#!/usr/bin/env python3

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at https://mozilla.org/MPL/2.0/.

import argparse
import csv
import itertools
import json
import os
import platform
import subprocess
from datetime import datetime
from functools import partial
from statistics import median, StatisticsError
from urllib.parse import urlsplit, urlunsplit, urljoin


DATE = datetime.now().strftime("%Y-%m-%d")
MACHINE = platform.machine()
SYSTEM = platform.system()


def load_manifest(filename):
    with open(filename, 'r') as f:
        text = f.read()
    return list(parse_manifest(text))


def parse_manifest(text):
    lines = filter(lambda x: x != "" and not x.startswith("#"),
                   map(lambda x: x.strip(), text.splitlines()))
    output = []
    for line in lines:
        if line.split(" ")[0] == "async":
            output.append((line.split(" ")[1], True))
        else:
            output.append((line.split(" ")[0], False))
    return output


def testcase_url(base, testcase):
    # The tp5 manifest hardwires http://localhost/ as the base URL,
    # which requires running the server as root in order to open
    # the server on port 80. To allow non-root users to run the test
    # case, we take the URL to be relative to a base URL.
    (scheme, netloc, path, query, fragment) = urlsplit(testcase)
    relative_url = urlunsplit(('', '', '.' + path, query, fragment))
    absolute_url = urljoin(base, relative_url)
    return absolute_url


def execute_test(url, command, timeout):
    try:
        return subprocess.check_output(
            command, stderr=subprocess.STDOUT, timeout=timeout
        )
    except subprocess.CalledProcessError as e:
        print("Unexpected Fail:")
        print(e)
        print("You may want to re-run the test manually:\n{}"
              .format(' '.join(command)))
    except subprocess.TimeoutExpired:
        print("Test FAILED due to timeout: {}".format(url))
    return ""


def run_servo_test(testcase, url, date, timeout, is_async):
    if is_async:
        print("Servo does not support async test!")
        # Return a placeholder
        return parse_log("", testcase, url, date)

    ua_script_path = "{}/user-agent-js".format(os.getcwd())
    command = [
        "../../../target/release/servo", url,
        "--userscripts=" + ua_script_path,
        "--headless",
        "-x", "-o", "output.png"
    ]
    log = ""
    try:
        log = subprocess.check_output(
            command, stderr=subprocess.STDOUT, timeout=timeout
        )
    except subprocess.CalledProcessError as e:
        print("Unexpected Fail:")
        print(e)
        print("You may want to re-run the test manually:\n{}".format(
            ' '.join(command)
        ))
    except subprocess.TimeoutExpired:
        print("Test FAILED due to timeout: {}".format(testcase))
    return parse_log(log, testcase, url, date)


def parse_log(log, testcase, url, date):
    blocks = []
    block = []
    copy = False
    for line_bytes in log.splitlines():
        line = line_bytes.decode('utf-8')

        if line.strip() == ("[PERF] perf block start"):
            copy = True
        elif line.strip() == ("[PERF] perf block end"):
            copy = False
            blocks.append(block)
            block = []
        elif copy and line.strip().startswith("[PERF]"):
            block.append(line)

    def parse_block(block):
        timing = {}
        for line in block:
            try:
                (_, key, value) = line.split(",")
            except:
                print("[DEBUG] failed to parse the following line:")
                print(line)
                print('[DEBUG] log:')
                print('-----')
                print(log)
                print('-----')
                return None

            if key == "testcase" or key == "title":
                timing[key] = value
            else:
                timing[key] = None if (value == "undefined") else int(value)

        return timing

    def valid_timing(timing, url=None):
        if (timing is None or
                testcase is None or
                timing.get('title') == 'Error loading page' or
                timing.get('testcase') != url):
            return False
        else:
            return True

    # We need to still include the failed tests, otherwise Treeherder will
    # consider the result to be a new test series, and thus a new graph. So we
    # use a placeholder with values = -1 to make Treeherder happy, and still be
    # able to identify failed tests (successful tests have time >=0).
    def create_placeholder(testcase):
        return {
            "system": SYSTEM,
            "machine": MACHINE,
            "date": date,
            "testcase": testcase,
            "title": "",
            "navigationStart": 0,
            "unloadEventStart": -1,
            "domLoading": -1,
            "fetchStart": -1,
            "responseStart": -1,
            "loadEventEnd": -1,
            "connectStart": -1,
            "domainLookupStart": -1,
            "redirectStart": -1,
            "domContentLoadedEventEnd": -1,
            "requestStart": -1,
            "secureConnectionStart": -1,
            "connectEnd": -1,
            "loadEventStart": -1,
            "domInteractive": -1,
            "domContentLoadedEventStart": -1,
            "redirectEnd": -1,
            "domainLookupEnd": -1,
            "unloadEventEnd": -1,
            "responseEnd": -1,
            "domComplete": -1,
        }

    # Set the testcase field to contain the original testcase name,
    # rather than the url.
    def set_testcase(timing, testcase=None, date=None):
        timing['testcase'] = testcase
        timing['system'] = SYSTEM
        timing['machine'] = MACHINE
        timing['date'] = date
        return timing

    valid_timing_for_case = partial(valid_timing, url=url)
    set_testcase_for_case = partial(set_testcase, testcase=testcase, date=date)
    timings = list(map(set_testcase_for_case, filter(valid_timing_for_case, map(parse_block, blocks))))

    if len(timings) == 0:
        print("Didn't find any perf data in the log, test timeout?")
        print('[DEBUG] log:')
        print('-----')
        print(log)
        print('-----')

        return [create_placeholder(testcase)]
    else:
        return timings


def filter_result_by_manifest(result_json, manifest, base):
    filtered = []
    for name, is_async in manifest:
        url = testcase_url(base, name)
        match = [tc for tc in result_json if tc['testcase'] == url]
        if len(match) == 0:
            raise Exception(("Missing test result: {}. This will cause a "
                             "discontinuity in the treeherder graph, "
                             "so we won't submit this data.").format(name))
        filtered += match
    return filtered


def take_result_median(result_json, expected_runs):
    median_results = []
    for k, g in itertools.groupby(result_json, lambda x: x['testcase']):
        group = list(g)
        if len(group) != expected_runs:
            print(("Warning: Not enough test data for {},"
                  " maybe some runs failed?").format(k))

        median_result = {}
        for k, _ in group[0].items():
            if k == "testcase" or k == "title":
                median_result[k] = group[0][k]
            else:
                try:
                    median_result[k] = median([x[k] for x in group
                                               if x[k] is not None])
                except StatisticsError:
                    median_result[k] = -1
        median_results.append(median_result)
    return median_results


def save_result_json(results, filename, manifest, expected_runs, base):

    results = filter_result_by_manifest(results, manifest, base)
    results = take_result_median(results, expected_runs)

    if len(results) == 0:
        with open(filename, 'w') as f:
            json.dump("No test result found in the log. All tests timeout?",
                      f, indent=2)
    else:
        with open(filename, 'w') as f:
            json.dump(results, f, indent=2)
    print("Result saved to {}".format(filename))


def save_result_csv(results, filename, manifest, expected_runs, base):

    fieldnames = [
        'system',
        'machine',
        'date',
        'testcase',
        'title',
        'connectEnd',
        'connectStart',
        'domComplete',
        'domContentLoadedEventEnd',
        'domContentLoadedEventStart',
        'domInteractive',
        'domLoading',
        'domainLookupEnd',
        'domainLookupStart',
        'fetchStart',
        'loadEventEnd',
        'loadEventStart',
        'navigationStart',
        'redirectEnd',
        'redirectStart',
        'requestStart',
        'responseEnd',
        'responseStart',
        'secureConnectionStart',
        'unloadEventEnd',
        'unloadEventStart',
    ]

    successes = [r for r in results if r['domComplete'] != -1]

    with open(filename, 'w', encoding='utf-8') as csvfile:
        writer = csv.DictWriter(csvfile, fieldnames)
        writer.writeheader()
        writer.writerows(successes)


def format_result_summary(results):
    failures = list(filter(lambda x: x['domComplete'] == -1, results))
    result_log = """
========================================
Total {total} tests; {suc} succeeded, {fail} failed.

Failure summary:
""".format(
        total=len(results),
        suc=len(list(filter(lambda x: x['domComplete'] != -1, results))),
        fail=len(failures)
    )
    uniq_failures = list(set(map(lambda x: x['testcase'], failures)))
    for failure in uniq_failures:
        result_log += " - {}\n".format(failure)

    result_log += "========================================\n"

    return result_log


def main():
    parser = argparse.ArgumentParser(
        description="Run page load test on servo"
    )
    parser.add_argument("tp5_manifest",
                        help="the test manifest in tp5 format")
    parser.add_argument("output_file",
                        help="filename for the output json")
    parser.add_argument("--base",
                        type=str,
                        default='http://localhost:8000/',
                        help="the base URL for tests. Default: http://localhost:8000/")
    parser.add_argument("--runs",
                        type=int,
                        default=20,
                        help="number of runs for each test case. Defult: 20")
    parser.add_argument("--timeout",
                        type=int,
                        default=300,  # 5 min
                        help=("kill the test if not finished in time (sec)."
                              " Default: 5 min"))
    parser.add_argument("--date",
                        type=str,
                        default=None,  # 5 min
                        help=("the date to use in the CSV file."))
    parser.add_argument("--engine",
                        type=str,
                        default='servo',
                        help=("The engine to run the tests on. Currently only"
                              " servo and gecko are supported."))
    args = parser.parse_args()
    if args.engine == 'servo':
        run_test = run_servo_test
    elif args.engine == 'gecko':
        import gecko_driver  # Load this only when we need gecko test
        run_test = gecko_driver.run_gecko_test
    date = args.date or DATE
    try:
        # Assume the server is up and running
        testcases = load_manifest(args.tp5_manifest)
        results = []
        for testcase, is_async in testcases:
            url = testcase_url(args.base, testcase)
            for run in range(args.runs):
                print("Running test {}/{} on {}".format(run + 1,
                                                        args.runs,
                                                        url))
                # results will be a mixure of timings dict and testcase strings
                # testcase string indicates a failed test
                results += run_test(testcase, url, date, args.timeout, is_async)
                print("Finished")
                # TODO: Record and analyze other performance.timing properties

        print(format_result_summary(results))
        if args.output_file.endswith('.csv'):
            save_result_csv(results, args.output_file, testcases, args.runs, args.base)
        else:
            save_result_json(results, args.output_file, testcases, args.runs, args.base)

    except KeyboardInterrupt:
        print("Test stopped by user, saving partial result")
        save_result_json(results, args.output_file, testcases, args.runs)


if __name__ == "__main__":
    main()