import logging
import json

from django.forms import widgets

logger = logging.getLogger(__name__)

class PrettyJSONWidget(widgets.Textarea):

    def format_value(self, value):
        try:
            value = json.dumps(json.loads(value), indent=2, sort_keys=True, ensure_ascii=False)
            # these lines will try to adjust size of TextArea to fit to content
            row_lengths = [len(r) for r in value.split('\n')]
            self.attrs['rows'] = min(max(len(row_lengths) + 2, 10), 30)
            self.attrs['cols'] = min(max(max(row_lengths) + 2, 40), 120)
            return value
        except Exception as e:
            logger.warning("Error while formatting JSON: {}".format(e))
            return super(PrettyJSONWidget, self).format_value(value)