'''Tool for a script to keep track changes performed on a large number
of objects.

StatsCount - when you are counting incidences of a small set of outcomes
StatsList - when you also want to remember an ID associated with each incidence

Examples:

from running_stats import StatsCount
package_stats = StatsCount()
for package in packages:
    if package.enabled:
        package.delete()
        package_stats.increment('deleted')
    else:
        package_stats.increment('not deleted')
print package_stats.report()
> deleted: 30
> not deleted: 70

from running_stats import StatsList
package_stats = StatsList()
for package in packages:
    if package.enabled:
        package.delete()
        package_stats.add('deleted', package.name)
    else:
        package_stats.add('not deleted' package.name)
print package_stats.report()
> deleted: 30 pollution-uk, flood-regions, river-quality, ...
> not deleted: 70 spending-bristol, ...

'''
from __future__ import print_function

import copy
import datetime


class StatsCount(dict):
    # {category:count}
    _init_value = 0
    report_value_limit = 150

    def __init__(self, *args, **kwargs):
        self._start_time = datetime.datetime.now()
        super(StatsCount, self).__init__(*args, **kwargs)

    def _init_category(self, category):
        if category not in self:
            self[category] = copy.deepcopy(self._init_value)

    def increment(self, category):
        self._init_category(category)
        self[category] += 1

    def report_value(self, category):
        '''Returns the value for a category and value to sort categories by.'''
        value = repr(self[category])
        if len(value) > self.report_value_limit:
            value = value[:self.report_value_limit] + '...'
        return (value, self[category])

    def report(self, indent=1, order_by_title=False, show_time_taken=True):
        lines = []
        indent_str = '\t' * indent
        report_dict = dict()
        for category in list(self.keys()):
            report_dict[category] = self.report_value(category)

        if order_by_title:
            items = sorted(report_dict.items())
        else:
            items = sorted(iter(report_dict.items()),
                           key=lambda x: -x[1][1])

        for category, value_tuple in items:
            value = value_tuple[0]
            lines.append(indent_str + '%s: %s' % (category, value))
        if not self:
            lines = [indent_str + 'None']

        if show_time_taken:
            time_taken = datetime.datetime.now() - self._start_time
            lines.append(indent_str + 'Time taken (h:m:s): %s' % time_taken)
        return '\n'.join(lines)


class StatsList(StatsCount):
    # {category:[values]}
    _init_value = []

    def add(self, category, value):
        self._init_category(category)
        self[category].append(value)
        return '%s: %s' % (category, value)  # so you can log it too

    def report_value(self, category):
        value = self[category]
        number_of_values = len(value)
        value_str = '%i %r' % (number_of_values, value)
        if len(value_str) > self.report_value_limit:
            value_str = value_str[:self.report_value_limit] + '...'
        return (value_str, number_of_values)


if __name__ == '__main__':
    package_stats = StatsList()
    package_stats.add('Success', 'good1')
    package_stats.add('Success', 'good2')
    package_stats.add('Success', 'good3')
    package_stats.add('Success', 'good4')
    package_stats.add('Failure', 'bad1')
    print(package_stats.report())

    print(StatsList().report())