# Copyright (c) 2016 Ultimaker B.V.
# Cura is released under the terms of the AGPLv3 or higher.

import configparser #To get version numbers from config files.
import os.path
import io

from UM import Resources
from UM.VersionUpgrade import VersionUpgrade # Superclass of the plugin.

class VersionUpgrade22to24(VersionUpgrade):

    def upgradeMachineInstance(self, serialised, filename):
        config = configparser.ConfigParser(interpolation = None)
        config.read_string(serialised) # Read the input string as config file.
        config.set("general", "version", "3")
        containers = config.get("general", "containers")
        container_list = containers.split(",")

        user_variants = self.__getUserVariants()
        name_path_dict = {}
        for variant in user_variants:
            name_path_dict[variant.get("name")] = variant.get("path")

        user_variant_names = set(container_list).intersection(name_path_dict.keys())
        if len(user_variant_names):
            # One of the user defined variants appears in the list of containers in the stack.

            for variant_name in user_variant_names:
                # Copy the variant to the machine_instances/*_settings.inst.cfg
                variant_config = configparser.ConfigParser(interpolation=None)
                variant_path = name_path_dict.get(variant_name)
                with open(variant_path, "r") as fhandle:
                    variant_config.read_file(fhandle)

                if variant_config.has_section("general") and variant_config.has_option("general", "name"):
                    config_name = variant_config.get("general", "name")
                    if config_name.endswith("_variant"):
                        config_name = config_name[:-len("_variant")] + "_settings"
                        variant_config.set("general", "name", config_name)

                if not variant_config.has_section("metadata"):
                    variant_config.add_section("metadata")
                variant_config.set("metadata", "type", "definition_changes")

                # "_settings.inst.cfg"
                resource_path = Resources.getDataStoragePath()
                machine_instances_dir = os.path.join(resource_path, "machine_instances")

                if variant_path.endswith("_variant.inst.cfg"):
                    variant_path = variant_path[:-len("_variant.inst.cfg")] + "_settings.inst.cfg"

                with open(os.path.join(machine_instances_dir, os.path.basename(variant_path)), "w") as fp:
                    variant_config.write(fp)

                # Change the name of variant and insert empty_variant into the stack.
                new_container_list = []
                for item in container_list:
                    if item == variant_name:
                        new_container_list.append(config_name)
                        new_container_list.append("empty_variant")
                    else:
                        new_container_list.append(item)

                container_list = new_container_list

            config.set("general", "containers", ",".join(container_list))

        output = io.StringIO()
        config.write(output)
        return [filename], [output.getvalue()]

    def __getUserVariants(self):
        resource_path = Resources.getDataStoragePath()
        variants_dir = os.path.join(resource_path, "variants")

        result = []
        for entry in os.scandir(variants_dir):
            if entry.name.endswith('.inst.cfg') and entry.is_file():
                config = configparser.ConfigParser(interpolation = None)
                with open(entry.path, "r") as fhandle:
                    config.read_file(fhandle)
                if config.has_section("general") and config.has_option("general", "name"):
                    result.append( { "path": entry.path, "name": config.get("general", "name") } )
        return result

    def getCfgVersion(self, serialised):
        parser = configparser.ConfigParser(interpolation = None)
        parser.read_string(serialised)
        return int(parser.get("general", "version")) #Explicitly give an exception when this fails. That means that the file format is not recognised.