########################################################################################################################
#    File: cache.py
#  Author: Dan Huckson, https://github.com/unodan
#    Date: 2018-10-29
########################################################################################################################
from os import path
from json import dump, load
from logging import info, error


class Cache:
    def __init__(self, file=None, **kwargs):
        if isinstance(file, dict):
            self.defaults = file
        else:
            if file and path.isfile(file):
                self.defaults = self.load(file)
            else:
                self.defaults = kwargs.get('data', {})

        if self.defaults is None:
            self.defaults = {}

        self.data = dict(self.defaults)

    @staticmethod
    def sanitize_uri(uri=''):
        if uri:
            uri = uri.replace('\\', '/')

        return uri

    def set(self, data=None, uri=None):

        def deep_iterate(value, _uri):
            _uri = self.sanitize_uri(_uri)

            def parse(segment, location):
                parts = location.split('/', 1)
                target = parts[0]

                if len(parts) > 1:
                    if target not in segment:
                        segment[target] = {}

                    parse(segment[target], parts[1])
                else:
                    segment[target] = value

            if _uri and '/' in _uri:
                parse(self.data, _uri)
            elif _uri is None or _uri == '.':
                self.data = value
            else:
                self.data = {**self.data, **{_uri: value}}

        if isinstance(data, dict):
            def iterate(member, location=None):
                for key, item in member.items():
                    if isinstance(item, dict):
                        iterate(item, key)
                    else:
                        deep_iterate(item, location + '/' + key)
            iterate(data, uri)
        else:
            deep_iterate(data, uri)

    def get(self, uri=None, default=None):

        uri = self.sanitize_uri(uri)

        def parse(segment, location):
            parts = location.split('/', 1)
            target = parts[0]

            if len(parts) > 1:
                if target not in segment:
                    return default
                else:
                    return parse(segment[target], parts[1])

            elif target in segment:
                return segment[target]

            return default

        if uri and '/' in uri:
            return parse(self.data, uri)
        elif uri == '.' or uri is None:
            return self.data
        else:
            data = None
            if self.data:
                data = self.data.get(uri, default)

            if not data:
                data = default

            return data

    def load(self, file):
        """
            Read JSON formatted data from external storage.
            :param file:
                Full path to the file.
            :return:
                Json data if successful else False.
        """
        try:
            with open(file, 'r') as f:
                self.data = load(f)
                info('json_read:Filename="' + file + '":Success')
                return self.data

        except OSError as e:
            error('json_read:Filename="' + file + '":' + e.strerror + ":Failed")
            return False

    def save(self, file):
        """
        Write JSON formatted data to external storage.
        :param file:
            Full path to the file.
        :return:
            True if successful else False.
        """
        try:
            with open(file, 'w') as f:
                dump(self.data, f, indent=4)

                info('json_write:Filename="' + file + '":Success')
                return False

        except OSError as e:
            error('json_write:Filename="' + file + '"' + e.strerror)
            return True

    def remove(self, uri):

        uri = self.sanitize_uri(uri)

        def parse(segment, location):
            parts = location.split('/', 1)
            target = parts[0]

            if len(parts) > 1:
                return parse(segment[target], parts[1])
            elif target in segment:
                del segment[target]

        if uri and '/' in uri:
            return parse(self.data, uri)

    def update(self, update_data, uri=''):

        def updater(data, _uri):
            for key, value in data.items():
                if isinstance(value, dict):
                    updater(value, _uri + key + '/')
                else:
                    self.set(value, _uri + key)

        updater(update_data, uri)