Example: some basic stuff for a signald plugin

example/dune

@@ -6,4 +6,4 @@
   (language c)
   (names description)
   (flags -fPIC))
- (libraries weechat_api weechat_plugin unix))
+ (libraries weechat_api weechat_plugin unix yojson))

example/plugin.ml

@@ -1,6 +1,44 @@
 open Weechat_api
 
 
+module List = struct
+  include List
+
+  let rec iter_opt f = function
+    | [] -> Some ()
+    | x :: xs ->
+      match f x with
+      | None -> None
+      | Some () -> iter_opt f xs
+end
+
+
+module Parsing = struct
+  let as_assoc = function
+    | `Assoc assoc -> Some assoc
+    | _ -> None
+
+  let as_string = function
+    | `String s -> Some s
+    | _ -> None
+
+  let as_list = function
+    | `List l -> Some l
+    | _ -> None
+end
+
+
+(* For nicer error handling *)
+
+let (>>=) = Option.bind
+let (let*) x f = Option.bind x f
+let (let+) x f = Option.map f x
+let (and+) x y =
+  match x, y with
+  | Some x, Some y -> Some (x, y)
+  | _ -> None
+
+
 let log = open_out "/tmp/weechat_signal.log" |> Format.formatter_of_out_channel
 let log args =
   Format.fprintf log args
@@ -9,6 +47,32 @@ let log args =
 module Signald = struct
   type t = {socket: Unix.file_descr; ic: in_channel}
 
+  exception SignalErr of string
+  let error fmt = Format.kasprintf (fun s -> raise (SignalErr s)) fmt
+
+  let username = ref ""
+
+  module Group = struct
+    type version = V1 | V2
+    type t = {
+      version: version;
+      title: string;
+      id: string;
+    }
+
+    let parse_v1 payload =
+      let* assoc = Parsing.as_assoc payload in
+      let+ title = List.assoc_opt "name" assoc >>= Parsing.as_string
+      and+ id = List.assoc_opt "groupId" assoc >>= Parsing.as_string in
+      {title; version = V1; id}
+
+    let parse_v2 payload =
+      let* assoc = Parsing.as_assoc payload in
+      let+ title = List.assoc_opt "title" assoc >>= Parsing.as_string
+      and+ id = List.assoc_opt "id" assoc >>= Parsing.as_string in
+      {title; version = V2; id}
+  end
+
   let make socket =
     let ic = Unix.in_channel_of_descr socket in
     {socket; ic}
@@ -17,14 +81,23 @@ module Signald = struct
     Format.kasprintf
       (fun s -> log "Sending: %s@." s;
         let _ = Unix.write_substring t.socket s 0 (String.length s) in
+        let _ = Unix.write_substring t.socket "\n" 0 1 in
         ())
 
   let subscribe t (number: string) =
-    send t {|{"type": "subscribe", "username": %s}|} number
+    username := number;
+    send t {|{"type": "subscribe", "username": "%s"}|} number
+
+  let list_groups t (number: string) =
+    send t {|{"type": "list_groups", "username": "%s"}|} number
 
   let close t = close_in t.ic
 end
 
+
+let groups = Hashtbl.create 19
+
+
 let init_signald path =
   let socket = Unix.(socket PF_UNIX SOCK_STREAM 0) in
   let rec try_connect retry =
@@ -37,10 +110,57 @@ let init_signald path =
   try_connect 1;
   Signald.make socket
 
+let update_group_list payload =
+  let okv1 =
+    match List.assoc_opt "groups" payload with
+    | None -> Some ()
+    | Some gv1 ->
+      let* gv1 = Parsing.as_list gv1 in
+      List.iter_opt
+        (fun g ->
+          let+ g = Signald.Group.parse_v1 g in
+          if not (Hashtbl.mem groups g.id) then
+            Hashtbl.add groups g.id g)
+        gv1
+  and okv2 =
+    match List.assoc_opt "groupsv2" payload with
+    | None -> Some ()
+    | Some gv2 ->
+      let* gv2 = Parsing.as_list gv2 in
+      List.iter_opt
+        (fun g ->
+          let+ g = Signald.Group.parse_v2 g in
+          if not (Hashtbl.mem groups g.id) then
+            Hashtbl.add groups g.id g)
+        gv2
+  in
+  match okv1, okv2 with
+  | Some (), Some () -> Some ()
+  | _ -> None
+
+let show_group_list buffer =
+  Hashtbl.iter
+    (fun _ (g: Signald.Group.t) ->
+      Weechat.printf buffer "[%s] %s\n" g.id g.title)
+    groups
+
+let process_line main_buffer line =
+  let payload = Yojson.Basic.from_string line in
+  let* assoc = Parsing.as_assoc payload in
+  let* typ = List.assoc_opt "type" assoc >>= Parsing.as_string in
+  match typ with
+  | "group_list" ->
+    let* data = List.assoc_opt "data" assoc in
+    let* data = Parsing.as_assoc data in
+    let* () = update_group_list data in
+    Some (show_group_list main_buffer)
+  | _ -> None
 let process_line main_buffer line =
-  (* Match on line["type"] here *)
-  Weechat.printf main_buffer "Unhandled input: %s" line;
-  0
+  match process_line main_buffer line with
+  | Some () -> 0
+  | None ->
+    Weechat.printf main_buffer "unhandled message from signald: %s" line;
+    0
 
 let plugin_init () =
   let signald_buffer = Weechat.buffer_new
@@ -54,12 +174,22 @@ let plugin_init () =
   let signald = init_signald "/run/signald/signald.sock" in
 
   let _ = Weechat.hook_command
-    "signalsub"
-    "Start receiving messages for a given number"
-    "number"
-    "number: phone number for which to receive messages"
+    "signal"
+    "Interact with weechat-ocaml-signal"
+    "list groups | subscribe NUMBER"
+    "TODO"
     ""
-    (fun _ argv _ -> Signald.subscribe signald argv.(1); 0)
+    (fun _ argv _ ->
+      if Array.length argv != 3 then -1
+      else
+        match argv.(1), argv.(2) with
+        | "list", "groups" ->
+          Signald.list_groups signald !Signald.username;
+          0
+        | "subscribe", username ->
+          Signald.subscribe signald username;
+          0
+        | _ -> -1)
   in
 
   let _ = Weechat.hook_fd