Check for Nerd Font and switch

lib/pretty/dune

@@ -3,5 +3,6 @@
  (libraries
   ansifmt
   shell
+  str
   ;; Internal dependencies
   extra))

lib/pretty/icon.ml

@@ -1,11 +1,93 @@
-let closed_char = "\u{ebda}"
-let open_char = "\u{ea64}"
-let merged_char = "\u{e725}"
-let arrow_left_char = "\u{f0a8}"
-let pwd_char = "\u{e5fd}"
-let dir_char = "\u{f4d4}"
-let empty_dir_char = "\u{f413}"
-let file_char = "\u{f4a5}"
-let bin_char = "\u{eae8}"
-let warning = "\u{26A0}"
-let issue_char = "\u{f41b}"
+type t = {
+  closed_char : string;
+  open_char : string;
+  merged_char : string;
+  arrow_left_char : string;
+  pwd_char : string;
+  dir_char : string;
+  empty_dir_char : string;
+  file_char : string;
+  bin_char : string;
+  warning : string;
+  issue_char : string;
+}
+
+let hack_nerd_font = "HackNerdFontMono"
+let fc_list_cmd = Printf.sprintf "fc-list | grep '%s'" hack_nerd_font
+let uname_cmd = {| uname |}
+
+type os_name =
+  | Linux
+  | MacOS
+
+let uname_result =
+  Shell.proc_stdout uname_cmd |> String.trim |> function
+  | "Linux" -> Some Linux
+  | "Darwin" -> Some MacOS
+  | _ -> None
+
+(* Based on the list of possible folders here: https://github.com/adrg/xdg/blob/master/README.md#other-directories*)
+let mac_font_dirs =
+  [
+    Unix.getenv "HOME" ^ "/Library/Fonts";
+    "/Library/Fonts";
+    "/System/Library/Fonts";
+    "/Network/Library/Fonts";
+  ]
+
+let string_contains str substr =
+  let re = Str.regexp_string substr in
+  try
+    ignore (Str.search_forward re str 0);
+    true
+  with Not_found -> false
+
+let rec font_exists_in_dirs font_name = function
+  | [] -> false
+  | dir :: dirs ->
+      if Sys.file_exists dir then
+        let files = Sys.readdir dir in
+        if Array.exists (fun file -> string_contains file font_name) files then
+          true
+        else font_exists_in_dirs font_name dirs
+      else font_exists_in_dirs font_name dirs
+
+(* We only support mac and linux right now - if the system is unix based and
+it's linux, we can use the fc-list cmd, otherwise on mac we look in common
+directories manually for our font *)
+let nerd_font_installed =
+  match uname_result with
+  | Some Linux ->
+      Shell.proc_stdout fc_list_cmd |> String.trim |> String.length > 0
+  | Some MacOS -> font_exists_in_dirs hack_nerd_font mac_font_dirs
+  | None -> false (* do we want this be false or true if we can't tell? *)
+
+let icons =
+  if nerd_font_installed then
+    {
+      closed_char = "\u{ebda}";
+      open_char = "\u{ea64}";
+      merged_char = "\u{e725}";
+      arrow_left_char = "\u{f0a8}";
+      pwd_char = "\u{e5fd}";
+      dir_char = "\u{f4d4}";
+      empty_dir_char = "\u{f413}";
+      file_char = "\u{f4a5}";
+      bin_char = "\u{eae8}";
+      warning = "\u{26A0}";
+      issue_char = "\u{f41b}";
+    }
+  else
+    {
+      closed_char = "x";
+      open_char = "o";
+      merged_char = "m";
+      arrow_left_char = "<-";
+      pwd_char = "*";
+      dir_char = "/";
+      empty_dir_char = "/";
+      file_char = "f";
+      bin_char = "b";
+      warning = "!";
+      issue_char = "i";
+    }

lib/pretty/icon.mli

@@ -0,0 +1,18 @@
+(** A record representing the icon set **)
+type t = {
+  closed_char : string;
+  open_char : string;
+  merged_char : string;
+  arrow_left_char : string;
+  pwd_char : string;
+  dir_char : string;
+  empty_dir_char : string;
+  file_char : string;
+  bin_char : string;
+  warning : string;
+  issue_char : string;
+}
+
+(** Populated with the current icon set based on if Nerd Font is available or or
+    not**)
+val icons : t

lib/pretty/pretty.ml

@@ -1,7 +1,8 @@
 module Doc = Doc
 module Layout = Layout
 module Style = Style
-module Icon = Icon
+
+let icons = Icon.icons
 
 let render ~width ~height doc =
   doc |> Doc.render ~width ~height |> Layout.to_lines |> Extra.String.unlines

lib/pretty/pretty.mli

@@ -13,11 +13,12 @@ module Doc = Doc
     {!Layout.t} is the output of {!Doc.render} with all the sizes calculated. *)
 module Layout = Layout
 
-(** Icons and symbols used for identifying different parts. Symbols from Hack
-    Nerd Font Mono are used when it's available. Symbols list:
+(** A record representign the Icons and symbols used for identifying different
+    parts. Symbols from Hack Nerd Font Mono are used when it's available.
+    Symbols list:
 
     - https://www.nerdfonts.com/cheat-sheet *)
-module Icon = Icon
+val icons : Icon.t
 
 (** Render a document into the final string
 

lib/tui/render/render.ml

@@ -8,8 +8,8 @@ type 'a t = {
 
 let fmt_issue_state (state : Gh.Issue.state) =
   match state with
-  | Open -> Layout.(fmt Style.issue_open Pretty.Icon.issue_char)
-  | Closed -> Layout.(fmt Style.issue_closed Pretty.Icon.issue_char)
+  | Open -> Layout.(fmt Style.issue_open Pretty.icons.issue_char)
+  | Closed -> Layout.(fmt Style.issue_closed Pretty.icons.issue_char)
 
 let fmt_title (issue : Gh.Issue.t) =
   let open Layout in

lib/tui/widget/code.ml

@@ -15,7 +15,7 @@ let pwd root_dir_path (fs : Fs.zipper) =
   let pwd_path = parents_path parents in
   let root_dir_name = Filename.basename root_dir_path in
   let full_path =
-    Pretty.Icon.pwd_char ^ " " ^ Filename.concat root_dir_name pwd_path
+    Pretty.icons.pwd_char ^ " " ^ Filename.concat root_dir_name pwd_path
   in
   Pretty.Doc.(fmt Style.directory full_path)
 
@@ -52,12 +52,12 @@ let fmt_file ~max_name_len (tree : Fs.tree) =
   match tree with
   | File { name; file_type; _ } -> (
       match Lazy.force file_type with
-      | Fs.Filec.Text -> Pretty.Icon.file_char ^ " " ^ pad name
-      | Fs.Filec.Binary -> Pretty.Icon.bin_char ^ " " ^ pad name)
+      | Fs.Filec.Text -> Pretty.icons.file_char ^ " " ^ pad name
+      | Fs.Filec.Binary -> Pretty.icons.bin_char ^ " " ^ pad name)
   | Dir { name; children = (lazy children) } -> (
       match children with
-      | [||] -> Pretty.Icon.empty_dir_char ^ " " ^ pad name
-      | _ -> Pretty.Icon.dir_char ^ " " ^ pad name)
+      | [||] -> Pretty.icons.empty_dir_char ^ " " ^ pad name
+      | _ -> Pretty.icons.dir_char ^ " " ^ pad name)
 
 let current_level_to_doc (cursor : Fs.dir_cursor) ~has_next ~is_file_chosen =
   let open Pretty.Doc in

lib/tui/widget/common.ml

@@ -4,7 +4,7 @@ let fmt_error (error : Gh.Client.error) =
   | No_github_token ->
       [
         str
-          (Pretty.Icon.warning
+          (Pretty.icons.warning
          ^ " GITHUB_TOKEN not found. Make sure it's configured in your \
             environment.");
         str "";
@@ -13,15 +13,15 @@ let fmt_error (error : Gh.Client.error) =
       ]
   | Bad_credentials { msg; doc_url; code } ->
       [
-        str (Format.sprintf "%s [%d] %s" Pretty.Icon.warning code msg);
+        str (Format.sprintf "%s [%d] %s" Pretty.icons.warning code msg);
         str "";
         str ("Documentation url: " ^ doc_url);
       ]
   | Curl_error { code; msg } ->
       [
         str
           (Format.sprintf "%s GitHub API returned error code: %d"
-             Pretty.Icon.warning code);
+             Pretty.icons.warning code);
         str "";
         str msg;
       ]

lib/tui/widget/generic.ml

@@ -66,7 +66,9 @@ let vlist_border ~scroll_start ~selected items =
         let first_line =
           Doc.(
             horizontal
-              [ fmt_selected_line hd; str " "; str Pretty.Icon.arrow_left_char ])
+              [
+                fmt_selected_line hd; str " "; str Pretty.icons.arrow_left_char;
+              ])
         in
         let other_lines = List.map fmt_selected_line tl in
         first_line :: other_lines

lib/tui/widget/pr.ml

@@ -7,9 +7,9 @@ let section (tab : Model.Pr.t) =
     | None ->
         let fmt_state = function
           | None -> str ""
-          | Some Gh.Pr.Merged -> fmt Style.pr_merged Pretty.Icon.merged_char
-          | Some Gh.Pr.Open -> fmt Style.pr_open Pretty.Icon.open_char
-          | Some Gh.Pr.Closed -> fmt Style.pr_closed Pretty.Icon.closed_char
+          | Some Gh.Pr.Merged -> fmt Style.pr_merged Pretty.icons.merged_char
+          | Some Gh.Pr.Open -> fmt Style.pr_open Pretty.icons.open_char
+          | Some Gh.Pr.Closed -> fmt Style.pr_closed Pretty.icons.closed_char
         in
         let fmt_pr (pr : Gh.Pr.t) =
           Pretty.Doc.(