# This file is part of beets.
# Copyright 2012, Blemjhoo Tezoulbr <baobab@heresiarch.info>.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

""" Clears tag fields in media files.""" 

import re
import logging
from beets.plugins import BeetsPlugin
from beets import ui
from beets.library import ITEM_KEYS
from beets.importer import action


__author__ = 'baobab@heresiarch.info'
__version__ = '0.10'


class ZeroPlugin(BeetsPlugin):

    _instance = None
    _log = logging.getLogger('beets')

    fields = []
    patterns = {}
    warned = False

    def __new__(cls, *args, **kwargs):
        if cls._instance is None:
            cls._instance = super(ZeroPlugin,
                                  cls).__new__(cls, *args, **kwargs)
        return cls._instance

    def __str__(self):
        return ('[zero]\n  fields = {0}\n  patterns = {1}\n  warned = {2}'
                .format(self.fields, self.patterns, self.warned))

    def configure(self, config):
        if not config.has_section('zero'):
            self._log.debug(u'[zero] plugin is not configured')
            return
        for f in ui.config_val(config, 'zero', 'fields', '').split():
            if f not in ITEM_KEYS:
                self._log.error(u'[zero] invalid field: {0}'.format(f))
            else:
                self.fields.append(f)
                p = ui.config_val(config, 'zero', f, '').split()
                if p:
                    self.patterns[f] = p
                else:
                    self.patterns[f] = ['.']

    def import_task_choice_event(self, task, config):
        """Listen for import_task_choice event."""
        if task.choice_flag == action.ASIS and not self.warned:
            self._log.warn(u'[zero] cannot zero in \"as-is\" mode')
            self.warned = True
        # TODO request write in as-is mode 

    @classmethod
    def match_patterns(cls, field, patterns):
        """Check if field (as string) is matching any of the patterns in 
        the list.
        """
        for p in patterns:
            if re.findall(p, unicode(field), flags=re.IGNORECASE):
                return True
        return False

    def write_event(self, item):
        """Listen for write event."""
        if not self.fields:
            self._log.warn(u'[zero] no fields, nothing to do')
            return
        for fn in self.fields:
            try:
                fval = getattr(item, fn)
            except AttributeError:
                self._log.error(u'[zero] no such field: {0}'.format(fn))
            else:
                if not self.match_patterns(fval, self.patterns[fn]):
                    self._log.debug(u'[zero] \"{0}\" ({1}) not match: {2}'
                                    .format(fval, fn, 
                                            ' '.join(self.patterns[fn])))
                    continue
                self._log.debug(u'[zero] \"{0}\" ({1}) match: {2}'
                                .format(fval, fn, ' '.join(self.patterns[fn])))
                setattr(item, fn, type(fval)())
                self._log.debug(u'[zero] {0}={1}'
                                .format(fn, getattr(item, fn)))


@ZeroPlugin.listen('import_task_choice')
def zero_choice(task, config):
    ZeroPlugin().import_task_choice_event(task, config)

@ZeroPlugin.listen('write')
def zero_write(item):
    ZeroPlugin().write_event(item)