(** An opam switch and the paths odd uses within it. *)

type t

val v : Fpath.t -> t
(** [v prefix] is the switch at [prefix]. A relative path is resolved against
    the current directory. *)

val detect : unit -> (t, [ `Msg of string ]) result
(** The current switch, from [$OPAM_SWITCH_PREFIX] or [opam var prefix]. *)

val prefix : t -> Fpath.t

val state_dir : t -> Fpath.t
(** [<prefix>/var/cache/odd], holding the log and lock. *)

val log_file : t -> Fpath.t
val lock_file : t -> Fpath.t

val work_dir : t -> Fpath.t
(** Scratch directory the driver is run from (it creates [_index]/[_mld]
    relative to its cwd). *)

val odoc_dir : t -> Fpath.t
(** [<prefix>/odoc] — the driver's default odoc/odocl/html output tree. (Kept
    separate from opam's own [<prefix>/doc], where packages install their
    documentation.) *)

val packages_dir : t -> Fpath.t
(** [<prefix>/.opam-switch/packages] — opam's record of installed package
    metadata. *)

val installed : t -> (string * string) list
(** Installed packages as [(name, version)], sorted by name, from the contents
    of {!packages_dir}. *)