Source file Download.ml

(* Claude Code
 *
 * Copyright (C) 2026 Yoann Padioleau
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License
 * (LGPL) as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *)

(* See Download.mli *)

(* the network, if the program granted it (run_app ~network): set once
 * by the platform, which calls us from deep in its drawing, where no
 * capability could be passed down call by call *)
let granted : Cap.network option ref = ref None

let grant (caps : < Cap.network ; .. >) : unit = granted := Some (caps :> Cap.network)

(* http:// and https:// by our own client (https://: our own TLS 1.3,
   Tls_client) *)
let http_url caps fname url =
  match Http_client.get caps url with
  | Ok (r : Http.response) when r.status / 100 = 2 -> Out_channel.with_open_bin fname (fun oc -> Out_channel.output_string oc r.body)
  | Ok r -> failwith (Printf.sprintf "%s: %d %s" url r.status r.reason)
  | Error msg -> failwith msg

let has_prefix (src : string) (p : string) : bool =
  String.length src >= String.length p && String.sub src 0 (String.length p) = p

let is_url (src : string) : bool =
  has_prefix src "http://" || has_prefix src "https://"

let local_file ~prefix (src : string) : string =
  if is_url src then begin
    match !granted with
    | None -> failwith (src ^ ": this program wasn't granted the network (run_app ~network, Cap.network)")
    | Some caps ->
        let fn = Filename.temp_file prefix (Filename.extension src) in
        http_url caps fn src;
        fn
  end
  else src