from django.db import connection
from django.template import RequestContext, loader
from django.utils.html import mark_safe
from django.shortcuts import render_to_response
from django.core import urlresolvers
from django.http import HttpResponseNotFound

from zerver.decorator import has_request_variables, REQ, zulip_internal
from zerver.models import get_realm, UserActivity, UserActivityInterval, Realm
from zerver.lib.timestamp import timestamp_to_datetime

from collections import defaultdict
from datetime import datetime, timedelta
import itertools
import time
import re
import pytz
eastern_tz = pytz.timezone('US/Eastern')

def make_table(title, cols, rows, has_row_class=False):

    if not has_row_class:
        def fix_row(row):
            return dict(cells=row, row_class=None)
        rows = map(fix_row, rows)

    data = dict(title=title, cols=cols, rows=rows)

    content = loader.render_to_string(
        'analytics/ad_hoc_query.html',
        dict(data=data)
    )

    return content

def dictfetchall(cursor):
    "Returns all rows from a cursor as a dict"
    desc = cursor.description
    return [
        dict(zip([col[0] for col in desc], row))
        for row in cursor.fetchall()
    ]


def get_realm_day_counts():
    query = '''
        select
            r.domain,
            (now()::date - pub_date::date) age,
            count(*) cnt
        from zerver_message m
        join zerver_userprofile up on up.id = m.sender_id
        join zerver_realm r on r.id = up.realm_id
        where
            (not up.is_bot)
        and
            pub_date > now()::date - interval '8 day'
        and
            r.domain not in ('zulip.com', 'mit.edu')
        group by
            r.domain,
            age
        order by
            r.domain,
            age
    '''
    cursor = connection.cursor()
    cursor.execute(query)
    rows = dictfetchall(cursor)
    cursor.close()

    counts = defaultdict(dict)
    for row in rows:
        counts[row['domain']][row['age']] = row['cnt']


    result = {}
    for domain in counts:
        cnts = [counts[domain].get(age, 0) for age in range(8)]
        min_cnt = min(cnts)
        max_cnt = max(cnts)

        def format_count(cnt):
            if cnt == min_cnt:
                good_bad = 'bad'
            elif cnt == max_cnt:
                good_bad = 'good'
            else:
                good_bad = 'neutral'

            return '<td class="number %s">%s</td>' % (good_bad, cnt)

        cnts = ''.join(map(format_count, cnts))
        result[domain] = dict(cnts=cnts)

    return result

def realm_summary_table(realm_minutes):
    query = '''
        SELECT
            realm.domain,
            coalesce(user_counts.active_user_count, 0) active_user_count,
            coalesce(at_risk_counts.at_risk_count, 0) at_risk_count,
            (
                SELECT
                    count(*)
                FROM zerver_userprofile up
                WHERE up.realm_id = realm.id
                AND is_active
                AND not is_bot
            ) user_profile_count,
            (
                SELECT
                    count(*)
                FROM zerver_userprofile up
                WHERE up.realm_id = realm.id
                AND is_active
                AND is_bot
            ) bot_count
        FROM zerver_realm realm
        LEFT OUTER JOIN
            (
                SELECT
                    up.realm_id realm_id,
                    count(distinct(ua.user_profile_id)) active_user_count
                FROM zerver_useractivity ua
                JOIN zerver_userprofile up
                    ON up.id = ua.user_profile_id
                WHERE
                    query in (
                        '/json/send_message',
                        'send_message_backend',
                        '/api/v1/send_message',
                        '/json/update_pointer'
                    )
                AND
                    last_visit > now() - interval '1 day'
                AND
                    not is_bot
                GROUP BY realm_id
            ) user_counts
            ON user_counts.realm_id = realm.id
        LEFT OUTER JOIN
            (
                SELECT
                    realm_id,
                    count(*) at_risk_count
                FROM (
                    SELECT
                        realm.id as realm_id,
                        up.email
                    FROM zerver_useractivity ua
                    JOIN zerver_userprofile up
                        ON up.id = ua.user_profile_id
                    JOIN zerver_realm realm
                        ON realm.id = up.realm_id
                    WHERE up.is_active
                    AND (not up.is_bot)
                    AND
                        ua.query in (
                            '/json/send_message',
                            'send_message_backend',
                           '/api/v1/send_message',
                            '/json/update_pointer'
                        )
                    GROUP by realm.id, up.email
                    HAVING max(last_visit) between
                        now() - interval '7 day' and
                        now() - interval '1 day'
                ) as at_risk_users
                GROUP BY realm_id
            ) at_risk_counts
            ON at_risk_counts.realm_id = realm.id
        WHERE
            realm.domain not in ('zulip.com', 'customer4.invalid', 'wdaher.com')
        AND EXISTS (
                SELECT *
                FROM zerver_useractivity ua
                JOIN zerver_userprofile up
                    ON up.id = ua.user_profile_id
                WHERE
                    query in (
                        '/json/send_message',
                        '/api/v1/send_message',
                        'send_message_backend',
                        '/json/update_pointer'
                    )
                AND
                    up.realm_id = realm.id
                AND
                    last_visit > now() - interval '2 week'
        )
        ORDER BY active_user_count DESC, domain ASC
        '''

    cursor = connection.cursor()
    cursor.execute(query)
    rows = dictfetchall(cursor)
    cursor.close()

    # get messages sent per day
    counts = get_realm_day_counts()
    for row in rows:
        try:
            row['history'] = counts[row['domain']]['cnts']
        except:
            row['history'] = ''

    # augment data with realm_minutes
    total_hours = 0
    for row in rows:
        domain = row['domain']
        minutes = realm_minutes.get(domain, 0)
        hours = minutes / 60.0
        total_hours += hours
        row['hours'] = str(int(hours))
        try:
            row['hours_per_user'] = '%.1f' % (hours / row['active_user_count'],)
        except:
            pass

    # formatting
    for row in rows:
        row['domain'] = realm_activity_link(row['domain'])

    # Count active sites
    def meets_goal(row):
        # We don't count toward company goals for obvious reasons, and
        # customer4.invalid is essentially a dup for users.customer4.invalid.
        if row['domain'] in ['zulip.com', 'customer4.invalid', 'wdaher.com']:
            return False
        return row['active_user_count'] >= 5

    num_active_sites = len(filter(meets_goal, rows))

    # create totals
    total_active_user_count = 0
    total_user_profile_count = 0
    total_bot_count = 0
    for row in rows:
        total_active_user_count += int(row['active_user_count'])
        total_user_profile_count += int(row['user_profile_count'])
        total_bot_count += int(row['bot_count'])


    rows.append(dict(
        domain='Total',
        active_user_count=total_active_user_count,
        user_profile_count=total_user_profile_count,
        bot_count=total_bot_count,
        hours=int(total_hours)
    ))

    content = loader.render_to_string(
        'analytics/realm_summary_table.html',
        dict(rows=rows, num_active_sites=num_active_sites)
    )
    return content


def user_activity_intervals():
    day_end = timestamp_to_datetime(time.time())
    day_start = day_end - timedelta(hours=24)

    output = "Per-user online duration for the last 24 hours:\n"
    total_duration = timedelta(0)

    all_intervals = UserActivityInterval.objects.filter(
        end__gte=day_start,
        start__lte=day_end
    ).select_related(
        'user_profile',
        'user_profile__realm'
    ).only(
        'start',
        'end',
        'user_profile__email',
        'user_profile__realm__domain'
    ).order_by(
        'user_profile__realm__domain',
        'user_profile__email'
    )

    by_domain = lambda row: row.user_profile.realm.domain
    by_email = lambda row: row.user_profile.email

    realm_minutes = {}

    for domain, realm_intervals in itertools.groupby(all_intervals, by_domain):
        realm_duration = timedelta(0)
        output += '<hr>%s\n' % (domain,)
        for email, intervals in itertools.groupby(realm_intervals, by_email):
            duration = timedelta(0)
            for interval in intervals:
                start = max(day_start, interval.start)
                end = min(day_end, interval.end)
                duration += end - start

            total_duration += duration
            realm_duration += duration
            output += "  %-*s%s\n" % (37, email, duration, )

        realm_minutes[domain] = realm_duration.total_seconds() / 60

    output += "\nTotal Duration:                      %s\n" % (total_duration,)
    output += "\nTotal Duration in minutes:           %s\n" % (total_duration.total_seconds() / 60.,)
    output += "Total Duration amortized to a month: %s" % (total_duration.total_seconds() * 30. / 60.,)
    content = mark_safe('<pre>' + output + '</pre>')
    return content, realm_minutes

def sent_messages_report(realm):
    title = 'Recently sent messages for ' + realm

    cols = [
        'Date',
        'Humans',
        'Bots'
    ]

    query = '''
        select
            series.day::date,
            humans.cnt,
            bots.cnt
        from (
            select generate_series(
                (now()::date - interval '2 week'),
                now()::date,
                interval '1 day'
            ) as day
        ) as series
        left join (
            select
                pub_date::date pub_date,
                count(*) cnt
            from zerver_message m
            join zerver_userprofile up on up.id = m.sender_id
            join zerver_realm r on r.id = up.realm_id
            where
                r.domain = %s
            and
                (not up.is_bot)
            and
                pub_date > now() - interval '2 week'
            group by
                pub_date::date
            order by
                pub_date::date
        ) humans on
            series.day = humans.pub_date
        left join (
            select
                pub_date::date pub_date,
                count(*) cnt
            from zerver_message m
            join zerver_userprofile up on up.id = m.sender_id
            join zerver_realm r on r.id = up.realm_id
            where
                r.domain = %s
            and
                up.is_bot
            and
                pub_date > now() - interval '2 week'
            group by
                pub_date::date
            order by
                pub_date::date
        ) bots on
            series.day = bots.pub_date
    '''
    cursor = connection.cursor()
    cursor.execute(query, [realm, realm])
    rows = cursor.fetchall()
    cursor.close()

    return make_table(title, cols, rows)

def ad_hoc_queries():
    def get_page(query, cols, title):
        cursor = connection.cursor()
        cursor.execute(query)
        rows = cursor.fetchall()
        rows = map(list, rows)
        cursor.close()

        def fix_rows(i, fixup_func):
            for row in rows:
                row[i] = fixup_func(row[i])

        for i, col in enumerate(cols):
            if col == 'Domain':
                fix_rows(i, realm_activity_link)
            elif col in ['Last time', 'Last visit']:
                fix_rows(i, format_date_for_activity_reports)

        content = make_table(title, cols, rows)

        return dict(
            content=content,
            title=title
        )

    pages = []

    ###

    for mobile_type in ['Android', 'ZulipiOS']:
        title = '%s usage' % (mobile_type,)

        query = '''
            select
                realm.domain,
                up.id user_id,
                client.name,
                sum(count) as hits,
                max(last_visit) as last_time
            from zerver_useractivity ua
            join zerver_client client on client.id = ua.client_id
            join zerver_userprofile up on up.id = ua.user_profile_id
            join zerver_realm realm on realm.id = up.realm_id
            where
                client.name like '%s'
            group by domain, up.id, client.name
            having max(last_visit) > now() - interval '2 week'
            order by domain, up.id, client.name
        ''' % (mobile_type,)

        cols = [
            'Domain',
            'User id',
            'Name',
            'Hits',
            'Last time'
        ]

        pages.append(get_page(query, cols, title))

    ###

    title = 'Desktop users'

    query = '''
        select
            realm.domain,
            client.name,
            sum(count) as hits,
            max(last_visit) as last_time
        from zerver_useractivity ua
        join zerver_client client on client.id = ua.client_id
        join zerver_userprofile up on up.id = ua.user_profile_id
        join zerver_realm realm on realm.id = up.realm_id
        where
            client.name like 'desktop%%'
        group by domain, client.name
        having max(last_visit) > now() - interval '2 week'
        order by domain, client.name
    '''

    cols = [
        'Domain',
        'Client',
        'Hits',
        'Last time'
    ]

    pages.append(get_page(query, cols, title))

    ###

    title = 'Integrations by domain'

    query = '''
        select
            realm.domain,
            case
                when query like '%%external%%' then split_part(query, '/', 5)
                else client.name
            end client_name,
            sum(count) as hits,
            max(last_visit) as last_time
        from zerver_useractivity ua
        join zerver_client client on client.id = ua.client_id
        join zerver_userprofile up on up.id = ua.user_profile_id
        join zerver_realm realm on realm.id = up.realm_id
        where
            (query in ('send_message_backend', '/api/v1/send_message')
            and client.name not in ('Android', 'ZulipiOS')
            and client.name not like 'test: Zulip%%'
            )
        or
            query like '%%external%%'
        group by domain, client_name
        having max(last_visit) > now() - interval '2 week'
        order by domain, client_name
    '''

    cols = [
        'Domain',
        'Client',
        'Hits',
        'Last time'
    ]

    pages.append(get_page(query, cols, title))

    ###

    title = 'Integrations by client'

    query = '''
        select
            case
                when query like '%%external%%' then split_part(query, '/', 5)
                else client.name
            end client_name,
            realm.domain,
            sum(count) as hits,
            max(last_visit) as last_time
        from zerver_useractivity ua
        join zerver_client client on client.id = ua.client_id
        join zerver_userprofile up on up.id = ua.user_profile_id
        join zerver_realm realm on realm.id = up.realm_id
        where
            (query in ('send_message_backend', '/api/v1/send_message')
            and client.name not in ('Android', 'ZulipiOS')
            and client.name not like 'test: Zulip%%'
            )
        or
            query like '%%external%%'
        group by client_name, domain
        having max(last_visit) > now() - interval '2 week'
        order by client_name, domain
    '''

    cols = [
        'Client',
        'Domain',
        'Hits',
        'Last time'
    ]

    pages.append(get_page(query, cols, title))

    return pages

@zulip_internal
@has_request_variables
def get_activity(request):
    duration_content, realm_minutes = user_activity_intervals()
    counts_content = realm_summary_table(realm_minutes)
    data = [
        ('Counts', counts_content),
        ('Durations', duration_content),
    ]
    for page in ad_hoc_queries():
        data.append((page['title'], page['content']))

    title = 'Activity'

    return render_to_response(
        'analytics/activity.html',
        dict(data=data, title=title, is_home=True),
        context_instance=RequestContext(request)
    )

def get_user_activity_records_for_realm(realm, is_bot):
    fields = [
        'user_profile__full_name',
        'user_profile__email',
        'query',
        'client__name',
        'count',
        'last_visit',
    ]

    records = UserActivity.objects.filter(
            user_profile__realm__domain=realm,
            user_profile__is_active=True,
            user_profile__is_bot=is_bot
    )
    records = records.order_by("user_profile__email", "-last_visit")
    records = records.select_related('user_profile', 'client').only(*fields)
    return records

def get_user_activity_records_for_email(email):
    fields = [
        'user_profile__full_name',
        'query',
        'client__name',
        'count',
        'last_visit'
    ]

    records = UserActivity.objects.filter(
            user_profile__email=email
    )
    records = records.order_by("-last_visit")
    records = records.select_related('user_profile', 'client').only(*fields)
    return records

def raw_user_activity_table(records):
    cols = [
        'query',
        'client',
        'count',
        'last_visit'
    ]

    def row(record):
        return [
                record.query,
                record.client.name,
                record.count,
                format_date_for_activity_reports(record.last_visit)
        ]

    rows = map(row, records)
    title = 'Raw Data'
    return make_table(title, cols, rows)

def get_user_activity_summary(records):
    summary = {}
    def update(action, record):
        if action not in summary:
            summary[action] = dict(
                    count=record.count,
                    last_visit=record.last_visit
            )
        else:
            summary[action]['count'] += record.count
            summary[action]['last_visit'] = max(
                    summary[action]['last_visit'],
                    record.last_visit
            )

    if records:
        summary['name'] = records[0].user_profile.full_name

    for record in records:
        client = record.client.name
        query = record.query

        update('use', record)

        if client == 'API':
            m = re.match('/api/.*/external/(.*)', query)
            if m:
                client = m.group(1)
                update(client, record)

        if client.startswith('desktop'):
            update('desktop', record)
        if client == 'website':
            update('website', record)
        if ('send_message' in query) or re.search('/api/.*/external/.*', query):
            update('send', record)
        if query in ['/json/update_pointer', '/api/v1/update_pointer']:
            update('pointer', record)
        update(client, record)


    return summary

def format_date_for_activity_reports(date):
    if date:
        return date.astimezone(eastern_tz).strftime('%Y-%m-%d %H:%M')
    else:
        return ''

def user_activity_link(email):
    url_name = 'analytics.views.get_user_activity'
    url = urlresolvers.reverse(url_name, kwargs=dict(email=email))
    email_link = '<a href="%s">%s</a>' % (url, email)
    return mark_safe(email_link)

def realm_activity_link(realm):
    url_name = 'analytics.views.get_realm_activity'
    url = urlresolvers.reverse(url_name, kwargs=dict(realm=realm))
    realm_link = '<a href="%s">%s</a>' % (url, realm)
    return mark_safe(realm_link)

def realm_client_table(user_summaries):
    exclude_keys = [
            'internal',
            'name',
            'use',
            'send',
            'pointer',
            'website',
            'desktop',
    ]

    rows = []
    for email, user_summary in user_summaries.items():
        email_link = user_activity_link(email)
        name = user_summary['name']
        for k, v in user_summary.items():
            if k in exclude_keys:
                continue
            client = k
            count = v['count']
            last_visit = v['last_visit']
            row = [
                    format_date_for_activity_reports(last_visit),
                    client,
                    name,
                    email_link,
                    count,
            ]
            rows.append(row)

    rows = sorted(rows, key=lambda r: r[0], reverse=True)

    cols = [
            'Last visit',
            'Client',
            'Name',
            'Email',
            'Count',
    ]

    title = 'Clients'

    return make_table(title, cols, rows)

def user_activity_summary_table(user_summary):
    rows = []
    for k, v in user_summary.items():
        if k == 'name':
            continue
        client = k
        count = v['count']
        last_visit = v['last_visit']
        row = [
                format_date_for_activity_reports(last_visit),
                client,
                count,
        ]
        rows.append(row)

    rows = sorted(rows, key=lambda r: r[0], reverse=True)

    cols = [
            'last_visit',
            'client',
            'count',
    ]

    title = 'User Activity'
    return make_table(title, cols, rows)

def realm_user_summary_table(all_records, admin_emails):
    user_records = {}

    def by_email(record):
        return record.user_profile.email

    for email, records in itertools.groupby(all_records, by_email):
        user_records[email] = get_user_activity_summary(list(records))

    def get_last_visit(user_summary, k):
        if k in user_summary:
            return user_summary[k]['last_visit']
        else:
            return None

    def get_count(user_summary, k):
        if k in user_summary:
            return user_summary[k]['count']
        else:
            return ''

    def is_recent(val):
        age = datetime.now(val.tzinfo) - val
        return age.total_seconds() < 5 * 60

    rows = []
    for email, user_summary in user_records.items():
        email_link = user_activity_link(email)
        sent_count = get_count(user_summary, 'send')
        cells = [user_summary['name'], email_link, sent_count]
        row_class = ''
        for field in ['use', 'send', 'pointer', 'desktop', 'ZulipiOS', 'Android']:
            val = get_last_visit(user_summary, field)
            if field == 'use':
                if val and is_recent(val):
                    row_class += ' recently_active'
                if email in admin_emails:
                    row_class += ' admin'
            val = format_date_for_activity_reports(val)
            cells.append(val)
        row = dict(cells=cells, row_class=row_class)
        rows.append(row)

    def by_used_time(row):
        return row['cells'][3]

    rows = sorted(rows, key=by_used_time, reverse=True)

    cols = [
            'Name',
            'Email',
            'Total sent',
            'Heard from',
            'Message sent',
            'Pointer motion',
            'Desktop',
            'ZulipiOS',
            'Android'
    ]

    title = 'Summary'

    content = make_table(title, cols, rows, has_row_class=True)
    return user_records, content

@zulip_internal
def get_realm_activity(request, realm):
    data = []
    all_records = {}
    all_user_records = {}

    try:
        admins = Realm.objects.get(domain=realm).get_admin_users()
    except Realm.DoesNotExist:
        return HttpResponseNotFound("Realm %s does not exist" % (realm,))

    admin_emails = {admin.email for admin in admins}

    for is_bot, page_title in [(False,  'Humans'), (True, 'Bots')]:
        all_records = get_user_activity_records_for_realm(realm, is_bot)
        all_records = list(all_records)

        user_records, content = realm_user_summary_table(all_records, admin_emails)
        all_user_records.update(user_records)

        data += [(page_title, content)]

    page_title = 'Clients'
    content = realm_client_table(all_user_records)
    data += [(page_title, content)]


    page_title = 'History'
    content = sent_messages_report(realm)
    data += [(page_title, content)]

    fix_name = lambda realm: realm.replace('.', '_')

    realm_link = 'https://stats1.zulip.net:444/render/?from=-7days'
    realm_link += '&target=stats.gauges.staging.users.active.%s.0_16hr' % (fix_name(realm),)

    title = realm
    return render_to_response(
        'analytics/activity.html',
        dict(data=data, realm_link=realm_link, title=title),
        context_instance=RequestContext(request)
    )

@zulip_internal
def get_user_activity(request, email):
    records = get_user_activity_records_for_email(email)

    data = []
    user_summary = get_user_activity_summary(records)
    content = user_activity_summary_table(user_summary)

    data += [('Summary', content)]

    content = raw_user_activity_table(records)
    data += [('Info', content)]

    title = email
    return render_to_response(
        'analytics/activity.html',
        dict(data=data, title=title),
        context_instance=RequestContext(request)
    )