ADD Print default usage subcommand

Author: orbitz

files/usage.json

@@ -1,6 +1,6 @@
 [
   {
-    "description": "Default AWS EC2 Instance hours (according to ChatGPT)",
+    "description": "Default AWS EC2 Instance hours",
     "match_query": "type = aws_instance and service_class = instance and purchase_option = on_demand and os = linux",
     "usage": {
       "time": 730

src/oiq/oiq_usage.ml

@@ -115,3 +115,5 @@ let of_channel in_chan =
 
 let match_ ms t =
   CCList.find_opt (fun { Entry.match_query; _ } -> Oiq_match_query.eval ms match_query) t.entries
+
+let to_yojson { entries } = [%to_yojson: Entry.t list] entries

src/oiq/oiq_usage.mli

@@ -63,7 +63,7 @@ module Entry : sig
 end
 
 type of_channel_err = [ `Usage_file_err of string ] [@@deriving show]
-type t
+type t [@@deriving to_yojson]
 
 val default : unit -> t
 val of_channel : in_channel -> (t, [> of_channel_err ]) result

src/oiq_cli/oiq_cli.ml

@@ -70,6 +70,11 @@ module Cli = struct
     C.Cmd.v
       (C.Cmd.info "price" ~doc ~exits)
       C.Term.(const f $ usage $ input $ output_format $ match_query $ region)
+
+  let print_default_usage_cmd f =
+    let doc = "Print default usage file." in
+    let exits = C.Cmd.Exit.defaults in
+    C.Cmd.v (C.Cmd.info "print-default-usage" ~doc ~exits) C.Term.(const f $ const ())
 end
 
 let reporter ppf =
@@ -153,6 +158,16 @@ let price usage input output_format match_query regions =
       Logs.err (fun m -> m "%a" Oiq.pp_price_err err);
       exit 1
 
+let print_default_usage () =
+  let default = Oiq_usage.default () in
+  print_endline @@ Yojson.Safe.pretty_to_string @@ Oiq_usage.to_yojson default
+
 let () =
   let info = Cmdliner.Cmd.info ~version:Cli.version "oiq" in
-  exit @@ Cmdliner.Cmd.eval @@ Cmdliner.Cmd.group info [ Cli.match_cmd match_; Cli.price_cmd price ]
+  exit
+  @@ Cmdliner.Cmd.eval
+  @@ Cmdliner.Cmd.group
+       info
+       [
+         Cli.match_cmd match_; Cli.price_cmd price; Cli.print_default_usage_cmd print_default_usage;
+       ]