#!/usr/bin/env python

#

# Copyright 2007 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.

#

"""Simple datastore view and interactive console, for use in dev_appserver."""

import cgi

import csv

import cStringIO

import datetime

import logging

import math

import mimetypes

import os

import os.path

import pickle

import pprint

import random

import sys

import time

import traceback

import types

import urllib

import urlparse

import wsgiref.handlers

try:

  from google.appengine.cron import groctimespecification

  from google.appengine.api import croninfo

except ImportError:

  HAVE_CRON = False

else:

  HAVE_CRON = True

from google.appengine.api import apiproxy_stub_map

from google.appengine.api import datastore

from google.appengine.api import datastore_admin

from google.appengine.api import datastore_types

from google.appengine.api import datastore_errors

from google.appengine.api import memcache

from google.appengine.api.labs import taskqueue

from google.appengine.api import users

from google.appengine.ext import db

from google.appengine.ext import webapp

from google.appengine.ext.webapp import template

_DEBUG = True

class ImageHandler(webapp.RequestHandler):

  """Serves a static image.

  This exists because we don't want to burden the user with specifying

  a static file handler for the image resources used by the admin tool.

  """

  PATH = '/images/.*'

  def get(self):

    image_name = os.path.basename(self.request.path)

    content_type, encoding = mimetypes.guess_type(image_name)

    if not content_type or not content_type.startswith('image/'):

      logging.debug('image_name=%r, content_type=%r, encoding=%r',

                    image_name, content_type, encoding)

      self.error(404)

      return

    directory = os.path.dirname(__file__)

    path = os.path.join(directory, 'templates', 'images', image_name)

    try:

      image_stream = open(path, 'rb')

    except IOError, e:

      logging.error('Cannot open image %s: %s', image_name, e)

      self.error(404)

      return

    try:

      image_data = image_stream.read()

    finally:

      image_stream.close()

    self.response.headers['Content-Type'] = content_type

    self.response.out.write(image_data)

class BaseRequestHandler(webapp.RequestHandler):

  """Supplies a common template generation function.

  When you call generate(), we augment the template variables supplied with

  the current user in the 'user' variable and the current webapp request

  in the 'request' variable.

  """

  def generate(self, template_name, template_values={}):

    base_path = self.base_path()

    values = {

      'application_name': self.request.environ['APPLICATION_ID'],

      'user': users.get_current_user(),

      'request': self.request,

      'home_path': base_path + DefaultPageHandler.PATH,

      'datastore_path': base_path + DatastoreQueryHandler.PATH,

      'datastore_edit_path': base_path + DatastoreEditHandler.PATH,

      'datastore_batch_edit_path': base_path + DatastoreBatchEditHandler.PATH,

      'interactive_path': base_path + InteractivePageHandler.PATH,

      'interactive_execute_path': base_path + InteractiveExecuteHandler.PATH,

      'memcache_path': base_path + MemcachePageHandler.PATH,

      'queues_path': base_path + QueuesPageHandler.PATH,

    }

    if HAVE_CRON:

      values['cron_path'] = base_path + CronPageHandler.PATH

    values.update(template_values)

    directory = os.path.dirname(__file__)

    path = os.path.join(directory, os.path.join('templates', template_name))

    self.response.out.write(template.render(path, values, debug=_DEBUG))

  def base_path(self):

    """Returns the base path of this admin app, which is chosen by the user.

    The user specifies which paths map to this application in their app.cfg.

    You can get that base path with this method. Combine with the constant

    paths specified by the classes to construct URLs.

    """

    path = self.__class__.PATH

    return self.request.path[:-len(path)]

  def filter_url(self, args):

    """Filters the current URL to only have the given list of arguments.

    For example, if your URL is /search?q=foo&num=100&start=10, then

       self.filter_url(['start', 'num']) => /search?num=100&start=10

       self.filter_url(['q']) => /search?q=10

       self.filter_url(['random']) => /search?

    """

    queries = []

    for arg in args:

      value = self.request.get(arg)

      if value:

        queries.append(arg + '=' + urllib.quote_plus(self.request.get(arg)))

    return self.request.path + '?' + '&'.join(queries)

  def in_production(self):

    """Detects if app is running in production.

    Returns a boolean.

    """

    server_software = os.environ['SERVER_SOFTWARE']

    return not server_software.startswith('Development')

class DefaultPageHandler(BaseRequestHandler):

  """Redirects to the Datastore application by default."""

  PATH = '/'

  def get(self):

    if self.request.path.endswith('/'):

      base = self.request.path[:-1]

    else:

      base = self.request.path

    self.redirect(base + DatastoreQueryHandler.PATH)

class InteractivePageHandler(BaseRequestHandler):

  """Shows our interactive console HTML."""

  PATH = '/interactive'

  def get(self):

    self.generate('interactive.html')

class InteractiveExecuteHandler(BaseRequestHandler):

  """Executes the Python code submitted in a POST within this context.

  For obvious reasons, this should only be available to administrators

  of the applications.

  """

  PATH = InteractivePageHandler.PATH + '/execute'

  def post(self):

    save_stdout = sys.stdout

    results_io = cStringIO.StringIO()

    try:

      sys.stdout = results_io

      code = self.request.get('code')

      code = code.replace("\r\n", "\n")

      try:

        compiled_code = compile(code, '<string>', 'exec')

        exec(compiled_code, globals())

      except Exception, e:

        traceback.print_exc(file=results_io)

    finally:

      sys.stdout = save_stdout

    results = results_io.getvalue()

    self.generate('interactive-output.html', {'output': results})

class CronPageHandler(BaseRequestHandler):

  """Shows information about configured cron jobs in this application."""

  PATH = '/cron'

  def get(self, now=None):

    """Shows template displaying the configured cron jobs."""

    if not now:

      now = datetime.datetime.now()

    values = {'request': self.request}

    cron_info = _ParseCronYaml()

    values['cronjobs'] = []

    values['now'] = str(now)

    if cron_info and cron_info.cron:

      for entry in cron_info.cron:

        job = {}

        values['cronjobs'].append(job)

        if entry.description:

          job['description'] = entry.description

        else:

          job['description'] = '(no description)'

        if entry.timezone:

          job['timezone'] = entry.timezone

        job['url'] = entry.url

        job['schedule'] = entry.schedule

        schedule = groctimespecification.GrocTimeSpecification(entry.schedule)

        matches = schedule.GetMatches(now, 3)

        job['times'] = []

        for match in matches:

          job['times'].append({'runtime': match.strftime("%Y-%m-%d %H:%M:%SZ"),

                               'difference': str(match - now)})

    self.generate('cron.html', values)

class QueuesPageHandler(BaseRequestHandler):

  """Shows information about configured (and default) task queues."""

  PATH = '/queues'

  def __init__(self):

    self.stub = apiproxy_stub_map.apiproxy.GetStub('taskqueue')

  def get(self):

    """Shows template displaying the configured task queues."""

    values = {

      'request': self.request,

      'queues': self.stub.GetQueues(),

    }

    self.generate('queues.html', values)

  def post(self):

    """Handle modifying actions and/or redirect to GET page."""

    if self.request.get('action:flushqueue'):

      self.stub.FlushQueue(self.request.get('queue'))

    self.redirect(self.request.path_url)

class TasksPageHandler(BaseRequestHandler):

  """Shows information about a queue's tasks."""

  PATH = '/tasks'

  PAGE_SIZE = 20

  def __init__(self):

    self.stub = apiproxy_stub_map.apiproxy.GetStub('taskqueue')

  def get(self):

    """Shows template displaying the queue's tasks."""

    queue = self.request.get('queue')

    start = int(self.request.get('start', 0))

    all_tasks = self.stub.GetTasks(queue)

    next_start = start + self.PAGE_SIZE

    tasks = all_tasks[start:next_start]

    current_page = int(start / self.PAGE_SIZE) + 1

    pages = []

    for number in xrange(int(math.ceil(len(all_tasks) /

                                       float(self.PAGE_SIZE)))):

      pages.append({

        'number': number + 1,

        'start': number * self.PAGE_SIZE

      })

    if not all_tasks[next_start:]:

      next_start = -1

    prev_start = start - self.PAGE_SIZE

    if prev_start < 0:

      prev_start = -1

    values = {

      'request': self.request,

      'queue_name': queue,

      'tasks': tasks,

      'start_base_url': self.filter_url(['queue']),

      'prev_start': prev_start,

      'next_start': next_start,

      'pages': pages,

      'current_page': current_page,

    }

    self.generate('tasks.html', values)

  def post(self):

    if self.request.get('action:deletetask'):

      self.stub.DeleteTask(self.request.get('queue'), self.request.get('task'))

    self.redirect(self.request.path_url + '?queue=' + self.request.get('queue'))

    return

class MemcachePageHandler(BaseRequestHandler):

  """Shows stats about memcache and query form to get values."""

  PATH = '/memcache'

  TYPES = ((str, str, 'String'),

           (unicode, unicode, 'Unicode String'),

           (bool, lambda value: MemcachePageHandler._ToBool(value), 'Boolean'),

           (int, int, 'Integer'),

           (long, long, 'Long Integer'),

           (float, float, 'Float'))

  DEFAULT_TYPESTR_FOR_NEW = 'String'

  @staticmethod

  def _ToBool(string_value):

    """Convert string to boolean value.

    Args:

      string_value: A string.

    Returns:

      Boolean.  True if string_value is "true", False if string_value is

      "false".  This is case-insensitive.

    Raises:

      ValueError: string_value not "true" or "false".

    """

    string_value_low = string_value.lower()

    if string_value_low not in ('false', 'true'):

      raise ValueError('invalid literal for boolean: %s' % string_value)

    return string_value_low == 'true'

  def _GetValueAndType(self, key):

    """Fetch value from memcache and detect its type.

    Args:

      key: String

    Returns:

      (value, type), value is a Python object or None if the key was not set in

      the cache, type is a string describing the type of the value.

    """

    try:

      value = memcache.get(key)

    except (pickle.UnpicklingError, AttributeError, EOFError, ImportError,

            IndexError), e:

      msg = 'Failed to retrieve value from cache: %s' % e

      return msg, 'error'

    if value is None:

      return None, self.DEFAULT_TYPESTR_FOR_NEW

    for typeobj, _, typestr in self.TYPES:

      if isinstance(value, typeobj):

        break

    else:

      typestr = 'pickled'

      value = pprint.pformat(value, indent=2)

    return value, typestr

  def _SetValue(self, key, type_, value):

    """Convert a string value and store the result in memcache.

    Args:

      key: String

      type_: String, describing what type the value should have in the cache.

      value: String, will be converted according to type_.

    Returns:

      Result of memcache.set(ket, converted_value).  True if value was set.

    Raises:

      ValueError: Value can't be converted according to type_.

    """

    for _, converter, typestr in self.TYPES:

      if typestr == type_:

        value = converter(value)

        break

    else:

      raise ValueError('Type %s not supported.' % type_)

    return memcache.set(key, value)

  def get(self):

    """Show template and prepare stats and/or key+value to display/edit."""

    values = {'request': self.request,

              'message': self.request.get('message')}

    edit = self.request.get('edit')

    key = self.request.get('key')

    if edit:

      key = edit

      values['show_stats'] = False

      values['show_value'] = False

      values['show_valueform'] = True

      values['types'] = [typestr for _, _, typestr in self.TYPES]

    elif key:

      values['show_stats'] = True

      values['show_value'] = True

      values['show_valueform'] = False

    else:

      values['show_stats'] = True

      values['show_valueform'] = False

      values['show_value'] = False

    if key:

      values['key'] = key

      values['value'], values['type'] = self._GetValueAndType(key)

      values['key_exists'] = values['value'] is not None

      if values['type'] in ('pickled', 'error'):

        values['writable'] = False

      else:

        values['writable'] = True

    if values['show_stats']:

      memcache_stats = memcache.get_stats()

      if not memcache_stats:

        memcache_stats = {'hits': 0, 'misses': 0, 'byte_hits': 0, 'items': 0,

                          'bytes': 0, 'oldest_item_age': 0}

      values['stats'] = memcache_stats

      try:

        hitratio = memcache_stats['hits'] * 100 / (memcache_stats['hits']

                                                   + memcache_stats['misses'])

      except ZeroDivisionError:

        hitratio = 0

      values['hitratio'] = hitratio

      delta_t = datetime.timedelta(seconds=memcache_stats['oldest_item_age'])

      values['oldest_item_age'] = datetime.datetime.now() - delta_t

    self.generate('memcache.html', values)

  def _urlencode(self, query):

    """Encode a dictionary into a URL query string.

    In contrast to urllib this encodes unicode characters as UTF8.

    Args:

      query: Dictionary of key/value pairs.

    Returns:

      String.

    """

    return '&'.join('%s=%s' % (urllib.quote_plus(k.encode('utf8')),

                               urllib.quote_plus(v.encode('utf8')))

                    for k, v in query.iteritems())

  def post(self):

    """Handle modifying actions and/or redirect to GET page."""

    next_param = {}

    if self.request.get('action:flush'):