import os, sys, json
import tkinter as tk
from tkinter import ttk
import gui_helper, util

class Config:
    def __init__(self, file_path, default_config):
        self.__file_path = file_path
        self.__default_config = default_config
        self.__current_config = {}

        if os.path.isfile(file_path):
            try:
                config_file = open(self.__file_path, "r")
                self.__current_config = json.loads(config_file.read())
                config_file.close()
            except:
                util.error("An exception occurred while trying to load the configuration.", handle_gracefully=False)
        else:
            # config not found
            dialog_interaction_handler = gui_helper.Window_Interaction_Handler()

            dialog = tk.Tk()
            dialog.title("No configuration found")
            ttk.Label(dialog, text="No configuration found!").pack()
            buttons_frame = tk.Frame(dialog)
            buttons_frame.pack()
            ttk.Button(buttons_frame, text="Create", command=lambda: dialog_interaction_handler.interact("create", True, additional_action=dialog.destroy)).grid(column=0, row=0)
            ttk.Button(buttons_frame, text="Quit", command=lambda: dialog_interaction_handler.interact("create", False, additional_action=dialog.destroy)).grid(column=1, row=0)
            dialog.resizable(0,0)
            dialog.mainloop()

            if dialog_interaction_handler.get_result("create"):
                self.__current_config = default_config
                try:
                    config_file = open(self.__file_path, "w")
                    config_file.write(json.dumps(self.__current_config))
                    config_file.close()
                except:
                    util.warn("Failed to save initial config file.", is_exception=True)
                    dialog = tk.Tk()
                    dialog.title("Failed to save initial config file")
                    ttk.Label(dialog, text="Failed to save the initial config file.\n" +
                                    "The IDE can still run, but it is likely that all changes to the configuration will be lost where they would be saved otherwise.").pack()
                    ttk.Button(dialog, text="Continue", command=dialog.destroy).pack()
                    dialog.resizable(0,0)
                    dialog.mainloop()
            else:
                util.error("No config present and user chose not to create one. Exiting.", is_exception=False, handle_gracefully=True)
                # exit with success exit code anyway because this is not a program failure
                sys.exit(util.EXIT_SUCCESS)

    def get_configuration_value(self, key):
        if not key in self.__current_config:
            util.info("Requested configuration value for "+str(key)+" not in configuration. Loading from default configuration.")
            try:
                self.__current_config[key] = self.__default_config[key]
            except KeyError:
                util.error("Requested an invalid configuration key.")
                return None
        return self.__current_config[key]

    def set_configuration_value(self, key, value, save_to_disk=True):
        if not key in self.__current_config:
            util.info("Writing configuration for previously unknown key "+str(key)+".")
        self.__current_config[key]=value
        if save_to_disk:
            try:
                config_file = open(self.__file_path, "w")
                config_file.write(json.dumps(self.__current_config))
                config_file.close()
            except:
                util.error("Failed to save config file.")