from contextlib import contextmanager
from unittest.mock import patch

import hypothesis.strategies as st
import pytest
from hypothesis import given

from vdirsyncer import exceptions
from vdirsyncer.cli.fetchparams import expand_fetch_params
from vdirsyncer.cli.fetchparams import STRATEGIES


@pytest.fixture
def mystrategy(monkeypatch):
    def strategy(x):
        calls.append(x)
        return x
    calls = []
    monkeypatch.setitem(STRATEGIES, 'mystrategy', strategy)
    return calls


@contextmanager
def dummy_strategy():
    def strategy(x):
        calls.append(x)
        return x

    calls = []
    with patch.dict(STRATEGIES, {"mystrategy": strategy}):
        yield calls


@pytest.fixture
def value_cache(monkeypatch):
    _cache = {}

    class FakeContext:
        fetched_params = _cache

        def find_object(self, _):
            return self

    def get_context(*a, **kw):
        return FakeContext()

    monkeypatch.setattr('click.get_current_context', get_context)
    return _cache


def test_key_conflict(monkeypatch, mystrategy):
    with pytest.raises(ValueError) as excinfo:
        expand_fetch_params({
            'foo': 'bar',
            'foo.fetch': ['mystrategy', 'baz']
        })

    assert 'Can\'t set foo.fetch and foo.' in str(excinfo.value)


@given(s=st.text(), t=st.text(min_size=1))
def test_fuzzing(s, t):
    with dummy_strategy():
        config = expand_fetch_params({f"{s}.fetch": ["mystrategy", t]})

    assert config[s] == t


@pytest.mark.parametrize('value', [
    [],
    'lol',
    42
])
def test_invalid_fetch_value(mystrategy, value):
    with pytest.raises(ValueError) as excinfo:
        expand_fetch_params({
            'foo.fetch': value
        })

    assert 'Expected a list' in str(excinfo.value) or \
        'Expected list of length > 0' in str(excinfo.value)


def test_unknown_strategy():
    with pytest.raises(exceptions.UserError) as excinfo:
        expand_fetch_params({
            'foo.fetch': ['unreal', 'asdf']
        })

    assert 'Unknown strategy' in str(excinfo.value)


def test_caching(monkeypatch, mystrategy, value_cache):
    orig_cfg = {'foo.fetch': ['mystrategy', 'asdf']}

    rv = expand_fetch_params(orig_cfg)
    assert rv['foo'] == 'asdf'
    assert mystrategy == ['asdf']
    assert len(value_cache) == 1

    rv = expand_fetch_params(orig_cfg)
    assert rv['foo'] == 'asdf'
    assert mystrategy == ['asdf']
    assert len(value_cache) == 1

    value_cache.clear()
    rv = expand_fetch_params(orig_cfg)
    assert rv['foo'] == 'asdf'
    assert mystrategy == ['asdf'] * 2
    assert len(value_cache) == 1


def test_failed_strategy(monkeypatch, value_cache):
    calls = []

    def strategy(x):
        calls.append(x)
        raise KeyboardInterrupt()

    monkeypatch.setitem(STRATEGIES, 'mystrategy', strategy)

    orig_cfg = {'foo.fetch': ['mystrategy', 'asdf']}

    for _ in range(2):
        with pytest.raises(KeyboardInterrupt):
            expand_fetch_params(orig_cfg)

    assert len(value_cache) == 1
    assert len(calls) == 1


def test_empty_value(monkeypatch, mystrategy):
    with pytest.raises(exceptions.UserError) as excinfo:
        expand_fetch_params({
            'foo.fetch': ['mystrategy', '']
        })

    assert 'Empty value for foo.fetch, this most likely indicates an error' \
        in str(excinfo.value)