def cmd_start(options):
    if options.stopped:
        arg=""
        if options.cdrom:
            arg=" -cdrom "+options.cdrom[0]
        if options.snapshot:
            arg=arg+" -snapshot"
        if options.args:
            arg=arg+" "+options.args
        cwd=os.getcwd()
        os.chdir(options.dir)
        os.system("./start%s" % arg)
        os.chdir(cwd)
        time.sleep(2)
        options.sock = connect_vm(options.dir)
    else:
        if options.snapshot or options.args:
            print >>sys.stderr, "Cannot change qemu options. VM is already running"
        if options.cdrom:
            options.file = options.cdrom[0]
            cmd_cdrom(options)    
    if options.gui:
        uri = spiceurl(options)
        os.system("remote-viewer %s &" % uri)
    elif not options.stopped:
        print >>sys.stderr,"VM already running"
def cmd_stop(options):
    if options.hard:

    else:
        print send_command(options.sock,"stopcapture "+m.group(1))
def cmd_version(options):
    print VERSION

def validate_size(size):
    return re.match('\d+[KMG]',size) is not None

def get_drives(vm_dir):
    """ Return list of drive files in the VW directory """
    result=[]
    with open(vm_dir+"/start") as f:
        for line in f:
            if (re.match("\s*-drive .*",line) and
                line.find("media=disk")>-1):
                m=re.search("file=([^,\s]*)",line)
                if m:
                    result.append(m.group(1))
    return result

def cmd_snapshot(options):
    if not options.stopped:
        print >>sys.stderr,"Cannot make snapshot of running VW"
        return 1
    drives=get_drives(options.dir)
    os.chdir(options.dir)
    newnames={}
    for i in drives:
        name,ext=os.path.splitext(i)
        newnames[i]=name+"."+options.snapname+"."+ext
        if os.path.exists(newnames[i]):
            print >>sys.stderr,"Snapshot %s already exists",options.snapname
            return 1
    for i in drives:
        os.rename(i,newnames[i])
        os.system("qemu-img create -f qcow2 -b \"%s\" \"%s\"" %(i,newnames[i]))
    return 0

def cmd_snapshots(options): 
    os.chdir(options.dir)
    drives = get_drives(options.dir)
    lst=[]
    info={}
    with os.popen("qemu-img info --backing-chain "+drives[0],"r") as f:
        for line in f:
           if line.find(": ")!= -1 :
               var,val=line.strip().split(": ")
               if val != "":
                    info[var]=val
           elif line[0]=='\n':
               lst.append(info)
               info = {}
        lst.append(info)
    for d in lst:
        print "%-30s  %+8s  %+8s"%(d["image"],d["virtual size"],d["disk size"])


def get_backing(drive):
    with os.popen('qemu-img info "%s"' % drive,"r") as f:
        for line in f:
            m=re.match("backing.file: (.*)$",line)
            if (m) :
                return m.group(1)
    return None                

def cmd_revert(options):
    # Removes latest snapshot images and creates new ones instead
    if not options.stopped:
        print >>sys.stderr,"Cannot revert running VW to snapshot"
        return 1
    os.chdir(options.dir)
    for drive in get_drives(options.dir):
        # Check if first  has backing file
        backing=get_backing(drive)
        if not backing:
            print >>sys.stderr,"Drive %s has no snapshots"%drive
            continue
        # Unlink current image
        os.unlink(drive)
        # create new image with same backing file
        os.system('qemu-img create -f qcow2 -b "%s" "%s"'%(backing,drive))

def cmd_commit(options):   
    #
    # Commits last snapshot changes into it's backing file
    #
    if options.stopped:
       #
       # Stoppend vm - last snapshot is commited into its backing file.
       # Backing file is made current drive image
       #
       os.chdir(options.dir)
       for drive in get_drives(options.dir):
            backing=get_backing(drive)
            if backing is None:
                continue
            os.system('qemu-img commit "%s"'%drive)
            os.unlink(drive)
            os.rename(backing,drive)
    else:
       #
       #
       # Check if we are running in the snapshot mode
       # 
       send_command(options.sock,"commit")

    


template="""#!/bin/sh
# Get machine name from current directory name
NAME=$(basename $(pwd))
# if remote access is enabled, then there should be
# SPICE_PASSWORD=password
QEMU_AUDIO_DRV=spice

# Power management
p=new_command(cmds,'start',help='Start VW and connect to console',
    description="Start VW if not running and connect to the console")
p.add_argument('--no-gui',dest='gui',action='store_const',const=False,
               default=True,help='do not open console window')
p.add_argument('--cdrom',metavar='filename.iso',dest='cdrom',nargs=1,
               help='connect specified iso image to VMs cdrom on start')
p.add_argument('--args',metavar='string',dest='args',nargs=1,default="",
                help="Specify extra QEMU options")
p.add_argument("--snapshot",action='store_const',const=True,default=False,
                help="Run without modifying disk image")
# Following commands don't need extra args
p=new_command(cmds,'stop',help='Shut down virtual machine',
         description="Terminate the VW, gracefully or ungracefully")
p.add_argument('--hard',help='Power off immediately', action='store_const',dest='hard',const=True,default=False)

new_command(cmds,'save',help='Save VW state and stop emulation',
    description="Save VW state and stop emulation")