ".pmc",
            ".pod",
            ".pot",
            ".prettierrc",
            ".properties",
            ".props",
            ".pt",
            ".pug",
            ".purs",
            ".py",
            ".pyx",
            ".r",
            ".rake",
            ".rb",
            ".rbw",
            ".rc",
            ".rdoc",
            ".rdoc_options",
            ".resx",
            ".rexx",
            ".rhtml",
            ".rjs",
            ".rlib",
            ".ron",
            ".rs",
            ".rss",
            ".rst",
            ".rtf",
            ".rvmrc",
            ".rxml",
            ".s",
            ".sass",
            ".scala",
            ".scm",
            ".scss",
            ".seestyle",
            ".sh",
            ".shtml",
            ".sln",
            ".sls",
            ".spec",
            ".sql",
            ".sqlite",
            ".sqlproj",
            ".srt",
            ".ss",
            ".sss",
            ".st",
            ".strings",
            ".sty",
            ".styl",
            ".stylus",
            ".sub",
            ".sublime-build",
            ".sublime-commands",
            ".sublime-completions",
            ".sublime-keymap",
            ".sublime-macro",
            ".sublime-menu",
            ".sublime-project",
            ".sublime-settings",
            ".sublime-workspace",
            ".sv",
            ".svc",
            ".svg",
            ".swift",
            ".t",
            ".tcl",
            ".tcsh",
            ".terminal",
            ".tex",
            ".text",
            ".textile",
            ".tg",
            ".tk",
            ".tmLanguage",
            ".tmpl",
            ".tmTheme",
            ".tpl",
            ".ts",
            ".tsv",
            ".tsx",
            ".tt",
            ".tt2",
            ".ttml",
            ".twig",
            ".txt",
            ".v",
            ".vb",
            ".vbproj",
            ".vbs",
            ".vcproj",
            ".vcxproj",
            ".vh",
            ".vhd",
            ".vhdl",
            ".vim",
            ".viminfo",
            ".vimrc",
            ".vm",
            ".vue",
            ".webapp",
            ".webmanifest",
            ".wsc",
            ".x-php",
            ".xaml",
            ".xht",
            ".xhtml",
            ".xml",
            ".xs",
            ".xsd",
            ".xsl",
            ".xslt",
            ".y",
            ".yaml",
            ".yml",
            ".zsh",
            ".zshrc"
        }
        .ToFrozenSet();

    public static IReadOnlyCollection<string> TextExtensions => textExtensions;

    [Obsolete("Use IsTextFile or IsTextExtension")]
    public static bool IsText([NotNullWhen(true)] string? extensionOrPath)
    {
        if (extensionOrPath == null)
        {
            return false;
        }

        if (extensionOrPath.Contains('.') ||
            extensionOrPath.Contains(Path.DirectorySeparatorChar) ||
            extensionOrPath.Contains(Path.AltDirectorySeparatorChar))
        {
            var extension = Path.GetExtension(extensionOrPath);
            return textExtensions.Contains(extension);
        }

        return textExtensions.Contains($".{extensionOrPath}");
    }

    [Obsolete("Use IsTextFile or IsTextExtension")]
    public static bool IsText(CharSpan extensionOrPath) =>
        IsText(extensionOrPath.ToString());
}