from aergia.aergia import Aergia
import yappi
import time
import unittest


class AergiaUnitTestCase(unittest.TestCase):

    interval = 0.01
    Aergia = Aergia(interval, True)
    # yappi is a singleton

    def setUp(self):
        self.Aergia.clear()

        yappi.stop()
        yappi.clear_stats()
        yappi.set_clock_type('wall')
        yappi.set_context_id_callback(None)
        yappi.set_context_name_callback(None)
        yappi.set_tag_callback(None)

    def assert_reasonable_delay(self, func_name, time_expected, samples):
        '''Compares the results reported by Aergia for FUNC_NAME
        with time_expected.'''
        time_actual = self.aergia_extract_values_by_func(samples, func_name)
        self.assert_roughly_equal(time_actual, time_expected)

    def assert_similar_delay(self, func_name, yappi_stats, aergia_samples):
        '''Compares the results reported by Aergia for FUNC_NAME
        with yappi.'''
        time_yappi = self.yappi_extract_values_by_func(yappi_stats, func_name)

        time_aergia = self.aergia_extract_values_by_func(
            aergia_samples, func_name)

        self.assert_roughly_equal(time_aergia, time_yappi)

    def assert_roughly_equal(self, v1, v2):
        '''Throws an exception if values V1 and V2 are not within 0.035
        seconds of each other. This number is influenced by instrumentation
        overhead, sampling inconsistency, etc.'''
        a = abs(v1 - v2)
        self.assertTrue(a <= .035, f'{v1} (actual) not roughly {v2} (expected)')

    def aergia_extract_values_by_func(self, samples, func_name):
        '''Returns the total number of samples for function name, given an
        Aergia SAMPLES object.'''
        return sum(
            value for key, value in samples.items()
            if key.func == func_name
        )

    def yappi_extract_values_by_func(self, stats, func_name):
        '''Returns the total number of samples for function name, given a
        yappi stats object.'''
        for s in stats:
            if s.name == func_name:
                return s.ttot

    def yappi_print_traceable_results(self, stats):
        '''Filters the list of yappi stats, printing information for only the same
        functions as Aergia. This is for manual testing.'''
        print(f"{'FILE':<30} {'FUNC':<30} {'SEC':<10}")
        for s in stats:
            fname = s.module
            if Aergia._should_trace(fname):
                fname = \
                    (fname if len(fname) <= 25 else fname[-25:])
                print(f"{fname}:{s.lineno}".ljust(30) +
                      f"{s.name:<30} {s.ttot:<10.4f}")


def burn_cpu(sec):
    t0 = time.perf_counter()
    elapsed = 0
    while (elapsed < sec):
        for _ in range(1000):
            pass
        elapsed = time.perf_counter() - t0


def burn_io(sec):
    time.sleep(sec)