#!/usr/bin/env python3
'''
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   _/      _/    _/_/_/  _/    _/    _/    _/_/_/  _/_/_/    _/  _/_/_/


Copyright 2025 bdunahu

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

Commentary:
Code:
'''

import argparse
import asyncio
import signal
import sys
import traceback
import time
import types
import os
from experiment import Experiment
from asyncio.base_events import _format_handle


class Nemesis(object):

    # the (ideal) interval between samples
    signal_interval = 0.0
    # the timestamp which the last sample was taken
    last_sample = None
    # the current experiment being run
    curr_experiment = None
    # results from previous experiments, represented as strings
    results = []
    # The duration of each performance experiment
    e_duration = None
    # The number of seconds remaining in this performance experiment.
    r_duration = None

    # temp
    task = None
    dilation = 1.0

    @staticmethod
    def __init__(task, speedup, e_duration, w_time, signal_interval=0.01):
        os.environ["PYTHONASYNCIODEBUG"] = "1"
        Nemesis.signal_interval = signal_interval
        Nemesis.e_duration = e_duration
        Nemesis.r_duration = w_time
        # temporary
        Nemesis.task = task
        Nemesis.speedup = speedup

    @staticmethod
    def start():
        Nemesis.last_sample = time.perf_counter()
        signal.signal(signal.SIGALRM,
                      Nemesis._signal_handler)
        signal.setitimer(signal.ITIMER_REAL,
                         Nemesis.signal_interval,
                         Nemesis.signal_interval)

    @staticmethod
    def stop():
        signal.setitimer(signal.ITIMER_REAL, 0)
        Nemesis._stop_experiment()
        for r in Nemesis.results:
            print()
            print(r)

    @staticmethod
    def _start_experiment():
        Nemesis.r_duration = Nemesis.e_duration
        Nemesis.curr_experiment = Experiment(Nemesis.task, Nemesis.speedup)

    @staticmethod
    def _stop_experiment():
        if Nemesis.curr_experiment is not None:
            print(f'finished running {Nemesis.curr_experiment.get_task()} with speedup {Nemesis.curr_experiment.get_speedup()}')
            Nemesis.results.append(Nemesis.curr_experiment.get_results())
            del Nemesis.curr_experiment

    @staticmethod
    def _signal_handler(sig, frame):
        curr_sample = time.perf_counter()
        passed_time = curr_sample - Nemesis.last_sample
        Nemesis.last_sample = curr_sample
        if Nemesis.curr_experiment:
            loops = Nemesis.curr_experiment.get_loops()
            # print(loops)
            for loop in loops:
                loop._update_ready(True)
                handles = Nemesis._get_waiting_handles(loop)
                Nemesis.curr_experiment.add_handles(handles, loop, passed_time)

        Nemesis.r_duration -= passed_time
        if (Nemesis.r_duration <= 0):
            Nemesis._stop_experiment()
            Nemesis._start_experiment()

    def _get_waiting_handles(loop):
        handles = []
        for handle in loop._ready:
            if (fmt_handle := _format_handle(handle)) is not None \
               and fmt_handle not in handles:
                # no duplicates
                handles.append(fmt_handle)
        return handles

    @staticmethod
    def _should_trace(filename):
        '''Returns FALSE if filename is uninteresting to the user.
        Don't depend on this. It's good enough for testing.'''
        # FIXME Assume GuixSD. Makes filtering easy
        if not filename:
            return False
        if '/gnu/store' in filename:
            return False
        if '/usr/local/lib/python' in filename:
            return False
        if 'site-packages' in filename:
            return False
        if 'propcache' in filename:
            return False
        if '.pyx' in filename:
            return False
        if filename[0] == '<':
            return False
        if 'nemesis' in filename:
            return False
        return True


the_globals = {
    '__name__': '__main__',
    '__doc__': None,
    '__package__': None,
    '__loader__': globals()['__loader__'],
    '__spec__': None,
    '__annotations__': {},
    '__builtins__': globals()['__builtins__'],
    '__file__': None,
    '__cached__': None,
}


if __name__ == "__main__":
    # parses CLI arguments and facilitates profiler runtime.
    parser = argparse.ArgumentParser(
        usage='%(prog)s [args] -- prog'
    )

    parser.add_argument('-i', '--interval',
                        help='The minimum amount of time inbetween \
                        samples in seconds.',
                        metavar='',
                        type=float,
                        default=0.01)
    parser.add_argument('-s', '--speedup',
                        help='The amount of virtual speedup.',
                        metavar='',
                        type=float,
                        default=0.5)
    parser.add_argument('-c', '--task',
                        help='The task to virtually speedup.',
                        metavar='',
                        type=str,
                        required=True)
    parser.add_argument('-e', '--experiment-duration',
                        help='The performance experiment duration. Defaults to 4 seconds.',
                        metavar='',
                        type=float,
                        default=4)
    parser.add_argument('-w', '--warmup-time',
                        help='Amount of time to wait until the first performance experiment. Default is the minimum time of 100 milliseconds',
                        metavar='',
                        type=float,
                        default=0.1)
    parser.add_argument('prog',
                        type=str,
                        nargs='*',
                        help='Path to the python script and its arguments.')
    args = parser.parse_args()

    sys.argv = args.prog
    try:
        with open(args.prog[0], 'r', encoding='utf-8') as fp:
            code = compile(fp.read(), args.prog[0], "exec")
            Nemesis(args.task,
                    args.speedup,
                    args.experiment_duration,
                    args.warmup_time,
                    args.interval).start()
            exec(code, the_globals)
            Nemesis.stop()
    except Exception:
        traceback.print_exc()