feat: use package-interface.json from Hex if it exists

Dockerfile

@@ -1,6 +1,6 @@
 FROM --platform=x86_64 ghcr.io/gleam-lang/gleam:v1.3.0-erlang-alpine AS builder
 
-RUN apk add ca-certificates
+RUN apk add build-base ca-certificates
 RUN mkdir -p /build/backend/src
 
 COPY apps/backend/gleam.toml /build/backend
@@ -13,7 +13,7 @@ RUN cd /build/backend && gleam export erlang-shipment
 FROM --platform=x86_64 ghcr.io/gleam-lang/gleam:v1.3.0-erlang-alpine as runner
 LABEL org.opencontainers.image.source https://github.com/ghivert/gloogle
 
-RUN apk add ca-certificates inotify-tools
+RUN apk add build-base ca-certificates inotify-tools
 
 WORKDIR /app
 

apps/backend/src/api/hex_repo.gleam

@@ -19,6 +19,7 @@ pub fn get_home() -> Result(String, Nil)
 fn extract_tar(
   tarbin: BitArray,
   base_name: String,
+  version: String,
   slug: String,
 ) -> Result(#(String, String, String), Nil)
 
@@ -136,7 +137,7 @@ fn extract_package_infos(name: String, version: String) {
   use body <- result.try(req)
   use #(interface_s, toml_s, res) <- result.try({
     body
-    |> extract_tar(name, slug)
+    |> extract_tar(name, version, slug)
     |> result.map_error(fn(_) {
       let content = "Impossible to extract tar for " <> package_name
       wisp.log_warning(content)

apps/backend/src/gloogle_hex_ffi.erl

@@ -1,25 +1,37 @@
 -module(gloogle_hex_ffi).
--export([extract_tar/3, remove_tar/1, is_match/2, get_home/0, set_level/1]).
+-export([extract_tar/4, remove_tar/1, is_match/2, get_home/0, set_level/1]).
 
 package_interface_path(ContentDest, BaseName) ->
   BuildFolder = <<"/build/dev/docs/">>,
   Package = <<"/package-interface.json">>,
   Path = <<ContentDest/binary, BuildFolder/binary, BaseName/binary, Package/binary>>,
   unicode:characters_to_binary(Path).
 
+save_file(ContentDest, HttpBody) ->
+  PackageInterfacePath = <<ContentDest/binary, "/package-interface.json">>,
+  file:write_file(PackageInterfacePath, HttpBody),
+  {unicode:characters_to_binary(PackageInterfacePath), <<"">>}.
+
 % Get the tarball package from Hex, build the package, extract the
 % package-interface.json and the gleam.toml.
-extract_tar(Binary, BaseName, Slug) ->
+extract_tar(Binary, BaseName, Version, Slug) ->
   PackagePath = <<"/tmp/", Slug/binary>>,
   ContentDest = <<PackagePath/binary, "/contents">>,
   Content = <<PackagePath/binary, "/contents.tar.gz">>,
   case erl_tar:extract({binary, Binary}, [{cwd, PackagePath}]) of
     {error, _} -> {error, nil};
     _ ->
+      Url = <<"https://hexdocs.pm/", BaseName/binary, "/", Version/binary, "/package-interface.json">>,
       erl_tar:extract(Content, [{cwd, ContentDest}, compressed]),
-      BuildCmd = <<"cd ", ContentDest/binary, " && gleam docs build">>,
-      Result = os:cmd(binary_to_list(BuildCmd)),
-      PackageInterface = package_interface_path(ContentDest, BaseName),
+      {PackageInterface, Result} =
+        case httpc:request(Url) of
+          {ok, {_, _, HttpBody}} -> save_file(ContentDest, HttpBody);
+          {ok, {_, HttpBody}} -> save_file(ContentDest, HttpBody);
+          {error, _} ->
+            BuildCmd = <<"cd ", ContentDest/binary, " && gleam docs build">>,
+            Res = os:cmd(binary_to_list(BuildCmd)),
+            {package_interface_path(ContentDest, BaseName), Res}
+        end,
       GleamToml = unicode:characters_to_binary(<<ContentDest/binary, "/gleam.toml">>),
       {ok, {PackageInterface, GleamToml, unicode:characters_to_binary(Result)}}
   end.