""" This module contains functions used by the test cases to hide the
architecture and/or the platform dependent nature of the tests. """

from __future__ import absolute_import

# System modules
import itertools
import re
import subprocess
import sys

# Third-party modules
import six
from six.moves.urllib import parse as urlparse

# LLDB modules
from . import configuration
import use_lldb_suite
import lldb


def check_first_register_readable(test_case):
    arch = test_case.getArchitecture()

    if arch in ['x86_64', 'i386']:
        test_case.expect("register read eax", substrs=['eax = 0x'])
    elif arch in ['arm']:
        test_case.expect("register read r0", substrs=['r0 = 0x'])
    elif arch in ['aarch64']:
        test_case.expect("register read x0", substrs=['x0 = 0x'])
    elif re.match("mips", arch):
        test_case.expect("register read zero", substrs=['zero = 0x'])
    elif arch in ['s390x']:
        test_case.expect("register read r0", substrs=['r0 = 0x'])
    else:
        # TODO: Add check for other architectures
        test_case.fail(
            "Unsupported architecture for test case (arch: %s)" %
            test_case.getArchitecture())


def _run_adb_command(cmd, device_id):
    device_id_args = []
    if device_id:
        device_id_args = ["-s", device_id]
    full_cmd = ["adb"] + device_id_args + cmd
    p = subprocess.Popen(
        full_cmd,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE)
    stdout, stderr = p.communicate()
    return p.returncode, stdout, stderr


def target_is_android():
    if not hasattr(target_is_android, 'result'):
        triple = lldb.DBG.GetSelectedPlatform().GetTriple()
        match = re.match(".*-.*-.*-android", triple)
        target_is_android.result = match is not None
    return target_is_android.result


def android_device_api():
    if not hasattr(android_device_api, 'result'):
        assert configuration.lldb_platform_url is not None
        device_id = None
        parsed_url = urlparse.urlparse(configuration.lldb_platform_url)
        host_name = parsed_url.netloc.split(":")[0]
        if host_name != 'localhost':
            device_id = host_name
            if device_id.startswith('[') and device_id.endswith(']'):
                device_id = device_id[1:-1]
        retcode, stdout, stderr = _run_adb_command(
            ["shell", "getprop", "ro.build.version.sdk"], device_id)
        if retcode == 0:
            android_device_api.result = int(stdout)
        else:
            raise LookupError(
                ">>> Unable to determine the API level of the Android device.\n"
                ">>> stdout:\n%s\n"
                ">>> stderr:\n%s\n" %
                (stdout, stderr))
    return android_device_api.result


def match_android_device(device_arch, valid_archs=None, valid_api_levels=None):
    if not target_is_android():
        return False
    if valid_archs is not None and device_arch not in valid_archs:
        return False
    if valid_api_levels is not None and android_device_api() not in valid_api_levels:
        return False

    return True


def finalize_build_dictionary(dictionary):
    if target_is_android():
        if dictionary is None:
            dictionary = {}
        dictionary["OS"] = "Android"
        if android_device_api() >= 16:
            dictionary["PIE"] = 1
    return dictionary


def getHostPlatform():
    """Returns the host platform running the test suite."""
    # Attempts to return a platform name matching a target Triple platform.
    if sys.platform.startswith('linux'):
        return 'linux'
    elif sys.platform.startswith('win32'):
        return 'windows'
    elif sys.platform.startswith('darwin'):
        return 'darwin'
    elif sys.platform.startswith('freebsd'):
        return 'freebsd'
    elif sys.platform.startswith('netbsd'):
        return 'netbsd'
    else:
        return sys.platform


def getDarwinOSTriples():
    return ['darwin', 'macosx', 'ios']


def getPlatform():
    """Returns the target platform which the tests are running on."""
    platform = lldb.DBG.GetSelectedPlatform().GetTriple().split('-')[2]
    if platform.startswith('freebsd'):
        platform = 'freebsd'
    elif platform.startswith('netbsd'):
        platform = 'netbsd'
    return platform


def platformIsDarwin():
    """Returns true if the OS triple for the selected platform is any valid apple OS"""
    return getPlatform() in getDarwinOSTriples()


class _PlatformContext(object):
    """Value object class which contains platform-specific options."""

    def __init__(self, shlib_environment_var, shlib_prefix, shlib_extension):
        self.shlib_environment_var = shlib_environment_var
        self.shlib_prefix = shlib_prefix
        self.shlib_extension = shlib_extension


def createPlatformContext():
    if platformIsDarwin():
        return _PlatformContext('DYLD_LIBRARY_PATH', 'lib', 'dylib')
    elif getPlatform() in ("freebsd", "linux", "netbsd"):
        return _PlatformContext('LD_LIBRARY_PATH', 'lib', 'so')
    else:
        return None


def hasChattyStderr(test_case):
    """Some targets produce garbage on the standard error output. This utility function
    determines whether the tests can be strict about the expected stderr contents."""
    if match_android_device(test_case.getArchitecture(), ['aarch64'], [22]):
        return True  # The dynamic linker on the device will complain about unknown DT entries
    return False
