"""
mbed SDK
Copyright (c) 2011-2015 ARM Limited

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Author: Przemyslaw Wirkus <Przemyslaw.Wirkus@arm.com>
"""

import re
import pkg_resources
from .host_test_plugins import HostTestPluginBase


class HostTestPluginResetMethod_Mbed(HostTestPluginBase):

    # Plugin interface
    name = 'HostTestPluginResetMethod_Mbed'
    type = 'ResetMethod'
    stable = True
    capabilities = ['default']
    required_parameters = ['serial']

    def __init__(self):
        """! ctor
        @details We can check module version by referring to version attribute
        import pkg_resources
        print pkg_resources.require("mbed-host-tests")[0].version
        '2.7'
        """
        HostTestPluginBase.__init__(self)
        self.re_float = re.compile(r"^\d+\.\d+")
        pyserial_version = pkg_resources.require("pyserial")[0].version
        self.pyserial_version = self.get_pyserial_version(pyserial_version)
        self.is_pyserial_v3 = float(self.pyserial_version) >= 3.0

    def get_pyserial_version(self, pyserial_version):
        """! Retrieve pyserial module version
        @return Returns float with pyserial module number
        """
        version = 3.0
        m = self.re_float.search(pyserial_version)
        if m:
            try:
                version = float(m.group(0))
            except ValueError:
                version = 3.0   # We will assume you've got latest (3.0+)
        return version

    def safe_sendBreak(self, serial):
        """! Closure for pyserial version dependant API calls
        """
        if self.is_pyserial_v3:
            return self._safe_sendBreak_v3_0(serial)
        return self._safe_sendBreak_v2_7(serial)

    def _safe_sendBreak_v2_7(self, serial):
        """! pyserial 2.7 API implementation of sendBreak/setBreak
        @details
        Below API is deprecated for pyserial 3.x versions!
        http://pyserial.readthedocs.org/en/latest/pyserial_api.html#serial.Serial.sendBreak
        http://pyserial.readthedocs.org/en/latest/pyserial_api.html#serial.Serial.setBreak
        """
        result = True
        try:
            serial.sendBreak()
        except:
            # In Linux a termios.error is raised in sendBreak and in setBreak.
            # The following setBreak() is needed to release the reset signal on the target mcu.
            try:
                serial.setBreak(False)
            except:
                result = False
        return result

    def _safe_sendBreak_v3_0(self, serial):
        """! pyserial 3.x API implementation of send_brea / break_condition
        @details
        http://pyserial.readthedocs.org/en/latest/pyserial_api.html#serial.Serial.send_break
        http://pyserial.readthedocs.org/en/latest/pyserial_api.html#serial.Serial.break_condition
        """
        result = True
        try:
            serial.send_break()
        except:
            # In Linux a termios.error is raised in sendBreak and in setBreak.
            # The following break_condition = False is needed to release the reset signal on the target mcu.
            try:
                serial.break_condition = False
            except Exception as e:
                self.print_plugin_error("Error while doing 'serial.break_condition = False' : %s"% str(e))
                result = False
        return result

    def setup(self, *args, **kwargs):
        """! Configure plugin, this function should be called before plugin execute() method is used.
        """
        return True

    def execute(self, capability, *args, **kwargs):
        """! Executes capability by name

        @param capability Capability name
        @param args Additional arguments
        @param kwargs Additional arguments
        @details Each capability e.g. may directly just call some command line program or execute building pythonic function
        @return Capability call return value
        """
        if not kwargs['serial']:
            self.print_plugin_error("Error: serial port not set (not opened?)")
            return False

        result = False
        if self.check_parameters(capability, *args, **kwargs) is True:
            if kwargs['serial']:
                if capability == 'default':
                    serial = kwargs['serial']
                    result = self.safe_sendBreak(serial)
        return result


def load_plugin():
    """! Returns plugin available in this module
    """
    return HostTestPluginResetMethod_Mbed()