// Copyright 2014 The Kyua Authors.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
//   notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors
//   may be used to endorse or promote products derived from this software
//   without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "engine/scheduler.hpp"

extern "C" {
#include <sys/types.h>

#include <signal.h>
#include <unistd.h>
}

#include <cstdlib>
#include <fstream>
#include <iostream>
#include <string>

#include <atf-c++.hpp>

#include "engine/config.hpp"
#include "engine/exceptions.hpp"
#include "model/context.hpp"
#include "model/metadata.hpp"
#include "model/test_case.hpp"
#include "model/test_program.hpp"
#include "model/test_result.hpp"
#include "utils/config/tree.ipp"
#include "utils/datetime.hpp"
#include "utils/defs.hpp"
#include "utils/env.hpp"
#include "utils/format/containers.ipp"
#include "utils/format/macros.hpp"
#include "utils/fs/operations.hpp"
#include "utils/fs/path.hpp"
#include "utils/optional.ipp"
#include "utils/passwd.hpp"
#include "utils/process/status.hpp"
#include "utils/sanity.hpp"
#include "utils/stacktrace.hpp"
#include "utils/stream.hpp"
#include "utils/test_utils.ipp"
#include "utils/text/exceptions.hpp"
#include "utils/text/operations.ipp"

namespace config = utils::config;
namespace datetime = utils::datetime;
namespace fs = utils::fs;
namespace passwd = utils::passwd;
namespace process = utils::process;
namespace scheduler = engine::scheduler;
namespace text = utils::text;

using utils::none;
using utils::optional;


namespace {


/// Checks if a string starts with a prefix.
///
/// \param str The string to be tested.
/// \param prefix The prefix to look for.
///
/// \return True if the string is prefixed as specified.
static bool
starts_with(const std::string& str, const std::string& prefix)
{
    return (str.length() >= prefix.length() &&
            str.substr(0, prefix.length()) == prefix);
}


/// Strips a prefix from a string and converts the rest to an integer.
///
/// \param str The string to be tested.
/// \param prefix The prefix to strip from the string.
///
/// \return The part of the string after the prefix converted to an integer.
static int
suffix_to_int(const std::string& str, const std::string& prefix)
{
    PRE(starts_with(str, prefix));
    try {
        return text::to_type< int >(str.substr(prefix.length()));
    } catch (const text::value_error& error) {
        std::cerr << F("Failed: %s\n") % error.what();
        std::abort();
    }
}


/// Mock interface definition for testing.
///
/// This scheduler interface does not execute external binaries.  It is designed
/// to simulate the scheduler of various programs with different exit statuses.
class mock_interface : public scheduler::interface {
    /// Executes the subprocess simulating an exec.
    ///
    /// This is just a simple wrapper over _exit(2) because we cannot use
    /// std::exit on exit from this mock interface.  The reason is that we do
    /// not want to invoke any destructors as otherwise we'd clear up the global
    /// scheduler state by mistake.  This wouldn't be a major problem if it
    /// wasn't because doing so deletes on-disk files and we want to leave them
    /// in place so that the parent process can test for them!
    ///
    /// \param exit_code Exit code.
    void
    do_exit(const int exit_code) const UTILS_NORETURN
    {
        std::cout.flush();
        std::cerr.flush();
        ::_exit(exit_code);
    }

    /// Executes a test case that creates various files and then fails.
    void
    exec_create_files_and_fail(void) const UTILS_NORETURN
    {
        std::cerr << "This should not be clobbered\n";
        atf::utils::create_file("first file", "");
        atf::utils::create_file("second-file", "");
        fs::mkdir_p(fs::path("dir1/dir2"), 0755);
        ::kill(::getpid(), SIGTERM);
        std::abort();
    }

    /// Executes a test case that deletes all files in the current directory.
    ///
    /// This is intended to validate that the test runs in an empty directory,
    /// separate from any control files that the scheduler may have created.
    void
    exec_delete_all(void) const UTILS_NORETURN
    {
        const int exit_code = ::system("rm *") == -1
            ? EXIT_FAILURE : EXIT_SUCCESS;

        // Recreate our own cookie.
        atf::utils::create_file("exec_test_was_called", "");

        do_exit(exit_code);
    }

    /// Executes a test case that returns a specific exit code.
    ///
    /// \param exit_code Exit status to terminate the program with.
    void
    exec_exit(const int exit_code) const UTILS_NORETURN
    {
        do_exit(exit_code);
    }

    /// Executes a test case that just fails.
    void
    exec_fail(void) const UTILS_NORETURN
    {
        std::cerr << "This should not be clobbered\n";
        ::kill(::getpid(), SIGTERM);
        std::abort();
    }

    /// Executes a test case that prints all input parameters to the functor.
    ///
    /// \param test_program The test program to execute.
    /// \param test_case_name Name of the test case to invoke, which must be a
    ///     number.
    /// \param vars User-provided variables to pass to the test program.
    void
    exec_print_params(const model::test_program& test_program,
                      const std::string& test_case_name,
                      const config::properties_map& vars) const
        UTILS_NORETURN
    {
        std::cout << F("Test program: %s\n") % test_program.relative_path();
        std::cout << F("Test case: %s\n") % test_case_name;
        for (config::properties_map::const_iterator iter = vars.begin();
             iter != vars.end(); ++iter) {
            std::cout << F("%s=%s\n") % (*iter).first % (*iter).second;
        }

        std::cerr << F("stderr: %s\n") % test_case_name;

        do_exit(EXIT_SUCCESS);
    }

public:
    /// Executes a test program's list operation.
    ///
    /// This method is intended to be called within a subprocess and is expected
    /// to terminate execution either by exec(2)ing the test program or by
    /// exiting with a failure.
    ///
    /// \param test_program The test program to execute.
    /// \param vars User-provided variables to pass to the test program.
    void
    exec_list(const model::test_program& test_program,
              const config::properties_map& vars)
        const UTILS_NORETURN
    {
        const std::string name = test_program.absolute_path().leaf_name();

        std::cerr << name;
        std::cerr.flush();
        if (name == "check_i_exist") {
            if (fs::exists(test_program.absolute_path())) {
                std::cout << "found\n";
                do_exit(EXIT_SUCCESS);
            } else {
                std::cout << "not_found\n";
                do_exit(EXIT_FAILURE);
            }
        } else if (name == "empty") {
            do_exit(EXIT_SUCCESS);
        } else if (name == "misbehave") {
            utils::abort_without_coredump();
        } else if (name == "timeout") {
            std::cout << "sleeping\n";
            std::cout.flush();
            ::sleep(100);
            utils::abort_without_coredump();
        } else if (name == "vars") {
            for (config::properties_map::const_iterator iter = vars.begin();
                 iter != vars.end(); ++iter) {
                std::cout << F("%s_%s\n") % (*iter).first % (*iter).second;
            }
            do_exit(15);
        } else {
            std::abort();
        }
    }

    /// Computes the test cases list of a test program.
    ///
    /// \param status The termination status of the subprocess used to execute
    ///     the exec_test() method or none if the test timed out.
    /// \param stdout_path Path to the file containing the stdout of the test.
    /// \param stderr_path Path to the file containing the stderr of the test.
    ///
    /// \return A list of test cases.
    model::test_cases_map
    parse_list(const optional< process::status >& status,
               const fs::path& stdout_path,
               const fs::path& stderr_path) const
    {
        const std::string name = utils::read_file(stderr_path);
        if (name == "check_i_exist") {
            ATF_REQUIRE(status.get().exited());
            ATF_REQUIRE_EQ(EXIT_SUCCESS, status.get().exitstatus());
        } else if (name == "empty") {
            ATF_REQUIRE(status.get().exited());
            ATF_REQUIRE_EQ(EXIT_SUCCESS, status.get().exitstatus());
        } else if (name == "misbehave") {
            throw std::runtime_error("misbehaved in parse_list");
        } else if (name == "timeout") {
            ATF_REQUIRE(!status);
        } else if (name == "vars") {
            ATF_REQUIRE(status.get().exited());
            ATF_REQUIRE_EQ(15, status.get().exitstatus());
        } else {
            ATF_FAIL("Invalid stderr contents; got " + name);
        }

        model::test_cases_map_builder test_cases_builder;

        std::ifstream input(stdout_path.c_str());
        ATF_REQUIRE(input);
        std::string line;
        while (std::getline(input, line).good()) {
            test_cases_builder.add(line);
        }

        return test_cases_builder.build();
    }

    /// Executes a test case of the test program.
    ///
    /// This method is intended to be called within a subprocess and is expected
    /// to terminate execution either by exec(2)ing the test program or by
    /// exiting with a failure.
    ///
    /// \param test_program The test program to execute.
    /// \param test_case_name Name of the test case to invoke.
    /// \param vars User-provided variables to pass to the test program.
    /// \param control_directory Directory where the interface may place control
    ///     files.
    void
    exec_test(const model::test_program& test_program,
              const std::string& test_case_name,
              const config::properties_map& vars,
              const fs::path& control_directory) const
    {
        const fs::path cookie = control_directory / "exec_test_was_called";
        std::ofstream control_file(cookie.c_str());
        if (!control_file) {
            std::cerr << "Failed to create " << cookie << '\n';
            std::abort();
        }
        control_file << test_case_name;
        control_file.close();

        if (test_case_name == "check_i_exist") {
            do_exit(fs::exists(test_program.absolute_path()) ? 0 : 1);
        } else if (starts_with(test_case_name, "cleanup_timeout")) {
            exec_exit(EXIT_SUCCESS);
        } else if (starts_with(test_case_name, "create_files_and_fail")) {
            exec_create_files_and_fail();
        } else if (test_case_name == "delete_all") {
            exec_delete_all();
        } else if (starts_with(test_case_name, "exit ")) {
            exec_exit(suffix_to_int(test_case_name, "exit "));
        } else if (starts_with(test_case_name, "fail")) {
            exec_fail();
        } else if (starts_with(test_case_name, "fail_body_fail_cleanup")) {
            exec_fail();
        } else if (starts_with(test_case_name, "fail_body_pass_cleanup")) {
            exec_fail();
        } else if (starts_with(test_case_name, "pass_body_fail_cleanup")) {
            exec_exit(EXIT_SUCCESS);
        } else if (starts_with(test_case_name, "print_params")) {
            exec_print_params(test_program, test_case_name, vars);
        } else if (starts_with(test_case_name, "skip_body_pass_cleanup")) {
            exec_exit(EXIT_SUCCESS);
        } else {
            std::cerr << "Unknown test case " << test_case_name << '\n';
            std::abort();
        }
    }

    /// Executes a test cleanup routine of the test program.
    ///
    /// This method is intended to be called within a subprocess and is expected
    /// to terminate execution either by exec(2)ing the test program or by
    /// exiting with a failure.
    ///
    /// \param test_case_name Name of the test case to invoke.
    void
    exec_cleanup(const model::test_program& /* test_program */,
                 const std::string& test_case_name,
                 const config::properties_map& /* vars */,
                 const fs::path& /* control_directory */) const
    {
        std::cout << "exec_cleanup was called\n";
        std::cout.flush();

        if (starts_with(test_case_name, "cleanup_timeout")) {
            ::sleep(100);
            std::abort();
        } else if (starts_with(test_case_name, "fail_body_fail_cleanup")) {
            exec_fail();
        } else if (starts_with(test_case_name, "fail_body_pass_cleanup")) {
            exec_exit(EXIT_SUCCESS);
        } else if (starts_with(test_case_name, "pass_body_fail_cleanup")) {
            exec_fail();
        } else if (starts_with(test_case_name, "skip_body_pass_cleanup")) {
            exec_exit(EXIT_SUCCESS);
        } else {
            std::cerr << "Should not have been called for a test without "
                "a cleanup routine" << '\n';
            std::abort();
        }
    }

    /// Computes the result of a test case based on its termination status.
    ///
    /// \param status The termination status of the subprocess used to execute
    ///     the exec_test() method or none if the test timed out.
    /// \param control_directory Path to the directory where the interface may
    ///     have placed control files.
    /// \param stdout_path Path to the file containing the stdout of the test.
    /// \param stderr_path Path to the file containing the stderr of the test.
    ///
    /// \return A test result.
    model::test_result
    compute_result(const optional< process::status >& status,
                   const fs::path& control_directory,
                   const fs::path& stdout_path,
                   const fs::path& stderr_path) const
    {
        // Do not use any ATF_* macros here.  Some of the tests below invoke
        // this code in a subprocess, and terminating such subprocess due to a
        // failed ATF_* macro yields mysterious failures that are incredibly
        // hard to debug.  (Case in point: the signal_handling test is racy by
        // nature, and the test run by exec_test() above may not have created
        // the cookie we expect below.  We don't want to "silently" exit if the
        // file is not there.)

        if (!status) {
            return model::test_result(model::test_result_broken,
                                      "Timed out");
        }

        if (status.get().exited()) {
            // Only sanity-check the work directory-related parameters in case
            // of a clean exit.  In all other cases, there is no guarantee that
            // these were ever created.
            const fs::path cookie = control_directory / "exec_test_was_called";
            if (!atf::utils::file_exists(cookie.str())) {
                return model::test_result(
                    model::test_result_broken,
                    "compute_result's control_directory does not seem to point "
                    "to the right location");
            }
            const std::string test_case_name = utils::read_file(cookie);

            if (!atf::utils::file_exists(stdout_path.str())) {
                return model::test_result(
                    model::test_result_broken,
                    "compute_result's stdout_path does not exist");
            }
            if (!atf::utils::file_exists(stderr_path.str())) {
                return model::test_result(
                    model::test_result_broken,
                    "compute_result's stderr_path does not exist");
            }

            if (test_case_name == "skip_body_pass_cleanup") {
                return model::test_result(
                    model::test_result_skipped,
                    F("Exit %s") % status.get().exitstatus());
            } else {
                return model::test_result(
                    model::test_result_passed,
                    F("Exit %s") % status.get().exitstatus());
            }
        } else {
            return model::test_result(
                model::test_result_failed,
                F("Signal %s") % status.get().termsig());
        }
    }
};


}  // anonymous namespace


/// Runs list_tests on the scheduler and returns the results.
///
/// \param test_name The name of the test supported by our exec_list function.
/// \param user_config Optional user settings for the test.
///
/// \return The loaded list of test cases.
static model::test_cases_map
check_integration_list(const char* test_name, const fs::path root,
                       const config::tree& user_config = engine::empty_config())
{
    const model::test_program program = model::test_program_builder(
        "mock", fs::path(test_name), root, "the-suite")
        .build();

    scheduler::scheduler_handle handle = scheduler::setup();
    const model::test_cases_map test_cases = handle.list_tests(&program,
                                                               user_config);
    handle.cleanup();

    return test_cases;
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__list_some);
ATF_TEST_CASE_BODY(integration__list_some)
{
    config::tree user_config = engine::empty_config();
    user_config.set_string("test_suites.the-suite.first", "test");
    user_config.set_string("test_suites.the-suite.second", "TEST");
    user_config.set_string("test_suites.abc.unused", "unused");

    const model::test_cases_map test_cases = check_integration_list(
        "vars", fs::path("."), user_config);

    const model::test_cases_map exp_test_cases = model::test_cases_map_builder()
        .add("first_test").add("second_TEST").build();
    ATF_REQUIRE_EQ(exp_test_cases, test_cases);
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__list_check_paths);
ATF_TEST_CASE_BODY(integration__list_check_paths)
{
    fs::mkdir_p(fs::path("dir1/dir2/dir3"), 0755);
    atf::utils::create_file("dir1/dir2/dir3/check_i_exist", "");

    const model::test_cases_map test_cases = check_integration_list(
        "dir2/dir3/check_i_exist", fs::path("dir1"));

    const model::test_cases_map exp_test_cases = model::test_cases_map_builder()
        .add("found").build();
    ATF_REQUIRE_EQ(exp_test_cases, test_cases);
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__list_timeout);
ATF_TEST_CASE_BODY(integration__list_timeout)
{
    scheduler::list_timeout = datetime::delta(1, 0);
    const model::test_cases_map test_cases = check_integration_list(
        "timeout", fs::path("."));

    const model::test_cases_map exp_test_cases = model::test_cases_map_builder()
        .add("sleeping").build();
    ATF_REQUIRE_EQ(exp_test_cases, test_cases);
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__list_fail);
ATF_TEST_CASE_BODY(integration__list_fail)
{
    const model::test_cases_map test_cases = check_integration_list(
        "misbehave", fs::path("."));

    ATF_REQUIRE_EQ(1, test_cases.size());
    const model::test_case& test_case = test_cases.begin()->second;
    ATF_REQUIRE_EQ("__test_cases_list__", test_case.name());
    ATF_REQUIRE(test_case.fake_result());
    ATF_REQUIRE_EQ(model::test_result(model::test_result_broken,
                                      "misbehaved in parse_list"),
                   test_case.fake_result().get());
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__list_empty);
ATF_TEST_CASE_BODY(integration__list_empty)
{
    const model::test_cases_map test_cases = check_integration_list(
        "empty", fs::path("."));

    ATF_REQUIRE_EQ(1, test_cases.size());
    const model::test_case& test_case = test_cases.begin()->second;
    ATF_REQUIRE_EQ("__test_cases_list__", test_case.name());
    ATF_REQUIRE(test_case.fake_result());
    ATF_REQUIRE_EQ(model::test_result(model::test_result_broken,
                                      "Empty test cases list"),
                   test_case.fake_result().get());
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__run_one);
ATF_TEST_CASE_BODY(integration__run_one)
{
    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case("exit 41").build_ptr();

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    const scheduler::exec_handle exec_handle = handle.spawn_test(
        program, "exit 41", user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());
    ATF_REQUIRE_EQ(exec_handle, result_handle->original_pid());
    ATF_REQUIRE_EQ(model::test_result(model::test_result_passed, "Exit 41"),
                   test_result_handle->test_result());
    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__run_many);
ATF_TEST_CASE_BODY(integration__run_many)
{
    static const std::size_t num_test_programs = 30;

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    // We mess around with the "current time" below, so make sure the tests do
    // not spuriously exceed their deadline by bumping it to a large number.
    const model::metadata infinite_timeout = model::metadata_builder()
        .set_timeout(datetime::delta(1000000L, 0)).build();

    std::size_t total_tests = 0;
    std::map< scheduler::exec_handle, model::test_program_ptr >
        exp_test_programs;
    std::map< scheduler::exec_handle, std::string > exp_test_case_names;
    std::map< scheduler::exec_handle, datetime::timestamp > exp_start_times;
    std::map< scheduler::exec_handle, int > exp_exit_statuses;
    for (std::size_t i = 0; i < num_test_programs; ++i) {
        const std::string test_case_0 = F("exit %s") % (i * 3 + 0);
        const std::string test_case_1 = F("exit %s") % (i * 3 + 1);
        const std::string test_case_2 = F("exit %s") % (i * 3 + 2);

        const model::test_program_ptr program = model::test_program_builder(
            "mock", fs::path(F("program-%s") % i),
            fs::current_path(), "the-suite")
            .set_metadata(infinite_timeout)
            .add_test_case(test_case_0)
            .add_test_case(test_case_1)
            .add_test_case(test_case_2)
            .build_ptr();

        const datetime::timestamp start_time = datetime::timestamp::from_values(
            2014, 12, 8, 9, 40, 0, i);

        scheduler::exec_handle exec_handle;

        datetime::set_mock_now(start_time);
        exec_handle = handle.spawn_test(program, test_case_0, user_config);
        exp_test_programs.insert(std::make_pair(exec_handle, program));
        exp_test_case_names.insert(std::make_pair(exec_handle, test_case_0));
        exp_start_times.insert(std::make_pair(exec_handle, start_time));
        exp_exit_statuses.insert(std::make_pair(exec_handle, i * 3));
        ++total_tests;

        datetime::set_mock_now(start_time);
        exec_handle = handle.spawn_test(program, test_case_1, user_config);
        exp_test_programs.insert(std::make_pair(exec_handle, program));
        exp_test_case_names.insert(std::make_pair(exec_handle, test_case_1));
        exp_start_times.insert(std::make_pair(exec_handle, start_time));
        exp_exit_statuses.insert(std::make_pair(exec_handle, i * 3 + 1));
        ++total_tests;

        datetime::set_mock_now(start_time);
        exec_handle = handle.spawn_test(program, test_case_2, user_config);
        exp_test_programs.insert(std::make_pair(exec_handle, program));
        exp_test_case_names.insert(std::make_pair(exec_handle, test_case_2));
        exp_start_times.insert(std::make_pair(exec_handle, start_time));
        exp_exit_statuses.insert(std::make_pair(exec_handle, i * 3 + 2));
        ++total_tests;
    }

    for (std::size_t i = 0; i < total_tests; ++i) {
        const datetime::timestamp end_time = datetime::timestamp::from_values(
            2014, 12, 8, 9, 50, 10, i);
        datetime::set_mock_now(end_time);
        scheduler::result_handle_ptr result_handle = handle.wait_any();
        const scheduler::test_result_handle* test_result_handle =
            dynamic_cast< const scheduler::test_result_handle* >(
                result_handle.get());

        const scheduler::exec_handle exec_handle =
            result_handle->original_pid();

        const model::test_program_ptr test_program = exp_test_programs.find(
            exec_handle)->second;
        const std::string& test_case_name = exp_test_case_names.find(
            exec_handle)->second;
        const datetime::timestamp& start_time = exp_start_times.find(
            exec_handle)->second;
        const int exit_status = exp_exit_statuses.find(exec_handle)->second;

        ATF_REQUIRE_EQ(model::test_result(model::test_result_passed,
                                          F("Exit %s") % exit_status),
                       test_result_handle->test_result());

        ATF_REQUIRE_EQ(test_program, test_result_handle->test_program());
        ATF_REQUIRE_EQ(test_case_name, test_result_handle->test_case_name());

        ATF_REQUIRE_EQ(start_time, result_handle->start_time());
        ATF_REQUIRE_EQ(end_time, result_handle->end_time());

        result_handle->cleanup();

        ATF_REQUIRE(!atf::utils::file_exists(
                        result_handle->stdout_file().str()));
        ATF_REQUIRE(!atf::utils::file_exists(
                        result_handle->stderr_file().str()));
        ATF_REQUIRE(!atf::utils::file_exists(
                        result_handle->work_directory().str()));

        result_handle.reset();
    }

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__run_check_paths);
ATF_TEST_CASE_BODY(integration__run_check_paths)
{
    fs::mkdir_p(fs::path("dir1/dir2/dir3"), 0755);
    atf::utils::create_file("dir1/dir2/dir3/program", "");

    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("dir2/dir3/program"), fs::path("dir1"), "the-suite")
        .add_test_case("check_i_exist").build_ptr();

    scheduler::scheduler_handle handle = scheduler::setup();

    (void)handle.spawn_test(program, "check_i_exist", engine::default_config());
    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());

    ATF_REQUIRE_EQ(model::test_result(model::test_result_passed, "Exit 0"),
                   test_result_handle->test_result());

    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__parameters_and_output);
ATF_TEST_CASE_BODY(integration__parameters_and_output)
{
    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case("print_params").build_ptr();

    config::tree user_config = engine::empty_config();
    user_config.set_string("test_suites.the-suite.one", "first variable");
    user_config.set_string("test_suites.the-suite.two", "second variable");

    scheduler::scheduler_handle handle = scheduler::setup();

    const scheduler::exec_handle exec_handle = handle.spawn_test(
        program, "print_params", user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());

    ATF_REQUIRE_EQ(exec_handle, result_handle->original_pid());
    ATF_REQUIRE_EQ(program, test_result_handle->test_program());
    ATF_REQUIRE_EQ("print_params", test_result_handle->test_case_name());
    ATF_REQUIRE_EQ(model::test_result(model::test_result_passed, "Exit 0"),
                   test_result_handle->test_result());

    const fs::path stdout_file = result_handle->stdout_file();
    ATF_REQUIRE(atf::utils::compare_file(
        stdout_file.str(),
        "Test program: the-program\n"
        "Test case: print_params\n"
        "one=first variable\n"
        "two=second variable\n"));
    const fs::path stderr_file = result_handle->stderr_file();
    ATF_REQUIRE(atf::utils::compare_file(
        stderr_file.str(), "stderr: print_params\n"));

    result_handle->cleanup();
    ATF_REQUIRE(!fs::exists(stdout_file));
    ATF_REQUIRE(!fs::exists(stderr_file));
    result_handle.reset();

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__fake_result);
ATF_TEST_CASE_BODY(integration__fake_result)
{
    const model::test_result fake_result(model::test_result_skipped,
                                         "Some fake details");

    model::test_cases_map test_cases;
    test_cases.insert(model::test_cases_map::value_type(
        "__fake__", model::test_case("__fake__", "ABC", fake_result)));

    const model::test_program_ptr program(new model::test_program(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite",
        model::metadata_builder().build(), test_cases));

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    (void)handle.spawn_test(program, "__fake__", user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());
    ATF_REQUIRE_EQ(fake_result, test_result_handle->test_result());
    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__cleanup__head_skips);
ATF_TEST_CASE_BODY(integration__cleanup__head_skips)
{
    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case("skip_me",
                       model::metadata_builder()
                       .add_required_config("variable-that-does-not-exist")
                       .set_has_cleanup(true)
                       .build())
        .build_ptr();

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    (void)handle.spawn_test(program, "skip_me", user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());
    ATF_REQUIRE_EQ(model::test_result(
                       model::test_result_skipped,
                       "Required configuration property "
                       "'variable-that-does-not-exist' not defined"),
                   test_result_handle->test_result());
    ATF_REQUIRE(!atf::utils::grep_file("exec_cleanup was called",
                                       result_handle->stdout_file().str()));
    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


/// Runs a test to verify the behavior of cleanup routines.
///
/// \param test_case The name of the test case to invoke.
/// \param exp_result The expected test result of the execution.
static void
do_cleanup_test(const char* test_case,
                const model::test_result& exp_result)
{
    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case(test_case)
        .set_metadata(model::metadata_builder().set_has_cleanup(true).build())
        .build_ptr();

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    (void)handle.spawn_test(program, test_case, user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());
    ATF_REQUIRE_EQ(exp_result, test_result_handle->test_result());
    ATF_REQUIRE(atf::utils::compare_file(
        result_handle->stdout_file().str(),
        "exec_cleanup was called\n"));
    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__cleanup__body_skips);
ATF_TEST_CASE_BODY(integration__cleanup__body_skips)
{
    do_cleanup_test(
        "skip_body_pass_cleanup",
        model::test_result(model::test_result_skipped, "Exit 0"));
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__cleanup__body_bad__cleanup_ok);
ATF_TEST_CASE_BODY(integration__cleanup__body_bad__cleanup_ok)
{
    do_cleanup_test(
        "fail_body_pass_cleanup",
        model::test_result(model::test_result_failed, "Signal 15"));
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__cleanup__body_ok__cleanup_bad);
ATF_TEST_CASE_BODY(integration__cleanup__body_ok__cleanup_bad)
{
    do_cleanup_test(
        "pass_body_fail_cleanup",
        model::test_result(model::test_result_broken, "Test case cleanup "
                           "did not terminate successfully"));
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__cleanup__body_bad__cleanup_bad);
ATF_TEST_CASE_BODY(integration__cleanup__body_bad__cleanup_bad)
{
    do_cleanup_test(
        "fail_body_fail_cleanup",
        model::test_result(model::test_result_failed, "Signal 15"));
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__cleanup__timeout);
ATF_TEST_CASE_BODY(integration__cleanup__timeout)
{
    scheduler::cleanup_timeout = datetime::delta(1, 0);
    do_cleanup_test(
        "cleanup_timeout",
        model::test_result(model::test_result_broken, "Test case cleanup "
                           "timed out"));
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__check_requirements);
ATF_TEST_CASE_BODY(integration__check_requirements)
{
    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case("exit 12")
        .set_metadata(model::metadata_builder()
                      .add_required_config("abcde").build())
        .build_ptr();

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    (void)handle.spawn_test(program, "exit 12", user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());
    ATF_REQUIRE_EQ(model::test_result(
                       model::test_result_skipped,
                       "Required configuration property 'abcde' not defined"),
                   test_result_handle->test_result());
    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__stacktrace);
ATF_TEST_CASE_BODY(integration__stacktrace)
{
    utils::prepare_coredump_test(this);

    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case("unknown-dumps-core").build_ptr();

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    (void)handle.spawn_test(program, "unknown-dumps-core", user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());
    ATF_REQUIRE_EQ(model::test_result(model::test_result_failed,
                                      F("Signal %s") % SIGABRT),
                   test_result_handle->test_result());
    ATF_REQUIRE(!atf::utils::grep_file("attempting to gather stack trace",
                                       result_handle->stdout_file().str()));
    ATF_REQUIRE( atf::utils::grep_file("attempting to gather stack trace",
                                       result_handle->stderr_file().str()));
    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


/// Runs a test to verify the dumping of the list of existing files on failure.
///
/// \param test_case The name of the test case to invoke.
/// \param exp_stderr Expected contents of stderr.
static void
do_check_list_files_on_failure(const char* test_case, const char* exp_stderr)
{
    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case(test_case).build_ptr();

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    (void)handle.spawn_test(program, test_case, user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    atf::utils::cat_file(result_handle->stdout_file().str(), "child stdout: ");
    ATF_REQUIRE(atf::utils::compare_file(result_handle->stdout_file().str(),
                                         ""));
    atf::utils::cat_file(result_handle->stderr_file().str(), "child stderr: ");
    ATF_REQUIRE(atf::utils::compare_file(result_handle->stderr_file().str(),
                                         exp_stderr));
    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__list_files_on_failure__none);
ATF_TEST_CASE_BODY(integration__list_files_on_failure__none)
{
    do_check_list_files_on_failure("fail", "This should not be clobbered\n");
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__list_files_on_failure__some);
ATF_TEST_CASE_BODY(integration__list_files_on_failure__some)
{
    do_check_list_files_on_failure(
        "create_files_and_fail",
        "This should not be clobbered\n"
        "Files left in work directory after failure: "
        "dir1, first file, second-file\n");
}


ATF_TEST_CASE_WITHOUT_HEAD(integration__prevent_clobbering_control_files);
ATF_TEST_CASE_BODY(integration__prevent_clobbering_control_files)
{
    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case("delete_all").build_ptr();

    const config::tree user_config = engine::empty_config();

    scheduler::scheduler_handle handle = scheduler::setup();

    (void)handle.spawn_test(program, "delete_all", user_config);

    scheduler::result_handle_ptr result_handle = handle.wait_any();
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());
    ATF_REQUIRE_EQ(model::test_result(model::test_result_passed, "Exit 0"),
                   test_result_handle->test_result());
    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();
}


ATF_TEST_CASE_WITHOUT_HEAD(debug_test);
ATF_TEST_CASE_BODY(debug_test)
{
    const model::test_program_ptr program = model::test_program_builder(
        "mock", fs::path("the-program"), fs::current_path(), "the-suite")
        .add_test_case("print_params").build_ptr();

    config::tree user_config = engine::empty_config();
    user_config.set_string("test_suites.the-suite.one", "first variable");
    user_config.set_string("test_suites.the-suite.two", "second variable");

    scheduler::scheduler_handle handle = scheduler::setup();

    const fs::path stdout_file("custom-stdout.txt");
    const fs::path stderr_file("custom-stderr.txt");

    scheduler::result_handle_ptr result_handle = handle.debug_test(
        program, "print_params", user_config, stdout_file, stderr_file);
    const scheduler::test_result_handle* test_result_handle =
        dynamic_cast< const scheduler::test_result_handle* >(
            result_handle.get());

    ATF_REQUIRE_EQ(program, test_result_handle->test_program());
    ATF_REQUIRE_EQ("print_params", test_result_handle->test_case_name());
    ATF_REQUIRE_EQ(model::test_result(model::test_result_passed, "Exit 0"),
                   test_result_handle->test_result());

    // The original output went to a file.  It's only an artifact of
    // debug_test() that we later get a copy in our own files.
    ATF_REQUIRE(stdout_file != result_handle->stdout_file());
    ATF_REQUIRE(stderr_file != result_handle->stderr_file());

    result_handle->cleanup();
    result_handle.reset();

    handle.cleanup();

    ATF_REQUIRE(atf::utils::compare_file(
        stdout_file.str(),
        "Test program: the-program\n"
        "Test case: print_params\n"
        "one=first variable\n"
        "two=second variable\n"));
    ATF_REQUIRE(atf::utils::compare_file(
        stderr_file.str(), "stderr: print_params\n"));
}


ATF_TEST_CASE_WITHOUT_HEAD(ensure_valid_interface);
ATF_TEST_CASE_BODY(ensure_valid_interface)
{
    scheduler::ensure_valid_interface("mock");

    ATF_REQUIRE_THROW_RE(engine::error, "Unsupported test interface 'mock2'",
                         scheduler::ensure_valid_interface("mock2"));
    scheduler::register_interface(
        "mock2", std::shared_ptr< scheduler::interface >(new mock_interface()));
    scheduler::ensure_valid_interface("mock2");

    // Standard interfaces should not be present unless registered.
    ATF_REQUIRE_THROW_RE(engine::error, "Unsupported test interface 'plain'",
                         scheduler::ensure_valid_interface("plain"));
}


ATF_TEST_CASE_WITHOUT_HEAD(registered_interface_names);
ATF_TEST_CASE_BODY(registered_interface_names)
{
    std::set< std::string > exp_names;

    exp_names.insert("mock");
    ATF_REQUIRE_EQ(exp_names, scheduler::registered_interface_names());

    scheduler::register_interface(
        "mock2", std::shared_ptr< scheduler::interface >(new mock_interface()));
    exp_names.insert("mock2");
    ATF_REQUIRE_EQ(exp_names, scheduler::registered_interface_names());
}


ATF_TEST_CASE_WITHOUT_HEAD(current_context);
ATF_TEST_CASE_BODY(current_context)
{
    const model::context context = scheduler::current_context();
    ATF_REQUIRE_EQ(fs::current_path(), context.cwd());
    ATF_REQUIRE(utils::getallenv() == context.env());
}


ATF_TEST_CASE_WITHOUT_HEAD(generate_config__empty);
ATF_TEST_CASE_BODY(generate_config__empty)
{
    const config::tree user_config = engine::empty_config();

    const config::properties_map exp_props;

    ATF_REQUIRE_EQ(exp_props,
                   scheduler::generate_config(user_config, "missing"));
}


ATF_TEST_CASE_WITHOUT_HEAD(generate_config__no_matches);
ATF_TEST_CASE_BODY(generate_config__no_matches)
{
    config::tree user_config = engine::empty_config();
    user_config.set_string("architecture", "foo");
    user_config.set_string("test_suites.one.var1", "value 1");

    const config::properties_map exp_props;

    ATF_REQUIRE_EQ(exp_props,
                   scheduler::generate_config(user_config, "two"));
}


ATF_TEST_CASE_WITHOUT_HEAD(generate_config__some_matches);
ATF_TEST_CASE_BODY(generate_config__some_matches)
{
    std::vector< passwd::user > mock_users;
    mock_users.push_back(passwd::user("nobody", 1234, 5678));
    passwd::set_mock_users_for_testing(mock_users);

    config::tree user_config = engine::empty_config();
    user_config.set_string("architecture", "foo");
    user_config.set_string("unprivileged_user", "nobody");
    user_config.set_string("test_suites.one.var1", "value 1");
    user_config.set_string("test_suites.two.var2", "value 2");

    config::properties_map exp_props;
    exp_props["unprivileged-user"] = "nobody";
    exp_props["var1"] = "value 1";

    ATF_REQUIRE_EQ(exp_props,
                   scheduler::generate_config(user_config, "one"));
}


ATF_INIT_TEST_CASES(tcs)
{
    scheduler::register_interface(
        "mock", std::shared_ptr< scheduler::interface >(new mock_interface()));

    ATF_ADD_TEST_CASE(tcs, integration__list_some);
    ATF_ADD_TEST_CASE(tcs, integration__list_check_paths);
    ATF_ADD_TEST_CASE(tcs, integration__list_timeout);
    ATF_ADD_TEST_CASE(tcs, integration__list_fail);
    ATF_ADD_TEST_CASE(tcs, integration__list_empty);

    ATF_ADD_TEST_CASE(tcs, integration__run_one);
    ATF_ADD_TEST_CASE(tcs, integration__run_many);

    ATF_ADD_TEST_CASE(tcs, integration__run_check_paths);
    ATF_ADD_TEST_CASE(tcs, integration__parameters_and_output);

    ATF_ADD_TEST_CASE(tcs, integration__fake_result);
    ATF_ADD_TEST_CASE(tcs, integration__cleanup__head_skips);
    ATF_ADD_TEST_CASE(tcs, integration__cleanup__body_skips);
    ATF_ADD_TEST_CASE(tcs, integration__cleanup__body_ok__cleanup_bad);
    ATF_ADD_TEST_CASE(tcs, integration__cleanup__body_bad__cleanup_ok);
    ATF_ADD_TEST_CASE(tcs, integration__cleanup__body_bad__cleanup_bad);
    ATF_ADD_TEST_CASE(tcs, integration__cleanup__timeout);
    ATF_ADD_TEST_CASE(tcs, integration__check_requirements);
    ATF_ADD_TEST_CASE(tcs, integration__stacktrace);
    ATF_ADD_TEST_CASE(tcs, integration__list_files_on_failure__none);
    ATF_ADD_TEST_CASE(tcs, integration__list_files_on_failure__some);
    ATF_ADD_TEST_CASE(tcs, integration__prevent_clobbering_control_files);

    ATF_ADD_TEST_CASE(tcs, debug_test);

    ATF_ADD_TEST_CASE(tcs, ensure_valid_interface);
    ATF_ADD_TEST_CASE(tcs, registered_interface_names);

    ATF_ADD_TEST_CASE(tcs, current_context);

    ATF_ADD_TEST_CASE(tcs, generate_config__empty);
    ATF_ADD_TEST_CASE(tcs, generate_config__no_matches);
    ATF_ADD_TEST_CASE(tcs, generate_config__some_matches);
}