managed-git/Git/Reference.fs

namespace Git


type ReferenceUpdate = { Was : Hash option ; Now : Hash }

[<RequireQualifiedAccess>]
module Reference =
    let write (r : Repository) (name : string) (hash : Hash) : ReferenceUpdate =
        let refFile =
            r.Fs.Path.Combine ((Repository.refDir r).FullName, "heads", name)
            |> r.Fs.FileInfo.FromFileName

        let was =
            if refFile.Exists then
                r.Fs.File.ReadAllText refFile.FullName
                |> Hash.ofString
                |> Some
            else
                do
                    use _v = refFile.Create ()
                    ()

                None

        r.Fs.File.WriteAllText (refFile.FullName, hash.ToString ())
        { Was = was ; Now = hash }

    let lookup (r : Repository) (name : string) : Hash option =
        let refFile =
            r.Fs.Path.Combine ((Repository.refDir r).FullName, "heads", name)
            |> r.Fs.FileInfo.FromFileName

        if refFile.Exists then
            Some (
                r.Fs.File.ReadAllText refFile.FullName
                |> Hash.ofString
            )
        else
            None