#
# Functions for interacting with the nodes table in the database
#
# Mark Huang <mlhuang@cs.princeton.edu>
# Copyright (C) 2006 The Trustees of Princeton University
#
# $Id: Nodes.py,v 1.29 2007/01/09 16:13:36 mlhuang Exp $
#

from types import StringTypes
import re

from PLC.Faults import *
from PLC.Parameter import Parameter
from PLC.Filter import Filter
from PLC.Debug import profile
from PLC.Table import Row, Table
from PLC.NodeNetworks import NodeNetwork, NodeNetworks
from PLC.BootStates import BootStates

def valid_hostname(hostname):
    # 1. Each part begins and ends with a letter or number.
    # 2. Each part except the last can contain letters, numbers, or hyphens.
    # 3. Each part is between 1 and 64 characters, including the trailing dot.
    # 4. At least two parts.
    # 5. Last part can only contain between 2 and 6 letters.
    good_hostname = r'^([a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?\.)+' \
                    r'[a-z]{2,6}$'
    return hostname and \
           re.match(good_hostname, hostname, re.IGNORECASE)

class Node(Row):
    """
    Representation of a row in the nodes table. To use, optionally
    instantiate with a dict of values. Update as you would a
    dict. Commit to the database with sync().
    """

    table_name = 'nodes'
    primary_key = 'node_id'
    join_tables = ['nodegroup_node', 'conf_file_node', 'nodenetworks', 'pcu_node', 'slice_node', 'slice_attribute', 'node_session', 'peer_node']
    fields = {
        'node_id': Parameter(int, "Node identifier"),
        'hostname': Parameter(str, "Fully qualified hostname", max = 255),
        'site_id': Parameter(int, "Site at which this node is located"),
        'boot_state': Parameter(str, "Boot state", max = 20),
        'model': Parameter(str, "Make and model of the actual machine", max = 255, nullok = True),
        'boot_nonce': Parameter(str, "(Admin only) Random value generated by the node at last boot", max = 128),
        'version': Parameter(str, "Apparent Boot CD version", max = 64),
        'ssh_rsa_key': Parameter(str, "Last known SSH host key", max = 1024),
        'date_created': Parameter(int, "Date and time when node entry was created", ro = True),
        'last_updated': Parameter(int, "Date and time when node entry was created", ro = True),
        'key': Parameter(str, "(Admin only) Node key", max = 256),
        'session': Parameter(str, "(Admin only) Node session value", max = 256, ro = True),
        'nodenetwork_ids': Parameter([int], "List of network interfaces that this node has"),
        'nodegroup_ids': Parameter([int], "List of node groups that this node is in"),
        'conf_file_ids': Parameter([int], "List of configuration files specific to this node"),
        # 'root_person_ids': Parameter([int], "(Admin only) List of people who have root access to this node"),
        'slice_ids': Parameter([int], "List of slices on this node"),
        'pcu_ids': Parameter([int], "List of PCUs that control this node"),
        'ports': Parameter([int], "List of PCU ports that this node is connected to"),
        'peer_id': Parameter(int, "Peer to which this node belongs", nullok = True),
        'peer_node_id': Parameter(int, "Foreign node identifier at peer", nullok = True),
        }

    # for Cache
    class_key = 'hostname'
    foreign_fields = ['boot_state','model','version']
    # forget about these ones, they are read-only anyway
    # handling them causes Cache to re-sync all over again 
    # 'date_created','last_updated'
    foreign_xrefs = [
	# in this case, we dont need the 'table' but Cache will look it up, so...
        {'field' : 'site_id' , 'class' : 'Site' , 'table' : 'unused-on-direct-refs' } ,
	]

    def validate_hostname(self, hostname):
        if not valid_hostname(hostname):
            raise PLCInvalidArgument, "Invalid hostname"

        conflicts = Nodes(self.api, [hostname])
        for node in conflicts:
            if 'node_id' not in self or self['node_id'] != node['node_id']:
                raise PLCInvalidArgument, "Hostname already in use"

        return hostname

    def validate_boot_state(self, boot_state):
        boot_states = [row['boot_state'] for row in BootStates(self.api)]
        if boot_state not in boot_states:
            raise PLCInvalidArgument, "Invalid boot state"

        return boot_state

    validate_date_created = Row.validate_timestamp
    validate_last_updated = Row.validate_timestamp

    def delete(self, commit = True):
        """
        Delete existing node.
        """

        assert 'node_id' in self

        # Clean up miscellaneous join tables
        for table in self.join_tables:
            self.api.db.do("DELETE FROM %s WHERE node_id = %d" % \
                           (table, self['node_id']))

        # Mark as deleted
        self['deleted'] = True
        self.sync(commit)


class Nodes(Table):
    """
    Representation of row(s) from the nodes table in the
    database.
    """

    def __init__(self, api, node_filter = None, columns = None):
        Table.__init__(self, api, Node, columns)

        sql = "SELECT %s FROM view_nodes WHERE deleted IS False" % \
              ", ".join(self.columns)

        if node_filter is not None:
            if isinstance(node_filter, (list, tuple, set)):
                # Separate the list into integers and strings
                ints = filter(lambda x: isinstance(x, (int, long)), node_filter)
                strs = filter(lambda x: isinstance(x, StringTypes), node_filter)
                node_filter = Filter(Node.fields, {'node_id': ints, 'hostname': strs})
                sql += " AND (%s)" % node_filter.sql(api, "OR")
            elif isinstance(node_filter, dict):
                node_filter = Filter(Node.fields, node_filter)
                sql += " AND (%s)" % node_filter.sql(api, "AND")

        self.selectall(sql)