# Test the runpy module
import unittest
import os
import os.path
import sys
import re
import tempfile
import importlib, importlib.machinery, importlib.util
import py_compile
import warnings
import pathlib
from test.support import (
    forget, make_legacy_pyc, unload, verbose, no_tracing,
    create_empty_file, temp_dir)
from test.support.script_helper import make_script, make_zip_script


import runpy
from runpy import _run_code, _run_module_code, run_module, run_path
# Note: This module can't safely test _run_module_as_main as it
# runs its tests in the current process, which would mess with the
# real __main__ module (usually test.regrtest)
# See test_cmd_line_script for a test that executes that code path


# Set up the test code and expected results
example_source = """\
# Check basic code execution
result = ['Top level assignment']
def f():
    result.append('Lower level reference')
f()
del f
# Check the sys module
import sys
run_argv0 = sys.argv[0]
run_name_in_sys_modules = __name__ in sys.modules
module_in_sys_modules = (run_name_in_sys_modules and
                         globals() is sys.modules[__name__].__dict__)
# Check nested operation
import runpy
nested = runpy._run_module_code('x=1\\n', mod_name='<run>')
"""

implicit_namespace = {
    "__name__": None,
    "__file__": None,
    "__cached__": None,
    "__package__": None,
    "__doc__": None,
    "__spec__": None
}
example_namespace =  {
    "sys": sys,
    "runpy": runpy,
    "result": ["Top level assignment", "Lower level reference"],
    "run_argv0": sys.argv[0],
    "run_name_in_sys_modules": False,
    "module_in_sys_modules": False,
    "nested": dict(implicit_namespace,
                   x=1, __name__="<run>", __loader__=None),
}
example_namespace.update(implicit_namespace)

class CodeExecutionMixin:
    # Issue #15230 (run_path not handling run_name correctly) highlighted a
    # problem with the way arguments were being passed from higher level APIs
    # down to lower level code. This mixin makes it easier to ensure full
    # testing occurs at those upper layers as well, not just at the utility
    # layer

    # Figuring out the loader details in advance is hard to do, so we skip
    # checking the full details of loader and loader_state
    CHECKED_SPEC_ATTRIBUTES = ["name", "parent", "origin", "cached",
                               "has_location", "submodule_search_locations"]

    def assertNamespaceMatches(self, result_ns, expected_ns):
        """Check two namespaces match.

           Ignores any unspecified interpreter created names
        """
        # Avoid side effects
        result_ns = result_ns.copy()
        expected_ns = expected_ns.copy()
        # Impls are permitted to add extra names, so filter them out
        for k in list(result_ns):
            if k.startswith("__") and k.endswith("__"):
                if k not in expected_ns:
                    result_ns.pop(k)
                if k not in expected_ns["nested"]:
                    result_ns["nested"].pop(k)
        # Spec equality includes the loader, so we take the spec out of the
        # result namespace and check that separately
        result_spec = result_ns.pop("__spec__")
        expected_spec = expected_ns.pop("__spec__")
        if expected_spec is None:
            self.assertIsNone(result_spec)
        else:
            # If an expected loader is set, we just check we got the right
            # type, rather than checking for full equality
            if expected_spec.loader is not None:
                self.assertEqual(type(result_spec.loader),
                                 type(expected_spec.loader))
            for attr in self.CHECKED_SPEC_ATTRIBUTES:
                k = "__spec__." + attr
                actual = (k, getattr(result_spec, attr))
                expected = (k, getattr(expected_spec, attr))
                self.assertEqual(actual, expected)
        # For the rest, we still don't use direct dict comparison on the
        # namespace, as the diffs are too hard to debug if anything breaks
        self.assertEqual(set(result_ns), set(expected_ns))
        for k in result_ns:
            actual = (k, result_ns[k])
            expected = (k, expected_ns[k])
            self.assertEqual(actual, expected)

    def check_code_execution(self, create_namespace, expected_namespace):
        """Check that an interface runs the example code correctly

           First argument is a callable accepting the initial globals and
           using them to create the actual namespace
           Second argument is the expected result
        """
        sentinel = object()
        expected_ns = expected_namespace.copy()
        run_name = expected_ns["__name__"]
        saved_argv0 = sys.argv[0]
        saved_mod = sys.modules.get(run_name, sentinel)
        # Check without initial globals
        result_ns = create_namespace(None)
        self.assertNamespaceMatches(result_ns, expected_ns)
        self.assertIs(sys.argv[0], saved_argv0)
        self.assertIs(sys.modules.get(run_name, sentinel), saved_mod)
        # And then with initial globals
        initial_ns = {"sentinel": sentinel}
        expected_ns["sentinel"] = sentinel
        result_ns = create_namespace(initial_ns)
        self.assertIsNot(result_ns, initial_ns)
        self.assertNamespaceMatches(result_ns, expected_ns)
        self.assertIs(sys.argv[0], saved_argv0)
        self.assertIs(sys.modules.get(run_name, sentinel), saved_mod)


class ExecutionLayerTestCase(unittest.TestCase, CodeExecutionMixin):
    """Unit tests for runpy._run_code and runpy._run_module_code"""

    def test_run_code(self):
        expected_ns = example_namespace.copy()
        expected_ns.update({
            "__loader__": None,
        })
        def create_ns(init_globals):
            return _run_code(example_source, {}, init_globals)
        self.check_code_execution(create_ns, expected_ns)

    def test_run_module_code(self):
        mod_name = "<Nonsense>"
        mod_fname = "Some other nonsense"
        mod_loader = "Now you're just being silly"
        mod_package = '' # Treat as a top level module
        mod_spec = importlib.machinery.ModuleSpec(mod_name,
                                                  origin=mod_fname,
                                                  loader=mod_loader)
        expected_ns = example_namespace.copy()
        expected_ns.update({
            "__name__": mod_name,
            "__file__": mod_fname,
            "__loader__": mod_loader,
            "__package__": mod_package,
            "__spec__": mod_spec,
            "run_argv0": mod_fname,
            "run_name_in_sys_modules": True,
            "module_in_sys_modules": True,
        })
        def create_ns(init_globals):
            return _run_module_code(example_source,
                                    init_globals,
                                    mod_name,
                                    mod_spec)
        self.check_code_execution(create_ns, expected_ns)

# TODO: Use self.addCleanup to get rid of a lot of try-finally blocks
class RunModuleTestCase(unittest.TestCase, CodeExecutionMixin):
    """Unit tests for runpy.run_module"""

    def expect_import_error(self, mod_name):
        try:
            run_module(mod_name)
        except ImportError:
            pass
        else:
            self.fail("Expected import error for " + mod_name)

    def test_invalid_names(self):
        # Builtin module
        self.expect_import_error("sys")
        # Non-existent modules
        self.expect_import_error("sys.imp.eric")
        self.expect_import_error("os.path.half")
        self.expect_import_error("a.bee")
        # Relative names not allowed
        self.expect_import_error(".howard")
        self.expect_import_error("..eaten")
        self.expect_import_error(".test_runpy")
        self.expect_import_error(".unittest")
        # Package without __main__.py
        self.expect_import_error("multiprocessing")

    def test_library_module(self):
        self.assertEqual(run_module("runpy")["__name__"], "runpy")

    def _add_pkg_dir(self, pkg_dir, namespace=False):
        os.mkdir(pkg_dir)
        if namespace:
            return None
        pkg_fname = os.path.join(pkg_dir, "__init__.py")
        create_empty_file(pkg_fname)
        return pkg_fname

    def _make_pkg(self, source, depth, mod_base="runpy_test",
                     *, namespace=False, parent_namespaces=False):
        # Enforce a couple of internal sanity checks on test cases
        if (namespace or parent_namespaces) and not depth:
            raise RuntimeError("Can't mark top level module as a "
                               "namespace package")
        pkg_name = "__runpy_pkg__"
        test_fname = mod_base+os.extsep+"py"
        pkg_dir = sub_dir = os.path.realpath(tempfile.mkdtemp())
        if verbose > 1: print("  Package tree in:", sub_dir)
        sys.path.insert(0, pkg_dir)
        if verbose > 1: print("  Updated sys.path:", sys.path[0])
        if depth:
            namespace_flags = [parent_namespaces] * depth
            namespace_flags[-1] = namespace
            for namespace_flag in namespace_flags:
                sub_dir = os.path.join(sub_dir, pkg_name)
                pkg_fname = self._add_pkg_dir(sub_dir, namespace_flag)
                if verbose > 1: print("  Next level in:", sub_dir)
                if verbose > 1: print("  Created:", pkg_fname)
        mod_fname = os.path.join(sub_dir, test_fname)
        with open(mod_fname, "w") as mod_file:
            mod_file.write(source)
        if verbose > 1: print("  Created:", mod_fname)
        mod_name = (pkg_name+".")*depth + mod_base
        mod_spec = importlib.util.spec_from_file_location(mod_name,
                                                          mod_fname)
        return pkg_dir, mod_fname, mod_name, mod_spec

    def _del_pkg(self, top):
        for entry in list(sys.modules):
            if entry.startswith("__runpy_pkg__"):
                del sys.modules[entry]
        if verbose > 1: print("  Removed sys.modules entries")
        del sys.path[0]
        if verbose > 1: print("  Removed sys.path entry")
        for root, dirs, files in os.walk(top, topdown=False):
            for name in files:
                try:
                    os.remove(os.path.join(root, name))
                except OSError as ex:
                    if verbose > 1: print(ex) # Persist with cleaning up
            for name in dirs:
                fullname = os.path.join(root, name)
                try:
                    os.rmdir(fullname)
                except OSError as ex:
                    if verbose > 1: print(ex) # Persist with cleaning up
        try:
            os.rmdir(top)
            if verbose > 1: print("  Removed package tree")
        except OSError as ex:
            if verbose > 1: print(ex) # Persist with cleaning up

    def _fix_ns_for_legacy_pyc(self, ns, alter_sys):
        char_to_add = "c"
        ns["__file__"] += char_to_add
        ns["__cached__"] = ns["__file__"]
        spec = ns["__spec__"]
        new_spec = importlib.util.spec_from_file_location(spec.name,
                                                          ns["__file__"])
        ns["__spec__"] = new_spec
        if alter_sys:
            ns["run_argv0"] += char_to_add


    def _check_module(self, depth, alter_sys=False,
                         *, namespace=False, parent_namespaces=False):
        pkg_dir, mod_fname, mod_name, mod_spec = (
               self._make_pkg(example_source, depth,
                              namespace=namespace,
                              parent_namespaces=parent_namespaces))
        forget(mod_name)
        expected_ns = example_namespace.copy()
        expected_ns.update({
            "__name__": mod_name,
            "__file__": mod_fname,
            "__cached__": mod_spec.cached,
            "__package__": mod_name.rpartition(".")[0],
            "__spec__": mod_spec,
        })
        if alter_sys:
            expected_ns.update({
                "run_argv0": mod_fname,
                "run_name_in_sys_modules": True,
                "module_in_sys_modules": True,
            })
        def create_ns(init_globals):
            return run_module(mod_name, init_globals, alter_sys=alter_sys)
        try:
            if verbose > 1: print("Running from source:", mod_name)
            self.check_code_execution(create_ns, expected_ns)
            importlib.invalidate_caches()
            __import__(mod_name)
            os.remove(mod_fname)
            if not sys.dont_write_bytecode:
                make_legacy_pyc(mod_fname)
                unload(mod_name)  # In case loader caches paths
                importlib.invalidate_caches()
                if verbose > 1: print("Running from compiled:", mod_name)
                self._fix_ns_for_legacy_pyc(expected_ns, alter_sys)
                self.check_code_execution(create_ns, expected_ns)
        finally:
            self._del_pkg(pkg_dir)
        if verbose > 1: print("Module executed successfully")

    def _check_package(self, depth, alter_sys=False,
                          *, namespace=False, parent_namespaces=False):
        pkg_dir, mod_fname, mod_name, mod_spec = (
               self._make_pkg(example_source, depth, "__main__",
                              namespace=namespace,
                              parent_namespaces=parent_namespaces))
        pkg_name = mod_name.rpartition(".")[0]
        forget(mod_name)
        expected_ns = example_namespace.copy()
        expected_ns.update({
            "__name__": mod_name,
            "__file__": mod_fname,
            "__cached__": importlib.util.cache_from_source(mod_fname),
            "__package__": pkg_name,
            "__spec__": mod_spec,
        })
        if alter_sys:
            expected_ns.update({
                "run_argv0": mod_fname,
                "run_name_in_sys_modules": True,