#!/usr/bin/env python

from invirt import database as db
from invirt.config import structs as config
import sqlalchemy as sa
from subprocess import Popen, PIPE

prefix = 'd_'

# First figure out what the database thinks our sets of disks and sizes are
db.connect()
s = sa.sql.select([db.machine_table.c.name, db.disk_table.c.guest_device_name,
                   db.disk_table.c.size],
                  db.machine_table.c.machine_id == db.disk_table.c.machine_id,
                  [db.machine_table, db.disk_table])
dbresult = db.session.execute(s)
db_disks = {}
for (machine, device, size) in dbresult.fetchall():
    db_disks['d_' + machine + '_' + device] = int(size)

# Now figure out what the disk images actually in existence look like
p = Popen(['/sbin/lvs', '--noheadings', '-o', 'lv_name,lv_size', '--units', 'm',
           '--unbuffered', '--nosuffix', '--separator', ':', config.lvm.vg],
          stdout=PIPE)
lvresult = p.communicate()[0]
lv_disks = {}
for lv in lvresult.split():
    (lvname, size) = lv.split(':')
    if not lvname.startswith(prefix):
        continue
    # We only want the whole number of MiB, to match the database
    lv_disks[lvname] = int(float(size))

missing_disks = []
orphaned_disks = []
size_discrepancies = []

for disk in db_disks:
    if disk not in lv_disks:
        missing_disks.append(disk)
    elif db_disks[disk] != lv_disks[disk]:
        size_discrepancies.append(disk)
for disk in lv_disks:
    if disk not in db_disks:
        orphaned_disks.append(disk)

if missing_disks:
    print '===== The following disks are in the DB but the LVs do not exist'
    missing_disks.sort()
    for disk in missing_disks:
        print disk.ljust(45) + 'DB: %s' % str(db_disks[disk]).rjust(6)
    print '\n'
if orphaned_disks:
    print '===== The following LVs exist but are not assigned to a VM'
    orphaned_disks.sort()
    for disk in orphaned_disks:
        print disk.ljust(59) + 'LVM: %s' % str(lv_disks[disk]).rjust(6)
    print '\n'
if size_discrepancies:
    print '===== The following disks have different sizes in the DB and LVM'
    size_discrepancies.sort()
    for disk in size_discrepancies:
        print disk.ljust(45) +\
              'DB: %s    LVM: %s' % (str(db_disks[disk]).rjust(6),
                                     str(lv_disks[disk]).rjust(6))
    print '\n'
print 'There are %i inconsistencies between the DB and LVM at this time.' %\
      (missing_disks.__len__() +
       orphaned_disks.__len__() +
       size_discrepancies.__len__())