#!/usr/bin/env python

#import pdb, sys; mypdb = pdb.Pdb(stdout=sys.stderr); mypdb.set_trace()

import copy
import datetime
import hashlib
import mock
import os.path
import pasn1
import shutil
import string
import tempfile
import unittest
import uuid

from contextlib import nested

# The UUID for the namespace representing the path to a file
_NAMESPACE_MEDASHARE_PATH = uuid.UUID('f6f36b62-3770-4a68-bc3d-dc3e31e429e6')

_defaulthash = 'sha512'
_validhashes = set([ 'sha256', 'sha512' ])
_hashlengths = { len(getattr(hashlib, x)().hexdigest()): x for x in _validhashes }

def _iterdictlist(obj):
	itms = obj.items()
	itms.sort()
	for k, v in itms:
		if isinstance(v, list):
			v = v[:]
			v.sort()
			for i in v:
				yield k, i
		else:
			yield k, v

# XXX - add validation
class MDBase(object):
	'''This is a simple wrapper that turns a JSON object into a pythonesc
	object where attribute accesses work.'''

	_generated_properties = {
		'uuid': uuid.uuid4,
		'modified': datetime.datetime.utcnow
	}
	_common_properties = [ 'type', 'created_by_ref' ] # XXX - add lang?
	_common_optional = [ 'overlay_refs' ]
	_common_names = set(_common_properties + _generated_properties.keys())

	def __init__(self, obj):
		obj = copy.deepcopy(obj)
		if 'type' not in obj:
			obj['type'] = self._type

		for x in self._common_properties:
			if x not in obj:
				raise ValueError('common property %s not present' % `x`)

		for x, fun in self._generated_properties.iteritems():
			if x not in obj:
				obj[x] = fun()

		self._obj = obj

	@classmethod
	def create_obj(cls, obj):
		'''Using obj as a base, create an instance of MDBase of the
		correct type.

		If the correct type is not found, a ValueError is raised.'''

		if isinstance(obj, cls):
			obj = obj._obj

		ty = obj['type']

		for i in MDBase.__subclasses__():
			if i._type == ty:
				return i(obj)
		else:
			raise ValueError('Unable to find class for type %s' %
			    `ty`)

	def new_version(self, *args):
		'''For each k, v pari, add the property k as an additional one
		(or new on if first), with the value v.'''

		obj = copy.deepcopy(self._obj)

		for k, v in args:
			obj.setdefault(k, []).append(v)

		del obj['modified']

		return self.create_obj(obj)

	def __getattr__(self, k):
		return self._obj[k]

	def __getitem__(self, k):
		return self._obj[k]

	def __to_dict__(self):
		return self._obj

	def __eq__(self, o):
		return cmp(self._obj, o) == 0

	def __contains__(self, k):
		return k in self._obj

	def items(self, skipcommon=True):
		return [ (k, v) for k, v in self._obj.items() if k not in
		    self._common_names ]

class MetaData(MDBase):
	_type = 'metadata'

def _trytodict(o):
	if isinstance(o, uuid.UUID):
		return 'unicode', str(o)
	try:
		return 'dict', o.__to_dict__()
	except Exception:	# pragma: no cover
		raise TypeError('unable to find __to_dict__ on %s: %s' % (type(o), `o`))

_asn1coder = pasn1.ASN1DictCoder(coerce=_trytodict)

class ObjectStore(object):
	'''A container to store for the various Metadata objects.'''

	# The _uuids property contains both the UUIDv4 for objects, and
	# looking up the UUIDv5 for FileObjects.

	def __init__(self, created_by_ref):
		self._created_by_ref = created_by_ref
		self._uuids = {}
		self._hashes = {}

	@staticmethod
	def makehash(hashstr, strict=True):
		'''Take a hash string, and return a valid hash string from it.

		This makes sure that it is of the correct type and length.

		If strict is False, the function will detect the length and
		return a valid hash if one can be found.'''

		try:
			hash, value = hashstr.split(':')
		except ValueError:
			if strict:
				raise

			hash = _hashlengths[len(hashstr)]
			value = hashstr

		if strict and len(str(value).translate(None, string.hexdigits.lower())) != 0:
			raise ValueError('value has invalid hex digits (must be lower case)', value)

		if hash in _validhashes:
			return ':'.join((hash, value))

		raise ValueError

	def __len__(self):
		return len(self._uuids)

	def store(self, fname):
		'''Write out the objects in the store to the file named
		fname.'''

		with open(fname, 'w') as fp:
			obj = {
				'created_by_ref': self._created_by_ref,
				'objects': self._uuids.values(),
			}
			fp.write(_asn1coder.dumps(obj))

	def loadobj(self, obj):
		'''Load obj into the data store.'''

		obj = MDBase.create_obj(obj)

		if not isinstance(obj.uuid, uuid.UUID):
			id = uuid.UUID(obj.uuid)
		else:
			id = obj.uuid

		self._uuids[id] = obj
		for j in obj.hashes:
			h = self.makehash(j)
			self._hashes.setdefault(h, []).append(obj)

	@classmethod
	def load(cls, fname):
		'''Load objects from the provided file name.

		Basic validation will be done on the objects in the file.

		The objects will be accessible via other methods.'''

		with open(fname) as fp:
			objs = _asn1coder.loads(fp.read())

		obj = cls(objs['created_by_ref'])
		for i in objs['objects']:
			obj.loadobj(i)

		return obj

	def by_id(self, id):
		'''Look up an object by it's UUID.'''

		if not isinstance(id, uuid.UUID):
			uid = uuid.UUID(id)
		else:
			uid = id

		return self._uuids[uid]

	def by_hash(self, hash):
		'''Look up an object by it's hash value.'''

		h = self.makehash(hash, strict=False)
		return self._hashes[h]

	def by_file(self, fname):
		'''Return a metadata object for the file named fname.'''

		fid = FileObject.make_id(fname)
		try:
			fobj = self.by_id(fid)
		except KeyError:
			# unable to find it
			fobj = FileObject.from_file(fname, self._created_by_ref)
			self.loadobj(fobj)

		for i in fobj.hashes:
			j = self.by_hash(i)

			# Filter out non-metadata objects
			j = [ x for x in j if x.type == 'metadata' ]
			if j:
				return j
		else:
			raise KeyError('unable to find metadata for file')

def _hashfile(fname):
	hash = getattr(hashlib, _defaulthash)()
	with open(fname) as fp:
		r = fp.read()
		hash.update(r)

	return '%s:%s' % (_defaulthash, hash.hexdigest())

class FileObject(MDBase):
	_type = 'file'

	@staticmethod
	def make_id(fname):
		'''Take a local file name, and make the id for it.  Note that
		converts from the local path separator to a forward slash so
		that it will be the same between Windows and Unix systems.'''

		fname = os.path.realpath(fname)
		return uuid.uuid5(_NAMESPACE_MEDASHARE_PATH,
			    '/'.join(os.path.split(fname)))

	@classmethod
	def from_file(cls, filename, created_by_ref):
		s = os.stat(filename)
		obj = {
			'dir': os.path.dirname(filename),
			'created_by_ref': created_by_ref,
			'filename': os.path.basename(filename),
			'id': cls.make_id(filename),
			'mtime': datetime.datetime.utcfromtimestamp(s.st_mtime),
			'size': s.st_size,
			'hashes': [ _hashfile(filename), ],
		}


		return cls(obj)

def enumeratedir(_dir, created_by_ref):
	'''Enumerate all the files and directories (not recursive) in _dir.

	Returned is a list of FileObjects.'''

	return map(lambda x: FileObject.from_file(os.path.join(_dir, x), created_by_ref),
	    os.listdir(_dir))

def main():
	from optparse import OptionParser

	parser = OptionParser()
	parser.add_option('-a', action='append', dest='add',
	    default=[], help='add the arg as metadata for files, tag=value')
	parser.add_option('-d', action='append', dest='delete',
	    default=[], help='delete the arg as metadata from files.  Either specify tag, and all tags are removed, or specify tag=value and that specific tag will be removed.')
	parser.add_option('-l', action='store_true', dest='list',
	    default=False, help='list metadata')

	options, args = parser.parse_args()

	storefname = os.path.expanduser('~/.medashare_store.pasn1')
	import sys
	#print >>sys.stderr, `storefname`
	objstr = ObjectStore.load(storefname)

	if options.list:
		for i in args:
			for j in objstr.by_file(i):
				#print >>sys.stderr, `j._obj`
				for k, v in _iterdictlist(j):
					print '%s:\t%s' % (k, v)
	elif options.add:
		addprops = map(lambda x: x.split('=', 1), options.add)
		for i in args:
			for j in objstr.by_file(i):
				nobj = j.new_version(*addprops)
				objstr.loadobj(nobj)
	elif options.delete:
		for i in args:
			for j in objstr.by_file(i):
				obj = j.__to_dict__()
				for k in options.delete:
					try:
						key, v = k.split('=', 1)
						obj[key].remove(v)
					except ValueError:
						del obj[k]
				nobj = MDBase(obj)
				objstr.loadobj(nobj)
	else: # pragma: no cover
		raise NotImplementedError

	objstr.store(storefname)

if __name__ == '__main__':	# pragma: no cover
	main()

class _TestCases(unittest.TestCase):
	created_by_ref = '867c7563-79ae-435c-a265-9d8509cefac5'
	def setUp(self):
		d = os.path.realpath(tempfile.mkdtemp())
		self.basetempdir = d
		self.tempdir = os.path.join(d, 'subdir')

		shutil.copytree(os.path.join('fixtures', 'testfiles'),
		   self.tempdir)

	def tearDown(self):
		shutil.rmtree(self.basetempdir)
		self.tempdir = None

	def test_mdbase(self):
		self.assertRaises(ValueError, MDBase.create_obj, { 'type': 'unknosldkfj' })
		self.assertRaises(ValueError, MDBase.create_obj, { 'type': 'metadata' })

		baseobj = {
			'type': 'metadata',
			'created_by_ref': self.created_by_ref,
		}
		origbase = copy.deepcopy(baseobj)

		# that when an MDBase object is created
		md = MDBase.create_obj(baseobj)

		# it doesn't modify the passed in object (when adding
		# generated properties)
		self.assertEqual(baseobj, origbase)

		# and it has the generted properties
		# Note: cannot mock the functions as they are already
		# referenced at creation time
		self.assertIn('uuid', md)
		self.assertIn('modified', md)

		# That you can create a new version using new_version
		md2 = md.new_version(('dc:creator', 'Jim Bob',))

		# that they are different
		self.assertNotEqual(md, md2)

		# and that the new modified time is different from the old
		self.assertNotEqual(md.modified, md2.modified)

		# and that the modification is present
		self.assertEqual(md2['dc:creator'], [ 'Jim Bob' ])

	def test_makehash(self):
		self.assertRaises(ValueError, ObjectStore.makehash, 'slkj')
		self.assertRaises(ValueError, ObjectStore.makehash, 'sha256:91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ADA')
		self.assertRaises(ValueError, ObjectStore.makehash, 'bogushash:9e0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ADA', strict=False)

		self.assertEqual(ObjectStore.makehash('cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e', strict=False), 'sha512:cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e')
		self.assertEqual(ObjectStore.makehash('e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855', strict=False), 'sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855')

	def test_enumeratedir(self):
		files = enumeratedir(self.tempdir, self.created_by_ref)
		ftest = files[0]
		fname = 'test.txt'

		# make sure that they are of type MDBase
		self.assertIsInstance(ftest, MDBase)

		oldid = ftest.id
		self.assertEqual(ftest.filename, fname)
		self.assertEqual(ftest.dir, self.tempdir)
		# XXX - do we add host information?
		self.assertEqual(ftest.id, uuid.uuid5(_NAMESPACE_MEDASHARE_PATH,
		    '/'.join(os.path.split(self.tempdir) +
		    ( fname, ))))
		self.assertEqual(ftest.mtime, datetime.datetime(2019, 5, 20, 21, 47, 36))
		self.assertEqual(ftest.size, 15)
		self.assertIn('sha512:7d5768d47b6bc27dc4fa7e9732cfa2de506ca262a2749cb108923e5dddffde842bbfee6cb8d692fb43aca0f12946c521cce2633887914ca1f96898478d10ad3f', ftest.hashes)

		# XXX - make sure works w/ relative dirs
		files = enumeratedir(os.path.relpath(self.tempdir),
		    self.created_by_ref)
		self.assertEqual(oldid, files[0].id)

	def test_mdbaseoverlay(self):
		objst = ObjectStore(self.created_by_ref)

		# that a base object
		bid = uuid.uuid4()
		objst.loadobj({
			'type': 'metadata',
			'uuid': bid,
			'modified': datetime.datetime(2019, 6, 10, 14, 3, 10),
			'created_by_ref': self.created_by_ref,
			'hashes': [ 'sha256:91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ada' ],
			'someprop': [ 'somevalue' ],
			'lang': 'en',
		})

		# can have an overlay object
		oid = uuid.uuid4()
		dhash = 'sha256:a7c96262c21db9a06fd49e307d694fd95f624569f9b35bb3ffacd880440f9787'
		objst.loadobj({
			'type': 'metadata',
			'uuid': oid,
			'modified': datetime.datetime(2019, 6, 10, 18, 3, 10),
			'created_by_ref': self.created_by_ref,
			'hashes': [ dhash ],
			'overlay_refs': [ bid ],
			'lang': 'en',
		})

		# and that when you get it's properties
		oobj = objst.by_id(oid)
		odict = dict(oobj.items())

		# that is has the overlays property
		self.assertEqual(odict['overlay_refs'], [ bid ])

	def test_objectstore(self):
		objst = ObjectStore.load(os.path.join('fixtures', 'sample.data.pasn1'))

		objst.loadobj({
			'type': 'metadata',
			'uuid': 'c9a1d1e2-3109-4efd-8948-577dc15e44e7',
			'modified': datetime.datetime(2019, 5, 31, 14, 3, 10),
			'created_by_ref': self.created_by_ref,
			'hashes': [ 'sha256:91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ada' ],
			'lang': 'en',
		})

		lst = objst.by_hash('91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ada')
		self.assertEqual(len(lst), 2)

		byid = objst.by_id('3e466e06-45de-4ecc-84ba-2d2a3d970e96')

		self.assertIsInstance(byid, MetaData)
		self.assertIn(byid, lst)

		r = byid

		self.assertEqual(r.uuid, '3e466e06-45de-4ecc-84ba-2d2a3d970e96')
		self.assertEqual(r['dc:creator'], [ u'John-Mark Gurney' ])

		fname = 'testfile.pasn1'
		objst.store(fname)

		with open(fname) as fp:
			objs = _asn1coder.loads(fp.read())

		os.unlink(fname)

		self.assertEqual(len(objs), len(objst))

		self.assertEqual(objs['created_by_ref'], self.created_by_ref)

		for i in objs['objects']:
			self.assertEqual(objst.by_id(i['uuid']), i)

		testfname = os.path.join(self.tempdir, 'test.txt')
		self.assertEqual(objst.by_file(testfname), [ byid ])
		self.assertEqual(objst.by_file(testfname), [ byid ])

		self.assertRaises(KeyError, objst.by_file, '/dev/null')

		# XXX make sure that object store contains fileobject

	# Tests to add:
	#   Non-duplicates when same metadata is located by multiple hashes.

	def test_main(self):
		# Test the main runner, this is only testing things that are
		# specific to running the program, like where the store is
		# created.

		# setup object store
		storefname = os.path.join(self.tempdir, 'storefname')
		shutil.copy(os.path.join('fixtures', 'sample.data.pasn1'), storefname)

		# setup test fname
		testfname = os.path.join(self.tempdir, 'test.txt')

		import sys
		import StringIO
		import itertools

		with mock.patch('os.path.expanduser', side_effect=itertools.repeat(storefname)) \
		    as eu:
			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-l', testfname ])) as (stdout, argv):
				main()
				self.assertEqual(stdout.getvalue(),
				    'dc:creator:\tJohn-Mark Gurney\nhashes:\tsha256:91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ada\nhashes:\tsha512:7d5768d47b6bc27dc4fa7e9732cfa2de506ca262a2749cb108923e5dddffde842bbfee6cb8d692fb43aca0f12946c521cce2633887914ca1f96898478d10ad3f\nlang:\ten\n')
			eu.assert_called_with('~/.medashare_store.pasn1')

			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-a', 'dc:creator=Another user', '-a', 'foo=bar=baz', testfname ])) as (stdout, argv):
				main()

			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-l', testfname ])) as (stdout, argv):
				main()
				self.assertEqual(stdout.getvalue(),
				    'dc:creator:\tAnother user\ndc:creator:\tJohn-Mark Gurney\nfoo:\tbar=baz\nhashes:\tsha256:91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ada\nhashes:\tsha512:7d5768d47b6bc27dc4fa7e9732cfa2de506ca262a2749cb108923e5dddffde842bbfee6cb8d692fb43aca0f12946c521cce2633887914ca1f96898478d10ad3f\nlang:\ten\n')

			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-d', 'dc:creator', testfname ])) as (stdout, argv):
				main()

			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-l', testfname ])) as (stdout, argv):
				main()
				self.assertEqual(stdout.getvalue(),
				    'foo:\tbar=baz\nhashes:\tsha256:91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ada\nhashes:\tsha512:7d5768d47b6bc27dc4fa7e9732cfa2de506ca262a2749cb108923e5dddffde842bbfee6cb8d692fb43aca0f12946c521cce2633887914ca1f96898478d10ad3f\nlang:\ten\n')

			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-a', 'foo=bleh', testfname ])) as (stdout, argv):
				main()

			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-l', testfname ])) as (stdout, argv):
				main()
				self.assertEqual(stdout.getvalue(),
				    'foo:\tbar=baz\nfoo:\tbleh\nhashes:\tsha256:91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ada\nhashes:\tsha512:7d5768d47b6bc27dc4fa7e9732cfa2de506ca262a2749cb108923e5dddffde842bbfee6cb8d692fb43aca0f12946c521cce2633887914ca1f96898478d10ad3f\nlang:\ten\n')

			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-d', 'foo=bar=baz', testfname ])) as (stdout, argv):
				main()

			with nested(mock.patch('sys.stdout',
			    StringIO.StringIO()), mock.patch('sys.argv',
			    [ 'progname', '-l', testfname ])) as (stdout, argv):
				main()
				self.assertEqual(stdout.getvalue(),
				    'foo:\tbleh\nhashes:\tsha256:91751cee0a1ab8414400238a761411daa29643ab4b8243e9a91649e25be53ada\nhashes:\tsha512:7d5768d47b6bc27dc4fa7e9732cfa2de506ca262a2749cb108923e5dddffde842bbfee6cb8d692fb43aca0f12946c521cce2633887914ca1f96898478d10ad3f\nlang:\ten\n')