////////////////////////////////////////////////////////////////////////////////
/// @brief test case for FailedServer job
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2017 ArangoDB GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Kaveh Vahedipour
/// @author Copyright 2017, ArangoDB GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "gtest/gtest.h"

#include "fakeit.hpp"

#include "Agency/AddFollower.h"
#include "Agency/AgentInterface.h"
#include "Agency/FailedServer.h"
#include "Agency/MoveShard.h"
#include "Agency/Node.h"
#include "lib/Basics/StringUtils.h"

#include <velocypack/Parser.h>
#include <velocypack/Slice.h>
#include <velocypack/velocypack-aliases.h>
#include <iostream>

using namespace arangodb;
using namespace arangodb::basics;
using namespace arangodb::consensus;
using namespace fakeit;

namespace arangodb {
namespace tests {
namespace failed_server_test {

const std::string PREFIX = "/arango";
const std::string DATABASE = "database";
const std::string COLLECTION = "collection";
const std::string SHARD = "shard";
const std::string SHARD_LEADER = "leader";
const std::string SHARD_FOLLOWER1 = "follower1";
const std::string SHARD_FOLLOWER2 = "follower2";
const std::string FREE_SERVER = "free";
const std::string FREE_SERVER2 = "free2";

bool aborts = false;

typedef std::function<std::unique_ptr<Builder>(Slice const&, std::string const&)> TestStructureType;

const char* agency =
#include "FailedServerTest.json"
    ;

Node createNodeFromBuilder(VPackBuilder const& builder) {
  VPackBuilder opBuilder;
  {
    VPackObjectBuilder a(&opBuilder);
    opBuilder.add("new", builder.slice());
  }

  Node node("");
  node.handle<SET>(opBuilder.slice());
  return node;
}

Builder createBuilder(char const* c) {
  VPackOptions options;
  options.checkAttributeUniqueness = true;
  VPackParser parser(&options);
  parser.parse(c);

  VPackBuilder builder;
  builder.add(parser.steal()->slice());
  return builder;
}

Node createNode(char const* c) {
  return createNodeFromBuilder(createBuilder(c));
}

Node createRootNode() { return createNode(agency); }

inline std::string typeName(Slice const& slice) {
  return std::string(slice.typeName());
}

class FailedServerTest : public ::testing::Test {
 protected:
  std::string const jobId = "1";
  std::shared_ptr<Builder> transBuilder;
  Node agency;
  write_ret_t fakeWriteResult;
  trans_ret_t fakeTransResult;

  FailedServerTest()
      : jobId("1"),
        transBuilder(std::make_shared<Builder>()),
        agency(createRootNode()),
        fakeWriteResult(true, "", std::vector<apply_ret_t>{APPLIED},
                        std::vector<index_t>{1}),
        fakeTransResult(true, "", 1, 0, transBuilder) {
    VPackArrayBuilder a(transBuilder.get());
    transBuilder->add(VPackValue((uint64_t)1));
  }
};

TEST_F(FailedServerTest, creating_a_job_should_create_a_job_in_todo) {
  Mock<AgentInterface> mockAgent;

  std::string jobId = "1";
  When(Method(mockAgent, write)).AlwaysDo([&](query_t const& q, consensus::AgentInterface::WriteMode w) -> write_ret_t {
    auto expectedJobKey = PREFIX + toDoPrefix + jobId;
    EXPECT_TRUE(typeName(q->slice()) == "array");
    EXPECT_TRUE(q->slice().length() == 1);
    EXPECT_TRUE(typeName(q->slice()[0]) == "array");
    EXPECT_TRUE(q->slice()[0].length() == 2);
    EXPECT_TRUE(typeName(q->slice()[0][0]) == "object");
    EXPECT_TRUE(q->slice()[0][0].length() == 2);
    EXPECT_TRUE(typeName(q->slice()[0][0].get(expectedJobKey)) == "object");

    auto job = q->slice()[0][0].get(expectedJobKey);
    EXPECT_TRUE(typeName(job.get("creator")) == "string");
    EXPECT_TRUE(typeName(job.get("type")) == "string");
    EXPECT_TRUE(job.get("type").copyString() == "failedServer");
    EXPECT_TRUE(typeName(job.get("server")) == "string");
    EXPECT_TRUE(job.get("server").copyString() == SHARD_LEADER);
    EXPECT_TRUE(typeName(job.get("jobId")) == "string");
    EXPECT_TRUE(typeName(job.get("timeCreated")) == "string");

    return fakeWriteResult;
  });
  When(Method(mockAgent, waitFor)).AlwaysReturn(AgentInterface::raft_commit_t::OK);
  auto& agent = mockAgent.get();
  auto builder = agency.toBuilder();
  FailedServer(agency(PREFIX), &agent, jobId, "unittest", SHARD_LEADER).create();
  Verify(Method(mockAgent, write));
}

TEST_F(FailedServerTest, the_state_is_still_bad_and_faileservers_is_still_in_snapshot_violate_good) {
  TestStructureType createTestStructure = [&](Slice const& s, std::string const& path) {
    std::unique_ptr<Builder> builder;
    if (path == "/arango/Plan/Collections/" + DATABASE + "/" + COLLECTION) {
      return builder;
    }
    builder = std::make_unique<Builder>();

    if (s.isObject()) {
      VPackObjectBuilder b(builder.get());
      for (auto const& it : VPackObjectIterator(s)) {
        auto childBuilder =
            createTestStructure(it.value, path + "/" + it.key.copyString());
        if (childBuilder) {
          builder->add(it.key.copyString(), childBuilder->slice());
        }
      }
      if (path == "/arango/Supervision/Health/leader") {
        builder->add("Status", VPackValue("GOOD"));
      }
    } else {
      builder->add(s);
    }

    return builder;
  };

  auto builder = createTestStructure(agency.toBuilder().slice(), "");
  ASSERT_TRUE(builder);
  Node agency = createNodeFromBuilder(*builder);

  Mock<AgentInterface> mockAgent;
  When(Method(mockAgent, write)).AlwaysDo([&](query_t const& q, consensus::AgentInterface::WriteMode w) -> write_ret_t {
    EXPECT_TRUE(typeName(q->slice()) == "array");
    EXPECT_TRUE(q->slice().length() == 1);
    EXPECT_TRUE(typeName(q->slice()[0]) == "array");
    // we always simply override! no preconditions...
    EXPECT_TRUE(q->slice()[0].length() == 2);
    EXPECT_TRUE(typeName(q->slice()[0][0]) == "object");
    EXPECT_TRUE(typeName(q->slice()[0][1]) == "object");

    auto writes = q->slice()[0][0];
    EXPECT_TRUE(typeName(writes.get("/arango/Target/ToDo/1")) == "object");
    EXPECT_TRUE(writes.get("/arango/Target/ToDo/1").get("server").copyString() == SHARD_LEADER);

    auto precond = q->slice()[0][1];
    EXPECT_TRUE(typeName(precond.get(
                    "/arango/Supervision/Health/leader/Status")) == "object");
    EXPECT_TRUE(
        precond.get("/arango/Supervision/Health/leader/Status").get("old").copyString() ==
        "BAD");
    EXPECT_TRUE(typeName(precond.get("/arango/Target/FailedServers").get("old")) ==
                "object");

    return fakeWriteResult;
  });

  When(Method(mockAgent, waitFor)).AlwaysReturn(AgentInterface::raft_commit_t::OK);
  auto& agent = mockAgent.get();
  FailedServer(agency(PREFIX), &agent, jobId, "unittest", SHARD_LEADER).create();

  Verify(Method(mockAgent, write));
}

TEST_F(FailedServerTest, the_state_is_still_bad_and_faileservers_is_still_in_snapshot_violate_failed) {
  TestStructureType createTestStructure = [&](Slice const& s, std::string const& path) {
    std::unique_ptr<Builder> builder;
    if (path == "/arango/Plan/Collections/" + DATABASE + "/" + COLLECTION) {
      return builder;
    }
    builder = std::make_unique<Builder>();

    if (s.isObject()) {
      VPackObjectBuilder b(builder.get());
      for (auto const& it : VPackObjectIterator(s)) {
        auto childBuilder =
            createTestStructure(it.value, path + "/" + it.key.copyString());
        if (childBuilder) {
          builder->add(it.key.copyString(), childBuilder->slice());
        }
      }
      if (path == "/arango/Supervision/Health/leader") {
        builder->add("Status", VPackValue("FAILED"));
      }
    } else {
      builder->add(s);
    }

    return builder;
  };

  auto builder = createTestStructure(agency.toBuilder().slice(), "");
  ASSERT_TRUE(builder);
  Node agency = createNodeFromBuilder(*builder);

  Mock<AgentInterface> mockAgent;
  When(Method(mockAgent, write)).AlwaysDo([&](query_t const& q, consensus::AgentInterface::WriteMode w) -> write_ret_t {
    EXPECT_TRUE(typeName(q->slice()) == "array");
    EXPECT_TRUE(q->slice().length() == 1);
    EXPECT_TRUE(typeName(q->slice()[0]) == "array");
    // we always simply override! no preconditions...
    EXPECT_TRUE(q->slice()[0].length() == 2);
    EXPECT_TRUE(typeName(q->slice()[0][0]) == "object");
    EXPECT_TRUE(typeName(q->slice()[0][1]) == "object");

    auto writes = q->slice()[0][0];
    EXPECT_TRUE(typeName(writes.get("/arango/Target/ToDo/1")) == "object");
    EXPECT_TRUE(writes.get("/arango/Target/ToDo/1").get("server").copyString() == SHARD_LEADER);

    auto precond = q->slice()[0][1];
    EXPECT_TRUE(typeName(precond.get(
                    "/arango/Supervision/Health/leader/Status")) == "object");
    EXPECT_TRUE(
        precond.get("/arango/Supervision/Health/leader/Status").get("old").copyString() ==
        "BAD");
    EXPECT_TRUE(typeName(precond.get("/arango/Target/FailedServers").get("old")) ==
                "object");

    return fakeWriteResult;
  });

  When(Method(mockAgent, waitFor)).AlwaysReturn(AgentInterface::raft_commit_t::OK);
  auto& agent = mockAgent.get();
  FailedServer(agency(PREFIX), &agent, jobId, "unittest", SHARD_LEADER).create();
}

TEST_F(FailedServerTest, the_state_is_still_bad_and_faileservers_is_still_in_snapshot) {
  TestStructureType createTestStructure = [&](Slice const& s, std::string const& path) {
    std::unique_ptr<Builder> builder;
    if (path == "/arango/Plan/Collections/" + DATABASE + "/" + COLLECTION) {
      return builder;
    }
    builder = std::make_unique<Builder>();

    if (s.isObject()) {
      VPackObjectBuilder b(builder.get());
      for (auto const& it : VPackObjectIterator(s)) {
        auto childBuilder =
            createTestStructure(it.value, path + "/" + it.key.copyString());
        if (childBuilder) {
          builder->add(it.key.copyString(), childBuilder->slice());
        }
      }
      if (path == "/arango/Target/ToDo") {
        char const* todo =
            R"=({"creator":"unittest","jobId":"1","server":"leader",
               "timeCreated":"2017-04-10T11:40:09Z","type":"failedServer"})=";
        builder->add(jobId, createBuilder(todo).slice());
      }
    } else {
      builder->add(s);
    }

    return builder;
  };

  auto builder = createTestStructure(agency.toBuilder().slice(), "");
  ASSERT_TRUE(builder);
  Node agency = createNodeFromBuilder(*builder);

  Mock<AgentInterface> mockAgent;
  When(Method(mockAgent, write)).AlwaysDo([&](query_t const& q, consensus::AgentInterface::WriteMode w) -> write_ret_t {
    EXPECT_TRUE(typeName(q->slice()) == "array");
    EXPECT_TRUE(q->slice().length() == 1);
    EXPECT_TRUE(typeName(q->slice()[0]) == "array");
    // we always simply override! no preconditions...
    EXPECT_TRUE(q->slice()[0].length() == 1);
    EXPECT_TRUE(typeName(q->slice()[0][0]) == "object");

    auto writes = q->slice()[0][0];
    EXPECT_TRUE(typeName(writes.get("/arango/Target/ToDo/1")) == "object");
    EXPECT_TRUE(typeName(writes.get("/arango/Target/ToDo/1").get("op")) ==
                "string");
    EXPECT_TRUE(writes.get("/arango/Target/ToDo/1").get("op").copyString() ==
                "delete");
    EXPECT_TRUE(typeName(writes.get("/arango/Target/Pending/1")) == "object");
    return fakeWriteResult;
  });

  When(Method(mockAgent, waitFor)).AlwaysReturn(AgentInterface::raft_commit_t::OK);
  auto& agent = mockAgent.get();
  FailedServer(agency("arango"), &agent, JOB_STATUS::TODO, jobId).start(aborts);

  Verify(Method(mockAgent, write));
}

TEST_F(FailedServerTest, the_state_is_still_bad_and_faileservers_is_still_in_snapshot_2) {
  TestStructureType createTestStructure = [&](Slice const& s, std::string const& path) {
    std::unique_ptr<Builder> builder;
    if (path == "/arango/Plan/Collections/" + DATABASE + "/" + COLLECTION) {
      return builder;
    }
    builder = std::make_unique<Builder>();

    if (s.isObject()) {
      VPackObjectBuilder b(builder.get());
      for (auto const& it : VPackObjectIterator(s)) {
        auto childBuilder =
            createTestStructure(it.value, path + "/" + it.key.copyString());
        if (childBuilder) {
          builder->add(it.key.copyString(), childBuilder->slice());
        }
      }
      if (path == "/arango/Target/ToDo") {
        char const* todo =
            R"=({"creator":"unittest","jobId":"1","server":"leader",
               "timeCreated":"2017-04-10T11:40:09Z","type":"failedServer"})=";
        builder->add(jobId, createBuilder(todo).slice());
      }
    } else {
      if (path == "/arango/Supervision/Health/leader/Status") {
        builder->add("/arango/Supervision/Health/leader/Status",
                     VPackValue("FAILED"));
      }
      builder->add(s);
    }

    return builder;
  };

  auto builder = createTestStructure(agency.toBuilder().slice(), "");
  ASSERT_TRUE(builder);
  Node agency = createNodeFromBuilder(*builder);

  Mock<AgentInterface> mockAgent;
  When(Method(mockAgent, write)).AlwaysDo([&](query_t const& q, consensus::AgentInterface::WriteMode w) -> write_ret_t {
    EXPECT_TRUE(typeName(q->slice()) == "array");
    EXPECT_TRUE(q->slice().length() == 1);
    EXPECT_TRUE(typeName(q->slice()[0]) == "array");
    // we always simply override! no preconditions...
    EXPECT_TRUE(q->slice()[0].length() == 1);
    EXPECT_TRUE(typeName(q->slice()[0][0]) == "object");

    auto writes = q->slice()[0][0];
    EXPECT_TRUE(typeName(writes.get("/arango/Target/ToDo/1")) == "object");
    EXPECT_TRUE(typeName(writes.get("/arango/Target/ToDo/1").get("op")) ==
                "string");
    EXPECT_TRUE(writes.get("/arango/Target/ToDo/1").get("op").copyString() ==
                "delete");
    EXPECT_TRUE(typeName(writes.get("/arango/Target/Pending/1")) == "object");
    return fakeWriteResult;
  });

  When(Method(mockAgent, waitFor)).AlwaysReturn(AgentInterface::raft_commit_t::OK);
  auto& agent = mockAgent.get();
  FailedServer(agency("arango"), &agent, JOB_STATUS::TODO, jobId).start(aborts);

  Verify(Method(mockAgent, write));
}

}  // namespace failed_server_test
}  // namespace tests
}  // namespace arangodb