2 files changed, 71 insertions, 0 deletions
diff --git a/lib/naming/config.ml b/lib/naming/config.ml
new file mode 100644
index 0000000..ce1b433
--- /dev/null
+++ b/lib/naming/config.ml
@@ -0,0 +1,43 @@
+module OI = Colitur_kernel.Overlay_ini
+
+type t = {
+  lang : string option;
+  overlays : string list;
+  template : string option;
+  format : string option;
+  unknown_keys : string list;
+}
+
+let empty = { lang = None; overlays = []; template = None; format = None; unknown_keys = [] }
+
+let lang t = t.lang
+let overlays t = t.overlays
+let template t = t.template
+let format t = t.format
+let unknown_keys t = t.unknown_keys
+
+let of_string text =
+  match OI.parse_sections text with
+  | Error e -> Error e
+  | Ok sections -> (
+      match List.find_opt (fun (s : OI.section) -> s.OI.name = "defaults") sections with
+      | None -> Ok empty
+      | Some s ->
+          let acc =
+            List.fold_left
+              (fun acc (k, v) ->
+                match k with
+                | "lang" -> { acc with lang = Some v }
+                | "template" -> { acc with template = Some v }
+                | "format" -> { acc with format = Some v }
+                (* accumulates: a user has more than one overlay *)
+                | "overlay" -> { acc with overlays = acc.overlays @ [ v ] }
+                | other -> { acc with unknown_keys = acc.unknown_keys @ [ other ] })
+              empty s.OI.fields
+          in
+          Ok acc)
+
+let resolve ~flag ~config ~default =
+  match flag with
+  | Some v -> (v, "flag")
+  | None -> ( match config with Some v -> (v, "config") | None -> (default, "default"))
diff --git a/lib/naming/config.mli b/lib/naming/config.mli
new file mode 100644
index 0000000..41ff429
--- /dev/null
+++ b/lib/naming/config.mli
@@ -0,0 +1,28 @@
+(** The config file: what the user wants by default, and where each value came
+    from.
+
+    Owns precedence and provenance and nothing else. Never reads the filesystem
+    -- callers hand it text -- so it is as testable as the language table.
+
+    A config file is OPTIONAL. With none, colitur behaves exactly as it does
+    without this feature, except that names resolve through the default
+    language. *)
+
+type t
+
+val empty : t
+val of_string : string -> (t, string) result
+
+val lang : t -> string option
+val overlays : t -> string list
+val template : t -> string option
+val format : t -> string option
+
+(** Keys present in the file that this build does not understand. Reported, never
+    fatal: a config written for a newer colitur must still work on an older one,
+    but silently ignoring a line the user wrote is how a typo becomes invisible. *)
+val unknown_keys : t -> string list
+
+(** [resolve ~flag ~config ~default] returns [(value, source)] with source one of
+    ["flag"], ["config"], ["default"]. Precedence is flag > config > default. *)
+val resolve : flag:string option -> config:string option -> default:string -> string * string