# Unit tests for OOMAnalyser
#
# Copyright (c) 2021-2022 Carsten Grohmann
# License: MIT (see LICENSE.txt)
# THIS PROGRAM COMES WITH NO WARRANTY

import http.server
import os
import re
import socketserver
import threading
import unittest
from selenium import webdriver
from selenium.common.exceptions import *
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.by import By
from webdriver_manager.chrome import ChromeDriverManager
import warnings

import OOMAnalyser


class MyRequestHandler(http.server.SimpleHTTPRequestHandler):
    def __init__(self, request, client_address, server, directory=None):
        self.directory = os.getcwd()
        super().__init__(request, client_address, server)

    # suppress all HTTP request messages
    def log_message(self, format, *args):
        # super().log_message(format, *args)
        pass


class ThreadedTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
    pass


class TestBase(unittest.TestCase):
    def get_lines(self, text, count):
        """
        Return the number of lines specified by count from given text

        @type text: str
        @type count: int
        """
        lines = text.splitlines()
        if count < 0:
            lines.reverse()
            count = count * -1
        lines = lines[:count]
        res = "\n".join(lines)
        return res

    def get_first_line(self, text):
        """
        Return the first line of the given text
        @type text: str
        """
        return self.get_lines(text, 1)

    def get_last_line(self, text):
        """
        Return the last line of the given text
        @type text: str
        """
        return self.get_lines(text, -1)


class TestInBrowser(TestBase):
    """Test OOM web page in a browser"""

    def setUp(self):
        warnings.simplefilter("ignore", ResourceWarning)

        ThreadedTCPServer.allow_reuse_address = True
        self.httpd = ThreadedTCPServer(("127.0.0.1", 8000), MyRequestHandler)
        server_thread = threading.Thread(target=self.httpd.serve_forever, args=(0.1,))
        server_thread.daemon = True
        server_thread.start()

        # silent Webdriver Manager
        os.environ["WDM_LOG_LEVEL"] = "0"

        # store driver locally
        os.environ["WDM_LOCAL"] = "1"

        s = Service(ChromeDriverManager().install())
        self.driver = webdriver.Chrome(service=s)
        self.driver.get("http://127.0.0.1:8000/OOMAnalyser.html")

    def tearDown(self):
        self.driver.close()
        self.httpd.shutdown()
        self.httpd.server_close()

    def assert_on_warn(self):
        notify_box = self.driver.find_element(By.ID, "notify_box")
        try:
            warning = notify_box.find_element(
                By.CLASS_NAME, "js-notify_box__msg--warning"
            )
        except NoSuchElementException:
            pass
        else:
            self.fail('Unexpected warning message: "%s"' % warning.text)

    def assert_on_error(self):
        error = self.get_error_text()
        if error:
            self.fail('Unexpected error message: "%s"' % error)

        for event in self.driver.get_log("browser"):
            # ignore favicon.ico errors
            if "favicon.ico" in event["message"]:
                continue
            self.fail('Error on browser console reported: "%s"' % event)

    def assert_on_warn_error(self):
        self.assert_on_warn()
        self.assert_on_error()

    def click_analyse(self):
        analyse = self.driver.find_element(By.XPATH, '//button[text()="Analyse"]')
        analyse.click()

    def get_error_text(self):
        """
        Return text from error notification box or an empty string if no error message exists

        @rtype: str
        """
        notify_box = self.driver.find_element(By.ID, "notify_box")
        try:
            notify_box.find_element(By.CLASS_NAME, "js-notify_box__msg--error")
        except NoSuchElementException:
            return ""
        return notify_box.text

    def click_reset(self):
        reset = self.driver.find_element(By.XPATH, '//button[text()="Reset"]')
        if reset.is_displayed():
            reset.click()
        else:
            new_analysis = self.driver.find_element(
                By.XPATH, '//a[contains(text(), "Step 1 - Enter your OOM message")]'
            )
            new_analysis.click()
        self.assert_on_warn_error()

    def analyse_oom(self, text):
        """
        Insert text and run analysis

        :param str text: OOM text to analyse
        """
        textarea = self.driver.find_element(By.ID, "textarea_oom")
        self.assertEqual(textarea.get_attribute("value"), "", "Empty textarea expected")
        textarea.send_keys(text)

        self.assertNotEqual(
            textarea.get_attribute("value"), "", "Missing OOM text in textarea"
        )

        h3_summary = self.driver.find_element(By.XPATH, '//h3[text()="Summary"]')
        self.assertFalse(
            h3_summary.is_displayed(),
            "Analysis details incl. <h3>Summary</h3> should be not displayed",
        )

        self.click_analyse()

    def check_results_rhel7(self):
        """Check the results of the analysis of the RHEL7 example"""
        self.assert_on_warn_error()
        h3_summary = self.driver.find_element(By.XPATH, '//h3[text()="Summary"]')
        self.assertTrue(
            h3_summary.is_displayed(),
            "Analysis details incl. <h3>Summary</h3> should be displayed",
        )

        trigger_proc_name = self.driver.find_element(By.CLASS_NAME, "trigger_proc_name")
        self.assertEqual(
            trigger_proc_name.text, "sed", "Unexpected trigger process name"
        )
        trigger_proc_pid = self.driver.find_element(By.CLASS_NAME, "trigger_proc_pid")
        self.assertEqual(
            trigger_proc_pid.text, "29481", "Unexpected trigger process pid"
        )
        trigger_proc_gfp_mask = self.driver.find_element(
            By.CLASS_NAME, "trigger_proc_gfp_mask"
        )
        self.assertEqual(
            trigger_proc_gfp_mask.text,
            "0x201da (GFP_KERNEL | GFP_USER | GFP_HIGHUSER | "
            "GFP_HIGHUSER_MOVABLE | __GFP_RECLAIMABLE | __GFP_COLD)",
            "Unexpected GFP Mask",
        )

        killed_proc_score = self.driver.find_element(By.CLASS_NAME, "killed_proc_score")
        self.assertEqual(
            killed_proc_score.text, "651", "Unexpected OOM score of killed process"
        )

        swap_cache_kb = self.driver.find_element(By.CLASS_NAME, "swap_cache_kb")
        self.assertEqual(swap_cache_kb.text, "45368 kBytes")
        swap_used_kb = self.driver.find_element(By.CLASS_NAME, "swap_used_kb")
        self.assertEqual(swap_used_kb.text, "8343236 kBytes")
        swap_free_kb = self.driver.find_element(By.CLASS_NAME, "swap_free_kb")
        self.assertEqual(swap_free_kb.text, "0 kBytes")
        swap_total_kb = self.driver.find_element(By.CLASS_NAME, "swap_total_kb")
        self.assertEqual(swap_total_kb.text, "8388604 kBytes")

        explanation = self.driver.find_element(By.ID, "explanation")
        self.assertTrue(
            "OOM killer was automatically triggered" in explanation.text,
            'Missing text "OOM killer was automatically triggered"',
        )

        explanation = self.driver.find_element(By.ID, "explanation")
        self.assertTrue(
            "system has 33519336 kBytes physical memory and 8388604 kBytes swap space."
            in explanation.text,
            "Physical and swap memory in summary not found",
        )
        self.assertTrue(
            "That's 41907940 kBytes total." in explanation.text,
            "Total memory in summary not found",
        )
        self.assertTrue(
            "94% (31705788 kBytes out of 33519336 kBytes) physical memory"
            in explanation.text,
            "Used physical memory in summary not found",
        )
        self.assertTrue(
            "99% (8343236 kBytes out of 8388604 kBytes) swap space" in explanation.text,
            "Used swap space in summary not found",
        )

        head = self.driver.find_element(By.ID, "pstable_header")
        self.assertTrue(
            "Page Table Entries" in head.text,
            'Missing column head line "Page Table Entries"',
        )

        self.check_swap_active()

    def check_results_ubuntu2110(self):
        """Check the results of the analysis of the Ubuntu example"""
        trigger_proc_gfp_mask = self.driver.find_element(
            By.CLASS_NAME, "trigger_proc_gfp_mask"
        )
        self.assertEqual(
            trigger_proc_gfp_mask.text, "0xcc0 (GFP_KERNEL)", "Unexpected GFP Mask"
        )

        dirty_pages = self.driver.find_element(By.CLASS_NAME, "dirty_pages")
        self.assertEqual(
            dirty_pages.text, "633 pages", "Unexpected number of dirty pages"
        )

        ram_pages = self.driver.find_element(By.CLASS_NAME, "ram_pages")
        self.assertEqual(
            ram_pages.text, "524158 pages", "Unexpected number of RAM pages"
        )

        explanation = self.driver.find_element(By.ID, "explanation")
        self.assertTrue(
            "OOM killer was manually triggered" in explanation.text,
            'Missing text "OOM killer was manually triggered"',
        )

        self.assertFalse(
            "with an OOM score of" in explanation.text,
            'No OOM score but text "with an OOM score of"',
        )

        explanation = self.driver.find_element(By.ID, "explanation")
        self.assertTrue(
            "system has 2096632 kBytes physical memory and no swap space"
            in explanation.text,
            "Physical and swap memory in summary not found",
        )
        self.assertTrue(
            "9% (209520 kBytes out of 2096632 kBytes) physical memory"
            in explanation.text,
            "Used physical memory in summary not found",
        )

        head = self.driver.find_element(By.ID, "pstable_header")
        self.assertTrue(
            "Page Table Bytes" in head.text,
            'Missing column head line "Page Table Bytes"',
        )

        self.check_swap_inactive()

    def check_swap_inactive(self):
        explanation = self.driver.find_element(By.ID, "explanation")
        self.assertTrue(
            "physical memory and no swap space" in explanation.text,
            'Missing text "physical memory and no swap space"',
        )
        self.assertFalse(
            "swap space are in use" in explanation.text,
            'No swap space but text "swap space are in use"',
        )

    def check_swap_active(self):
        explanation = self.driver.find_element(By.ID, "explanation")
        self.assertTrue(
            "swap space are in use" in explanation.text,
            'Swap space active but no text "swap space are in use"',
        )

    def test_010_load_page(self):
        """Test if the page is loading"""
        assert "OOMAnalyser" in self.driver.title

    def test_020_load_js(self):
        """Test if JS is loaded"""
        elem = self.driver.find_element(By.ID, "version")
        self.assertIsNotNone(elem.text, "Version statement not set - JS not loaded")

    def test_030_insert_and_analyse_rhel7_example(self):
        """Test loading and analysing RHEL7 example"""
        textarea = self.driver.find_element(By.ID, "textarea_oom")
        self.assertEqual(textarea.get_attribute("value"), "", "Empty textarea expected")
        insert_example = self.driver.find_element(
            By.XPATH, '//button[contains(text(), "RHEL7" )]'
        )
        insert_example.click()
        self.assertNotEqual(
            textarea.get_attribute("value"), "", "Missing OOM text in textarea"
        )

        h3_summary = self.driver.find_element(By.XPATH, '//h3[text()="Summary"]')
        self.assertFalse(
            h3_summary.is_displayed(),
            "Analysis details incl. <h3>Summary</h3> should be not displayed",
        )

        self.click_analyse()
        self.check_results_rhel7()

    def test_031_insert_and_analyse_ubuntu_example(self):
        """Test loading and analysing Ubuntu 21.10 example"""
        textarea = self.driver.find_element(By.ID, "textarea_oom")
        self.assertEqual(textarea.get_attribute("value"), "", "Empty textarea expected")
        insert_example = self.driver.find_element(
            By.XPATH, '//button[contains(text(), "Ubuntu" )]'
        )
        insert_example.click()
        self.assertNotEqual(
            textarea.get_attribute("value"), "", "Missing OOM text in textarea"
        )

        h3_summary = self.driver.find_element(By.XPATH, '//h3[text()="Summary"]')
        self.assertFalse(
            h3_summary.is_displayed(),
            "Analysis details incl. <h3>Summary</h3> should be not displayed",
        )

        self.click_analyse()
        self.check_results_ubuntu2110()

    def test_032_empty_textarea(self):
        """Test "Analyse" with empty textarea"""
        textarea = self.driver.find_element(By.ID, "textarea_oom")
        self.assertEqual(textarea.get_attribute("value"), "", "Empty textarea expected")
        # textarea.send_keys(text)

        self.assertEqual(
            textarea.get_attribute("value"),
            "",
            "Expected empty text area, but text found",
        )

        h3_summary = self.driver.find_element(By.XPATH, '//h3[text()="Summary"]')
        self.assertFalse(
            h3_summary.is_displayed(),
            "Analysis details incl. <h3>Summary</h3> should be not displayed",
        )

        self.click_analyse()
        self.assertEqual(
            self.get_error_text(),
            "ERROR: Empty OOM text. Please insert an OOM message block.",
        )
        self.click_reset()

    def test_033_begin_but_no_end(self):
        """Test incomplete OOM text - just the beginning"""
        example = """\
sed invoked oom-killer: gfp_mask=0x201da, order=0, oom_score_adj=0
sed cpuset=/ mems_allowed=0-1
CPU: 4 PID: 29481 Comm: sed Not tainted 3.10.0-514.6.1.el7.x86_64 #1
        """
        self.analyse_oom(example)
        self.assertEqual(
            self.get_error_text(),
            "ERROR: The inserted OOM is incomplete! The initial pattern was "
            "found but not the final.",
        )
        self.click_reset()

    def test_034_no_begin_but_end(self):
        """Test incomplete OOM text - just the end"""
        example = """\
Out of memory: Kill process 6576 (java) score 651 or sacrifice child
Killed process 6576 (java) total-vm:33914892kB, anon-rss:20629004kB, file-rss:0kB, shmem-rss:0kB
        """
        self.analyse_oom(example)
        self.assertEqual(
            self.get_error_text(),
            "ERROR: Failed to extract kernel version from OOM text",
        )
        self.click_reset()

    def test_035_leading_journalctl_input(self):
        """Test loading input from journalctl"""
        # prepare example
        example_lines = OOMAnalyser.OOMDisplay.example_rhel7.split("\n")
        res = []

        # unescape #012 - see OOMAnalyser.OOMEntity._rsyslog_unescape_lf()
        for line in example_lines:
            if "#012" in line:
                res.extend(line.split("#012"))
            else:
                res.append(line)
        example_lines = res
        res = []

        # add date/time prefix except for "Mem-Info:" block
        pattern = r"^ (active_file|unevictable|slab_reclaimable|mapped|free):.+$"
        rec = re.compile(pattern)
        for line in example_lines:
            match = rec.search(line)
            if match:
                line = "                                             {}".format(line)
            else:
                line = "Apr 01 14:13:32 mysrv <kern.warning> kernel: {}".format(line)
            res.append(line)
        example = "\n".join(res)

        self.analyse_oom(example)
        self.check_results_rhel7()
        self.click_reset()

    def test_040_trigger_proc_space(self):
        """Test trigger process name contains a space"""
        example = OOMAnalyser.OOMDisplay.example_rhel7
        example = example.replace("sed", "VM Monitoring Task")

        self.analyse_oom(example)
        self.assert_on_warn_error()
        h3_summary = self.driver.find_element(By.XPATH, '//h3[text()="Summary"]')
        self.assertTrue(
            h3_summary.is_displayed(),
            "Analysis details incl. <h3>Summary</h3> should be displayed",
        )

    def test_050_kill_proc_space(self):
        """Test killed process name contains a space"""
        example = OOMAnalyser.OOMDisplay.example_rhel7
        example = example.replace("mysqld", "VM Monitoring Task")

        self.analyse_oom(example)
        self.assert_on_warn_error()
        h3_summary = self.driver.find_element(By.XPATH, '//h3[text()="Summary"]')
        self.assertTrue(
            h3_summary.is_displayed(),
            "Analysis details incl. <h3>Summary</h3> should be displayed",
        )

    def test_060_removal_of_leading_but_useless_columns(self):
        """Test removal of leading but useless columns"""
        self.analyse_oom(OOMAnalyser.OOMDisplay.example_rhel7)
        self.check_results_rhel7()
        self.click_reset()
        for prefix in [
            "[11686.888109] ",
            "Apr 01 14:13:32 mysrv: ",
            "Apr 01 14:13:32 mysrv kernel: ",
            "Apr 01 14:13:32 mysrv <kern.warning> kernel: ",
            "Apr 01 14:13:32 mysrv kernel: [11686.888109] ",
            "kernel:",
            "Apr 01 14:13:32 mysrv <kern.warning> kernel:",
        ]:
            lines = OOMAnalyser.OOMDisplay.example_rhel7.split("\n")
            lines = ["{}{}".format(prefix, line) for line in lines]
            oom_text = "\n".join(lines)
            self.analyse_oom(oom_text)

            self.check_results_rhel7()
            self.click_reset()

    def test_070_manually_triggered_OOM(self):
        """Test for manually triggered OOM"""
        example = OOMAnalyser.OOMDisplay.example_rhel7
        example = example.replace("order=0", "order=-1")
        self.analyse_oom(example)
        self.assert_on_warn_error()

        explanation = self.driver.find_element(By.ID, "explanation")
        self.assertTrue(
            "OOM killer was manually triggered" in explanation.text,
            'Missing text "OOM killer was manually triggered"',
        )

    def test_080_swap_deactivated(self):
        """Test w/o swap or with deactivated swap"""
        example = OOMAnalyser.OOMDisplay.example_rhel7
        example = example.replace("Total swap = 8388604kB", "Total swap = 0kB")
        self.analyse_oom(example)
        self.assert_on_warn_error()

        self.check_swap_inactive()
        self.click_reset()

        example = OOMAnalyser.OOMDisplay.example_rhel7
        example = re.sub(r"\d+ pages in swap cac.*\n*", "", example, re.MULTILINE)
        example = re.sub(r"Swap cache stats.*\n*", "", example)
        example = re.sub(r"Free swap.*\n*", "", example)
        example = re.sub(r"Total swap.*\n*", "", example)

        self.analyse_oom(example)
        self.assert_on_warn_error()
        self.check_swap_inactive()


class TestPython(TestBase):
    def test_001_trigger_proc_space(self):
        """Test RE to find name of trigger process"""
        first = self.get_first_line(OOMAnalyser.OOMDisplay.example_rhel7)
        pattern = OOMAnalyser.OOMAnalyser.oom_result.kconfig.EXTRACT_PATTERN[
            "invoked oom-killer"
        ][0]
        rec = re.compile(pattern, re.MULTILINE)
        match = rec.search(first)
        self.assertTrue(
            match,
            "Error: re.search('invoked oom-killer') failed for simple process name",
        )

        first = first.replace("sed", "VM Monitoring Task")
        match = rec.search(first)
        self.assertTrue(
            match,
            "Error: re.search('invoked oom-killer') failed for process name with space",
        )

    def test_002_killed_proc_space(self):
        """Test RE to find name of killed process"""
        text = self.get_lines(OOMAnalyser.OOMDisplay.example_rhel7, -2)
        pattern = OOMAnalyser.OOMAnalyser.oom_result.kconfig.EXTRACT_PATTERN[
            "Process killed by OOM"
        ][0]
        rec = re.compile(pattern, re.MULTILINE)
        match = rec.search(text)
        self.assertTrue(
            match,
            "Error: re.search('Process killed by OOM') failed for simple process name",
        )

        text = text.replace("sed", "VM Monitoring Task")
        match = rec.search(text)
        self.assertTrue(
            match,
            "Error: re.search('Process killed by OOM') failed for process name with space",
        )

    def test_003_OOMEntity_number_of_columns_to_strip(self):
        """Test stripping useless / leading columns"""
        oom_entity = OOMAnalyser.OOMEntity(OOMAnalyser.OOMDisplay.example_rhel7)
        for pos, line in [
            (
                1,
                "[11686.888109] CPU: 4 PID: 29481 Comm: sed Not tainted 3.10.0-514.6.1.el7.x86_64 #1",
            ),
            (
                5,
                "Apr 01 14:13:32 mysrv kernel: CPU: 4 PID: 29481 Comm: sed Not tainted 3.10.0-514.6.1.el7.x86_64 #1",
            ),
            (
                6,
                "Apr 01 14:13:32 mysrv kernel: [11686.888109] CPU: 4 PID: 29481 Comm: sed Not tainted 3.10.0-514.6.1.el7.x86_64 #1",
            ),
        ]:
            to_strip = oom_entity._number_of_columns_to_strip(line)
            self.assertEqual(
                to_strip,
                pos,
                'Calc wrong number of columns to strip for "%s": got: %d, expect: %d'
                % (line, to_strip, pos),
            )

    def test_004_extract_block_from_next_pos(self):
        """Test extracting a single block (all lines till the next line with a colon)"""
        oom = OOMAnalyser.OOMEntity(OOMAnalyser.OOMDisplay.example_rhel7)
        analyser = OOMAnalyser.OOMAnalyser(oom)
        text = analyser._extract_block_from_next_pos("Hardware name:")
        expected = """\
Hardware name: HP ProLiant DL385 G7, BIOS A18 12/08/2012
 ffff880182272f10 00000000021dcb0a ffff880418207938 ffffffff816861ac
 ffff8804182079c8 ffffffff81681157 ffffffff810eab9c ffff8804182fe910
 ffff8804182fe928 0000000000000202 ffff880182272f10 ffff8804182079b8
"""
        self.assertEqual(text, expected)

    def test_005_extract_kernel_version(self):
        """Test extracting kernel version"""
        oom = OOMAnalyser.OOMEntity(OOMAnalyser.OOMDisplay.example_rhel7)
        analyser = OOMAnalyser.OOMAnalyser(oom)
        for text, kversion in [
            (
                "CPU: 0 PID: 19163 Comm: kworker/0:0 Tainted: G           OE     5.4.0-80-lowlatency #90~18.04.1-Ubuntu",
                "5.4.0-80-lowlatency",
            ),
            (
                "CPU: 4 PID: 1 Comm: systemd Not tainted 3.10.0-1062.9.1.el7.x86_64 #1",
                "3.10.0-1062.9.1.el7.x86_64",
            ),
        ]:
            analyser.oom_entity.text = text
            success = analyser._identify_kernel_version()
            self.assertTrue(
                analyser._identify_kernel_version(), analyser.oom_result.error_msg
            )
            self.assertEqual(analyser.oom_result.kversion, kversion)

    def test_006_choosing_kernel_config(self):
        """Test choosing the right kernel configuration"""
        for kcfg, kversion in [
            (
                OOMAnalyser.KernelConfig_5_8(),
                "CPU: 4 PID: 29481 Comm: sed Not tainted 5.13.0-514 #1",
            ),
            (
                OOMAnalyser.KernelConfig_5_8(),
                "CPU: 4 PID: 29481 Comm: sed Not tainted 5.8.0-514 #1",
            ),
            (
                OOMAnalyser.KernelConfig_4_6(),
                "CPU: 4 PID: 29481 Comm: sed Not tainted 4.6.0-514 #1",
            ),
            (
                OOMAnalyser.KernelConfigRhel7(),
                "CPU: 4 PID: 29481 Comm: sed Not tainted 3.10.0-1062.9.1.el7.x86_64 #1",
            ),
            (
                OOMAnalyser.KernelConfig_5_0(),
                "CPU: 4 PID: 29481 Comm: sed Not tainted 5.5.1 #1",
            ),
            (
                OOMAnalyser.KernelConfig_5_8(),
                "CPU: 4 PID: 29481 Comm: sed Not tainted 5.23.0 #1",
            ),
            (
                OOMAnalyser.KernelConfig_5_8(),
                "CPU: 4 PID: 29481 Comm: sed Not tainted 6.12.0 #1",
            ),
            (
                OOMAnalyser.BaseKernelConfig(),
                "CPU: 4 PID: 29481 Comm: sed Not tainted 2.33.0 #1",
            ),
        ]:
            oom = OOMAnalyser.OOMEntity(kversion)
            analyser = OOMAnalyser.OOMAnalyser(oom)
            analyser._identify_kernel_version()
            analyser._choose_kernel_config()
            result = analyser.oom_result.kconfig
            self.assertEqual(
                type(result),
                type(kcfg),
                'Mismatch between expected kernel config "%s" and chosen config "%s" for kernel version "%s"'
                % (type(kcfg), type(result), kversion),
            )


if __name__ == "__main__":
    unittest.main(verbosity=2)