""" Config module. """

#  ISC License
#
#  Copyright (c) 2020, Paul Wilhelm, M. Sc. <anfrage@paulwilhelm.de>
#
#  Permission to use, copy, modify, and/or distribute this software for any
#  purpose with or without fee is hereby granted, provided that the above
#  copyright notice and this permission notice appear in all copies.
#
#  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
#  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
#  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
#  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
#  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
#  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
#  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

import os
import configparser
from PyQt5.QtWidgets import QMessageBox
from magneticalc.Debug import Debug
from magneticalc.Perspective_Presets import Perspective_Presets
from magneticalc.Version import Version
from magneticalc.Wire_Presets import Wire_Presets


class Config:
    """ Config class. """

    # Formatting settings
    FloatPrecision = 4
    CoordinatePrecision = 6

    # Enable to additionally debug read access to configuration
    DebugGetters = False

    # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    # Default wire preset
    DefaultWirePreset = "Straight Line"

    # Default perspective preset
    DefaultPerspectivePreset = "Isometric"

    # Default configuration
    Default = {
        "version"                       : Version.String,
        "backend"                       : "0",
        "auto_calculation"              : "True",
        "num_cores"                     : "0",
        "wire_points_base"              : None,  # Will be set in __init__
        "wire_stretch"                  : "0.1000, 1.0000, 1.0000",
        "wire_slicer_limit"             : "0.0500",
        "wire_dc"                       : "1.0000",
        "rotational_symmetry_count"     : "30",
        "rotational_symmetry_radius"    : "1.0000",
        "rotational_symmetry_axis"      : "2",
        "rotational_symmetry_offset"    : "0",
        "sampling_volume_padding"       : "1, 1, 1",
        "sampling_volume_resolution"    : "10",
        "field_type"                    : "1",
        "field_distance_limit"          : "0.0008",
        "color_metric"                  : "Log Magnitude",
        "alpha_metric"                  : "Magnitude",
        "field_point_scale"             : "1.0000",
        "field_arrow_scale"             : "0.1250",
        "field_boost"                   : "0.0000",
        "display_magnitude_labels"      : "False",
        "show_wire_segments"            : "True",
        "show_wire_points"              : "True",
        "show_colored_labels"           : "False",
        "show_coordinate_system"        : "True",
        "show_perspective_info"         : "True",
        "dark_background"               : "True",
        "azimuth"                       : None,  # Will be set in __init__
        "elevation"                     : None,  # Will be set in __init__
        "scale_factor"                  : "3.0000",
        "constraint_count"              : "0"
    }

    def __init__(self):
        """
        Initializes the configuration.
        """
        Debug(self, ": Init")

        # Populate defaults
        self.Default["wire_points_base"] = Config.points_to_str(
            Wire_Presets.get_by_id(Config.DefaultWirePreset)["points"]
        )
        self.Default["azimuth"] = Perspective_Presets.get_by_id(Config.DefaultPerspectivePreset)["azimuth"]
        self.Default["elevation"] = Perspective_Presets.get_by_id(Config.DefaultPerspectivePreset)["elevation"]

        self._config = None

        self._synced = False
        self._changed_callback = None

        self._filename = None

    # ------------------------------------------------------------------------------------------------------------------

    def set_changed_callback(self, config_changed_callback):
        """
        Sets the callback for any changes to the configuration.

        @param config_changed_callback: Gets called when the filename or the synchronization flag changed
        """
        self._changed_callback = config_changed_callback

    # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    def get_synced(self) -> bool:
        """
        Returns the synchronization state of the current session.
        """
        return self._synced

    # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    def set_filename(self, filename: str):
        """
        Sets the filename for the current session.

        @param filename: Filename
        """
        self._filename = os.path.join(os.path.dirname(os.path.dirname(__file__)), filename)
        Debug(self, ".set_filename: file://" + self._filename.replace(" ", "%20"), force=True)

    def get_filename(self) -> str:
        """
        Gets the filename of the current session.

        @return: Filename
        """
        return self._filename

    # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    def load(self):
        """
        Loads the configuration from file.

        """
        Debug(self, ".load()", force=True)

        self._config = configparser.ConfigParser()

        self._config.read(self._filename)

        self.set_defaults()

        self._synced = True
        if self._changed_callback is not None:
            self._changed_callback()

    def set_defaults(self):
        """
        Sets the default key-value pairs. Creates empty "User" section if not present.
        """
        self._config["DEFAULT"] = Config.Default

        if "User" not in self._config:
            Debug(self, ".set_defaults(): Creating empty User section")
            self._config["User"] = {}

    # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    def save(self):
        """
        Saves the configuration to file.
        """
        Debug(self, ".save()", force=True)

        with open(self._filename, "w") as file:
            self._config.write(file)

        self._synced = True
        if self._changed_callback is not None:
            self._changed_callback()

    def close(self):
        """
        Finally auto-saves configuration to file.
        """
        Debug(self, ".close()")

        if not self._synced:
            messagebox = QMessageBox()
            messagebox.setWindowTitle("Configuration Changed")
            messagebox.setText("Do you want to save your changes?")
            messagebox.setIcon(QMessageBox.Question)
            messagebox.setStandardButtons(QMessageBox.Yes | QMessageBox.No)
            messagebox.setDefaultButton(QMessageBox.Yes)
            if messagebox.exec() == QMessageBox.Yes:
                self.save()

    # ------------------------------------------------------------------------------------------------------------------

    def get_bool(self, key: str) -> bool:
        """
        Gets boolean value, convert from string.

        @param key: Key
        @return: Value
        """
        return self.get_str(key) == "True"

    def get_float(self, key: str) -> float:
        """
        Gets float value, convert from string.

        @param key: Key
        @return: Value
        """
        return float(self.get_str(key))

    def get_int(self, key: str) -> int:
        """
        Gets integer value, convert from string.

        @param key: Key
        @return: Value
        """
        return int(self.get_str(key))

    def get_points(self, key: str):
        """
        Gets list of 3D points, convert from string.

        @param key: Key
        @return: List of 3D points
        """
        return Config.str_to_points(self.get_str(key))

    def get_point(self, key: str):
        """
        Gets a single 3D point, convert from string.

        @param key: Key
        @return: Single 3D point
        """
        return Config.str_to_point(self.get_str(key))

    def get_str(self, key: str) -> str:
        """
        Reads a configuration value. Key must be in "Default" section and may be overridden in "User" section.

        @param key: Key
        @return: Value
        """
        if self.DebugGetters:
            Debug(self, f".get_str({key})")

        value = self._config.get("User", key)
        return value

    # ------------------------------------------------------------------------------------------------------------------

    def set_bool(self, key: str, value: bool):
        """
        Sets boolean value, convert to string.

        @param key: Key
        @param value: Value
        """
        self.set_str(key, "True" if value else "False")

    def set_float(self, key: str, value: float):
        """
        Sets float value, convert to string.

        @param key: Key
        @param value: Value
        """
        self.set_str(key, f"{float(value):.{Config.FloatPrecision}f}")

    def set_int(self, key: str, value: int):
        """
        Sets integer value, convert to string.

        @param key: Key
        @param value: Value
        """
        self.set_str(key, str(int(value)))

    def set_points(self, key: str, value):
        """
        Sets list of 3D points, convert to string.

        @param key: Key
        @param value: List of 3D points
        """
        self.set_str(key, Config.points_to_str(value))

    def set_point(self, key: str, value):
        """
        Sets a single 3D point, convert to string.

        @param key: Key
        @param value: Single 3D point
        """
        self.set_str(key, Config.point_to_str(value))

    def set_str(self, key: str, value: str):
        """
        Writes a configuration value. Key must be in "Default" section and may be overridden in "User" section.

        @param key: Key
        @param value: Value
        """
        Debug(self, f".set_str({key}, {value})")

        self._config.set("User", key, value)
        self._synced = False
        if self._changed_callback is not None:
            self._changed_callback()

    def set_get_bool(self, key: str, value: bool) -> bool:
        """
        If value is not None, writes and returns key-value; otherwise (if value is None), reads and returns key-value.

        @param key: Key
        @param value: Value or None
        """
        if value is None:
            return self.get_bool(key)
        else:
            self.set_bool(key, value)
            return value

    def set_get_float(self, key: str, value: float) -> float:
        """
        If value is not None, writes and returns key-value; otherwise (if value is None), reads and returns key-value.

        @param key: Key
        @param value: Value or None
        """
        if value is None:
            return self.get_float(key)
        else:
            self.set_float(key, value)
            return value

    def set_get_int(self, key: str, value: int) -> int:
        """
        If value is not None, writes and returns key-value; otherwise (if value is None), reads and returns key-value.

        @param key: Key
        @param value: Value or None
        """
        if value is None:
            return self.get_int(key)
        else:
            self.set_int(key, value)
            return value

    def set_get_points(self, key: str, value):
        """
        If value is not None, writes and returns key-value; otherwise (if value is None), reads and returns key-value.

        @param key: Key
        @param value: Value or None
        """
        if value is None:
            return self.get_points(key)
        else:
            self.set_points(key, value)
            return value

    def set_get_point(self, key: str, value):
        """
        If value is not None, writes and returns key-value; otherwise (if value is None), reads and returns key-value.

        @param key: Key
        @param value: Value or None
        """
        if value is None:
            return self.get_point(key)
        else:
            self.set_point(key, value)
            return value

    def set_get_str(self, key: str, value: str) -> str:
        """
        If value is not None, writes and returns key-value; otherwise (if value is None), reads and returns key-value.

        @param key: Key
        @param value: Value or None
        """
        if value is None:
            return self.get_str(key)
        else:
            self.set_str(key, value)
            return value

    # ------------------------------------------------------------------------------------------------------------------

    @staticmethod
    def point_to_str(point) -> str:
        """
        Converts a single 3D point to string.

        @param point: Single 3D point
        @return: String
        """
        return \
            f"{point[0]:+0.0{Config.CoordinatePrecision}f}, " \
            f"{point[1]:+0.0{Config.CoordinatePrecision}f}, " \
            f"{point[2]:+0.0{Config.CoordinatePrecision}f}"

    @staticmethod
    def points_to_str(points) -> str:
        """
        Converts list of 3D points to string.

        @param points: List of 3D points
        @return: String
        """
        return "; ".join([Config.point_to_str(point) for point in points])

    @staticmethod
    def str_to_point(str_point: str):
        """
        Converts string to single 3D point.

        @param str_point: String
        @return: Single 3D point
        """
        return [float(coord) for coord in str_point.split(",")]

    @staticmethod
    def str_to_points(str_points: str):
        """
        Converts string to list of 3D points.

        @param str_points: String
        @return: List of 3D points
        """
        return [Config.str_to_point(str_point) for str_point in str_points.split(";")]

    # ------------------------------------------------------------------------------------------------------------------

    def get_generic(self, _key: str, _type):
        """
        Gets some "_key"-"_value" of data type "_type".

        @param _key: Key
        @param _type: Data type
        @return _value: Data (type determined by "_type")
        """
        set_func = {
            "bool"  : self.get_bool,
            "float" : self.get_float,
            "int"   : self.get_int,
            "point" : self.get_point,
            "points": self.get_points,
            "str"   : self.get_str
        }

        # noinspection PyArgumentList
        return set_func.get(_type)(_key)

    def set_generic(self, _key: str, _type, _value):
        """
        Sets some "_key"-"_value" of data type "_type".

        @param _key: Key
        @param _type: Data type
        @param _value: Data (type determined by "_type")
        """
        set_func = {
            "bool"  : self.set_bool,
            "float" : self.set_float,
            "int"   : self.set_int,
            "point" : self.set_point,
            "points": self.set_points,
            "str"   : self.set_str
        }

        # noinspection PyArgumentList
        set_func.get(_type)(_key, _value)

    def set_get_dict(self, prefix: str, suffix: str, types, values):
        """
        If "values" is None, reads and returns all key-values in "types".
        Note: The actual keys saved in the configuration file are prefixed with "prefix", and suffixed with "suffix".

        If "values" is not None, writes and returns all key-values in "types".
        Note: In this case, "values" must have the same keys as "types.

        @param prefix: Prefix
        @param suffix: Suffix
        @param types: Key:Type (Dictionary)
        @param values: Key:Value (Dictionary) or None
        """
        if values is None:
            result = {}
            for _key, _type in types.items():
                result[_key] = self.get_generic(prefix + _key + suffix, _type)
            return result
        else:
            for _key, _type in types.items():
                self.set_generic(prefix + _key + suffix, _type, values[_key])
            return values
