#!/usr/bin/env python

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import codecs


class History(object):
    def __init__(self, filepath, token=None):
        self.filepath = filepath
        self.token = token

    @classmethod
    def _match(self, line, match_terms):
        if match_terms is None:
            return True
        for term in match_terms.split():
            if term not in line:
                return False
        return True

    def get(self, match_terms=None, limit=0):
        limit = int(limit or 0)
        with codecs.open(self.filepath, mode='r', encoding='utf-8') as f:
            result = [u'%s.  \t%s' % (
                i + 1, line) for i, line in enumerate(f.readlines())
                if self._match(line, match_terms)]
            return result[- limit:]

    def add(self, line):
        line = line.replace(self.token, '...') if self.token else line
        with open(self.filepath, 'a+') as f:
            f.write(line + '\n')

    def clean(self):
        with open(self.filepath, 'w'):
            pass

    def retrieve(self, cmd_id):
        """
        :param cmd_id: (int) the id of the command to retrieve can be positive
            or negative, zero values are ignored

        :returns: (str) the stored command record without the id
        """
        cmd_id = int(cmd_id)
        if not cmd_id:
            return None
        with open(self.filepath) as f:
            try:
                cmd_list = f.readlines()[:-1]  # exclude current command
                return cmd_list[cmd_id - (1 if cmd_id > 0 else 0)]
            except IndexError:
                return None