symuid/symuid/library/itunes.py

# -*- coding: utf-8 -*-

import dateutil.parser
import xml.etree.ElementTree


class XmlDict:

    def __init__(self, node):
        assert isinstance(node, xml.etree.ElementTree.Element), node
        assert node.tag == 'dict', node.tag
        self._node = node

    def _get_value_node(self, key):
        # WORKAROUND method getnext() is sadly not available
        for child_idx, child_node in enumerate(self._node):
            if child_node.tag == 'key' and child_node.text == key:
                return self._node[child_idx + 1]
        raise KeyError(key)

    def __getitem__(self, key):
        value_node = self._get_value_node(key)
        if value_node.tag == 'string':
            return value_node.text
        elif value_node.tag == 'integer':
            return int(value_node.text)
        elif value_node.tag == 'date':
            return dateutil.parser.parse(value_node.text)
        else:
            return value_node


class XmlLibrary:

    def __init__(self, path):
        self._tree = xml.etree.ElementTree.parse(path)
        self._root_dict = XmlDict(self._tree.find('./dict'))
        self._id = self._root_dict['Library Persistent ID']
        assert isinstance(self._id, str), self._id
        assert len(self._id) > 4

    @property
    def id(self):
        return self._id