// Copyright 2018 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 <lib/zx/port.h>
#include <lib/zx/vmar.h>

#include "garnet/lib/debugger_utils/jobs.h"
#include "garnet/lib/debugger_utils/sysinfo.h"
#include "garnet/lib/debugger_utils/util.h"

#include "gtest/gtest.h"

namespace debugger_utils {
namespace {

TEST(JobsTest, SkipTopJob) {
  auto job = GetDefaultJob();
  auto jid = GetKoid(job.get());

  JobTreeJobCallback job_callback = [&](zx::job* job, zx_koid_t koid,
                                        zx_koid_t parent_koid,
                                        int depth) -> zx_status_t {
    if (koid == jid) {
      return ZX_ERR_STOP;
    }
    return ZX_OK;
  };
  EXPECT_EQ(WalkJobTree(job, &job_callback, nullptr, nullptr), ZX_OK);
  EXPECT_TRUE(job.is_valid());
}

TEST(JobsTest, ThisProcessAndStop) {
  auto job = GetDefaultJob();
  auto pid = GetKoid(zx_process_self());

  JobTreeProcessCallback process_callback =
      [&](zx::process* process, zx_koid_t koid, zx_koid_t parent_koid,
          int depth) -> zx_status_t {
    if (koid == pid) {
      return ZX_ERR_STOP;
    }
    return ZX_OK;
  };
  EXPECT_EQ(WalkJobTree(job, nullptr, &process_callback, nullptr),
            ZX_ERR_STOP);
}

TEST(JobsTest, ThisThreadAndStop) {
  auto job = GetDefaultJob();
  auto tid = GetKoid(zx_thread_self());

  JobTreeThreadCallback thread_callback =
      [&](zx::thread* thread, zx_koid_t koid, zx_koid_t parent_koid,
          int depth) -> zx_status_t {
    if (koid == tid) {
      return ZX_ERR_STOP;
    }
    return ZX_OK;
  };
  EXPECT_EQ(WalkJobTree(job, nullptr, nullptr, &thread_callback), ZX_ERR_STOP);
}

static zx_status_t GetHandleInfo(zx_handle_t handle,
                                 zx_info_handle_basic_t* info) {
  return zx_object_get_info(handle, ZX_INFO_HANDLE_BASIC, info, sizeof(*info),
                            nullptr, nullptr);
}

static void TestKoids(zx_handle_t task, zx_koid_t koid, zx_koid_t parent_koid) {
  zx_info_handle_basic_t info;
  ASSERT_EQ(GetHandleInfo(task, &info), ZX_OK);
  EXPECT_EQ(koid, info.koid);
  EXPECT_EQ(parent_koid, info.related_koid);
}

static void TestDepth(const zx::job& search_job, zx_handle_t target_job,
                      zx_handle_t target_process, zx_handle_t target_thread) {
  auto jid = GetKoid(target_job);
  auto pid = GetKoid(target_process);
  auto tid = GetKoid(target_thread);

  // |WalkJobTree()| doesn't search the job it's passed.
  int job_depth;
  if (GetKoid(search_job.get()) == jid) {
    job_depth = 0;
  } else {
    job_depth = -1;
  }
  int process_depth = -1;
  int thread_depth = -1;

  JobTreeJobCallback job_callback =
    [&](zx::job* task, zx_koid_t koid, zx_koid_t parent_koid,
        int depth) -> zx_status_t {
    TestKoids(task->get(), koid, parent_koid);
    EXPECT_GE(depth, 0);
    if (koid == jid) {
      job_depth = depth;
    }
    return ZX_OK;
  };
  JobTreeProcessCallback process_callback =
      [&](zx::process* task, zx_koid_t koid, zx_koid_t parent_koid,
          int depth) -> zx_status_t {
    TestKoids(task->get(), koid, parent_koid);
    EXPECT_GT(depth, 0);
    if (koid == pid) {
      process_depth = depth;
    }
    return ZX_OK;
  };
  JobTreeThreadCallback thread_callback =
    [&](zx::thread* task, zx_koid_t koid, zx_koid_t parent_koid,
        int depth) -> zx_status_t {
    TestKoids(task->get(), koid, parent_koid);
    EXPECT_GT(depth, 1);
    if (koid == tid) {
      thread_depth = depth;
    }
    return ZX_OK;
  };

  EXPECT_EQ(WalkJobTree(search_job, &job_callback, &process_callback,
                        &thread_callback),
            ZX_OK);
  EXPECT_EQ(job_depth + 1, process_depth);
  EXPECT_EQ(process_depth + 1, thread_depth);
}

static void BuildTestProcess(const zx::job& parent_job, zx::job* job,
                             zx::process* process, zx::vmar* vmar,
                             zx::thread* thread) {
  ASSERT_EQ(zx::job::create(parent_job, 0, job), ZX_OK);
  const char process_name[] = "child-job-test-process";
  ASSERT_EQ(zx::process::create(*job, process_name,
                                sizeof(process_name) - 1, 0u, process, vmar),
                                ZX_OK);
  const char thread_name[] = "child-job-test-thread";
  ASSERT_EQ(zx::thread::create(*process, thread_name, sizeof(thread_name) - 1,
                               0u, thread), ZX_OK);
  zx::port port;
  ASSERT_EQ(zx::port::create(0u, &port), ZX_OK);
  ASSERT_EQ(zx_task_bind_exception_port(process->get(), port.get(), 0u, 0u),
            ZX_OK);
  // Threads aren't added to the list of the process's children until they're
  // started. Work around this. The thread will crash, but we don't care about
  // that, we just need the thread to be a child of the process. The process
  // hasn't been started yet, so we need to start the thread as the initial
  // thread of the process.
  // N.B. It is up to the caller to kill the process to ensure the exception
  // from the crash doesn't propagate to the system crash handler.
  ASSERT_EQ(process->start(*thread, 0u, 0u, zx::handle{port.release()}, 0u),
            ZX_OK);
}

TEST(JobsTest, ChildJob) {
  auto search_job = GetDefaultJob();
  zx::job job;
  zx::process process;
  zx::vmar vmar;
  zx::thread thread;

  BuildTestProcess(search_job, &job, &process, &vmar, &thread);
  TestDepth(search_job, job.get(), process.get(), thread.get());

  // Make sure the process is killed before the port (which the process owns)
  // is closed so that the exception from crashing isn't propagated.
  EXPECT_EQ(process.kill(), ZX_OK);
}

TEST(JobsTest, RootJob) {
  // Make sure we can find ourselves from the root job.
  // This will likely evolve or be replaced, but it's useful to test
  // current functionality.
  auto search_job = GetRootJob();
  zx::job job;
  zx::process process;
  zx::vmar vmar;
  zx::thread thread;

  BuildTestProcess(search_job, &job, &process, &vmar, &thread);
  TestDepth(search_job, job.get(), process.get(), thread.get());
}

TEST(JobsTest, FindProcess) {
  auto job = GetDefaultJob();
  auto pid = GetKoid(zx_process_self());
  auto process = FindProcess(job.get(), pid);
  zx_info_handle_basic_t info;
  ASSERT_EQ(GetHandleInfo(process.get(), &info), ZX_OK);
  EXPECT_EQ(info.koid, pid);
}

TEST(JobsTest, TakeChildJobOwnership) {
  auto top_job = GetDefaultJob();
  zx::job parent_job;
  ASSERT_EQ(zx::job::create(top_job, 0, &parent_job), ZX_OK);
  zx::job child_job;
  ASSERT_EQ(zx::job::create(parent_job, 0, &child_job), ZX_OK);
  auto child_job_koid = GetKoid(child_job.get());
  zx::job my_job;

  JobTreeJobCallback job_callback = [&](zx::job* job, zx_koid_t koid,
                                        zx_koid_t parent_koid,
                                        int depth) -> zx_status_t {
    if (koid == child_job_koid) {
      EXPECT_EQ(depth, 2);
      my_job = std::move(*job);
      return ZX_ERR_STOP;
    }
    return ZX_OK;
  };
  EXPECT_EQ(WalkJobTree(top_job, &job_callback, nullptr, nullptr),
            ZX_ERR_STOP);
  EXPECT_TRUE(top_job.is_valid());
  EXPECT_TRUE(my_job.is_valid());
  EXPECT_EQ(GetKoid(my_job.get()), child_job_koid);
}

}  // namespace
}  // namespace debugger_utils