/*
 * Copyright (c) 2020-2021, the SerenityOS developers.
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/Function.h>
#include <AK/JsonObject.h>
#include <AK/JsonValue.h>
#include <AK/QuickSort.h>
#include <AK/URL.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/DirIterator.h>
#include <LibCore/File.h>
#include <LibGUI/Application.h>
#include <LibGUI/BoxLayout.h>
#include <LibGUI/Widget.h>
#include <LibGUI/Window.h>
#include <LibJS/Interpreter.h>
#include <LibJS/Lexer.h>
#include <LibJS/Parser.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/JSONObject.h>
#include <LibTest/Results.h>
#include <LibWeb/HTML/Parser/HTMLDocumentParser.h>
#include <LibWeb/InProcessWebView.h>
#include <LibWeb/Loader/ResourceLoader.h>
#include <signal.h>
#include <sys/time.h>

#define TOP_LEVEL_TEST_NAME "__$$TOP_LEVEL$$__"

struct ParserError {
    JS::Parser::Error error;
    String hint;
};

struct JSFileResult {
    String name;
    Optional<ParserError> error {};
    double time_taken { 0 };
    // A failed test takes precedence over a skipped test, which both have
    // precedence over a passed test
    Test::Result most_severe_test_result { Test::Result::Pass };
    Vector<Test::Suite> suites {};
    Vector<String> logged_messages {};
};

Function<void(const URL&)> g_on_page_change;

class TestRunnerObject final : public JS::Object {
    JS_OBJECT(TestRunnerObject, JS::Object);

public:
    explicit TestRunnerObject(JS::GlobalObject&);
    virtual void initialize(JS::GlobalObject&) override;
    virtual ~TestRunnerObject() override;

private:
    JS_DECLARE_NATIVE_FUNCTION(change_page);
};

TestRunnerObject::TestRunnerObject(JS::GlobalObject& global_object)
    : Object(*global_object.object_prototype())
{
}

void TestRunnerObject::initialize(JS::GlobalObject& global_object)
{
    Object::initialize(global_object);
    define_native_function("changePage", change_page, 1);
}

TestRunnerObject::~TestRunnerObject()
{
}

JS_DEFINE_NATIVE_FUNCTION(TestRunnerObject::change_page)
{
    auto url = vm.argument(0).to_string(global_object);
    if (vm.exception())
        return {};

    if (g_on_page_change)
        g_on_page_change(url);

    return JS::js_undefined();
}

class TestRunner {
public:
    TestRunner(String web_test_root, String js_test_root, Web::InProcessWebView& page_view, bool print_times)
        : m_web_test_root(move(web_test_root))
        , m_js_test_root(move(js_test_root))
        , m_print_times(print_times)
        , m_page_view(page_view)
    {
    }

    void run();

private:
    JSFileResult run_file_test(const String& test_path);
    void print_file_result(const JSFileResult& file_result) const;
    void print_test_results() const;

    String m_web_test_root;
    String m_js_test_root;
    bool m_print_times;

    double m_total_elapsed_time_in_ms { 0 };
    Test::Counts m_counts;

    RefPtr<Web::InProcessWebView> m_page_view;

    RefPtr<JS::Program> m_js_test_common;
    RefPtr<JS::Program> m_web_test_common;
};

static void cleanup_and_exit()
{
    // Clear the taskbar progress.
#ifdef __serenity__
    fprintf(stderr, "\033]9;-1;\033\\");
#endif
    exit(1);
}

#if 0
static void handle_sigabrt(int)
{
    dbgln("test-web: SIGABRT received, cleaning up.");
    cleanup_and_exit();
}
#endif

static double get_time_in_ms()
{
    struct timeval tv1;
    auto return_code = gettimeofday(&tv1, nullptr);
    VERIFY(return_code >= 0);
    return static_cast<double>(tv1.tv_sec) * 1000.0 + static_cast<double>(tv1.tv_usec) / 1000.0;
}

template<typename Callback>
void iterate_directory_recursively(const String& directory_path, Callback callback)
{
    Core::DirIterator directory_iterator(directory_path, Core::DirIterator::Flags::SkipDots);

    while (directory_iterator.has_next()) {
        auto file_path = directory_iterator.next_full_path();
        if (Core::File::is_directory(file_path)) {
            iterate_directory_recursively(file_path, callback);
        } else {
            callback(move(file_path));
        }
    }
}

static Vector<String> get_test_paths(const String& test_root)
{
    Vector<String> paths;

    iterate_directory_recursively(test_root, [&](const String& file_path) {
        if (!file_path.ends_with("test-common.js") && !file_path.ends_with(".html") && !file_path.ends_with(".ts"))
            paths.append(file_path);
    });

    quick_sort(paths);

    return paths;
}

void TestRunner::run()
{
    size_t progress_counter = 0;
    auto test_paths = get_test_paths(m_web_test_root);

    g_on_page_change = [this](auto& page_to_load) {
        if (!page_to_load.is_valid()) {
            printf("Invalid page URL (%s) on page change", page_to_load.to_string().characters());
            cleanup_and_exit();
        }

        VERIFY(m_page_view->document());

        // We want to keep the same document since the interpreter is tied to the document,
        // and we don't want to lose the test state. So, we just clear the document and
        // give a new parser the existing document to work on.
        m_page_view->document()->remove_all_children();

        Web::LoadRequest request;
        request.set_url(page_to_load);

        Web::ResourceLoader::the().load_sync(
            request,
            [&](auto data, auto&, auto) {
                Web::HTML::HTMLDocumentParser parser(*m_page_view->document(), data, "utf-8");
                parser.run(page_to_load);
            },
            [page_to_load](auto& error, auto) {
                printf("Failed to load test page: %s (%s)", page_to_load.to_string().characters(), error.characters());
                cleanup_and_exit();
            });
    };

    for (auto& path : test_paths) {
        ++progress_counter;
        print_file_result(run_file_test(path));
#ifdef __serenity__
        fprintf(stderr, "\033]9;%zu;%zu;\033\\", progress_counter, test_paths.size());
#endif
    }

#ifdef __serenity__
    fprintf(stderr, "\033]9;-1;\033\\");
#endif

    print_test_results();
}

static Result<NonnullRefPtr<JS::Program>, ParserError> parse_file(const String& file_path)
{
    auto file = Core::File::construct(file_path);
    auto result = file->open(Core::IODevice::ReadOnly);
    if (!result) {
        printf("Failed to open the following file: \"%s\"\n", file_path.characters());
        cleanup_and_exit();
    }

    auto contents = file->read_all();
    String test_file_string(reinterpret_cast<const char*>(contents.data()), contents.size());
    file->close();

    auto parser = JS::Parser(JS::Lexer(test_file_string));
    auto program = parser.parse_program();

    if (parser.has_errors()) {
        auto error = parser.errors()[0];
        return Result<NonnullRefPtr<JS::Program>, ParserError>(ParserError { error, error.source_location_hint(test_file_string) });
    }

    return Result<NonnullRefPtr<JS::Program>, ParserError>(program);
}

static Optional<JsonValue> get_test_results(JS::Interpreter& interpreter)
{
    auto result = interpreter.vm().get_variable("__TestResults__", interpreter.global_object());
    auto json_string = JS::JSONObject::stringify_impl(interpreter.global_object(), result, JS::js_undefined(), JS::js_undefined());

    auto json = JsonValue::from_string(json_string);
    if (!json.has_value())
        return {};

    return json.value();
}

JSFileResult TestRunner::run_file_test(const String& test_path)
{
    double start_time = get_time_in_ms();
    VERIFY(m_page_view->document());
    auto& old_interpreter = m_page_view->document()->interpreter();

    if (!m_js_test_common) {
        auto result = parse_file(String::formatted("{}/test-common.js", m_js_test_root));
        if (result.is_error()) {
            printf("Unable to parse %s/test-common.js\n", m_js_test_root.characters());
            printf("%s\n", result.error().error.to_string().characters());
            printf("%s\n", result.error().hint.characters());
            cleanup_and_exit();
        }
        m_js_test_common = result.value();
    }

    if (!m_web_test_common) {
        auto result = parse_file(String::formatted("{}/test-common.js", m_web_test_root));
        if (result.is_error()) {
            printf("Unable to parse %s/test-common.js\n", m_web_test_root.characters());
            printf("%s\n", result.error().error.to_string().characters());
            printf("%s\n", result.error().hint.characters());
            cleanup_and_exit();
        }
        m_web_test_common = result.value();
    }

    auto file_program = parse_file(test_path);
    if (file_program.is_error())
        return { test_path, file_program.error() };

    // Setup the test on the current page to get "__PageToLoad__".
    old_interpreter.run(old_interpreter.global_object(), *m_web_test_common);
    old_interpreter.run(old_interpreter.global_object(), *file_program.value());
    auto page_to_load = URL(old_interpreter.vm().get_variable("__PageToLoad__", old_interpreter.global_object()).as_string().string());
    if (!page_to_load.is_valid()) {
        printf("Invalid page URL for %s", test_path.characters());
        cleanup_and_exit();
    }

    JSFileResult file_result;

    Web::LoadRequest request;
    request.set_url(page_to_load);

    Web::ResourceLoader::the().load_sync(
        request,
        [&](auto data, auto&, auto) {
            // Create a new parser and immediately get its document to replace the old interpreter.
            auto document = Web::DOM::Document::create();
            Web::HTML::HTMLDocumentParser parser(document, data, "utf-8");
            auto& new_interpreter = parser.document().interpreter();

            // FIXME: This is a hack while we're refactoring Interpreter/VM stuff.
            JS::VM::InterpreterExecutionScope scope(new_interpreter);

            // Setup the test environment and call "__BeforeInitialPageLoad__"
            new_interpreter.global_object().define_property(
                "libweb_tester",
                new_interpreter.heap().allocate<TestRunnerObject>(new_interpreter.global_object(), new_interpreter.global_object()),
                JS::Attribute::Enumerable | JS::Attribute::Configurable);
            new_interpreter.run(new_interpreter.global_object(), *m_js_test_common);
            new_interpreter.run(new_interpreter.global_object(), *m_web_test_common);
            new_interpreter.run(new_interpreter.global_object(), *file_program.value());

            auto& before_initial_page_load = new_interpreter.vm().get_variable("__BeforeInitialPageLoad__", new_interpreter.global_object()).as_function();
            [[maybe_unused]] auto rc_before = new_interpreter.vm().call(before_initial_page_load, JS::js_undefined());
            if (new_interpreter.exception())
                new_interpreter.vm().clear_exception();

            // Now parse the HTML page.
            parser.run(page_to_load);
            m_page_view->set_document(&parser.document());

            // Finally run the test by calling "__AfterInitialPageLoad__"
            auto& after_initial_page_load = new_interpreter.vm().get_variable("__AfterInitialPageLoad__", new_interpreter.global_object()).as_function();
            [[maybe_unused]] auto rc_after = new_interpreter.vm().call(after_initial_page_load, JS::js_undefined());
            if (new_interpreter.exception())
                new_interpreter.vm().clear_exception();

            auto test_json = get_test_results(new_interpreter);
            if (!test_json.has_value()) {
                printf("Received malformed JSON from test \"%s\"\n", test_path.characters());
                cleanup_and_exit();
            }

            file_result = { test_path.substring(m_web_test_root.length() + 1, test_path.length() - m_web_test_root.length() - 1) };

            // Collect logged messages
            auto& arr = new_interpreter.vm().get_variable("__UserOutput__", new_interpreter.global_object()).as_array();
            for (auto& entry : arr.indexed_properties()) {
                auto message = entry.value_and_attributes(&new_interpreter.global_object()).value;
                file_result.logged_messages.append(message.to_string_without_side_effects());
            }

            test_json.value().as_object().for_each_member([&](const String& suite_name, const JsonValue& suite_value) {
                Test::Suite suite { suite_name };

                VERIFY(suite_value.is_object());

                suite_value.as_object().for_each_member([&](const String& test_name, const JsonValue& test_value) {
                    Test::Case test { test_name, Test::Result::Fail, "" };

                    VERIFY(test_value.is_object());
                    VERIFY(test_value.as_object().has("result"));

                    auto result = test_value.as_object().get("result");
                    VERIFY(result.is_string());
                    auto result_string = result.as_string();
                    if (result_string == "pass") {
                        test.result = Test::Result::Pass;
                        m_counts.tests_passed++;
                    } else if (result_string == "fail") {
                        test.result = Test::Result::Fail;
                        m_counts.tests_failed++;
                        suite.most_severe_test_result = Test::Result::Fail;
                        VERIFY(test_value.as_object().has("details"));
                        auto details = test_value.as_object().get("details");
                        VERIFY(result.is_string());
                        test.details = details.as_string();
                    } else {
                        test.result = Test::Result::Skip;
                        if (suite.most_severe_test_result == Test::Result::Pass)
                            suite.most_severe_test_result = Test::Result::Skip;
                        m_counts.tests_skipped++;
                    }

                    suite.tests.append(test);
                });

                if (suite.most_severe_test_result == Test::Result::Fail) {
                    m_counts.suites_failed++;
                    file_result.most_severe_test_result = Test::Result::Fail;
                } else {
                    if (suite.most_severe_test_result == Test::Result::Skip && file_result.most_severe_test_result == Test::Result::Pass)
                        file_result.most_severe_test_result = Test::Result::Skip;
                    m_counts.suites_passed++;
                }

                file_result.suites.append(suite);
            });

            m_counts.files_total++;

            file_result.time_taken = get_time_in_ms() - start_time;
            m_total_elapsed_time_in_ms += file_result.time_taken;
        },
        [page_to_load](auto& error, auto) {
            printf("Failed to load test page: %s (%s)", page_to_load.to_string().characters(), error.characters());
            cleanup_and_exit();
        });

    return file_result;
}

enum Modifier {
    BG_RED,
    BG_GREEN,
    FG_RED,
    FG_GREEN,
    FG_ORANGE,
    FG_GRAY,
    FG_BLACK,
    FG_BOLD,
    ITALIC,
    CLEAR,
};

static void print_modifiers(Vector<Modifier> modifiers)
{
    for (auto& modifier : modifiers) {
        auto code = [&]() -> String {
            switch (modifier) {
            case BG_RED:
                return "\033[48;2;255;0;102m";
            case BG_GREEN:
                return "\033[48;2;102;255;0m";
            case FG_RED:
                return "\033[38;2;255;0;102m";
            case FG_GREEN:
                return "\033[38;2;102;255;0m";
            case FG_ORANGE:
                return "\033[38;2;255;102;0m";
            case FG_GRAY:
                return "\033[38;2;135;139;148m";
            case FG_BLACK:
                return "\033[30m";
            case FG_BOLD:
                return "\033[1m";
            case ITALIC:
                return "\033[3m";
            case CLEAR:
                return "\033[0m";
            }
            VERIFY_NOT_REACHED();
        };
        printf("%s", code().characters());
    }
}

void TestRunner::print_file_result(const JSFileResult& file_result) const
{
    if (file_result.most_severe_test_result == Test::Result::Fail || file_result.error.has_value()) {
        print_modifiers({ BG_RED, FG_BLACK, FG_BOLD });
        printf(" FAIL ");
        print_modifiers({ CLEAR });
    } else {
        if (m_print_times || file_result.most_severe_test_result != Test::Result::Pass) {
            print_modifiers({ BG_GREEN, FG_BLACK, FG_BOLD });
            printf(" PASS ");
            print_modifiers({ CLEAR });
        } else {
            return;
        }
    }

    printf(" %s", file_result.name.characters());

    if (m_print_times) {
        print_modifiers({ CLEAR, ITALIC, FG_GRAY });
        if (file_result.time_taken < 1000) {
            printf(" (%dms)\n", static_cast<int>(file_result.time_taken));
        } else {
            printf(" (%.3fs)\n", file_result.time_taken / 1000.0);
        }
        print_modifiers({ CLEAR });
    } else {
        printf("\n");
    }

    if (!file_result.logged_messages.is_empty()) {
        print_modifiers({ FG_GRAY, FG_BOLD });
#ifdef __serenity__
        printf("     ℹ Console output:\n");
#else
        // This emoji has a second invisible byte after it. The one above does not
        printf("    ℹ️  Console output:\n");
#endif
        print_modifiers({ CLEAR, FG_GRAY });
        for (auto& message : file_result.logged_messages)
            printf("         %s\n", message.characters());
    }

    if (file_result.error.has_value()) {
        auto test_error = file_result.error.value();

        print_modifiers({ FG_RED });
#ifdef __serenity__
        printf("     ❌ The file failed to parse\n\n");
#else
        // No invisible byte here, but the spacing still needs to be altered on the host
        printf("    ❌ The file failed to parse\n\n");
#endif
        print_modifiers({ FG_GRAY });
        for (auto& message : test_error.hint.split('\n', true)) {
            printf("         %s\n", message.characters());
        }
        print_modifiers({ FG_RED });
        printf("         %s\n\n", test_error.error.to_string().characters());

        return;
    }

    if (file_result.most_severe_test_result != Test::Result::Pass) {
        for (auto& suite : file_result.suites) {
            if (suite.most_severe_test_result == Test::Result::Pass)
                continue;

            bool failed = suite.most_severe_test_result == Test::Result::Fail;

            print_modifiers({ FG_GRAY, FG_BOLD });

            if (failed) {
#ifdef __serenity__
                printf("     ❌ Suite:  ");
#else
                // No invisible byte here, but the spacing still needs to be altered on the host
                printf("    ❌ Suite:  ");
#endif
            } else {
#ifdef __serenity__
                printf("     ⚠ Suite:  ");
#else
                // This emoji has a second invisible byte after it. The one above does not
                printf("    ⚠️  Suite:  ");
#endif
            }

            print_modifiers({ CLEAR, FG_GRAY });

            if (suite.name == TOP_LEVEL_TEST_NAME) {
                printf("<top-level>\n");
            } else {
                printf("%s\n", suite.name.characters());
            }
            print_modifiers({ CLEAR });

            for (auto& test : suite.tests) {
                if (test.result == Test::Result::Pass)
                    continue;

                print_modifiers({ FG_GRAY, FG_BOLD });
                printf("         Test:   ");
                if (test.result == Test::Result::Fail) {
                    print_modifiers({ CLEAR, FG_RED });
                    printf("%s (failed):\n", test.name.characters());
                    printf("                 %s\n", test.details.characters());
                } else {
                    print_modifiers({ CLEAR, FG_ORANGE });
                    printf("%s (skipped)\n", test.name.characters());
                }
                print_modifiers({ CLEAR });
            }
        }
    }
}

void TestRunner::print_test_results() const
{
    printf("\nTest Suites: ");
    if (m_counts.suites_failed) {
        print_modifiers({ FG_RED });
        printf("%d failed, ", m_counts.suites_failed);
        print_modifiers({ CLEAR });
    }
    if (m_counts.suites_passed) {
        print_modifiers({ FG_GREEN });
        printf("%d passed, ", m_counts.suites_passed);
        print_modifiers({ CLEAR });
    }
    printf("%d total\n", m_counts.suites_failed + m_counts.suites_passed);

    printf("Tests:       ");
    if (m_counts.tests_failed) {
        print_modifiers({ FG_RED });
        printf("%d failed, ", m_counts.tests_failed);
        print_modifiers({ CLEAR });
    }
    if (m_counts.tests_skipped) {
        print_modifiers({ FG_ORANGE });
        printf("%d skipped, ", m_counts.tests_skipped);
        print_modifiers({ CLEAR });
    }
    if (m_counts.tests_passed) {
        print_modifiers({ FG_GREEN });
        printf("%d passed, ", m_counts.tests_passed);
        print_modifiers({ CLEAR });
    }
    printf("%d total\n", m_counts.tests_failed + m_counts.tests_passed);

    printf("Files:       %d total\n", m_counts.files_total);

    printf("Time:        ");
    if (m_total_elapsed_time_in_ms < 1000.0) {
        printf("%dms\n\n", static_cast<int>(m_total_elapsed_time_in_ms));
    } else {
        printf("%-.3fs\n\n", m_total_elapsed_time_in_ms / 1000.0);
    }
}

int main(int argc, char** argv)
{
    bool print_times = false;
    bool show_window = false;

#if 0
    struct sigaction act;
    memset(&act, 0, sizeof(act));
    act.sa_flags = SA_NOCLDWAIT;
    act.sa_handler = handle_sigabrt;
    int rc = sigaction(SIGABRT, &act, nullptr);
    if (rc < 0) {
        perror("sigaction");
        return 1;
    }
#endif

    Core::ArgsParser args_parser;
    args_parser.add_option(print_times, "Show duration of each test", "show-time", 't');
    args_parser.add_option(show_window, "Show window while running tests", "window", 'w');
    args_parser.parse(argc, argv);

    auto app = GUI::Application::construct(argc, argv);
    auto window = GUI::Window::construct();
    auto& main_widget = window->set_main_widget<GUI::Widget>();
    main_widget.set_fill_with_background_color(true);
    main_widget.set_layout<GUI::VerticalBoxLayout>();
    auto& view = main_widget.add<Web::InProcessWebView>();

    view.set_document(Web::DOM::Document::create());

    if (show_window) {
        window->set_title("LibWeb Test Window");
        window->resize(640, 480);
        window->show();
    }

#ifdef __serenity__
    TestRunner("/home/anon/web-tests", "/home/anon/js-tests", view, print_times).run();
#else
    char* serenity_source_dir = getenv("SERENITY_SOURCE_DIR");
    if (!serenity_source_dir) {
        printf("test-web requires the SERENITY_SOURCE_DIR environment variable to be set");
        return 1;
    }
    TestRunner(String::formatted("{}/Userland/Libraries/LibWeb/Tests", serenity_source_dir), String::formatted("{}/Userland/Libraries/LibJS/Tests", serenity_source_dir), view, print_times).run();
#endif
    return 0;
}