refactor!: pkg_model -> pkg_asset

C/mediapipe_api/BUILD

@@ -1,5 +1,5 @@
 load("@rules_pkg//:pkg.bzl", "pkg_zip")
-load("//mediapipe_api:import_model.bzl", "pkg_model")
+load("//mediapipe_api:import_model.bzl", "pkg_asset")
 
 cc_library(
     name = "mediapipe_c",
@@ -129,7 +129,7 @@ pkg_zip(
     # TODO: keep directory structure
 )
 
-pkg_model(
+pkg_asset(
     name = "mediapipe_models",
     srcs = [
         "@com_google_mediapipe//mediapipe/models:face_detection_front.tflite",

C/mediapipe_api/import_model.bzl

@@ -1,37 +1,48 @@
 load("@rules_pkg//:pkg.bzl", "pkg_zip")
 
-def pkg_model(name, srcs = [], **kwargs):
-    """Package MediaPipe models
-    This task renames model files so that they can be added to an AssetBundle (e.g. x.tflte -> x.bytes) and zip them.
+def pkg_asset(name, srcs = [], **kwargs):
+    """Package MediaPipe assets
+    This task renames asset files so that they can be added to an AssetBundle (e.g. x.tflte -> x.bytes) and zip them.
 
     Args:
       name: the name of the output zip file
       srcs: files to be packaged
     """
 
-    for src in srcs:
-      _rename_file(src)
+    rename_target = "normalize_%s_exts" % name
+    _normalize_exts(name = rename_target, srcs = srcs)
 
     pkg_zip(
       name = name,
-      srcs = [_export_file_path(src) for src in srcs],
+      srcs = [":" + rename_target],
       **kwargs,
     )
 
-def _rename_file(src):
-    export_file = _export_file_path(src)
-
-    native.genrule(
-        name = "export_" + export_file,
-        srcs = [src],
-        outs = [export_file],
-        cmd = "cp $< $@",
-    )
-
-def _export_file_path(src):
-    [prefix, base_name] = src.split(":") # src must contain one colon
-    name_arr = base_name.split(".")
-    [name, ext] = [base_name, ""] if len(name_arr) == 1 else ["".join(name_arr[:-1]), name_arr[-1]]
-    export_file_ext = "bytes" if ext == "tflite" else "txt"
-
-    return "{}.{}".format(name, export_file_ext)
+def _normalize_exts_impl(ctx):
+    output_files = []
+
+    for src in ctx.files.srcs:
+        if src.extension in ctx.attr.bytes_exts:
+            dest = ctx.actions.declare_file(src.path[:-1 * len(src.extension)] + "bytes")
+            ctx.actions.run_shell(
+              inputs = [src],
+              outputs = [dest],
+              arguments = [src.path, dest.path],
+              command = "test $1 != $2 && cp $1 $2",
+              progress_message = "Copying %s to %s...".format(src.path, dest.path),
+            )
+            output_files.append(dest)
+        else:
+            output_files.append(src)
+
+    return [
+      DefaultInfo(files = depset(output_files)),
+    ]
+
+_normalize_exts = rule(
+    implementation = _normalize_exts_impl,
+    attrs = {
+        "srcs": attr.label_list(allow_files = True),
+        "bytes_exts": attr.string_list(default = ["jpg", "tflite", "uuu"]),
+    },
+)