# Copyright 2008 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Django template library for Gerrit."""

import cgi
import logging

from google.appengine.api import memcache
from google.appengine.api import users

import django.template
import django.utils.safestring
from django.utils.safestring import mark_safe
from django.utils.timesince import timesince

from memcache import CachedDict
import models
import view_util

register = django.template.Library()

class _CachedUser(object):
  """Important data about an Account, pickled into memcache for
     faster access when rendering pages to clients.
  """
  email = None
  real_name = None
  exists = False

def _store_users(emails):
  def _cache(pair):
    email, account = pair
    r = _CachedUser()
    if account:
      r.email = account.email
      r.real_name = account.real_name
      r.exists = account.real_name_entered
    else:
      r.email = email
      r.real_name = email
      if '@' in r.real_name:
        r.real_name = r.real_name.split('@', 1)[0]
    if r.real_name is None:
      r.real_name = 'Unknown Person (%s)' % r.email
    return r
  all = zip(emails, models.Account.get_accounts_for_emails(emails))
  return map(_cache, all)
_user_cache = CachedDict(prefix = 'CachedUser:',
                         compute_multi = _store_users,
                         timeout = 300)

def _to_email(u):
  if isinstance(u, users.User):
    return u.email()
  return u

def prefetch_names(emails):
  _user_cache.prefetch(map(_to_email, emails))


@register.filter
def real_name(email, arg=None):
  """Render an email address or a User object as a real_name.

  If the input is a user object that equals the current user,
  'me' is returned, unless the filter argument is non-empty.
  Example:
    {{foo|real_name}} may render 'me';
    {{foo|real_name:"x"}} will never render 'me'.
  """
  return real_names([email], arg)

@register.filter
def real_names(email_list, arg=None):
  """Render a list of email addresses or User objects as real_names.

  Each list item is first formatter via the real_name() filter above,
  and then the resulting strings are separated by commas.
  The filter argument is the same as for real_name() above.
  """
  if arg:
    user = None
  else:
    user = users.get_current_user()

  email_list = map(_to_email, email_list)
  all = _user_cache.get_multi(email_list)

  names = []
  for email in email_list:
    if user and user.email() == email:
      names.append('me')
    else:
      names.append(all[email].real_name)
  return ', '.join(names)


@register.filter
def show_user(email, arg=None):
  """Render a link to the user's dashboard, with text being
     the real_name.
  """
  return show_users([email], arg)

@register.filter
def show_users(email_list, arg=None):
  """Render list of links to each user's dashboard, with text
     being the real_name.
  """
  if arg:
    user = None
  else:
    user = users.get_current_user()

  email_list = map(_to_email, email_list)
  all = _user_cache.get_multi(email_list)

  names = []
  for email in email_list:
    if user and user.email() == email:
      names.append('me')
    else:
      u = all[email]
      if u.exists:
        names.append(
          '<a href="/user/%(link)s"'
          ' onMouseOver="M_showUserInfoPopup(this)">'
          '%(name)s</a>'
          % {'link': cgi.escape(u.email.replace('@',',,')),
             'name': cgi.escape(u.real_name)}
        )
      else:
        names.append(cgi.escape(u.real_name))
  return mark_safe(', '.join(names))


def _init_lgtm_text():
  r = {}
  for key, value in models.LGTM_CHOICES:
    r[key] = value
  return r
_lgtm_text = _init_lgtm_text()

@register.filter
def review_status_text(status, arg=None):
  try:
    return _lgtm_text[status]
  except KeyError:
    return ''


_lgtm_icon = {
  'lgtm':    mark_safe('<img src="/static/check.png" />'),
  'yes':     mark_safe('<font color="#08a400">+1</font>'),
  'abstain': '',
  'no':      mark_safe('<font color="#d10000"><b>-1</b></font>'),
  'reject':  mark_safe('<img src="/static/x.png" />'),
}

@register.filter
def review_status_icons(status, arg=None):
  try:
    return _lgtm_icon[status]
  except KeyError:
    return ''


@register.filter
def form_xsrf(url, arg=None):
  x = view_util.xsrf_for(url)
  return mark_safe('<input type="hidden" name="xsrf" value="%s" />' % x)

@register.filter
def bare_xsrf(url, arg=None):
  return mark_safe(view_util.xsrf_for(url))

_abbrev_units = {
  'year': 'y',     'years': 'y',
  'month': 'mo',   'months': 'm',
  'week': 'w',     'weeks': 'w',
  'day': 'd',      'days': 'd',
  'hour': 'h',     'hours': 'h',
  'minute': 'min', 'minutes': 'mins',
}

@register.filter
def abbrevtimesince(d, arg=None):
  r = []
  for p in timesince(d).split(', '):
    cnt, unit = p.split(' ', 2)
    try:
      r.append('%s %s' % (cnt, _abbrev_units[unit]))
    except KeyError:
      r.append(p)
  return ', '.join(r)