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

from django.db.models import Q, Count
import datetime
import copy


def _get_milestones_stats_for_backlog(project):
    """
    Get collection of stats for each millestone of project.
    Data returned by this function are used on backlog.
    """
    current_evolution = 0
    current_team_increment = 0
    current_client_increment = 0
    optimal_points_per_sprint = project.total_story_points / (project.total_milestones)
    future_team_increment = sum(project.future_team_increment.values())
    future_client_increment = sum(project.future_client_increment.values())

    milestones = project.milestones.order_by('estimated_start')

    for current_milestone in range(0, max(milestones.count(), project.total_milestones)):
        optimal_points = (project.total_story_points -
                            (optimal_points_per_sprint * current_milestone))

        evolution = (project.total_story_points - current_evolution
                        if current_evolution is not None else None)

        if current_milestone < milestones.count():
            ml = milestones[current_milestone]
            milestone_name = ml.name
            team_increment = current_team_increment
            client_increment = current_client_increment

            current_evolution += sum(ml.closed_points.values())
            current_team_increment += sum(ml.team_increment_points.values())
            current_client_increment += sum(ml.client_increment_points.values())
        else:
            milestone_name = "Future sprint"
            team_increment = current_team_increment + future_team_increment,
            client_increment = current_client_increment + future_client_increment,
            current_evolution = None

        yield {
            'name': milestone_name,
            'optimal': optimal_points,
            'evolution': evolution,
            'team-increment': team_increment,
            'client-increment': client_increment,
        }

    optimal_points -= optimal_points_per_sprint
    evolution = (project.total_story_points - current_evolution
                    if current_evolution is not None else None)
    yield {
        'name': 'Project End',
        'optimal': optimal_points,
        'evolution': evolution,
        'team-increment': team_increment,
        'client-increment': client_increment,
    }


def _count_status_object(status_obj, counting_storage):
    if status_obj.id in counting_storage:
        counting_storage[status_obj.id]['count'] += 1
    else:
        counting_storage[status_obj.id] = {}
        counting_storage[status_obj.id]['count'] = 1
        counting_storage[status_obj.id]['name'] = status_obj.name
        counting_storage[status_obj.id]['id'] = status_obj.id
        counting_storage[status_obj.id]['color'] = status_obj.color

def _count_owned_object(user_obj, counting_storage):
    if user_obj:
        if user_obj.id in counting_storage:
            counting_storage[user_obj.id]['count'] += 1
        else:
            counting_storage[user_obj.id] = {}
            counting_storage[user_obj.id]['count'] = 1
            counting_storage[user_obj.id]['username'] = user_obj.username
            counting_storage[user_obj.id]['id'] = user_obj.id
            counting_storage[user_obj.id]['color'] = user_obj.color
    else:
        if 0 in counting_storage:
            counting_storage[0]['count'] += 1
        else:
            counting_storage[0] = {}
            counting_storage[0]['count'] = 1
            counting_storage[0]['username'] = 'Unassigned'
            counting_storage[0]['id'] = 0
            counting_storage[0]['color'] = 'black'

def get_stats_for_project_issues(project):
    project_issues_stats = {
        'total_issues': 0,
        'issues_per_type': {},
        'issues_per_status': {},
        'issues_per_priority': {},
        'issues_per_severity': {},
        'issues_per_owner': {},
        'issues_per_assigned_to': {},
        'last_four_weeks_days': {
            'by_open_closed': {'open': [], 'closed': []},
            'by_severity': {},
            'by_priority': {},
            'by_status': {},
        }

    }

    for issue in project.issues.all().prefetch_related('status', 'priority', 'type', 'severity', 'owner', 'assigned_to'):
        project_issues_stats['total_issues'] += 1
        _count_status_object(issue.type, project_issues_stats['issues_per_type'])
        _count_status_object(issue.status, project_issues_stats['issues_per_status'])
        _count_status_object(issue.priority, project_issues_stats['issues_per_priority'])
        _count_status_object(issue.severity, project_issues_stats['issues_per_severity'])
        _count_owned_object(issue.owner, project_issues_stats['issues_per_owner'])
        _count_owned_object(issue.assigned_to, project_issues_stats['issues_per_assigned_to'])

    for severity in project_issues_stats['issues_per_severity'].values():
        project_issues_stats['last_four_weeks_days']['by_severity'][severity['id']] = copy.copy(severity)
        del(project_issues_stats['last_four_weeks_days']['by_severity'][severity['id']]['count'])
        project_issues_stats['last_four_weeks_days']['by_severity'][severity['id']]['data'] = []

    for priority in project_issues_stats['issues_per_priority'].values():
        project_issues_stats['last_four_weeks_days']['by_priority'][priority['id']] = copy.copy(priority)
        del(project_issues_stats['last_four_weeks_days']['by_priority'][priority['id']]['count'])
        project_issues_stats['last_four_weeks_days']['by_priority'][priority['id']]['data'] = []

    for status in project_issues_stats['issues_per_status'].values():
        project_issues_stats['last_four_weeks_days']['by_status'][status['id']] = copy.copy(status)
        del(project_issues_stats['last_four_weeks_days']['by_status'][status['id']]['count'])
        project_issues_stats['last_four_weeks_days']['by_status'][status['id']]['data'] = []

    for x in range(27, -1, -1):
        day = datetime.date.today() - datetime.timedelta(days=x)
        next_day = day + datetime.timedelta(days=1)
        project_issues_stats['last_four_weeks_days']['by_open_closed']['open'].append(
            project.issues.filter(created_date__gte=day, created_date__lt=next_day).count()
        )
        project_issues_stats['last_four_weeks_days']['by_open_closed']['closed'].append(
            project.issues.filter(finished_date__gte=day, finished_date__lt=next_day).count()
        )
        open_this_day = project.issues.filter(created_date__lt=next_day)
        open_this_day = open_this_day.filter(Q(finished_date__gt=day) | Q(finished_date__isnull=True))
        open_this_day = open_this_day.filter(status__is_closed=False)
        for severity in project_issues_stats['last_four_weeks_days']['by_severity']:
            project_issues_stats['last_four_weeks_days']['by_severity'][severity]['data'].append(
                open_this_day.filter(severity_id=severity).count()
            )

        for priority in project_issues_stats['last_four_weeks_days']['by_priority']:
            project_issues_stats['last_four_weeks_days']['by_priority'][priority]['data'].append(
                open_this_day.filter(priority_id=priority).count()
            )

        for status in project_issues_stats['last_four_weeks_days']['by_status']:
            project_issues_stats['last_four_weeks_days']['by_status'][status]['data'].append(
                open_this_day.filter(status_id=status).count()
            )

    return project_issues_stats


def get_stats_for_project(project):
    project_stats = {
        'name': project.name,
        'total_milestones': project.total_milestones,
        'total_points': project.total_story_points,
        'closed_points': sum(project.closed_points.values()),
        'defined_points': sum(project.defined_points.values()),
        'assigned_points': sum(project.assigned_points.values()),
        'milestones': _get_milestones_stats_for_backlog(project)
    }
    return project_stats