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

"""
utils for apps/indicator
"""

from django.contrib.auth.models import User
from django.shortcuts import get_object_or_404
from django.utils.timezone import utc

from indicator import models as im
from sciblog import models as sciblogm

import re
import datetime


# follow_indicator {{{
def follow_indicator(user_id, indicator_id):
    """
    用户关注指标
    """
    try:
        user = get_object_or_404(User, id=user_id)
        indicator = im.Indicator.objects.get(id=indicator_id)
        ui, created = im.UserIndicator.objects.get_or_create(user=user)
        ui.followedIndicators.add(indicator)
        # to remove the indicator from 'followedHistories' if exists
        if indicator in ui.followedHistories.all():
            ui.followedHistories.remove(indicator)
        ui.save()
        return True
    except:
        return False
# }}}


# unfollow_indicator {{{
def unfollow_indicator(user_id, indicator_id):
    """
    用户取消关注指标
    """
    try:
        user = get_object_or_404(User, id=user_id)
        indicator = im.Indicator.objects.get(id=indicator_id)
        ui, created = im.UserIndicator.objects.get_or_create(user=user)
        ui.followedIndicators.remove(indicator)
        # add indicator to 'followedHistories'
        ui.followedHistories.add(indicator)
        ui.save()
        return True
    except:
        return False
# }}}


# get_indicator {{{
def get_indicator(category_id="all", startswith="all"):
    """
    根据指定的 category_id 和 startswith 获取 indicator
    返回一个 dict
    Dict format:
    dict = {
        'a': [ {'pinyin': 'aa', ...}, {'pinyin': 'ab', ...}, ... ],
        'b': [ {'pinyin': 'ba', ...}, {'pinyin': 'bb', ...}, ... ],
        ...
    }
    """

    _idict = {}
    if category_id == 'all':
        iqueryset = im.Indicator.objects.all()
    else:
        try:
            cid = int(category_id)
            cate = im.IndicatorCategory.objects.get(id=cid)
            iqueryset = cate.indicators.all()
        except ValueError:
            raise ValueError(u'category_id 不是整数型')
            return _idict
        except im.IndicatorCategory.DoesNotExist:
            raise ValueError(u'id=%s 的 IndicatorCategory 不存在'
                    % cid)
            return _idict

    if startswith == 'all':
        starts = map(chr, range(ord('a'), ord('z')+1))
    else:
        starts = []
        _str = startswith.lower()
        for i in _str:
            if i >= 'a' and i <= 'z':
                starts.append(i)

    for l in starts:
        iq = iqueryset.filter(pinyin__istartswith=l).order_by('pinyin')
        _idict[l] = [ i.dump() for i in iq ]
    return _idict
# }}}


# get_followed_indicator {{{
def get_followed_indicator(user_id, category_id="all", startswith="all"):
    """
    获取已关注的指标
    返回 dict, 格式与 get_indicator() 一致
    """

    u = User.objects.get(id=user_id)
    ui, created = im.UserIndicator.objects.get_or_create(user=u)
    ui.save()
    _idict = {}
    iqueryset = ui.followedIndicators.all()
    if not category_id == 'all':
        try:
            cid = int(category_id)
            iqueryset = iqueryset.filter(categories__id=cid)
        except ValueError:
            raise ValueError(u'category_id 不是整数型')
            return _idict

    if startswith == 'all':
        starts = map(chr, range(ord('a'), ord('z')+1))
    else:
        starts = []
        _str = startswith.lower()
        for i in _str:
            if i >= 'a' and i <= 'z':
                starts.append(i)

    for l in starts:
        iq = iqueryset.filter(pinyin__istartswith=l).order_by('pinyin')
        _idict[l] = [ i.dump() for i in iq ]
    return _idict
# }}}


# get_unfollowed_indicator {{{
def get_unfollowed_indicator(user_id, category_id="all", startswith="all"):
    """
    获取未关注的指标
    返回 dict, 格式与 get_indicator() 一致
    """

    u = User.objects.get(id=user_id)
    ui, created = im.UserIndicator.objects.get_or_create(user=u)
    ui.save()
    _idict = {}
    # XXX: if 'exclude(followed_indicators=ui)' OK??
    iqueryset = im.Indicator.objects.exclude(followed_indicators=ui)
    if not category_id == 'all':
        try:
            cid = int(category_id)
            iqueryset = iqueryset.filter(categories__id=cid)
        except ValueError:
            raise ValueError(u'category_id 不是整数型')
            return _idict

    if startswith == 'all':
        starts = map(chr, range(ord('a'), ord('z')+1))
    else:
        starts = []
        _str = startswith.lower()
        for i in _str:
            if i >= 'a' and i <= 'z':
                starts.append(i)

    for l in starts:
        iq = iqueryset.filter(pinyin__istartswith=l).order_by('pinyin')
        _idict[l] = [ i.dump() for i in iq ]
    return _idict
# }}}


# get_record {{{
def get_record(user_id, indicator_id, begin=None, end=None, number=None, std=False):
    """
    args 'begin' and 'end' to specify the date range.
    arg 'std=True' to get data in standard unit

    if 'begin=None', then the earliest date is given;
    if 'end=None', then the latest date is given.

    if 'number' given, then return the lastest number of records.
    if there is not that much, then return all the records.

    the date range filter *first*, then number filter

    return dict format: (data sorted by 'date')
    rdata = {
        'failed': False,
        'number_req': number_of_records_request,
        'begin_req': begin_req,
        'end_req': end_req,
        'number_rsp': number_of_records_response,
        'begin_rsp': begin_rsp,
        'end_rsp': end_rsp,
        'has_more': True|False,
        'has_earlier': True|False,
        'has_later': True|False,
        'data': [d1r1.get_data(), d1r2.get_data(), ...],
    }
    """
    # default parameters
    number_req = None
    begin_req = None
    end_req = None
    #
    uid = int(user_id)
    indid = int(indicator_id)
    all_records = im.IndicatorRecord.objects.\
            filter(user__id=uid, indicator__id=indid).\
            order_by('date', 'created_at')
    # check if 'all_records' empty
    if not all_records:
        return {'failed': True}
    # check date range and given number
    if (begin is None) and (end is None):
        # select by given 'number'
        if number is not None:
            try:
                number_req = int(number)
                records = all_records.reverse()[:number_req]
            except ValueError:
                raise ValueError(u"number='%s' 错误" % number)
                return {'failed': True}
        else:
            records = all_records.reverse()
        # convert to list, and re-sort by 'date'
        records_list = list(records)
        records_list.reverse()
    else:
        # check date range
        # begin
        if begin is None:
            begin = all_records[0].date
        elif isinstance(begin, datetime.date):
            begin_req = begin.isoformat()
        else:
            raise ValueError(u"begin='%s' 不是合法的日期" % begin)
            return {'failed': True}
        # end
        if end is None:
            end = all_records.reverse()[0].date
        elif isinstance(end, datetime.date):
            end_req = end.isoformat()
        else:
            raise ValueError(u"end='%s' 不是合法的日期" % end)
            return {'failed': True}
        # filter by date range
        records = all_records.filter(date__range=(begin, end))
        records_list = list(records)

    # process records
    number_rsp = len(records_list)
    begin_rsp_py = records_list[0].date
    begin_rsp = begin_rsp_py.isoformat()
    end_rsp_py = records_list[-1].date
    end_rsp = end_rsp_py.isoformat()
    # has_earlier, has_later, has_more
    has_earlier = False
    has_later = False
    has_more = False
    r_earlier = all_records.filter(date__lt=begin_rsp_py)
    r_later = all_records.filter(date__gt=end_rsp_py)
    if r_earlier:
        has_earlier = True
    if r_later:
        has_later = True
    if has_earlier or has_later:
        has_more = True
    #
    _rdata = {
        'failed': False,
        'number_req': number_req,
        'begin_req': begin_req,
        'end_req': end_req,
        'number_rsp': number_rsp,
        'begin_rsp': begin_rsp,
        'end_rsp': end_rsp,
        'has_more': has_more,
        'has_earlier': has_earlier,
        'has_later': has_later,
        'data': [],
    }
    for r in records_list:
        # get data
        if std:
            _data = r.get_data_std()
        else:
            _data = r.get_data()
        # append data
        _rdata['data'].append(_data)

    # return
    return _rdata
# }}}


# get_num_record {{{
def get_num_record(user_id, indicator_id, number, end=None, std=False):
    """
    return the *latest* number records.
    args 'end' to specify the end date range.
    arg 'std=True' to get data in standard unit

    return dict format: (data sorted by 'date')
    rdata = {
        'failed': False,
        'number_req': number_of_records_request,
        'begin_req': begin_req,
        'end_req': end_req,
        'number_rsp': number_of_records_response,
        'begin_rsp': begin_rsp,
        'end_rsp': end_rsp,
        'has_more': True|False,
        'has_earlier': True|False,
        'has_later': True|False,
        'data': [r1.get_data(), r2.get_data(), ...],
    }
    """
    # default parameters
    number_req = None
    begin_req = None
    end_req = None
    #
    uid = int(user_id)
    indid = int(indicator_id)
    all_records = im.IndicatorRecord.objects.\
            filter(user__id=uid, indicator__id=indid).\
            order_by('date', 'created_at')
    # check if 'all_records' empty
    if not all_records:
        return {'failed': True}
    # check end date
    if end is None:
        end = all_records.reverse()[0].date
    elif isinstance(end, datetime.date):
        end_req = end.isoformat()
    else:
        raise ValueError(u"end='%s' 不是合法的日期" % end)
        return {'failed': True}
    records = all_records.filter(date__lte=end)
    # check number (required param)
    try:
        number_req = int(number)
        records_list = list(records.reverse()[:number_req])
    except ValueError:
        raise ValueError(u"number='%s' 错误" % number)
        return {'failed': True}
    # re-sort by 'date'
    records_list.reverse()

    # process records
    number_rsp = len(records_list)
    begin_rsp_py = records_list[0].date
    begin_rsp = begin_rsp_py.isoformat()
    end_rsp_py = records_list[-1].date
    end_rsp = end_rsp_py.isoformat()
    # has_earlier, has_later, has_more
    has_earlier = False
    has_later = False
    has_more = False
    r_earlier = all_records.filter(date__lt=begin_rsp_py)
    r_later = all_records.filter(date__gt=end_rsp_py)
    if r_earlier:
        has_earlier = True
    if r_later:
        has_later = True
    if has_earlier or has_later:
        has_more = True
    #
    _rdata = {
        'failed': False,
        'number_req': number_req,
        'begin_req': begin_req,
        'end_req': end_req,
        'number_rsp': number_rsp,
        'begin_rsp': begin_rsp,
        'end_rsp': end_rsp,
        'has_more': has_more,
        'has_earlier': has_earlier,
        'has_later': has_later,
        'data': [],
    }
    for r in records_list:
        # get data
        if std:
            _data = r.get_data_std()
        else:
            _data = r.get_data()
        # append data
        _rdata['data'].append(_data)

    # return
    return _rdata
# }}}


# get_record_std {{{
def get_record_std(**kwargs):
    return get_record(std=True, **kwargs)
# }}}


# get_num_record_std {{{
def get_num_record_std(**kwargs):
    return get_num_record(std=True, **kwargs)
# }}}


# add_recordhistory {{{
def add_recordhistory(user_id, record_id, reason, created_at=None):
    """
    add 'RecordHistory' for the given record
    """
    user = get_object_or_404(User, id=user_id)
    record = get_object_or_404(im.IndicatorRecord, id=record_id)
    # check user
    if user.is_staff or user == record.user:
        pass
    else:
        print u'Error: User id="%s" has no permission' % user_id
        return False

    # check reason
    if (reason is None or not reason.strip()):
        print u'Error: reason="%s" blank' % reason
        return False

    # check datetime_utc
    dt_created_at = None
    if created_at:
        if isinstance(created_at, datetime.datetime):
            # specified 'created_at'
            dt_created_at = created_at.replace(tzinfo=utc)
        else:
            print u'Error: given created_at="%s" not python datetime' % created_at
            return False

    # create new RecordHistory
    new_rh = im.RecordHistory(indicatorRecord=record, reason=reason)
    if created_at:
        new_rh.created_at = dt_created_at
    #
    new_rh.save()
    return True
# }}}


# types of recommended indicators, and weights {{{
RI_TYPES = {
    'ANNOTATION_COLLECTED': u'ANN_CL',
    'BLOG_CATCHED': u'BLG_CT',
    'BLOG_COLLECTED': u'BLG_CL',
    'OTHER': u'OTHER',
    'ERROR': u'ERROR',      # no 'RelatedIndicator' data
}
RI_WEIGHTS = {
    RI_TYPES['ANNOTATION_COLLECTED']: 4.0,
    RI_TYPES['BLOG_CATCHED']: 3.0,
    RI_TYPES['BLOG_COLLECTED']: 2.0,
    RI_TYPES['OTHER']: 1.0,
    RI_TYPES['ERROR']: 0.0,
}
# }}}


# calc_indicator_weight {{{
def calc_indicator_weight(user_id, indicator_id):
    """
    calculate the weight of given indicator
    used by 'recommend_indicator'

    return format:
    {'weight': w, 'type': t}
    """
    # weight = weight_type * relatedindicator.weight
    user = User.objects.get(id=user_id)
    ri_qs = im.RelatedIndicator.objects.filter(indicator__id=indicator_id)
    if not ri_qs:
        # queryset empty: no 'RelatedIndicator' for this indicator
        type = RI_TYPES['ERROR']
        w = 0.0
        return {'weight': w, 'type': type}
    # queryset not empty
    annotation_ri_qs = ri_qs.filter(annotation__collected_by=user)
    blogcatch_ri_qs = ri_qs.filter(blog__catched_by=user)
    blogcollect_ri_qs = ri_qs.filter(blog__collected_by=user)
    weights = []
    if annotation_ri_qs:
        # related to annotations collected by user
        type = RI_TYPES['ANNOTATION_COLLECTED']
        for ri in annotation_ri_qs:
            w = RI_WEIGHTS[type] * ri.weight
            weights.append({'weight': w, 'type': type})
    elif blogcatch_ri_qs:
        # related to blogs catched by user
        type = RI_TYPES['BLOG_CATCHED']
        for ri in blogcatch_ri_qs:
            w = RI_WEIGHTS[type] * ri.weight
            weights.append({'weight': w, 'type': type})
    elif blogcollect_ri_qs:
        # related to blogs collected by user
        type = RI_TYPES['BLOG_COLLECTED']
        for ri in blogcollect_ri_qs:
            w = RI_WEIGHTS[type] * ri.weight
            weights.append({'weight': w, 'type': type})
    else:
        # other type, use 'ri_qs' here
        type = RI_TYPES['OTHER']
        for ri in ri_qs:
            w = RI_WEIGHTS[type] * ri.weight
            weights.append({'weight': w, 'type': type})
    # sort results
    weights_sorted = sorted(weights, key = lambda item: item['weight'])
    # return final result
    return weights_sorted[-1]
# }}}


# recommend_indicator {{{
def recommend_indicator(user_id, number=1, auto_follow=False):
    """
    recommend unfollowed indicator for user,
    based on his/her readings and collections.

    if auto_follow=True, then the recommended indicators are
    followed automatically.

    return a list of recommended indicators in format:
    [ {'id': id, 'weight': w, 'type': t}, ... ]
    """
    user_id = int(user_id)
    number = int(number)
    # get unfollowed indicators
    u = User.objects.get(id=user_id)
    ui, created = im.UserIndicator.objects.get_or_create(user=u)
    # XXX: is 'exclude(followed_indicators=ui)' OK??
    uf_ind_qs = im.Indicator.objects.exclude(followed_indicators=ui)
    # calc weight for each unfollowed indicator
    weights = []
    for ind in uf_ind_qs:
        wdict = calc_indicator_weight(user_id, ind.id)
        weights.append({
            'id': ind.id,
            'weight': wdict.get('weight'),
            'type': wdict.get('type'),
        })
    # sort 'weights' dict list by key 'weight'
    weights_sorted = sorted(weights, key=lambda item: item['weight'])
    weights_sorted.reverse()
    # results with largest weights
    results = weights_sorted[:number]
    # update 'lastRecommendTime' of 'UserIndicator'
    now_utc = datetime.datetime.utcnow().replace(tzinfo=utc)
    ui.lastRecommendTime = now_utc
    # updated followedIndicators of 'auto_follow=True'
    if auto_follow:
        for wi in results:
            follow_indicator(user_id, wi['id'])
    # save 'UserIndicator'
    ui.save()
    #
    return results
# }}}


# format_data {{{
def format_data(indicator_obj, value=None, val_max=None, val_min=None, type="html"):
    """
    format given data according to the dataType of given Indicator,
    make it proper for django templates
    e.g.:
    if number very big, then display in 'exponent notation'

    if 'type="html"', then return the html code for displaying
    on the web page;
    elif 'type="text"', then return the plain text format.

    used in '.views.indicator_status()'
    """
    # threshold to show a float number in scientific notation
    float_threshold = 9999.9
    # float display format: fixed point, exponent notation
    fix_fmt = '{:,.1f}'    # comma as a thousands separator
    exp_fmt = '{:.2e}'
    # regex to process exponent notation
    rep = re.compile(r'^(?P<sign>[-+]?)(?P<num>\d\.\d+)[eE]\+?(?P<expminus>-?)0*(?P<exp>[1-9]+)$')
    # range symbol (range: low $symbol$ high)
    range_sym_html = u'&sim;'
    range_sym_text = u'~'
    # default return value
    value_str = u''

    # check 'type'
    if (type == "html") or (type == "text"):
        pass
    else:
        print u'Error: unsupported type="%s"' % type
        return None

    # check given 'indicator_obj'
    ind = indicator_obj
    if not isinstance(ind, im.Indicator):
        print u'Error: given indicator_obj NOT a instance of Indicator'
        raise ValueError(u'Given indicator_obj NOT a instance of Indicator')
        return None
    # get dataType
    dataType = ind.dataType

    if value is not None:
        # a) record float data; b) record integer/pm data;
        # c) confine integer/pm data.
        if dataType == ind.INTEGER_TYPE:
            # TODO: process 'integer type' data
            value_str = u'INTEGER: %s' % value
        elif dataType == ind.PM_TYPE:
            if value == u'+':
                if type == "html":
                    value_str = u'阳性(+)'
                else:
                    value_str = u'+'
            else:
                if type == "html":
                    value_str = u'阳性(-)'
                else:
                    value_str = u'-'
        elif dataType in [ind.FLOAT_TYPE, ind.FLOAT_RANGE_TYPE]:
            # process float number
            value = float(value)
            if value <= float_threshold:
                if type == "html":
                    value_str = fix_fmt.format(value)
                else:
                    value_str = u"%s" % value
            else:
                value_expstr = exp_fmt.format(value)
                # convert to html exponent format
                m = rep.match(value_expstr)
                if type == "html":
                    value_str = u"%s%s&times;10<sup>%s%s</sup>" % (
                            m.group('sign'), m.group('num'),
                            m.group('expminus'), m.group('exp'))
                else:
                    value_str = u"%s%se%s%s" % (
                            m.group('sign'), m.group('num'),
                            m.group('expminus'), m.group('exp'))
        else:
            # unknown XXX
            return None
    elif (val_max is not None) and (val_min is not None):
        # a) record range data; b) confine range.
        # val_max
        if val_max <= float_threshold:
            val_max_str = fix_fmt.format(val_max)
        else:
            val_max_expstr = exp_fmt.format(val_max)
            # convert to html exponent format
            m = rep.match(val_max_expstr)
            if type == "html":
                val_max_str = u"%s%s&times;10<sup>%s%s</sup>" % (
                        m.group('sign'), m.group('num'),
                        m.group('expminus'), m.group('exp'))
            else:
                val_max_str = u"%s%se%s%s" % (
                        m.group('sign'), m.group('num'),
                        m.group('expminus'), m.group('exp'))
        # val_min
        if val_min <= float_threshold:
            val_min_str = fix_fmt.format(val_min)
        else:
            val_min_expstr = exp_fmt.format(val_min)
            # convert to html exponent format
            m = rep.match(val_min_expstr)
            if type == "html":
                val_min_str = u"%s%s&times;10<sup>%s%s</sup>" % (
                        m.group('sign'), m.group('num'),
                        m.group('expminus'), m.group('exp'))
            else:
                val_min_str = u"%s%se%s%s" % (
                        m.group('sign'), m.group('num'),
                        m.group('expminus'), m.group('exp'))
        # value_str
        if type == "html":
            value_str = u'%s %s %s' % (val_min_str,
                    range_sym_html, val_max_str)
        else:
            value_str = u'%s %s %s' % (val_min_str,
                    range_sym_text, val_max_str)
    else:
        # other type??
        return None

    return value_str
# }}}