// Copyright 2011 The Kyua Authors.
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#include "cli/cmd_debug.hpp"

extern "C" {
#include <unistd.h>
}

#include <cstdlib>
#include <iostream>

#include "cli/common.ipp"
#include "drivers/debug_test.hpp"
#include "engine/filters.hpp"
#include "utils/cmdline/exceptions.hpp"
#include "utils/cmdline/options.hpp"
#include "utils/cmdline/parser.ipp"
#include "utils/cmdline/ui.hpp"
#include "utils/format/macros.hpp"
#include "utils/fs/path.hpp"
#include "utils/process/child.ipp"
#include "utils/process/executor.hpp"
#include "utils/process/operations.hpp"
#include "utils/process/status.hpp"

namespace cmdline = utils::cmdline;
namespace config = utils::config;
namespace executor = utils::process::executor;
namespace process = utils::process;

using cli::cmd_debug;
using utils::process::args_vector;
using utils::process::child;


namespace {


const cmdline::bool_option pause_before_cleanup_upon_fail_option(
    'p',
    "pause-before-cleanup-upon-fail",
    "Pauses right before the test cleanup upon fail");


const cmdline::bool_option pause_before_cleanup_option(
    "pause-before-cleanup",
    "Pauses right before the test cleanup");


static const char* DEFAULT_CMD = "$SHELL";
const cmdline::string_option execute_option(
    'x', "execute",
    "A command to run within the given execenv upon test failure",
    "cmd", DEFAULT_CMD, true);


/// Functor to execute a program.
class execute {
    const std::string& _cmd;
    executor::exit_handle& _eh;

public:
    /// Constructor.
    ///
    /// \param program Program binary absolute path.
    /// \param args Program arguments.
    execute(
        const std::string& cmd_,
        executor::exit_handle& eh_) :
        _cmd(cmd_),
        _eh(eh_)
    {
    }

    /// Body of the subprocess.
    void
    operator()(void)
    {
        if (::chdir(_eh.work_directory().c_str()) == -1) {
            std::cerr << "execute: chdir() errors: "
                << strerror(errno) << ".\n";
            std::exit(EXIT_FAILURE);
        }

        std::string program_path = "/bin/sh";
        const char* shell = std::getenv("SHELL");
        if (shell)
            program_path = shell;

        args_vector av;
        if (!(_cmd.empty() || _cmd == DEFAULT_CMD)) {
            av.push_back("-c");
            av.push_back(_cmd);
        }

        process::exec(utils::fs::path(program_path), av);
    }
};


/// The debugger interface implementation.
class dbg : public engine::debugger {
    /// Object to interact with the I/O of the program.
    cmdline::ui* _ui;

    /// Representation of the command line to the subcommand.
    const cmdline::parsed_cmdline& _cmdline;

public:
    /// Constructor.
    ///
    /// \param ui_ Object to interact with the I/O of the program.
    /// \param cmdline Representation of the command line to the subcommand.
    dbg(cmdline::ui* ui, const cmdline::parsed_cmdline& cmdline) :
        _ui(ui), _cmdline(cmdline)
    {}

    void before_cleanup(
        const model::test_program_ptr&,
        const model::test_case&,
        optional< model::test_result >& result,
        executor::exit_handle& eh) const
    {
        if (_cmdline.has_option(pause_before_cleanup_upon_fail_option
            .long_name())) {
            if (result && !result.get().good()) {
                _ui->out("The test failed and paused right before its cleanup "
                    "routine.");
                _ui->out(F("Test work dir: %s") % eh.work_directory().str());
                _ui->out("Press <Enter> to continue...");
                (void) std::cin.get();
            }
        } else if (_cmdline.has_option(pause_before_cleanup_option
            .long_name())) {
            _ui->out("The test paused right before its cleanup routine.");
            _ui->out(F("Test work dir: %s") % eh.work_directory().str());
            _ui->out("Press <Enter> to continue...");
            (void) std::cin.get();
        }
    };

    void upon_test_failure(
        const model::test_program_ptr&,
        const model::test_case&,
        optional< model::test_result >&,
        executor::exit_handle& eh) const
    {
        if (!_cmdline.has_option(execute_option.long_name()))
            return;
        const std::string& cmd = _cmdline.get_option<cmdline::string_option>(
            execute_option.long_name());
        std::unique_ptr< process::child > child = child::fork_interactive(
            execute(cmd, eh));
        (void) child->wait();
    };

};


}  // anonymous namespace


/// Default constructor for cmd_debug.
cmd_debug::cmd_debug(void) : cli_command(
    "debug", "test_case", 1, 1,
    "Executes a single test case providing facilities for debugging")
{
    add_option(build_root_option);
    add_option(kyuafile_option);

    add_option(pause_before_cleanup_upon_fail_option);
    add_option(pause_before_cleanup_option);

    add_option(cmdline::path_option(
        "stdout", "Where to direct the standard output of the test case",
        "path", "/dev/stdout"));

    add_option(cmdline::path_option(
        "stderr", "Where to direct the standard error of the test case",
        "path", "/dev/stderr"));

    add_option(execute_option);
}


/// Entry point for the "debug" subcommand.
///
/// \param ui Object to interact with the I/O of the program.
/// \param cmdline Representation of the command line to the subcommand.
/// \param user_config The runtime debuguration of the program.
///
/// \return 0 if everything is OK, 1 if any of the necessary documents cannot be
/// opened.
int
cmd_debug::run(cmdline::ui* ui, const cmdline::parsed_cmdline& cmdline,
               const config::tree& user_config)
{
    const std::string& test_case_name = cmdline.arguments()[0];
    if (test_case_name.find(':') == std::string::npos)
        throw cmdline::usage_error(F("'%s' is not a test case identifier "
                                     "(missing ':'?)") % test_case_name);
    const engine::test_filter filter = engine::test_filter::parse(
        test_case_name);

    engine::debugger_ptr debugger = nullptr;
    if (cmdline.has_option(pause_before_cleanup_upon_fail_option.long_name())
        || cmdline.has_option(pause_before_cleanup_option.long_name())
        || cmdline.has_option(execute_option.long_name())) {
        debugger = std::shared_ptr< engine::debugger >(new dbg(ui, cmdline));
    }

    const drivers::debug_test::result result = drivers::debug_test::drive(
        debugger,
        kyuafile_path(cmdline), build_root_path(cmdline), filter, user_config,
        cmdline.get_option< cmdline::path_option >("stdout"),
        cmdline.get_option< cmdline::path_option >("stderr"));

    ui->out(F("%s  ->  %s") % cli::format_test_case_id(result.test_case) %
            cli::format_result(result.test_result));

    return result.test_result.good() ? EXIT_SUCCESS : EXIT_FAILURE;
}