pub const Directory = struct {
    source: std.Build.LazyPath,
    sub_path: []const u8,
    options: Options,

    pub const Options = struct {
        /// File paths that end in any of these suffixes will be excluded from copying.
        exclude_extensions: []const []const u8 = &.{},
        /// Only file paths that end in any of these suffixes will be included in copying.
        /// `null` means that all suffixes will be included.
        /// `exclude_extensions` takes precedence over `include_extensions`.
        include_extensions: ?[]const []const u8 = null,

        pub fn dupe(opts: Options, b: *std.Build) Options {
            return .{
                .exclude_extensions = b.dupeStrings(opts.exclude_extensions),
                .include_extensions = if (opts.include_extensions) |incs| b.dupeStrings(incs) else null,
            };
        }

        pub fn pathIncluded(opts: Options, path: []const u8) bool {
            for (opts.exclude_extensions) |ext| {
                if (std.mem.endsWith(u8, path, ext))
                    return false;
            }
            if (opts.include_extensions) |incs| {
                for (incs) |inc| {
                    if (std.mem.endsWith(u8, path, inc))
                        return true;
                } else {
                    return false;
                }
            }
            return true;
        }
    };
}