# This file contains functions and variables related to reading and writing configuration files.
# The configparser module is used for processing. Config files are of type .ini

# import packages:
from configparser import ConfigParser
from tkinter import messagebox

# import other project files:
import globals as g
import cage_func as func
# noinspection PyPep8Naming
import User_Interface as ui

global CONFIG_FILE  # string storing the path of the used config file
global CONFIG_OBJECT  # object of type ConfigParser(), storing all configuration information
# CONFIG_OBJECT is what is mostly read/written by the program
# CONFIG_FILE is only used to export/import to/from a file


def get_config_from_file(file):  # read a config file to a config_object
    config_object = ConfigParser()  # initialize config parser
    config_object.read(file)  # open config file
    return config_object  # return config object, that contains all info from the file


def write_config_to_file(config_object):  # write contents of config object to a config file
    with open(CONFIG_FILE, 'w') as conf:  # Write changes to config file
        config_object.write(conf)


def read_from_config(section, key, config_object):  # read a specific value from a config object
    try:
        section_obj = config_object[section]  # get relevant section
        value = section_obj[key]  # get relevant value in the section
        return value
    except KeyError as e:  # a section or key was used, that does not exist
        ui.ui_print("Error while reading config file:", e)
        raise KeyError("Could not find key", key, "in config file.")


def edit_config(section, key, value, override=False):  # edit a specific value in the CONFIG_OBJECT
    # section: Section of the config, e.g. "X-Axis" or "PORTS"
    # key: name of the value in the section, e.g. max_amps
    # value: new value to be written into the config
    # override: Bool to allow user to force writing a value into the config, even if it exceeds the safe limit

    global CONFIG_OBJECT  # get the global config object to edit it

    # ToDo (optional): add check for data types, e.g. int for arduino ports
    # Check if value to write is within acceptable limits (set in dictionary in globals.py):
    try:
        value_ok = 'OK'
        if section in g.AXIS_NAMES and not override:  # only check values in axis sections and not if check overridden
            value_ok = func.value_in_limits(section, key, value)  # check if value is ok, too high or too low

            if value_ok == 'HIGH':  # value is too high
                max_value = g.default_arrays[key][1][g.AXIS_NAMES.index(section)]  # get max value for message printing
                message = "Prevented writing too high value for {s} {k} to config file:\n" \
                          "{v}, max. {mv} allowed. Erroneous values may damage equipment!" \
                    .format(s=section, k=key, v=value, mv=max_value)
                raise ValueError(message)  # return an error with the message attached

            elif value_ok == 'LOW':  # value is too low
                min_value = g.default_arrays[key][2][g.AXIS_NAMES.index(section)]  # get min value for message printing
                message = "Prevented writing too low value for {s} {k} to config file:\n" \
                          "{v}, max. {mv} allowed. Erroneous values may damage equipment!" \
                    .format(s=section, k=key, v=value, mv=min_value)
                raise ValueError(message)  # return an error with the message attached

        if value_ok == 'OK' or override:  # value is within limits or user has overridden the checks
            try:
                section_obj = CONFIG_OBJECT[section]  # get relevant section in the config
            except KeyError:  # there is no such section
                ui.ui_print("Could not find section", section, "in config file, creating new.")
                CONFIG_OBJECT.add_section(section)  # create the missing section
                section_obj = CONFIG_OBJECT[section]  # get the object of the section
            try:
                section_obj[key] = str(value)  # set value for correct entry in the section
            except KeyError:  # there is no entry with this key
                ui.ui_print("Could not find key", key, "in config file, creating new.")
                CONFIG_OBJECT.set(section, key, str(value))  # create the entry and set the value

    except KeyError as e:  # key for section or specific value does not exist in the dictionary for max/min values
        ui.ui_print("Error while editing config file:", e)
        raise KeyError("Could not find key", key, "in config file.")  # return an error


def check_config(config_object):  # check all numeric values in the config and see if they are within safe limits
    ui.ui_print("Checking config file for values exceeding limits:")

    concerns = {}  # initialize dictionary for found problems
    problem_counter = 0  # count the number of values that exceed limits
    i = 0
    for axis in g.AXIS_NAMES:  # go through all 3 axes
        concerns[axis] = []  # create dictionary entry for this axis
        for key in g.default_arrays.keys():  # go over entries in this axis
            value = float(read_from_config(axis, key, config_object))  # read value to check from config file
            max_value = g.default_arrays[key][1][i]  # get max value
            min_value = g.default_arrays[key][2][i]  # get min value

            if not min_value <= value <= max_value:  # value is not in safe limits
                concerns[axis].append(key)  # add this entry to the problem dictionary
                problem_counter += 1

        if len(concerns[axis]) == 0:  # no problems were found for this axis
            concerns[axis].append("No problems detected.")

        ui.ui_print(axis, ":", *concerns[axis])  # print out results for this axis
        i += 1
    if problem_counter > 0:  # some values are not ok
        # shop pup-up warning message:
        messagebox.showwarning("Warning!", "Found %i value(s) exceeding limits in config file. Check values "
                                           "to ensure correct operation and avoid equipment damage!" % problem_counter)
        g.app.show_frame(ui.Configuration)  # open configuration window so user can check values


def reset_config_to_default():  # reset values in config object to defaults (set in globals.py)
    config = ConfigParser()  # reinitialize empty config object
    global CONFIG_OBJECT  # get the global config object
    CONFIG_OBJECT = config  # reset it to the empty object

    i = 0
    for axis_name in g.AXIS_NAMES:  # go through axes
        config.add_section(axis_name)  # add section for this axis
        for key in g.default_arrays.keys():  # go through dictionary with default values
            config.set(axis_name, key, str(g.default_arrays[key][0][i]))  # set values
        i += 1

    config.add_section("PORTS")  # add section for PSU serial ports
    for key in g.default_ports.keys():  # go through dictionary of default serial ports
        config.set("PORTS", key, str(g.default_ports[key]))  # set the value for each axis