from __future__ import absolute_import, division, print_function

import dask

from dask.local import start_state_from_dask, get_sync, finish_task, sortkey
from dask.order import order
from dask.utils_test import GetFunctionTestMixin, inc, add


fib_dask = {'f0': 0, 'f1': 1, 'f2': 1, 'f3': 2, 'f4': 3, 'f5': 5, 'f6': 8}


def test_start_state():
    dsk = {'x': 1, 'y': 2, 'z': (inc, 'x'), 'w': (add, 'z', 'y')}
    result = start_state_from_dask(dsk)

    expected = {'cache': {'x': 1, 'y': 2},
                'dependencies': {'w': set(['y', 'z']),
                                 'x': set([]),
                                 'y': set([]),
                                 'z': set(['x'])},
                'dependents': {'w': set([]),
                               'x': set(['z']),
                               'y': set(['w']),
                               'z': set(['w'])},
                'finished': set([]),
                'released': set([]),
                'running': set([]),
                'ready': ['z'],
                'waiting': {'w': set(['z'])},
                'waiting_data': {'x': set(['z']),
                                 'y': set(['w']),
                                 'z': set(['w'])}}
    assert result == expected


def test_start_state_looks_at_cache():
    dsk = {'b': (inc, 'a')}
    cache = {'a': 1}
    result = start_state_from_dask(dsk, cache)
    assert result['dependencies']['b'] == set(['a'])
    assert result['ready'] == ['b']


def test_start_state_with_redirects():
    dsk = {'x': 1, 'y': 'x', 'z': (inc, 'y')}
    result = start_state_from_dask(dsk)
    assert result['cache'] == {'x': 1}


def test_start_state_with_independent_but_runnable_tasks():
    assert start_state_from_dask({'x': (inc, 1)})['ready'] == ['x']


def test_start_state_with_tasks_no_deps():
    dsk = {'a': [1, (inc, 2)],
           'b': [1, 2, 3, 4],
           'c': (inc, 3)}
    state = start_state_from_dask(dsk)
    assert list(state['cache'].keys()) == ['b']
    assert 'a' in state['ready'] and 'c' in state['ready']
    deps = dict((k, set()) for k in 'abc')
    assert state['dependencies'] == deps
    assert state['dependents'] == deps


def test_finish_task():
    dsk = {'x': 1, 'y': 2, 'z': (inc, 'x'), 'w': (add, 'z', 'y')}
    sortkey = order(dsk).get
    state = start_state_from_dask(dsk)
    state['ready'].remove('z')
    state['running'] = set(['z', 'other-task'])
    task = 'z'
    result = 2

    state['cache']['z'] = result
    finish_task(dsk, task, state, set(), sortkey)

    assert state == {'cache': {'y': 2, 'z': 2},
                     'dependencies': {'w': set(['y', 'z']),
                                      'x': set([]),
                                      'y': set([]),
                                      'z': set(['x'])},
                     'finished': set(['z']),
                     'released': set(['x']),
                     'running': set(['other-task']),
                     'dependents': {'w': set([]),
                                    'x': set(['z']),
                                    'y': set(['w']),
                                    'z': set(['w'])},
                     'ready': ['w'],
                     'waiting': {},
                     'waiting_data': {'y': set(['w']),
                                      'z': set(['w'])}}


class TestGetAsync(GetFunctionTestMixin):
    get = staticmethod(get_sync)

    def test_get_sync_num_workers(self):
        self.get({'x': (inc, 'y'), 'y': 1}, 'x', num_workers=2)


def test_cache_options():
    try:
        from chest import Chest
    except ImportError:
        return
    cache = Chest()

    def inc2(x):
        assert 'y' in cache
        return x + 1

    with dask.set_options(cache=cache):
        get_sync({'x': (inc2, 'y'), 'y': 1}, 'x')


def test_sort_key():
    L = ['x', ('x', 1), ('z', 0), ('x', 0)]
    assert sorted(L, key=sortkey) == ['x', ('x', 0), ('x', 1), ('z', 0)]


def test_callback():
    f = lambda x: x + 1
    dsk = {'a': (f, 1)}
    from dask.threaded import get

    def start_callback(key, d, state):
        assert key == 'a' or key is None
        assert d == dsk
        assert isinstance(state, dict)

    def end_callback(key, value, d, state, worker_id):
        assert key == 'a' or key is None
        assert value == 2 or value is None
        assert d == dsk
        assert isinstance(state, dict)

    get(dsk, 'a', start_callback=start_callback, end_callback=end_callback)


def test_exceptions_propagate():
    class MyException(Exception):
        def __init__(self, a, b):
            self.a = a
            self.b = b

        def __str__(self):
            return "My Exception!"

    def f():
        raise MyException(1, 2)

    from dask.threaded import get

    try:
        get({'x': (f,)}, 'x')
        assert False
    except MyException as e:
        assert "My Exception!" in str(e)
        assert 'a' in dir(e)
        assert e.a == 1
        assert e.b == 2


def test_ordering():
    L = []

    def append(i):
        L.append(i)

    dsk = {('x', i): (append, i) for i in range(10)}
    x_keys = sorted(dsk)
    dsk['y'] = (lambda *args: None, list(x_keys))

    get_sync(dsk, 'y')

    assert L == sorted(L, reverse=True)
