import os
from twisted.trial import unittest
from twisted.python.failure import Failure
from twisted.internet import defer
from cStringIO import StringIO

from allmydata import upload, encode, uri
from allmydata.interfaces import IFileURI
from allmydata.util.assertutil import precondition
from foolscap import eventual

class Uploadable(unittest.TestCase):
    def shouldEqual(self, data, expected):
        self.failUnless(isinstance(data, list))
        for e in data:
            self.failUnless(isinstance(e, str))
        s = "".join(data)
        self.failUnlessEqual(s, expected)

    def test_filehandle(self):
        s = StringIO("a"*41)
        u = upload.FileHandle(s)
        d = u.get_size()
        d.addCallback(self.failUnlessEqual, 41)
        d.addCallback(lambda res: u.read(1))
        d.addCallback(self.shouldEqual, "a")
        d.addCallback(lambda res: u.read(80))
        d.addCallback(self.shouldEqual, "a"*40)
        d.addCallback(lambda res: u.close()) # this doesn't close the filehandle
        d.addCallback(lambda res: s.close()) # that privilege is reserved for us
        return d

    def test_filename(self):
        basedir = "upload/Uploadable/test_filename"
        os.makedirs(basedir)
        fn = os.path.join(basedir, "file")
        f = open(fn, "w")
        f.write("a"*41)
        f.close()
        u = upload.FileName(fn)
        d = u.get_size()
        d.addCallback(self.failUnlessEqual, 41)
        d.addCallback(lambda res: u.read(1))
        d.addCallback(self.shouldEqual, "a")
        d.addCallback(lambda res: u.read(80))
        d.addCallback(self.shouldEqual, "a"*40)
        d.addCallback(lambda res: u.close())
        return d

    def test_data(self):
        s = "a"*41
        u = upload.Data(s)
        d = u.get_size()
        d.addCallback(self.failUnlessEqual, 41)
        d.addCallback(lambda res: u.read(1))
        d.addCallback(self.shouldEqual, "a")
        d.addCallback(lambda res: u.read(80))
        d.addCallback(self.shouldEqual, "a"*40)
        d.addCallback(lambda res: u.close())
        return d

class FakePeer:
    def __init__(self, mode="good"):
        self.ss = FakeStorageServer(mode)

    def callRemote(self, methname, *args, **kwargs):
        def _call():
            meth = getattr(self, methname)
            return meth(*args, **kwargs)
        return defer.maybeDeferred(_call)

    def get_service(self, sname):
        assert sname == "storageserver"
        return self.ss

class FakeStorageServer:
    def __init__(self, mode):
        self.mode = mode
    def callRemote(self, methname, *args, **kwargs):
        def _call():
            meth = getattr(self, methname)
            return meth(*args, **kwargs)
        d = eventual.fireEventually()
        d.addCallback(lambda res: _call())
        return d

    def allocate_buckets(self, storage_index, renew_secret, cancel_secret,
                         sharenums, share_size, canary):
        #print "FakeStorageServer.allocate_buckets(num=%d, size=%d)" % (len(sharenums), share_size)
        if self.mode == "full":
            return (set(), {},)
        elif self.mode == "already got them":
            return (set(sharenums), {},)
        else:
            return (set(),
                    dict([( shnum, FakeBucketWriter(share_size) )
                          for shnum in sharenums]),
                    )

class FakeBucketWriter:
    # a diagnostic version of storageserver.BucketWriter
    def __init__(self, size):
        self.data = StringIO()
        self.closed = False
        self._size = size

    def callRemote(self, methname, *args, **kwargs):
        def _call():
            meth = getattr(self, "remote_" + methname)
            return meth(*args, **kwargs)
        d = eventual.fireEventually()
        d.addCallback(lambda res: _call())
        return d

    def remote_write(self, offset, data):
        precondition(not self.closed)
        precondition(offset >= 0)
        precondition(offset+len(data) <= self._size,
                     "offset=%d + data=%d > size=%d" %
                     (offset, len(data), self._size))
        self.data.seek(offset)
        self.data.write(data)

    def remote_close(self):
        precondition(not self.closed)
        self.closed = True

class FakeClient:
    def __init__(self, mode="good"):
        self.mode = mode
    def get_permuted_peers(self, storage_index, include_myself):
        return [ ("%20d"%fakeid, "%20d"%fakeid, FakePeer(self.mode),)
                 for fakeid in range(50) ]
    def get_push_to_ourselves(self):
        return None
    def get_encoding_parameters(self):
        return None

DATA = """
Once upon a time, there was a beautiful princess named Buttercup. She lived
in a magical land where every file was stored securely among millions of
machines, and nobody ever worried about their data being lost ever again.
The End.
"""
assert len(DATA) > upload.Uploader.URI_LIT_SIZE_THRESHOLD

SIZE_ZERO = 0
SIZE_SMALL = 16
SIZE_LARGE = len(DATA)

class GoodServer(unittest.TestCase):
    def setUp(self):
        self.node = FakeClient(mode="good")
        self.u = upload.Uploader()
        self.u.running = True
        self.u.parent = self.node

    def _check_small(self, newuri, size):
        u = IFileURI(newuri)
        self.failUnless(isinstance(u, uri.LiteralFileURI))
        self.failUnlessEqual(len(u.data), size)

    def _check_large(self, newuri, size):
        u = IFileURI(newuri)
        self.failUnless(isinstance(u, uri.CHKFileURI))
        self.failUnless(isinstance(u.storage_index, str))
        self.failUnlessEqual(len(u.storage_index), 16)
        self.failUnless(isinstance(u.key, str))
        self.failUnlessEqual(len(u.key), 16)
        self.failUnlessEqual(u.size, size)

    def get_data(self, size):
        return DATA[:size]

    def test_data_zero(self):
        data = self.get_data(SIZE_ZERO)
        d = self.u.upload_data(data)
        d.addCallback(self._check_small, SIZE_ZERO)
        return d

    def test_data_small(self):
        data = self.get_data(SIZE_SMALL)
        d = self.u.upload_data(data)
        d.addCallback(self._check_small, SIZE_SMALL)
        return d

    def test_data_large(self):
        data = self.get_data(SIZE_LARGE)
        d = self.u.upload_data(data)
        d.addCallback(self._check_large, SIZE_LARGE)
        return d

    def test_data_large_odd_segments(self):
        data = self.get_data(SIZE_LARGE)
        segsize = int(SIZE_LARGE / 2.5)
        # we want 3 segments, since that's not a power of two
        d = self.u.upload_data(data, {"max_segment_size": segsize})
        d.addCallback(self._check_large, SIZE_LARGE)
        return d

    def test_filehandle_zero(self):
        data = self.get_data(SIZE_ZERO)
        d = self.u.upload_filehandle(StringIO(data))
        d.addCallback(self._check_small, SIZE_ZERO)
        return d

    def test_filehandle_small(self):
        data = self.get_data(SIZE_SMALL)
        d = self.u.upload_filehandle(StringIO(data))
        d.addCallback(self._check_small, SIZE_SMALL)
        return d

    def test_filehandle_large(self):
        data = self.get_data(SIZE_LARGE)
        d = self.u.upload_filehandle(StringIO(data))
        d.addCallback(self._check_large, SIZE_LARGE)
        return d

    def test_filename_zero(self):
        fn = "Uploader-test_filename_zero.data"
        f = open(fn, "wb")
        data = self.get_data(SIZE_ZERO)
        f.write(data)
        f.close()
        d = self.u.upload_filename(fn)
        d.addCallback(self._check_small, SIZE_ZERO)
        return d

    def test_filename_small(self):
        fn = "Uploader-test_filename_small.data"
        f = open(fn, "wb")
        data = self.get_data(SIZE_SMALL)
        f.write(data)
        f.close()
        d = self.u.upload_filename(fn)
        d.addCallback(self._check_small, SIZE_SMALL)
        return d

    def test_filename_large(self):
        fn = "Uploader-test_filename_large.data"
        f = open(fn, "wb")
        data = self.get_data(SIZE_LARGE)
        f.write(data)
        f.close()
        d = self.u.upload_filename(fn)
        d.addCallback(self._check_large, SIZE_LARGE)
        return d

class FullServer(unittest.TestCase):
    def setUp(self):
        self.node = FakeClient(mode="full")
        self.u = upload.Uploader()
        self.u.running = True
        self.u.parent = self.node

    def _should_fail(self, f):
        self.failUnless(isinstance(f, Failure) and f.check(encode.NotEnoughPeersError))

    def test_data_large(self):
        data = DATA
        d = self.u.upload_data(data)
        d.addBoth(self._should_fail)
        return d


# TODO:
#  upload with exactly 75 peers (shares_of_happiness)
#  have a download fail
#  cancel a download (need to implement more cancel stuff)