from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

import os
import sys


def test_import_from_collection(monkeypatch):
    collection_root = os.path.join(os.path.dirname(__file__), 'fixtures', 'collections')
    collection_path = os.path.join(collection_root, 'ansible_collections/my_namespace/my_collection/plugins/module_utils/my_util.py')

    # the trace we're expecting to be generated when running the code below:
    # answer = question()
    expected_trace_log = [
        (collection_path, 5, 'call'),
        (collection_path, 6, 'line'),
        (collection_path, 6, 'return'),
    ]

    # define the collection root before any ansible code has been loaded
    # otherwise config will have already been loaded and changing the environment will have no effect
    monkeypatch.setenv('ANSIBLE_COLLECTIONS_PATHS', collection_root)

    from ansible.utils.collection_loader import AnsibleCollectionLoader

    for index in [idx for idx, obj in enumerate(sys.meta_path) if isinstance(obj, AnsibleCollectionLoader)]:
        # replace any existing collection loaders that may exist
        # since these were loaded during unit test collection
        # they will not have the correct configuration
        sys.meta_path[index] = AnsibleCollectionLoader()

    # make sure the collection loader is installed
    # this will be a no-op if the collection loader is already installed
    # which will depend on whether or not any tests being run imported ansible.plugins.loader during unit test collection
    from ansible.plugins.loader import _configure_collection_loader
    _configure_collection_loader()  # currently redundant, the import above already calls this

    from ansible_collections.my_namespace.my_collection.plugins.module_utils.my_util import question

    original_trace_function = sys.gettrace()
    trace_log = []

    if original_trace_function:
        # enable tracing while preserving the existing trace function (coverage)
        def my_trace_function(frame, event, arg):
            trace_log.append((frame.f_code.co_filename, frame.f_lineno, event))

            # the original trace function expects to have itself set as the trace function
            sys.settrace(original_trace_function)
            # call the original trace function
            original_trace_function(frame, event, arg)
            # restore our trace function
            sys.settrace(my_trace_function)

            return my_trace_function
    else:
        # no existing trace function, so our trace function is much simpler
        def my_trace_function(frame, event, arg):
            trace_log.append((frame.f_code.co_filename, frame.f_lineno, event))

            return my_trace_function

    sys.settrace(my_trace_function)

    try:
        # run a minimal amount of code while the trace is running
        # adding more code here, including use of a context manager, will add more to our trace
        answer = question()
    finally:
        sys.settrace(original_trace_function)

    # make sure relative imports work from collections code
    # these require __package__ to be set correctly
    import ansible_collections.my_namespace.my_collection.plugins.module_utils.my_other_util
    import ansible_collections.my_namespace.my_collection.plugins.action.my_action

    # verify that code loaded from a collection does not inherit __future__ statements from the collection loader
    if sys.version_info[0] == 2:
        # if the collection code inherits the division future feature from the collection loader this will fail
        assert answer == 1
    else:
        assert answer == 1.5

    # verify that the filename and line number reported by the trace is correct
    # this makes sure that collection loading preserves file paths and line numbers
    assert trace_log == expected_trace_log