// Copyright 2015 The Cobalt Authors. All Rights Reserved.
//
// 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 <memory>
#include <string>

#include "base/optional.h"
#include "base/run_loop.h"
#include "cobalt/loader/fetcher_factory.h"
#include "cobalt/loader/file_fetcher.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace cobalt {
namespace loader {
namespace {

class StubFetcherHandler : public Fetcher::Handler {
 public:
  explicit StubFetcherHandler(base::RunLoop* run_loop) : run_loop_(run_loop) {}

  // From Fetcher::Handler.
  void OnReceived(Fetcher* fetcher, const char* data, size_t size) override {
    CheckSameFetcher(fetcher);
  }
  void OnDone(Fetcher* fetcher) override {
    CheckSameFetcher(fetcher);
    base::MessageLoop::current()->task_runner()->PostTask(
        FROM_HERE, run_loop_->QuitClosure());
  }
  void OnError(Fetcher* fetcher, const std::string& error_message) override {
    CheckSameFetcher(fetcher);
    error_message_ = error_message;
    base::MessageLoop::current()->task_runner()->PostTask(
        FROM_HERE, run_loop_->QuitClosure());
  }

  Fetcher* fetcher() const { return fetcher_; }

  const base::Optional<std::string>& error_message() const {
    return error_message_;
  }

 private:
  void CheckSameFetcher(Fetcher* fetcher) {
    EXPECT_TRUE(fetcher);
    if (fetcher_ == nullptr) {
      fetcher_ = fetcher;
      return;
    }
    EXPECT_EQ(fetcher_, fetcher);
  }

  base::RunLoop* run_loop_;
  Fetcher* fetcher_ = nullptr;
  base::Optional<std::string> error_message_;
};

}  // namespace

class FetcherFactoryTest : public ::testing::Test {
 protected:
  FetcherFactoryTest() : message_loop_(base::MessageLoop::TYPE_DEFAULT) {}
  ~FetcherFactoryTest() override {}

  base::MessageLoop message_loop_;
  FetcherFactory fetcher_factory_;
  std::unique_ptr<Fetcher> fetcher_;
};

TEST_F(FetcherFactoryTest, InvalidURL) {
  base::RunLoop run_loop;
  StubFetcherHandler stub_fetcher_handler(&run_loop);

  fetcher_ = fetcher_factory_.CreateFetcher(
      GURL("invalid-url"), disk_cache::kOther, &stub_fetcher_handler);
  EXPECT_TRUE(fetcher_);

  run_loop.Run();
  EXPECT_EQ(fetcher_.get(), stub_fetcher_handler.fetcher());
  EXPECT_TRUE(stub_fetcher_handler.error_message().has_value());
}

TEST_F(FetcherFactoryTest, EmptyFileURL) {
  base::RunLoop run_loop;
  StubFetcherHandler stub_fetcher_handler(&run_loop);

  fetcher_ = fetcher_factory_.CreateFetcher(
      GURL("file:///"), disk_cache::kOther, &stub_fetcher_handler);
  EXPECT_TRUE(fetcher_);

  run_loop.Run();
  EXPECT_EQ(fetcher_.get(), stub_fetcher_handler.fetcher());
  EXPECT_TRUE(stub_fetcher_handler.error_message().has_value());
}

TEST_F(FetcherFactoryTest, FileURLCannotConvertToFilePath) {
  base::RunLoop run_loop;
  StubFetcherHandler stub_fetcher_handler(&run_loop);

  fetcher_ = fetcher_factory_.CreateFetcher(
      GURL("file://file.txt"), disk_cache::kOther, &stub_fetcher_handler);
  EXPECT_TRUE(fetcher_);

  run_loop.Run();
  EXPECT_EQ(fetcher_.get(), stub_fetcher_handler.fetcher());
  EXPECT_TRUE(stub_fetcher_handler.error_message().has_value());
}

TEST_F(FetcherFactoryTest, MultipleCreations) {
  // Having a RunLoop ensures that any callback created by
  // FileFetcher will be able to run. We then quit the message loop in the
  // StubFetcherHandler when either OnDone() or OnError() has occurred.
  base::RunLoop run_loop;
  StubFetcherHandler stub_fetcher_handler(&run_loop);

  fetcher_ =
      fetcher_factory_.CreateFetcher(GURL("file:///nonempty-url-1"),
                                     disk_cache::kOther, &stub_fetcher_handler);
  EXPECT_TRUE(fetcher_);

  fetcher_ =
      fetcher_factory_.CreateFetcher(GURL("file:///nonempty-url-2"),
                                     disk_cache::kOther, &stub_fetcher_handler);
  EXPECT_TRUE(fetcher_);
  run_loop.Run();
  EXPECT_EQ(fetcher_.get(), stub_fetcher_handler.fetcher());
}

}  // namespace loader
}  // namespace cobalt