from cache.Cache import BaseCache
from core.global_symbols import Removed, NotFound
from core.utils import sheerka_deepcopy


class ListCache(BaseCache):
    """
    An in memory FIFO cache object
    When the max_size is reach the first element that was put is removed
    Items of this cache are list
    """

    def _put(self, key, value, alt_sdp):
        if key in self._cache:
            self._cache[key].append(value)
        else:
            self._sync(key)

            if key not in self._cache and alt_sdp and not self._is_cleared:
                previous = self._alt_sdp_get(alt_sdp, key)
                if previous not in (NotFound, Removed):
                    self._cache[key] = sheerka_deepcopy(previous)

            if key in self._cache:
                self._cache[key].append(value)
            else:
                self._cache[key] = [value]

        self._add_to_add(key)
        return True

    def _update(self, old_key, old_value, new_key, new_value, alt_sdp):
        self._sync(old_key, new_key)

        if old_key not in self._cache and alt_sdp and not self._is_cleared:
            # no value found in local cache or remote repository
            # Use the values from alt_sdp
            previous = self._alt_sdp_get(alt_sdp, old_key)
            if previous in (NotFound, Removed):
                raise KeyError(old_key)

            self._cache[old_key] = sheerka_deepcopy(previous)
            self._current_size += len(previous)

        if old_key != new_key:
            self._cache[old_key].remove(old_value)
            if len(self._cache[old_key]) == 0:
                if not self._is_cleared and alt_sdp and self._extend_exists(alt_sdp, old_key):
                    self._cache[old_key] = Removed
                    self._add_to_add(old_key)
                    self._current_size += 1
                else:
                    del (self._cache[old_key])
                    self._add_to_remove(old_key)
            else:
                self._add_to_add(old_key)

            self._put(new_key, new_value, alt_sdp)
            self._add_to_add(new_key)
        else:
            for i in range(len(self._cache[new_key])):
                if self._cache[new_key][i] == old_value:
                    self._cache[new_key][i] = new_value  # avoid add and remove in dict
                    break  # only the first one is affected
            self._add_to_add(new_key)