import os
import re
import logging
import datetime
import time

from pylons import config as pylonsconfig
from ckan.lib.cli import CkanCommand
import ckan.model as model

import dbutil

log = logging.getLogger('ckanext.googleanalytics')
PACKAGE_URL = '/dataset/'  # XXX get from routes...
DEFAULT_RESOURCE_URL_TAG = '/downloads/'

RESOURCE_URL_REGEX = re.compile('/dataset/[a-z0-9-_]+/resource/([a-z0-9-_]+)')
DATASET_EDIT_REGEX = re.compile('/dataset/edit/([a-z0-9-_]+)')


class GetAuthToken(CkanCommand):
    """ Get's the Google auth token

    Usage: paster getauthtoken <credentials_file>

    Where <credentials_file> is the file name containing the details
    for the service (obtained from https://code.google.com/apis/console).
    By default this is set to credentials.json
    """
    summary = __doc__.split('\n')[0]
    usage = __doc__
    max_args = 1
    min_args = 0

    def command(self):
        """
        In this case we don't want a valid service, but rather just to
        force the user through the auth flow. We allow this to complete to
        act as a form of verification instead of just getting the token and
        assuming it is correct.
        """
        from ga_auth import init_service
        init_service('token.dat',
                      self.args[0] if self.args else 'credentials.json')


class InitDB(CkanCommand):
    """Initialise the local stats database tables
    """
    summary = __doc__.split('\n')[0]
    usage = __doc__
    max_args = 0
    min_args = 0

    def command(self):
        self._load_config()
        model.Session.remove()
        model.Session.configure(bind=model.meta.engine)
        dbutil.init_tables()
        log.info("Set up statistics tables in main database")


class LoadAnalytics(CkanCommand):
    """Parse data from Google Analytics API and store it
    in a local database

    Options:
        <token_file> internal [date] use ckan internal tracking tables
                        token_file specifies the OAUTH token file
                        date specifies start date for retrieving
                        analytics data YYYY-MM-DD format
    """
    summary = __doc__.split('\n')[0]
    usage = __doc__
    max_args = 3
    min_args = 1
    TEST_HOST = None
    CONFIG = None

    def command(self):
        if not self.CONFIG:
            self._load_config()
            self.CONFIG = pylonsconfig

        self.resource_url_tag = self.CONFIG.get(
            'googleanalytics_resource_prefix',
            DEFAULT_RESOURCE_URL_TAG)

        # funny dance we need to do to make sure we've got a
        # configured session
        model.Session.remove()
        model.Session.configure(bind=model.meta.engine)
        self.parse_and_save()

    def internal_save(self, packages_data, summary_date):
        engine = model.meta.engine
        # clear out existing data before adding new
        sql = '''DELETE FROM tracking_summary
                 WHERE tracking_date='%s'; ''' % summary_date
        engine.execute(sql)

        for url, count in packages_data.iteritems():
            # If it matches the resource then we should mark it as a resource.
            # For resources we don't currently find the package ID.
            if RESOURCE_URL_REGEX.match(url):
                tracking_type = 'resource'
            else:
                tracking_type = 'page'

            sql = '''INSERT INTO tracking_summary
                     (url, count, tracking_date, tracking_type)
                     VALUES (%s, %s, %s, %s);'''
            engine.execute(sql, url, count, summary_date, tracking_type)

        # get ids for dataset urls
        sql = '''UPDATE tracking_summary t
                 SET package_id = COALESCE(
                     (SELECT id FROM package p WHERE t.url =  %s || p.name)
                     ,'~~not~found~~')
                 WHERE t.package_id IS NULL AND tracking_type = 'page';'''
        engine.execute(sql, PACKAGE_URL)

        # get ids for dataset edit urls which aren't captured otherwise
        sql = '''UPDATE tracking_summary t
                 SET package_id = COALESCE(
                     (SELECT id FROM package p WHERE t.url =  %s || p.name)
                     ,'~~not~found~~')
                 WHERE t.package_id = '~~not~found~~' AND tracking_type = 'page';'''
        engine.execute(sql, '%sedit/' % PACKAGE_URL)

        # update summary totals for resources
        sql = '''UPDATE tracking_summary t1
                 SET running_total = (
                    SELECT sum(count)
                    FROM tracking_summary t2
                    WHERE t1.url = t2.url
                    AND t2.tracking_date <= t1.tracking_date
                 ) + t1.count
                 ,recent_views = (
                    SELECT sum(count)
                    FROM tracking_summary t2
                    WHERE t1.url = t2.url
                    AND t2.tracking_date <= t1.tracking_date AND t2.tracking_date >= t1.tracking_date - 14
                 ) + t1.count
                 WHERE t1.running_total = 0 AND tracking_type = 'resource';'''
        engine.execute(sql)

        # update summary totals for pages
        sql = '''UPDATE tracking_summary t1
                 SET running_total = (
                    SELECT sum(count)
                    FROM tracking_summary t2
                    WHERE t1.package_id = t2.package_id
                    AND t2.tracking_date <= t1.tracking_date
                 ) + t1.count
                 ,recent_views = (
                    SELECT sum(count)
                    FROM tracking_summary t2
                    WHERE t1.package_id = t2.package_id
                    AND t2.tracking_date <= t1.tracking_date AND t2.tracking_date >= t1.tracking_date - 14
                 ) + t1.count
                 WHERE t1.running_total = 0 AND tracking_type = 'page'
                 AND t1.package_id IS NOT NULL
                 AND t1.package_id != '~~not~found~~';'''
        engine.execute(sql)

    def bulk_import(self):
        if len(self.args) == 3:
            # Get summeries from specified date
            start_date = datetime.datetime.strptime(self.args[2], '%Y-%m-%d')
        else:
            # No date given. See when we last have data for and get data
            # from 2 days before then in case new data is available.
            # If no date here then use 2010-01-01 as the start date
            engine = model.meta.engine
            sql = '''SELECT tracking_date from tracking_summary
                     ORDER BY tracking_date DESC LIMIT 1;'''
            result = engine.execute(sql).fetchall()
            if result:
                start_date = result[0]['tracking_date']
                start_date += datetime.timedelta(-2)
                # convert date to datetime
                combine = datetime.datetime.combine
                start_date = combine(start_date, datetime.time(0))
            else:
                start_date = datetime.datetime(2011, 1, 1)
        end_date = datetime.datetime.now()
        while start_date < end_date:
            stop_date = start_date + datetime.timedelta(1)
            packages_data = self.get_ga_data_new(start_date=start_date,
                                                 end_date=stop_date)
            self.internal_save(packages_data, start_date)
            # sleep to rate limit requests
            time.sleep(0.25)
            start_date = stop_date
            log.info('%s received %s' % (len(packages_data), start_date))
            print '%s received %s' % (len(packages_data), start_date)

    def get_ga_data_new(self, start_date=None, end_date=None):
        """Get raw data from Google Analtyics for packages and
        resources.

        Returns a dictionary like::

           {'identifier': 3}
        """
        start_date = start_date.strftime("%Y-%m-%d")
        end_date = end_date.strftime("%Y-%m-%d")

        packages = {}
        query = 'ga:pagePath=~%s,ga:pagePath=~%s' % \
                    (PACKAGE_URL, self.resource_url_tag)
        metrics = 'ga:uniquePageviews'
        sort = '-ga:uniquePageviews'

        start_index = 1
        max_results = 10000
        # data retrival is chunked
        completed = False
        while not completed:
            results = self.service.data().ga().get(ids='ga:%s' % self.profile_id,
                                 filters=query,
                                 dimensions='ga:pagePath',
                                 start_date=start_date,
                                 start_index=start_index,
                                 max_results=max_results,
                                 metrics=metrics,
                                 sort=sort,
                                 end_date=end_date).execute()
            result_count = len(results.get('rows', []))
            if result_count < max_results:
                completed = True

            for result in results.get('rows', []):
                package = result[0]
                package = '/' + '/'.join(package.split('/')[2:])
                count = result[1]
                packages[package] = int(count)

            start_index += max_results

            # rate limiting
            time.sleep(0.2)
        return packages

    def parse_and_save(self):
        """Grab raw data from Google Analytics and save to the database"""
        from ga_auth import (init_service, get_profile_id)

        tokenfile = self.args[0]
        if not os.path.exists(tokenfile):
            raise Exception('Cannot find the token file %s' % self.args[0])

        try:
            self.service = init_service(self.args[0], None)
        except TypeError:
            print ('Have you correctly run the getauthtoken task and '
                   'specified the correct file here')
            raise Exception('Unable to create a service')
        self.profile_id = get_profile_id(self.service)

        if len(self.args) > 1:
            if len(self.args) > 2 and self.args[1].lower() != 'internal':
                raise Exception('Illegal argument %s' % self.args[1])
            self.bulk_import()
        else:
            query = 'ga:pagePath=~%s,ga:pagePath=~%s' % \
                    (PACKAGE_URL, self.resource_url_tag)
            packages_data = self.get_ga_data(query_filter=query)
            self.save_ga_data(packages_data)
            log.info("Saved %s records from google" % len(packages_data))

    def save_ga_data(self, packages_data):
        """Save tuples of packages_data to the database
        """
        for identifier, visits in packages_data.items():
            recently = visits.get('recent', 0)
            ever = visits.get('ever', 0)
            matches = RESOURCE_URL_REGEX.match(identifier)
            if matches:
                resource_url = identifier[len(self.resource_url_tag):]
                resource = model.Session.query(model.Resource).autoflush(True)\
                           .filter_by(id=matches.group(1)).first()
                if not resource:
                    log.warning("Couldn't find resource %s" % resource_url)
                    continue
                dbutil.update_resource_visits(resource.id, recently, ever)
                log.info("Updated %s with %s visits" % (resource.id, visits))
            else:
                package_name = identifier[len(PACKAGE_URL):]
                if "/" in package_name:
                    log.warning("%s not a valid package name" % package_name)
                    continue
                item = model.Package.by_name(package_name)
                if not item:
                    log.warning("Couldn't find package %s" % package_name)
                    continue
                dbutil.update_package_visits(item.id, recently, ever)
                log.info("Updated %s with %s visits" % (item.id, visits))
        model.Session.commit()

    def ga_query(self, query_filter=None, from_date=None, to_date=None,
                 start_index=1, max_results=10000, metrics=None, sort=None):
        """Execute a query against Google Analytics
        """
        if not to_date:
            now = datetime.datetime.now()
            to_date = now.strftime("%Y-%m-%d")
        if isinstance(from_date, datetime.date):
            from_date = from_date.strftime("%Y-%m-%d")
        if not metrics:
            metrics = 'ga:visits,ga:visitors,ga:newVisits,ga:uniquePageviews'
        if not sort:
            sort = '-ga:uniquePageviews'

        print '%s -> %s' % (from_date, to_date)

        results = self.service.data().ga().get(ids='ga:' + self.profile_id,
                                      start_date=from_date,
                                      end_date=to_date,
                                      dimensions='ga:pagePath',
                                      metrics=metrics,
                                      sort=sort,
                                      start_index=start_index,
                                      filters=query_filter,
                                      max_results=max_results
                                      ).execute()
        return results

    def get_ga_data(self, query_filter=None, start_date=None, end_date=None):
        """Get raw data from Google Analtyics for packages and
        resources, and for both the last two weeks and ever.

        Returns a dictionary like::

           {'identifier': {'recent':3, 'ever':6}}
        """
        now = datetime.datetime.now()
        recent_date = now - datetime.timedelta(14)
        recent_date = recent_date.strftime("%Y-%m-%d")
        floor_date = datetime.date(2005, 1, 1)
        packages = {}
        queries = ['ga:pagePath=~%s' % PACKAGE_URL]
        dates = {'recent': recent_date, 'ever': floor_date}
        for date_name, date in dates.iteritems():
            for query in queries:
                results = self.ga_query(query_filter=query,
                                        metrics='ga:uniquePageviews',
                                        from_date=date)
                if 'rows' in results:
                    for result in results.get('rows'):
                        package = result[0]
                        if not package.startswith(PACKAGE_URL):
                            package = '/' + '/'.join(package.split('/')[2:])

                        count = result[1]
                        # Make sure we add the different representations of the same
                        # dataset /mysite.com & /www.mysite.com ...
                        val = 0
                        if package in packages and date_name in packages[package]:
                            val += packages[package][date_name]
                        packages.setdefault(package, {})[date_name] = \
                            int(count) + val
        return packages