import contextlib
import itertools
import os
import re
import shutil
import subprocess
import sys
import sysconfig
import tempfile
import textwrap
import unittest
from pathlib import Path
from test import support

if sys.platform != "win32":
    raise unittest.SkipTest("test only applies to Windows")

# Get winreg after the platform check
import winreg


PY_EXE = "py.exe"
if sys.executable.casefold().endswith("_d.exe".casefold()):
    PY_EXE = "py_d.exe"

# Registry data to create. On removal, everything beneath top-level names will
# be deleted.
TEST_DATA = {
    "PythonTestSuite": {
        "DisplayName": "Python Test Suite",
        "SupportUrl": "https://www.python.org/",
        "3.100": {
            "DisplayName": "X.Y version",
            "InstallPath": {
                None: sys.prefix,
                "ExecutablePath": "X.Y.exe",
            }
        },
        "3.100-32": {
            "DisplayName": "X.Y-32 version",
            "InstallPath": {
                None: sys.prefix,
                "ExecutablePath": "X.Y-32.exe",
            }
        },
        "3.100-arm64": {
            "DisplayName": "X.Y-arm64 version",
            "InstallPath": {
                None: sys.prefix,
                "ExecutablePath": "X.Y-arm64.exe",
                "ExecutableArguments": "-X fake_arg_for_test",
            }
        },
        "ignored": {
            "DisplayName": "Ignored because no ExecutablePath",
            "InstallPath": {
                None: sys.prefix,
            }
        },
    }
}


TEST_PY_ENV = dict(
    PY_PYTHON="PythonTestSuite/3.100",
    PY_PYTHON2="PythonTestSuite/3.100-32",
    PY_PYTHON3="PythonTestSuite/3.100-arm64",
)


TEST_PY_COMMANDS = "\n".join([
    "[defaults]",
    *[f"{k.lower()}={v}" for k, v in TEST_PY_ENV.items()]
])


def create_registry_data(root, data):
    def _create_registry_data(root, key, value):
        if isinstance(value, dict):
            # For a dict, we recursively create keys
            with winreg.CreateKeyEx(root, key) as hkey:
                for k, v in value.items():
                    _create_registry_data(hkey, k, v)
        elif isinstance(value, str):
            # For strings, we set values. 'key' may be None in this case
            winreg.SetValueEx(root, key, None, winreg.REG_SZ, value)
        else:
            raise TypeError("don't know how to create data for '{}'".format(value))

    for k, v in data.items():
        _create_registry_data(root, k, v)


def enum_keys(root):
    for i in itertools.count():
        try:
            yield winreg.EnumKey(root, i)
        except OSError as ex:
            if ex.winerror == 259:
                break
            raise


def delete_registry_data(root, keys):
    ACCESS = winreg.KEY_WRITE | winreg.KEY_ENUMERATE_SUB_KEYS
    for key in list(keys):
        with winreg.OpenKey(root, key, access=ACCESS) as hkey:
            delete_registry_data(hkey, enum_keys(hkey))
        winreg.DeleteKey(root, key)


def is_installed(tag):
    key = rf"Software\Python\PythonCore\{tag}\InstallPath"
    for root, flag in [
        (winreg.HKEY_CURRENT_USER, 0),
        (winreg.HKEY_LOCAL_MACHINE, winreg.KEY_WOW64_64KEY),
        (winreg.HKEY_LOCAL_MACHINE, winreg.KEY_WOW64_32KEY),
    ]:
        try:
            winreg.CloseKey(winreg.OpenKey(root, key, access=winreg.KEY_READ | flag))
            return True
        except OSError:
            pass
    return False


class PreservePyIni:
    def __init__(self, path, content):
        self.path = Path(path)
        self.content = content
        self._preserved = None

    def __enter__(self):
        try:
            self._preserved = self.path.read_bytes()
        except FileNotFoundError:
            self._preserved = None
        self.path.write_text(self.content, encoding="utf-16")

    def __exit__(self, *exc_info):
        if self._preserved is None:
            self.path.unlink()
        else:
            self.path.write_bytes(self._preserved)


class RunPyMixin:
    py_exe = None

    @classmethod
    def find_py(cls):
        py_exe = None
        if sysconfig.is_python_build(True):
            py_exe = Path(sys.executable).parent / PY_EXE
        else:
            for p in os.getenv("PATH").split(";"):
                if p:
                    py_exe = Path(p) / PY_EXE
                    if py_exe.is_file():
                        break
            else:
                py_exe = None

        # Test launch and check version, to exclude installs of older
        # releases when running outside of a source tree
        if py_exe:
            try:
                with subprocess.Popen(
                    [py_exe, "-h"],
                    stdin=subprocess.PIPE,
                    stdout=subprocess.PIPE,
                    stderr=subprocess.PIPE,
                    encoding="ascii",
                    errors="ignore",
                ) as p:
                    p.stdin.close()
                    version = next(p.stdout).splitlines()[0].rpartition(" ")[2]
                    p.stdout.read()
                    p.wait(10)
                if not sys.version.startswith(version):
                    py_exe = None
            except OSError:
                py_exe = None

        if not py_exe:
            raise unittest.SkipTest(
                "cannot locate '{}' for test".format(PY_EXE)
            )
        return py_exe

    def run_py(self, args, env=None, allow_fail=False, expect_returncode=0):
        if not self.py_exe:
            self.py_exe = self.find_py()

        ignore = {"VIRTUAL_ENV", "PY_PYTHON", "PY_PYTHON2", "PY_PYTHON3"}
        env = {
            **{k.upper(): v for k, v in os.environ.items() if k.upper() not in ignore},
            **{k.upper(): v for k, v in (env or {}).items()},
            "PYLAUNCHER_DEBUG": "1",
            "PYLAUNCHER_DRYRUN": "1",
        }
        with subprocess.Popen(
            [self.py_exe, *args],
            env=env,
            stdin=subprocess.PIPE,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
        ) as p:
            p.stdin.close()
            p.wait(10)
            out = p.stdout.read().decode("utf-8", "replace")
            err = p.stderr.read().decode("ascii", "replace")
        if p.returncode != expect_returncode and support.verbose and not allow_fail:
            print("++ COMMAND ++")
            print([self.py_exe, *args])
            print("++ STDOUT ++")
            print(out)
            print("++ STDERR ++")
            print(err)
        if allow_fail and p.returncode != expect_returncode:
            raise subprocess.CalledProcessError(p.returncode, [self.py_exe, *args], out, err)
        else:
            self.assertEqual(expect_returncode, p.returncode)
        data = {
            s.partition(":")[0]: s.partition(":")[2].lstrip()
            for s in err.splitlines()
            if not s.startswith("#") and ":" in s
        }
        data["stdout"] = out
        data["stderr"] = err
        return data

    def py_ini(self, content):
        if not self.py_exe:
            self.py_exe = self.find_py()
        return PreservePyIni(self.py_exe.with_name("py.ini"), content)

    @contextlib.contextmanager
    def script(self, content, encoding="utf-8"):
        file = Path(tempfile.mktemp(dir=os.getcwd()) + ".py")
        file.write_text(content, encoding=encoding)
        try:
            yield file
        finally:
            file.unlink()

    @contextlib.contextmanager
    def fake_venv(self):
        venv = Path.cwd() / "Scripts"
        venv.mkdir(exist_ok=True, parents=True)
        venv_exe = (venv / Path(sys.executable).name)
        venv_exe.touch()
        try:
            yield venv_exe, {"VIRTUAL_ENV": str(venv.parent)}
        finally:
            shutil.rmtree(venv)


class TestLauncher(unittest.TestCase, RunPyMixin):
    @classmethod
    def setUpClass(cls):
        with winreg.CreateKey(winreg.HKEY_CURRENT_USER, rf"Software\Python") as key:
            create_registry_data(key, TEST_DATA)

        if support.verbose:
            p = subprocess.check_output("reg query HKCU\\Software\\Python /s")
            #print(p.decode('mbcs'))


    @classmethod
    def tearDownClass(cls):
        with winreg.OpenKey(winreg.HKEY_CURRENT_USER, rf"Software\Python", access=winreg.KEY_WRITE | winreg.KEY_ENUMERATE_SUB_KEYS) as key:
            delete_registry_data(key, TEST_DATA)


    def test_version(self):
        data = self.run_py(["-0"])
        self.assertEqual(self.py_exe, Path(data["argv0"]))
        self.assertEqual(sys.version.partition(" ")[0], data["version"])

    def test_help_option(self):
        data = self.run_py(["-h"])
        self.assertEqual("True", data["SearchInfo.help"])

    def test_list_option(self):
        for opt, v1, v2 in [
            ("-0", "True", "False"),
            ("-0p", "False", "True"),
            ("--list", "True", "False"),
            ("--list-paths", "False", "True"),
        ]:
            with self.subTest(opt):
                data = self.run_py([opt])
                self.assertEqual(v1, data["SearchInfo.list"])
                self.assertEqual(v2, data["SearchInfo.listPaths"])

    def test_list(self):
        data = self.run_py(["--list"])
        found = {}
        expect = {}
        for line in data["stdout"].splitlines():
            m = re.match(r"\s*(.+?)\s+?(\*\s+)?(.+)$", line)
            if m:
                found[m.group(1)] = m.group(3)
        for company in TEST_DATA:
            company_data = TEST_DATA[company]
            tags = [t for t in company_data if isinstance(company_data[t], dict)]
            for tag in tags:
                arg = f"-V:{company}/{tag}"
                expect[arg] = company_data[tag]["DisplayName"]
            expect.pop(f"-V:{company}/ignored", None)

        actual = {k: v for k, v in found.items() if k in expect}
        try:
            self.assertDictEqual(expect, actual)
        except:
            if support.verbose:
                print("*** STDOUT ***")
                print(data["stdout"])
            raise

    def test_list_paths(self):
        data = self.run_py(["--list-paths"])
        found = {}
        expect = {}
        for line in data["stdout"].splitlines():
            m = re.match(r"\s*(.+?)\s+?(\*\s+)?(.+)$", line)
            if m:
                found[m.group(1)] = m.group(3)
        for company in TEST_DATA:
            company_data = TEST_DATA[company]
            tags = [t for t in company_data if isinstance(company_data[t], dict)]
            for tag in tags:
                arg = f"-V:{company}/{tag}"
                install = company_data[tag]["InstallPath"]
                try:
                    expect[arg] = install["ExecutablePath"]
                    try:
                        expect[arg] += " " + install["ExecutableArguments"]
                    except KeyError:
                        pass
                except KeyError:
                    expect[arg] = str(Path(install[None]) / Path(sys.executable).name)

            expect.pop(f"-V:{company}/ignored", None)

        actual = {k: v for k, v in found.items() if k in expect}
        try:
            self.assertDictEqual(expect, actual)
        except:
            if support.verbose:
                print("*** STDOUT ***")
                print(data["stdout"])
            raise

    def test_filter_to_company(self):
        company = "PythonTestSuite"
        data = self.run_py([f"-V:{company}/"])
        self.assertEqual("X.Y.exe", data["LaunchCommand"])
        self.assertEqual(company, data["env.company"])
        self.assertEqual("3.100", data["env.tag"])

    def test_filter_to_tag(self):
        company = "PythonTestSuite"
        data = self.run_py([f"-V:3.100"])
        self.assertEqual("X.Y.exe", data["LaunchCommand"])
        self.assertEqual(company, data["env.company"])
        self.assertEqual("3.100", data["env.tag"])

        data = self.run_py([f"-V:3.100-3"])
        self.assertEqual("X.Y-32.exe", data["LaunchCommand"])
        self.assertEqual(company, data["env.company"])
        self.assertEqual("3.100-32", data["env.tag"])

        data = self.run_py([f"-V:3.100-a"])
        self.assertEqual("X.Y-arm64.exe -X fake_arg_for_test", data["LaunchCommand"])
        self.assertEqual(company, data["env.company"])
        self.assertEqual("3.100-arm64", data["env.tag"])

    def test_filter_to_company_and_tag(self):
        company = "PythonTestSuite"
        data = self.run_py([f"-V:{company}/3.1"])
        self.assertEqual("X.Y.exe", data["LaunchCommand"])
        self.assertEqual(company, data["env.company"])
        self.assertEqual("3.100", data["env.tag"])

    def test_search_major_3(self):
        try:
            data = self.run_py(["-3"], allow_fail=True)
        except subprocess.CalledProcessError:
            raise unittest.SkipTest("requires at least one Python 3.x install")
        self.assertEqual("PythonCore", data["env.company"])
        self.assertTrue(data["env.tag"].startswith("3."), data["env.tag"])

    def test_search_major_3_32(self):
        try:
            data = self.run_py(["-3-32"], allow_fail=True)
        except subprocess.CalledProcessError:
            if not any(is_installed(f"3.{i}-32") for i in range(5, 11)):
                raise unittest.SkipTest("requires at least one 32-bit Python 3.x install")
            raise
        self.assertEqual("PythonCore", data["env.company"])
        self.assertTrue(data["env.tag"].startswith("3."), data["env.tag"])
        self.assertTrue(data["env.tag"].endswith("-32"), data["env.tag"])

    def test_search_major_2(self):
        try:
            data = self.run_py(["-2"], allow_fail=True)
        except subprocess.CalledProcessError:
            if not is_installed("2.7"):
                raise unittest.SkipTest("requires at least one Python 2.x install")
        self.assertEqual("PythonCore", data["env.company"])
        self.assertTrue(data["env.tag"].startswith("2."), data["env.tag"])

    def test_py_default(self):
        with self.py_ini(TEST_PY_COMMANDS):
            data = self.run_py(["-arg"])
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100", data["SearchInfo.tag"])
        self.assertEqual("X.Y.exe -arg", data["stdout"].strip())

    def test_py2_default(self):
        with self.py_ini(TEST_PY_COMMANDS):
            data = self.run_py(["-2", "-arg"])
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100-32", data["SearchInfo.tag"])
        self.assertEqual("X.Y-32.exe -arg", data["stdout"].strip())

    def test_py3_default(self):
        with self.py_ini(TEST_PY_COMMANDS):
            data = self.run_py(["-3", "-arg"])
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100-arm64", data["SearchInfo.tag"])
        self.assertEqual("X.Y-arm64.exe -X fake_arg_for_test -arg", data["stdout"].strip())

    def test_py_default_env(self):
        data = self.run_py(["-arg"], env=TEST_PY_ENV)
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100", data["SearchInfo.tag"])
        self.assertEqual("X.Y.exe -arg", data["stdout"].strip())

    def test_py2_default_env(self):
        data = self.run_py(["-2", "-arg"], env=TEST_PY_ENV)
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100-32", data["SearchInfo.tag"])
        self.assertEqual("X.Y-32.exe -arg", data["stdout"].strip())

    def test_py3_default_env(self):
        data = self.run_py(["-3", "-arg"], env=TEST_PY_ENV)
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100-arm64", data["SearchInfo.tag"])
        self.assertEqual("X.Y-arm64.exe -X fake_arg_for_test -arg", data["stdout"].strip())

    def test_py_default_in_list(self):
        data = self.run_py(["-0"], env=TEST_PY_ENV)
        default = None
        for line in data["stdout"].splitlines():
            m = re.match(r"\s*-V:(.+?)\s+?\*\s+(.+)$", line)
            if m:
                default = m.group(1)
                break
        self.assertEqual("PythonTestSuite/3.100", default)

    def test_virtualenv_in_list(self):
        with self.fake_venv() as (venv_exe, env):
            data = self.run_py(["-0p"], env=env)
            for line in data["stdout"].splitlines():
                m = re.match(r"\s*\*\s+(.+)$", line)
                if m:
                    self.assertEqual(str(venv_exe), m.group(1))
                    break
            else:
                self.fail("did not find active venv path")

            data = self.run_py(["-0"], env=env)
            for line in data["stdout"].splitlines():
                m = re.match(r"\s*\*\s+(.+)$", line)
                if m:
                    self.assertEqual("Active venv", m.group(1))
                    break
            else:
                self.fail("did not find active venv entry")

    def test_virtualenv_with_env(self):
        with self.fake_venv() as (venv_exe, env):
            data1 = self.run_py([], env={**env, "PY_PYTHON": "PythonTestSuite/3"})
            data2 = self.run_py(["-V:PythonTestSuite/3"], env={**env, "PY_PYTHON": "PythonTestSuite/3"})
        # Compare stdout, because stderr goes via ascii
        self.assertEqual(data1["stdout"].strip(), str(venv_exe))
        self.assertEqual(data1["SearchInfo.lowPriorityTag"], "True")
        # Ensure passing the argument doesn't trigger the same behaviour
        self.assertNotEqual(data2["stdout"].strip(), str(venv_exe))
        self.assertNotEqual(data2["SearchInfo.lowPriorityTag"], "True")

    def test_py_shebang(self):
        with self.py_ini(TEST_PY_COMMANDS):
            with self.script("#! /usr/bin/env python -prearg") as script:
                data = self.run_py([script, "-postarg"])
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100", data["SearchInfo.tag"])
        self.assertEqual(f"X.Y.exe -prearg {script} -postarg", data["stdout"].strip())

    def test_py2_shebang(self):
        with self.py_ini(TEST_PY_COMMANDS):
            with self.script("#! /usr/bin/env python2 -prearg") as script:
                data = self.run_py([script, "-postarg"])
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100-32", data["SearchInfo.tag"])
        self.assertEqual(f"X.Y-32.exe -prearg {script} -postarg", data["stdout"].strip())

    def test_py3_shebang(self):
        with self.py_ini(TEST_PY_COMMANDS):
            with self.script("#! /usr/bin/env python3 -prearg") as script:
                data = self.run_py([script, "-postarg"])
        self.assertEqual("PythonTestSuite", data["SearchInfo.company"])
        self.assertEqual("3.100-arm64", data["SearchInfo.tag"])
        self.assertEqual(f"X.Y-arm64.exe -X fake_arg_for_test -prearg {script} -postarg", data["stdout"].strip())

    def test_install(self):
        data = self.run_py(["-V:3.10"], env={"PYLAUNCHER_ALWAYS_INSTALL": "1"}, expect_returncode=111)
        cmd = data["stdout"].strip()
        # If winget is runnable, we should find it. Otherwise, we'll be trying
        # to open the Store.
        try:
            subprocess.check_call(["winget.exe", "--version"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
        except FileNotFoundError:
            self.assertIn("ms-windows-store://", cmd)
        else:
            self.assertIn("winget.exe", cmd)
        # Both command lines include the store ID
        self.assertIn("9PJPW5LDXLZ5", cmd)