#!/usr/bin/env python

#**************************************************************************
#   Copyright (C) 2018 by Mark Wainright                                  *
#                                                                         *
#   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.             *
#**************************************************************************

program = 'mk6state'
version = '0.1'
author  = 'Mark Wainright'
verdate = '20180423'

from sys import exit, argv
from os import getenv, system
from os.path import isfile, isdir
from string import split, strip, upper, find
import subprocess
import glob

def usage(prog):
    print '\n%s ver %s  %s  %s' % (program, version, author, verdate)
    print 'A program to change the state of a mark6 module'
    print 'Module state can be played, erased, recorded, or cataloged.'
    print 'Module state is stored in the metadata state file on each'
    print 'disk in the module.'
    print '\nUsage: %s [options] <desired state> <slot number, MSN, scan file>' % prog
    print """
Options can include:

  --verbose
  -v         Send more output to the screen  (use -v -v for extra info)

  --quiet
  -q         Be quieter in operation

  --erase
  -e         Option to confirm erase state change

  --help
  -h         Print this help information and quit

This program should be run locally on a mark6 unit.

A module can be selected for state change by slot number, module serial number (MSN),
or by the name of a scan file on the module.

This script can be used to erase a module and change state to erased.  The -e option
and desired state erased must be used together to confirm erasure.

Examples:

  mk6state -v cataloged 1               # change state of module in slot 1 to cataloged 

  mk6state -v played LBO%0001           # change state of module with MSN LBO%0001 to played

  mk6state -v recorded AB123_KP_No0001  # change state of module with scan file AB123_KP_No0001 to recorded
  
  mk6state -v -e erased 2               # change state of module in slot 2 to erased and erase module

"""
    exit(1)

def getSlotByMSN(modident):
    for slot in ['1', '2', '3', '4']:
        for disk in range(8):
            msnfilepath = '/mnt/disks/.meta/' + slot + '/' + str(disk) + '/eMSN'
            if isfile(msnfilepath) == True:
                msnfile = open(msnfilepath)
                msndata = msnfile.read()
                msnfile.close()
                if modident in msndata:
                    return slot
                else:
                    break
            else:
                continue
    print "could not find slot by MSN", modident
    exit(1)

def getSlotByScanFile(modident):
    for slot in ['1', '2', '3', '4']:
        for disk in range(8):
            scanfilepath = '/mnt/disks/' + slot + '/' + str(disk) + '/data/' + modident
            if isfile(scanfilepath) == True:
                return slot
            else:
                continue
    print "could not find slot by scan file", modident
    exit(1)

verbose = 2
state = ''
modident = ''
erase = False

if len(argv) == 1:
    print 'Use -h option for help'
    exit(1)

for a in argv[1:]:
    if a[0] == '-':
	if a in ['-v', '--verbose']:
            verbose += 1
	elif a in ['-q', '--quiet']:
            verbose -= 1
	elif a in ['-e', '--erase']:
            erase = True
        elif a in ['-h', '--help']:
            usage(argv[0])
        else:
            print 'Unknown option: ', a
            exit(1)
    elif len(state) == 0:
        state = a
    else:
        modident = a

if state not in ['played','erased','recorded','cataloged']:
    print 'state must be played, erased, recorded or cataloged'
    exit(1)

if state == "erased" and erase == False:
    print "must use -e option to confirm state change to", state
    exit(1)

if len(modident) == 0:
    print 'must provide a module identifier: slot, MSN, scan file'
    exit(1)

if len(modident) == 1:
    if modident not in ['1', '2', '3', '4']:
        print 'slot must be 1, 2, 3, or 4'
        exit(1)
    slot = modident
elif len(modident) == 8 and '%' in modident:
    slot = getSlotByMSN(modident)
else:
    slot = getSlotByScanFile(modident)

if state == "erased" and erase == False:
    print "must use -e option to confirm state change to", state
    exit(1)

if verbose > 2:
    print 'change slot', slot, 'to state', state

for disk in range(8):
    # check for eMSN file in metadata to confirm mount
    msnfilepath = '/mnt/disks/.meta/' + slot + '/' + str(disk) + '/eMSN'
    if isfile(msnfilepath) == True:
        # change .meta mount permissions to read-write
        metamountpoint = '/mnt/disks/.meta/' + slot + '/' + str(disk)
        remountcmd = ["sudo", "mount", "-o", "rw,remount", metamountpoint]
        rc = subprocess.call(remountcmd)
        if rc != 0:
            print "remount to read-write failed on slot", slot, "disk", disk, ",continuing"
            continue

        # write state file
        statefilepath = '/mnt/disks/.meta/' + slot + '/' + str(disk) + '/state'
        statefile = open(statefilepath, 'w')
        statefile.write(state + '\n')
        statefile.close()
        if verbose > 2:
            print 'change disk', disk, 'to state', state

        # erase disk if state change is erased
        if state == 'erased':
            if verbose > 2:
                print "erasing slot", slot, "disk", disk
            # change data mount to read-write
            datamountpoint = '/mnt/disks/' + slot + '/' + str(disk)
            remountcmd = ["sudo", "mount", "-o", "rw,remount", datamountpoint]
            rc = subprocess.call(remountcmd)
            # move data directory
            movecmd = ["mv", "-f", "/mnt/disks/" + slot + "/" + str(disk) + "/data", "/mnt/disks/" + slot + "/" + str(disk) + "/data-remove",]
            rc = subprocess.call(movecmd)
            # make new data directory
            mkdircmd = ["mkdir", "/mnt/disks/" + slot + "/" + str(disk) + "/data"]
            rc = subprocess.call(mkdircmd)
            # change permissions on data directory
            permcmd = ["chmod", "777", "/mnt/disks/" + slot + "/" + str(disk) + "/data"]
            rc = subprocess.call(permcmd)
            # change ownership of data directory
            ownercmd = ["sudo", "chown", "root:nmstaff", "/mnt/disks/" + slot + "/" + str(disk) + "/data"]
            rc = subprocess.call(ownercmd)
            # remove old data directory and do not wait for subprocess
            rmdircmd = ["rm", "-rf", "/mnt/disks/" + slot + "/" + str(disk) + "/data-remove"]
            rc = subprocess.Popen(rmdircmd)
            # change data mount to read only
            remountcmd = ["sudo", "mount", "-o", "ro,remount", datamountpoint]
            rc = subprocess.call(remountcmd)

        # change .meta mount permissions to read only
        remountcmd = ["sudo", "mount", "-o", "ro,remount", metamountpoint]
        rc = subprocess.call(remountcmd)
        if rc != 0:
            print "remount to read only failed on slot", slot, "disk", disk, ",continuing"

    else:
        continue