Add an AndroidBuild implementation for cvd fetch-ed builds

Bug: b/471835731

Author: Databean

base/cvd/cuttlefish/host/commands/assemble_cvd/android_build/BUILD.bazel

@@ -29,6 +29,25 @@ cf_cc_library(
     ],
 )
 
+cf_cc_library(
+    name = "fetched_android_build",
+    srcs = ["fetched_android_build.cc"],
+    hdrs = ["fetched_android_build.h"],
+    deps = [
+        "//cuttlefish/common/libs/key_equals_value",
+        "//cuttlefish/host/commands/assemble_cvd/android_build",
+        "//cuttlefish/host/commands/assemble_cvd/android_build:combined_android_build",
+        "//cuttlefish/host/commands/assemble_cvd/android_build:img_zip",
+        "//cuttlefish/host/commands/assemble_cvd/android_build:target_files",
+        "//cuttlefish/host/libs/config:fetcher_config",
+        "//cuttlefish/host/libs/config:file_source",
+        "//cuttlefish/result",
+        "//libbase",
+        "@abseil-cpp//absl/strings:str_format",
+        "@fmt",
+    ],
+)
+
 cf_cc_library(
     name = "find_build_archive",
     srcs = ["find_build_archive.cc"],

base/cvd/cuttlefish/host/commands/assemble_cvd/android_build/fetched_android_build.cc

@@ -0,0 +1,53 @@
+//
+// Copyright (C) 2025 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "cuttlefish/host/commands/assemble_cvd/android_build/fetched_android_build.h"
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "cuttlefish/host/commands/assemble_cvd/android_build/android_build.h"
+#include "cuttlefish/host/commands/assemble_cvd/android_build/combined_android_build.h"
+#include "cuttlefish/host/commands/assemble_cvd/android_build/img_zip.h"
+#include "cuttlefish/host/commands/assemble_cvd/android_build/target_files.h"
+#include "cuttlefish/host/libs/config/fetcher_config.h"
+#include "cuttlefish/host/libs/config/file_source.h"
+#include "cuttlefish/result/result.h"
+
+namespace cuttlefish {
+
+Result<std::unique_ptr<AndroidBuild>> FetchedAndroidBuild(
+    const FetcherConfig& config, FileSource source) {
+  Result<std::unique_ptr<AndroidBuild>> img_zip = ImgZip(config, source);
+  Result<std::unique_ptr<AndroidBuild>> target = TargetFiles(config, source);
+
+  if (!img_zip.ok() && !target.ok()) {
+    CF_EXPECT(std::move(img_zip));
+    return CF_ERR("unreachable");
+  }
+
+  std::vector<std::unique_ptr<AndroidBuild>> builds;
+  if (img_zip.ok()) {
+    builds.emplace_back(std::move(*img_zip));
+  }
+  if (target.ok()) {
+    builds.emplace_back(std::move(*target));
+  }
+  return CF_EXPECT(
+      CombinedAndroidBuild("FetchedAndroidBuild", std::move(builds)));
+}
+
+}  // namespace cuttlefish

base/cvd/cuttlefish/host/commands/assemble_cvd/android_build/fetched_android_build.h

@@ -0,0 +1,31 @@
+//
+// Copyright (C) 2025 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <memory>
+
+#include "cuttlefish/host/commands/assemble_cvd/android_build/android_build.h"
+#include "cuttlefish/host/libs/config/fetcher_config.h"
+#include "cuttlefish/host/libs/config/file_source.h"
+#include "cuttlefish/result/result.h"
+
+namespace cuttlefish {
+
+/** Represents a build downloaded by `cvd fetch`.  */
+Result<std::unique_ptr<AndroidBuild>> FetchedAndroidBuild(const FetcherConfig&,
+                                                          FileSource);
+
+}  // namespace cuttlefish