# -*- coding: utf-8 -*-
# vim: set et sts=2:
##############################################################################
#
# Copyright (c) 2010, 2011, 2012 Vifib SARL and Contributors.
# All Rights Reserved.
#
# WARNING: This program as such is intended to be used by professional
# programmers who take the whole responsibility of assessing all potential
# consequences resulting from its eventual inadequacies and bugs
# End users who are looking for a ready-to-use solution with commercial
# guarantees and support are strongly advised to contract a Free Software
# Service Company
#
# This program is Free Software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 3
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
##############################################################################

from lxml import etree
import sqlite3
from slapos.slap.slap import Computer, ComputerPartition, \
    SoftwareRelease, SoftwareInstance, NotFoundError
from slapos.proxy.db_version import DB_VERSION

from flask import g, Flask, request, abort
import xml_marshaller
app = Flask(__name__)


class UnauthorizedError(Exception):
  pass


def xml2dict(xml):
  result_dict = {}
  if xml is not None and xml != '':
    tree = etree.fromstring(xml.encode('utf-8'))
    for element in tree.iter(tag=etree.Element):
      if element.tag == 'parameter':
        key = element.get('id')
        value = result_dict.get(key, None)
        if value is not None:
          value = value + ' ' + element.text
        else:
          value = element.text
        result_dict[key] = value
  return result_dict


def dict2xml(dictionary):
  instance = etree.Element('instance')
  for parameter_id, parameter_value in dictionary.iteritems():
    # cast everything to string
    parameter_value = str(parameter_value)
    etree.SubElement(instance, "parameter",
                     attrib={'id': parameter_id}).text = parameter_value
  return etree.tostring(instance,
                        pretty_print=True,
                        xml_declaration=True,
                        encoding='utf-8')


def partitiondict2partition(partition):
  for key, value in partition.iteritems():
    if type(value) is unicode:
      partition[key] = value.encode()
  slap_partition = ComputerPartition(partition['computer_reference'],
      partition['reference'])
  slap_partition._software_release_document = None
  slap_partition._requested_state = 'destroyed'
  slap_partition._need_modification = 0
  slap_partition._instance_guid = '%s-%s' % (partition['computer_reference'], partition['reference'])

  if partition['software_release']:
    slap_partition._need_modification = 1
    slap_partition._requested_state = partition['requested_state']
    slap_partition._parameter_dict = xml2dict(partition['xml'])
    address_list = []
    for address in execute_db('partition_network',
                              'SELECT * FROM %s WHERE partition_reference=? AND computer_reference=?',
                              [partition['reference'], partition['computer_reference']]):
      address_list.append((address['reference'], address['address']))
    slap_partition._parameter_dict['ip_list'] = address_list
    slap_partition._parameter_dict['slap_software_type'] = \
        partition['software_type']
    if partition['slave_instance_list'] is not None:
      slap_partition._parameter_dict['slave_instance_list'] = \
          xml_marshaller.xml_marshaller.loads(partition['slave_instance_list'])
    else:
      slap_partition._parameter_dict['slave_instance_list'] = []
    slap_partition._connection_dict = xml2dict(partition['connection_xml'])
    slap_partition._software_release_document = SoftwareRelease(
      software_release=partition['software_release'],
      computer_guid=partition['computer_reference'])

  return slap_partition


def execute_db(table, query, args=(), one=False, db_version=None, log=False):
  if not db_version:
    db_version = DB_VERSION
  query = query % (table + db_version,)
  if log:
    print query
  try:
    cur = g.db.execute(query, args)
  except:
    app.logger.error('There was some issue during processing query %r on table %r with args %r' % (query, table, args))
    raise
  rv = [dict((cur.description[idx][0], value)
    for idx, value in enumerate(row)) for row in cur.fetchall()]
  return (rv[0] if rv else None) if one else rv


def connect_db():
  return sqlite3.connect(app.config['DATABASE_URI'])

def _getTableList():
  return g.db.execute("SELECT name FROM sqlite_master WHERE type='table' ORDER BY Name").fetchall()

def _getCurrentDatabaseSchemaVersion():
  """
  Return version of database schema.
  As there is no actual definition of version, analyse
  name of all tables (containing version) and take the
  highest version (as several versions can live in the db).
  """
  # XXX: define an actual version and proper migration/repair procedure.
  version = -1
  for table_name in _getTableList():
    try:
      table_version = int(table_name[0][-2:])
    except ValueError:
      table_version = int(table_name[0][-1:])
    if table_version > version:
      version = table_version
  return str(version)

def _upgradeDatabaseIfNeeded():
  """
  Analyses current database compared to defined schema,
  and adapt tables/data it if needed.
  """
  current_schema_version = _getCurrentDatabaseSchemaVersion()
  # If version of current database is not old, do nothing
  if current_schema_version == DB_VERSION:
    return
 
  schema = app.open_resource('schema.sql')
  schema = schema.read() % dict(version=DB_VERSION, computer=app.config['computer_id'])
  g.db.cursor().executescript(schema)
  g.db.commit()

  if current_schema_version == '-1':
    return

  # Migrate all data to new tables
  app.logger.info('Old schema detected: Migrating old tables...')
  app.logger.info('Note that old tables are not alterated.')
  for table in ('software', 'computer', 'partition', 'slave', 'partition_network'):
    for row in execute_db(table, 'SELECT * from %s', db_version=current_schema_version):
      columns = ', '.join(row.keys())
      placeholders = ':'+', :'.join(row.keys())
      query = 'INSERT INTO %s (%s) VALUES (%s)' % ('%s', columns, placeholders)
      execute_db(table, query, row, log=True)

  g.db.commit()

is_schema_already_executed = False
@app.before_request
def before_request():
  g.db = connect_db()
  global is_schema_already_executed
  if not is_schema_already_executed:
    _upgradeDatabaseIfNeeded()
    is_schema_already_executed = True


@app.after_request
def after_request(response):
  g.db.commit()
  g.db.close()
  return response

@app.route('/getComputerInformation', methods=['GET'])
def getComputerInformation():
  # Kept only for backward compatiblity
  return getFullComputerInformation()

@app.route('/getFullComputerInformation', methods=['GET'])
def getFullComputerInformation():
  computer_id = request.args['computer_id']
  computer_list = execute_db('computer', 'SELECT * FROM %s WHERE reference=?', [computer_id])
  if len(computer_list) != 1:
    # Backward compatibility
    if computer_id != app.config['computer_id']:
      raise NotFoundError('%s is not registered.' % computer_id)
  slap_computer = Computer(computer_id)
  slap_computer._software_release_list = []
  for sr in execute_db('software', 'select * from %s WHERE computer_reference=?', [computer_id]):
    slap_computer._software_release_list.append(SoftwareRelease(
      software_release=sr['url'], computer_guid=computer_id))
  slap_computer._computer_partition_list = []
  for partition in execute_db('partition', 'SELECT * FROM %s WHERE computer_reference=?', [computer_id]):
    slap_computer._computer_partition_list.append(partitiondict2partition(
      partition))
  return xml_marshaller.xml_marshaller.dumps(slap_computer)

@app.route('/setComputerPartitionConnectionXml', methods=['POST'])
def setComputerPartitionConnectionXml():
  slave_reference = request.form['slave_reference'].encode()
  computer_partition_id = request.form['computer_partition_id'].encode()
  computer_id = request.form['computer_id'].encode()
  connection_xml = request.form['connection_xml'].encode()
  connection_dict = xml_marshaller.xml_marshaller.loads(
                                            connection_xml)
  connection_xml = dict2xml(connection_dict)
  if slave_reference == 'None':
    query = 'UPDATE %s SET connection_xml=? WHERE reference=? AND computer_reference=?'
    argument_list = [connection_xml, computer_partition_id, computer_id]
    execute_db('partition', query, argument_list)
    return 'done'
  else:
    query = 'UPDATE %s SET connection_xml=? , hosted_by=? WHERE reference=?'
    argument_list = [connection_xml, computer_partition_id, slave_reference]
    execute_db('slave', query, argument_list)
    return 'done'

@app.route('/buildingSoftwareRelease', methods=['POST'])
def buildingSoftwareRelease():
  return 'Ignored'

@app.route('/availableSoftwareRelease', methods=['POST'])
def availableSoftwareRelease():
  return 'Ignored'

@app.route('/softwareReleaseError', methods=['POST'])
def softwareReleaseError():
  return 'Ignored'

@app.route('/buildingComputerPartition', methods=['POST'])
def buildingComputerPartition():
  return 'Ignored'

@app.route('/availableComputerPartition', methods=['POST'])
def availableComputerPartition():
  return 'Ignored'

@app.route('/softwareInstanceError', methods=['POST'])
def softwareInstanceError():
  return 'Ignored'

@app.route('/softwareInstanceBang', methods=['POST'])
def softwareInstanceBang():
  return 'Ignored'

@app.route('/startedComputerPartition', methods=['POST'])
def startedComputerPartition():
  return 'Ignored'

@app.route('/stoppedComputerPartition', methods=['POST'])
def stoppedComputerPartition():
  return 'Ignored'

@app.route('/destroyedComputerPartition', methods=['POST'])
def destroyedComputerPartition():
  return 'Ignored'

@app.route('/useComputer', methods=['POST'])
def useComputer():
  return 'Ignored'

@app.route('/loadComputerConfigurationFromXML', methods=['POST'])
def loadComputerConfigurationFromXML():
  xml = request.form['xml']
  computer_dict = xml_marshaller.xml_marshaller.loads(str(xml))
  execute_db('computer', 'INSERT OR REPLACE INTO %s values(:reference, :address, :netmask)',
             computer_dict)
  for partition in computer_dict['partition_list']:
    partition['computer_reference'] = computer_dict['reference']
    execute_db('partition', 'INSERT OR IGNORE INTO %s (reference, computer_reference) values(:reference, :computer_reference)', partition)
    execute_db('partition_network', 'DELETE FROM %s WHERE partition_reference = ? AND computer_reference = ?',
               [partition['reference'], partition['computer_reference']])
    for address in partition['address_list']:
      address['reference'] = partition['tap']['name']
      address['partition_reference'] = partition['reference']
      address['computer_reference'] = partition['computer_reference']
      execute_db('partition_network', 'INSERT OR REPLACE INTO %s (reference, partition_reference, computer_reference, address, netmask) values(:reference, :partition_reference, :computer_reference, :addr, :netmask)', address)

  return 'done'

@app.route('/registerComputerPartition', methods=['GET'])
def registerComputerPartition():
  computer_reference = request.args['computer_reference'].encode()
  computer_partition_reference = request.args['computer_partition_reference'].encode()
  partition = execute_db('partition', 'SELECT * FROM %s WHERE reference=? and computer_reference=?',
      [computer_partition_reference, computer_reference], one=True)
  if partition is None:
    raise UnauthorizedError
  return xml_marshaller.xml_marshaller.dumps(
      partitiondict2partition(partition))

@app.route('/supplySupply', methods=['POST'])
def supplySupply():
  url = request.form['url']
  computer_id = request.form['computer_id']
  if request.form['state'] == 'destroyed':
    execute_db('software', 'DELETE FROM %s WHERE url = ? AND computer_reference=?',
               [url, computer_id])
  else:
    execute_db('software', 'INSERT OR REPLACE INTO %s VALUES(?, ?)', [url, computer_id])
  return '%r added' % url


@app.route('/requestComputerPartition', methods=['POST'])
def requestComputerPartition():
  shared_xml = request.form.get('shared_xml')
  share = xml_marshaller.xml_marshaller.loads(shared_xml.encode())
  if not share:
    return request_not_shared()
  else:
    return request_slave()


@app.route('/softwareInstanceRename', methods=['POST'])
def softwareInstanceRename():
  new_name = request.form['new_name'].encode()
  computer_partition_id = request.form['computer_partition_id'].encode()
  computer_id = request.form['computer_id'].encode()

  q = 'UPDATE %s SET partition_reference = ? WHERE reference = ? AND computer_reference = ?'
  execute_db('partition', q, [new_name, computer_partition_id, computer_id])
  return 'done'

@app.route('/getComputerPartitionStatus', methods=['GET'])
def getComputerPartitionStatus():
  return xml_marshaller.xml_marshaller.dumps('Not implemented.')

def request_not_shared():
  software_release = request.form['software_release'].encode()
  # some supported parameters
  software_type = request.form.get('software_type').encode()
  partition_reference = request.form.get('partition_reference', '').encode()
  filter_kw = request.form.get('filter_xml', None)
  partition_id = request.form.get('computer_partition_id', '').encode()
  partition_parameter_kw = request.form.get('partition_parameter_xml', None)
  requested_state = xml_marshaller.xml_marshaller.loads(request.form.get('state').encode())
  if partition_parameter_kw:
    partition_parameter_kw = xml_marshaller.xml_marshaller.loads(
                                              partition_parameter_kw.encode())
  else:
    partition_parameter_kw = {}
  if filter_kw:
    filter_kw = xml_marshaller.xml_marshaller.loads(filter_kw.encode())
    requested_computer_id = filter_kw.get('computer_guid', app.config['computer_id'])
  else:
    requested_computer_id = app.config['computer_id']

  instance_xml = dict2xml(partition_parameter_kw)
  args = []
  a = args.append
  q = 'SELECT * FROM %s WHERE partition_reference=?'
  a(partition_reference)

  partition = execute_db('partition', q, args, one=True)

  args = []
  a = args.append
  q = 'UPDATE %s SET slap_state="busy"'

  if requested_state:
    q += ', requested_state=?'
    a(requested_state)

  # If partition doesn't exist: create it and insert parameters
  # XXX add support for automatic deployment on specific node depending on available SR and partitions on each Node.
  # Note: only deploy on default node if SLA not specified
  if partition is None:
    partition = execute_db('partition',
        'SELECT * FROM %s WHERE slap_state="free" and computer_reference=?',
        [requested_computer_id], one=True)
    if partition is None:
      app.logger.warning('No more free computer partition')
      abort(404)
    q += ' ,software_release=?'
    a(software_release)
    if partition_reference:
      q += ' ,partition_reference=?'
      a(partition_reference)
    if partition_id:
      q += ' ,requested_by=?'
      a(partition_id)
    if not software_type:
      software_type = 'RootSoftwareInstance'

  #
  # XXX change software_type when requested
  #
  if software_type:
    q += ' ,software_type=?'
    a(software_type)

  # Else: only update partition_parameter_kw
  if instance_xml:
    q += ' ,xml=?'
    a(instance_xml)
  q += ' WHERE reference=? AND computer_reference=?'
  a(partition['reference'].encode())
  a(partition['computer_reference'].encode())

  execute_db('partition', q, args)
  args = []
  partition = execute_db('partition', 'SELECT * FROM %s WHERE reference=? and computer_reference=?',
      [partition['reference'].encode(), partition['computer_reference'].encode()], one=True)
  address_list = []
  for address in execute_db('partition_network', 'SELECT * FROM %s WHERE partition_reference=?', [partition['reference']]):
    address_list.append((address['reference'], address['address']))

  if not requested_state:
    requested_state = 'started'
  # XXX it should be ComputerPartition, not a SoftwareInstance
  software_instance = SoftwareInstance(_connection_dict=xml2dict(partition['connection_xml']),
                                       _parameter_dict=xml2dict(partition['xml']),
                                       connection_xml=partition['connection_xml'],
                                       slap_computer_id=partition['computer_reference'].encode(),
                                       slap_computer_partition_id=partition['reference'],
                                       slap_software_release_url=partition['software_release'],
                                       slap_server_url='slap_server_url',
                                       slap_software_type=partition['software_type'],
                                       _instance_guid='%s-%s' % (partition['computer_reference'].encode(), partition['reference']),
                                       _requested_state=requested_state,
                                       ip_list=address_list)
  return xml_marshaller.xml_marshaller.dumps(software_instance)


def request_slave():
  """
  Function to organise link between slave and master.
  Slave information are stored in places:
  1. slave table having information such as slave reference,
      connection information to slave (given by slave master),
      hosted_by and asked_by reference.
  2. A dictionary in slave_instance_list of selected slave master
      in which are stored slave_reference, software_type, slave_title and
      partition_parameter_kw stored as individual keys.
  """
  software_release = request.form['software_release'].encode()
  # some supported parameters
  software_type = request.form.get('software_type').encode()
  partition_reference = request.form.get('partition_reference', '').encode()
  partition_id = request.form.get('computer_partition_id', '').encode()
  # Contain slave parameters to be given to slave master
  partition_parameter_kw = request.form.get('partition_parameter_xml', None)
  if partition_parameter_kw:
    partition_parameter_kw = xml_marshaller.xml_marshaller.loads(
                                              partition_parameter_kw.encode())
  else:
    partition_parameter_kw = {}

  filter_kw = request.form.get('filter_xml', None)
  if filter_kw:
    filter_kw = xml_marshaller.xml_marshaller.loads(filter_kw.encode())
    requested_computer_id = filter_kw.get('computer_guid', app.config['computer_id'])
  else:
    requested_computer_id = app.config['computer_id']

  instance_xml = dict2xml(partition_parameter_kw)
  # We will search for a master corresponding to request
  args = []
  a = args.append
  q = 'SELECT * FROM %s WHERE software_release=? and computer_reference=?'
  a(software_release)
  a(requested_computer_id)
  if software_type:
    q += ' AND software_type=?'
    a(software_type)
  if 'instance_guid' in filter_kw:
    q += ' AND reference=?'
    a(filter_kw['instance_guid'])

  partition = execute_db('partition', q, args, one=True)
  if partition is None:
    app.logger.warning('No partition corresponding to slave request: %s' % args)
    abort(404)

  # We set slave dictionary as described in docstring
  new_slave = {}
  slave_reference = partition_id + '_' + partition_reference
  new_slave['slave_title'] = slave_reference
  new_slave['slap_software_type'] = software_type
  new_slave['slave_reference'] = slave_reference

  for key in partition_parameter_kw:
    if partition_parameter_kw[key] is not None:
      new_slave[key] = partition_parameter_kw[key]

  # Add slave to partition slave_list if not present else replace information
  slave_instance_list = partition['slave_instance_list']
  if slave_instance_list is None:
    slave_instance_list = []
  else:
    slave_instance_list = xml_marshaller.xml_marshaller.loads(slave_instance_list.encode())
    for x in slave_instance_list:
      if x['slave_reference'] == slave_reference:
        slave_instance_list.remove(x)

  slave_instance_list.append(new_slave)

  # Update slave_instance_list in database
  args = []
  a = args.append
  q = 'UPDATE %s SET slave_instance_list=?'
  a(xml_marshaller.xml_marshaller.dumps(slave_instance_list))
  q += ' WHERE reference=? and computer_reference=?'
  a(partition['reference'].encode())
  a(requested_computer_id)
  execute_db('partition', q, args)
  args = []
  partition = execute_db('partition', 'SELECT * FROM %s WHERE reference=? and computer_reference=?',
      [partition['reference'].encode(), requested_computer_id], one=True)

  # Add slave to slave table if not there
  slave = execute_db('slave', 'SELECT * FROM %s WHERE reference=? and computer_reference=?',
                     [slave_reference, requested_computer_id], one=True)
  if slave is None:
    execute_db('slave',
               'INSERT OR IGNORE INTO %s (reference,computer_reference,asked_by,hosted_by) values(:reference,:computer_reference,:asked_by,:hosted_by)',
               [slave_reference, requested_computer_id, partition_id, partition['reference']])
    slave = execute_db('slave', 'SELECT * FROM %s WHERE reference=? and computer_reference=?',
                       [slave_reference, requested_computer_id], one=True)

  address_list = []
  for address in execute_db('partition_network',
                            'SELECT * FROM %s WHERE partition_reference=? and computer_reference=?',
                            [partition['reference'], partition['computer_reference']]):
    address_list.append((address['reference'], address['address']))

  # XXX it should be ComputerPartition, not a SoftwareInstance
  software_instance = SoftwareInstance(_connection_dict=xml2dict(slave['connection_xml']),
                                       _parameter_dict=xml2dict(instance_xml),
                                       slap_computer_id=partition['computer_reference'],
                                       slap_computer_partition_id=slave['hosted_by'],
                                       slap_software_release_url=partition['software_release'],
                                       slap_server_url='slap_server_url',
                                       slap_software_type=partition['software_type'],
                                       ip_list=address_list)

  return xml_marshaller.xml_marshaller.dumps(software_instance)


@app.route('/getSoftwareReleaseListFromSoftwareProduct', methods=['GET'])
def getSoftwareReleaseListFromSoftwareProduct():
  software_product_reference = request.args.get('software_product_reference')
  software_release_url = request.args.get('software_release_url')

  if software_release_url:
    assert(software_product_reference is None)
    raise NotImplementedError('software_release_url parameter is not supported yet.')
  else:
    assert(software_product_reference is not None)
    if app.config['software_product_list'].has_key(software_product_reference):
      software_release_url_list =\
          [app.config['software_product_list'][software_product_reference]]
    else:
      software_release_url_list = []
    return xml_marshaller.xml_marshaller.dumps(software_release_url_list)

