# Copyright 2018 the authors.
# This file is part of Hy, which is free software licensed under the Expat
# license. See the LICENSE.

import os
import sys
import ast
import imp
import tempfile
import runpy
import importlib

from fractions import Fraction

import pytest

import hy
from hy.errors import HyTypeError
from hy.lex import LexException
from hy.compiler import hy_compile
from hy.importer import hy_parse, HyLoader, cache_from_source


def test_basics():
    "Make sure the basics of the importer work"

    assert os.path.isfile('tests/resources/__init__.py')
    resources_mod = importlib.import_module('tests.resources')
    assert hasattr(resources_mod, 'kwtest')

    assert os.path.isfile('tests/resources/bin/__init__.hy')
    bin_mod = importlib.import_module('tests.resources.bin')
    assert hasattr(bin_mod, '_null_fn_for_import_test')


def test_runpy():
    # XXX: `runpy` won't update cached bytecode!  Don't know if that's
    # intentional or not.

    basic_ns = runpy.run_path('tests/resources/importer/basic.hy')
    assert 'square' in basic_ns

    main_ns = runpy.run_path('tests/resources/bin')
    assert main_ns['visited_main'] == 1
    del main_ns

    main_ns = runpy.run_module('tests.resources.bin')
    assert main_ns['visited_main'] == 1

    with pytest.raises(IOError):
        runpy.run_path('tests/resources/foobarbaz.py')


def test_stringer():
    _ast = hy_compile(hy_parse("(defn square [x] (* x x))"), '')

    assert type(_ast.body[0]) == ast.FunctionDef


def test_imports():
    path = os.getcwd() + "/tests/resources/importer/a.hy"
    testLoader = HyLoader("tests.resources.importer.a", path)

    def _import_test():
        try:
            return testLoader.load_module()
        except:
            return "Error"

    assert _import_test() == "Error"
    assert _import_test() is not None


def test_import_error_reporting():
    "Make sure that (import) reports errors correctly."

    def _import_error_test():
        try:
            _ = hy_compile(hy_parse("(import \"sys\")"), '')
        except HyTypeError:
            return "Error reported"

    assert _import_error_test() == "Error reported"
    assert _import_error_test() is not None


@pytest.mark.skipif(os.environ.get('PYTHONDONTWRITEBYTECODE'),
                    reason="Bytecode generation is suppressed")
def test_import_autocompiles():
    "Test that (import) byte-compiles the module."

    with tempfile.NamedTemporaryFile(suffix='.hy', delete=True) as f:
        f.write(b'(defn pyctest [s] (+ "X" s "Y"))')
        f.flush()

        pyc_path = cache_from_source(f.name)

        try:
            os.remove(pyc_path)
        except (IOError, OSError):
            pass

        test_loader = HyLoader("mymodule", f.name).load_module()

        assert hasattr(test_loader, 'pyctest')
        assert os.path.exists(pyc_path)

        os.remove(pyc_path)


def test_eval():
    def eval_str(s):
        return hy.eval(hy.read_str(s))

    assert eval_str('[1 2 3]') == [1, 2, 3]
    assert eval_str('{"dog" "bark" "cat" "meow"}') == {
        'dog': 'bark', 'cat': 'meow'}
    assert eval_str('(, 1 2 3)') == (1, 2, 3)
    assert eval_str('#{3 1 2}') == {1, 2, 3}
    assert eval_str('1/2') == Fraction(1, 2)
    assert eval_str('(.strip " fooooo   ")') == 'fooooo'
    assert eval_str(
        '(if True "this is if true" "this is if false")') == "this is if true"
    assert eval_str('(lfor num (range 100) :if (= (% num 2) 1) (pow num 2))') == [
        pow(num, 2) for num in range(100) if num % 2 == 1]


def test_reload():
    """Copied from CPython's `test_import.py`"""

    def unlink(filename):
        os.unlink(source)
        bytecode = cache_from_source(source)
        if os.path.isfile(bytecode):
            os.unlink(bytecode)

    TESTFN = 'testfn'
    source = TESTFN + os.extsep + "hy"
    with open(source, "w") as f:
        f.write("(setv a 1)")
        f.write("(setv b 2)")

    sys.path.insert(0, os.curdir)
    try:
        mod = importlib.import_module(TESTFN)
        assert TESTFN in sys.modules
        assert mod.a == 1
        assert mod.b == 2

        # On WinXP, just replacing the .py file wasn't enough to
        # convince reload() to reparse it.  Maybe the timestamp didn't
        # move enough.  We force it to get reparsed by removing the
        # compiled file too.
        unlink(source)

        # Now damage the module.
        with open(source, "w") as f:
            f.write("(setv a 10)")
            f.write("(setv b (// 20 0))")

        with pytest.raises(ZeroDivisionError):
            imp.reload(mod)

        # But we still expect the module to be in sys.modules.
        mod = sys.modules.get(TESTFN)
        assert mod is not None

        # We should have replaced a w/ 10, but the old b value should
        # stick.
        assert mod.a == 10
        assert mod.b == 2

        # Now fix the issue and reload the module.
        unlink(source)

        with open(source, "w") as f:
            f.write("(setv a 11)")
            f.write("(setv b (// 20 1))")

        imp.reload(mod)

        mod = sys.modules.get(TESTFN)
        assert mod is not None

        assert mod.a == 11
        assert mod.b == 20

        # Now cause a LexException
        unlink(source)

        with open(source, "w") as f:
            f.write("(setv a 11")
            f.write("(setv b (// 20 1))")

        with pytest.raises(LexException):
            imp.reload(mod)

        mod = sys.modules.get(TESTFN)
        assert mod is not None

        assert mod.a == 11
        assert mod.b == 20

        # Fix it and retry
        unlink(source)

        with open(source, "w") as f:
            f.write("(setv a 12)")
            f.write("(setv b (// 10 1))")

        imp.reload(mod)

        mod = sys.modules.get(TESTFN)
        assert mod is not None

        assert mod.a == 12
        assert mod.b == 10

    finally:
        del sys.path[0]
        unlink(source)
        del sys.modules[TESTFN]