// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "filesystem-mounter.h"

#include <fidl/fuchsia.io/cpp/wire_test_base.h>
#include <fidl/fuchsia.io/cpp/wire_types.h>
#include <lib/async-loop/cpp/loop.h>
#include <lib/fidl/llcpp/server.h>
#include <lib/sync/completion.h>
#include <lib/zx/channel.h>
#include <zircon/fidl.h>
#include <zircon/time.h>

#include <mutex>

#include <cobalt-client/cpp/in_memory_logger.h>
#include <gtest/gtest.h>

#include "src/lib/testing/predicates/status.h"
#include "src/storage/blobfs/mount.h"
#include "src/storage/fshost/block-watcher.h"
#include "src/storage/fshost/config.h"
#include "src/storage/fshost/constants.h"
#include "src/storage/fshost/fs-manager.h"
#include "src/storage/fshost/fshost-fs-provider.h"
#include "src/storage/fshost/metrics_cobalt.h"

namespace fshost {
namespace {

std::unique_ptr<FsHostMetrics> MakeMetrics() {
  return std::make_unique<FsHostMetricsCobalt>(std::make_unique<cobalt_client::Collector>(
      std::make_unique<cobalt_client::InMemoryLogger>()));
}

class FilesystemMounterHarness : public testing::Test {
 public:
  FilesystemMounterHarness()
      : config_(DefaultConfig()), manager_(FshostBootArgs::Create(), MakeMetrics()) {}

 protected:
  FsManager& manager() {
    if (!watcher_) {
      watcher_.emplace(manager_, &config_);
      EXPECT_OK(manager_.Initialize({}, {}, config_, *watcher_));
      manager_.ReadyForShutdown();
    }
    return manager_;
  }

  fshost_config::Config config_;

 private:
  FsManager manager_;
  std::optional<BlockWatcher> watcher_;
};

using MounterTest = FilesystemMounterHarness;

TEST_F(MounterTest, CreateFilesystemManager) { manager(); }

TEST_F(MounterTest, CreateFilesystemMounter) { FilesystemMounter mounter(manager(), &config_); }

enum class FilesystemType {
  kBlobfs,
  kMinfs,
  kFactoryfs,
};

class TestMounter : public FilesystemMounter {
 public:
  class FakeDirectoryImpl : public fidl::testing::WireTestBase<fuchsia_io::Directory> {
   public:
    void NotImplemented_(const std::string& name, fidl::CompleterBase& completer) override {
      ADD_FAILURE() << "Unexpected call to " << name;
      completer.Close(ZX_ERR_NOT_SUPPORTED);
    }

    void Describe(DescribeRequestView request, DescribeCompleter::Sync& completer) override {
      completer.Reply(
          fuchsia_io::wire::NodeInfo::WithDirectory(fuchsia_io::wire::DirectoryObject()));
    }

    void Open(OpenRequestView request, OpenCompleter::Sync& _completer) override {}
  };

  template <typename... Args>
  explicit TestMounter(Args&&... args)
      : FilesystemMounter(std::forward<Args>(args)...),
        loop_(&kAsyncLoopConfigNoAttachToCurrentThread) {
    loop_.StartThread("filesystem-mounter-test");
  }

  void ExpectFilesystem(FilesystemType fs) { expected_filesystem_ = fs; }

  zx::status<> LaunchFsComponent(zx::channel block_device,
                                 fuchsia_fs_startup::wire::StartOptions options,
                                 const std::string& fs_name) final {
    switch (expected_filesystem_) {
      case FilesystemType::kBlobfs:
        EXPECT_EQ(fs_name, "blobfs");
        break;
      default:
        ADD_FAILURE() << "Unexpected filesystem type";
    }

    return zx::ok();
  }

  zx_status_t LaunchFs(int argc, const char** argv, zx_handle_t* hnd, uint32_t* ids, size_t len,
                       uint32_t fs_flags) final {
    if (argc != 2) {
      return ZX_ERR_INVALID_ARGS;
    }

    switch (expected_filesystem_) {
      case FilesystemType::kMinfs:
        EXPECT_EQ(std::string_view(argv[0]), kMinfsPath);
        EXPECT_EQ(fs_flags, unsigned{FS_SVC});
        EXPECT_EQ(len, 2ul);
        break;
      case FilesystemType::kFactoryfs:
        EXPECT_EQ(std::string_view(argv[0]), kFactoryfsPath);
        EXPECT_EQ(fs_flags, unsigned{FS_SVC});
        break;
      default:
        ADD_FAILURE() << "Unexpected filesystem type";
    }

    EXPECT_EQ(std::string_view(argv[1]), "mount");

    EXPECT_EQ(ids[0], PA_DIRECTORY_REQUEST);
    EXPECT_EQ(ids[1], FS_HANDLE_BLOCK_DEVICE_ID);

    fidl::BindServer(loop_.dispatcher(),
                     fidl::ServerEnd<fuchsia_io::Directory>(zx::channel(hnd[0])),
                     std::make_unique<FakeDirectoryImpl>());

    // Close all other handles.
    for (size_t i = 1; i < len; i++) {
      EXPECT_OK(zx_handle_close(hnd[i]));
    }

    return ZX_OK;
  }

 private:
  FilesystemType expected_filesystem_ = FilesystemType::kBlobfs;
  std::mutex flags_lock_;
  async::Loop loop_;
};

TEST_F(MounterTest, DurableMount) {
  config_.durable() = true;
  TestMounter mounter(manager(), &config_);

  mounter.ExpectFilesystem(FilesystemType::kMinfs);
  ASSERT_OK(mounter.MountDurable(zx::channel(), fs_management::MountOptions()));
  ASSERT_TRUE(mounter.DurableMounted());
}

TEST_F(MounterTest, FactoryMount) {
  config_.factory() = true;
  TestMounter mounter(manager(), &config_);

  mounter.ExpectFilesystem(FilesystemType::kFactoryfs);
  ASSERT_OK(mounter.MountFactoryFs(zx::channel(), fs_management::MountOptions()));

  ASSERT_TRUE(mounter.FactoryMounted());
}

}  // namespace
}  // namespace fshost