import io

try:

    import unittest2 as unittest

except ImportError:

    import unittest

try:

    import hypothesis

    import hypothesis.strategies as strategies

except ImportError:

    hypothesis = None

import zstd

class TestCompressionParameters(unittest.TestCase):

    def test_init_bad_arg_type(self):

        with self.assertRaises(TypeError):

            zstd.CompressionParameters()

        with self.assertRaises(TypeError):

            zstd.CompressionParameters(0, 1)

    def test_bounds(self):

        zstd.CompressionParameters(zstd.WINDOWLOG_MIN,

                                   zstd.CHAINLOG_MIN,

                                   zstd.HASHLOG_MIN,

                                   zstd.SEARCHLOG_MIN,

                                   zstd.SEARCHLENGTH_MIN,

                                   zstd.TARGETLENGTH_MIN,

                                   zstd.STRATEGY_FAST)

        zstd.CompressionParameters(zstd.WINDOWLOG_MAX,

                                   zstd.CHAINLOG_MAX,

                                   zstd.HASHLOG_MAX,

                                   zstd.SEARCHLOG_MAX,

                                   zstd.SEARCHLENGTH_MAX,

                                   zstd.TARGETLENGTH_MAX,

                                   zstd.STRATEGY_BTOPT)

    def test_get_compression_parameters(self):

        p = zstd.get_compression_parameters(1)

        self.assertIsInstance(p, zstd.CompressionParameters)

        self.assertEqual(p[0], 19)

if hypothesis:

    s_windowlog = strategies.integers(min_value=zstd.WINDOWLOG_MIN,

                                      max_value=zstd.WINDOWLOG_MAX)

    s_chainlog = strategies.integers(min_value=zstd.CHAINLOG_MIN,

                                     max_value=zstd.CHAINLOG_MAX)

    s_hashlog = strategies.integers(min_value=zstd.HASHLOG_MIN,

                                    max_value=zstd.HASHLOG_MAX)

    s_searchlog = strategies.integers(min_value=zstd.SEARCHLOG_MIN,

                                      max_value=zstd.SEARCHLOG_MAX)

    s_searchlength = strategies.integers(min_value=zstd.SEARCHLENGTH_MIN,

                                         max_value=zstd.SEARCHLENGTH_MAX)

    s_targetlength = strategies.integers(min_value=zstd.TARGETLENGTH_MIN,

                                         max_value=zstd.TARGETLENGTH_MAX)

    s_strategy = strategies.sampled_from((zstd.STRATEGY_FAST,

                                          zstd.STRATEGY_DFAST,

                                          zstd.STRATEGY_GREEDY,

                                          zstd.STRATEGY_LAZY,

                                          zstd.STRATEGY_LAZY2,

                                          zstd.STRATEGY_BTLAZY2,

                                          zstd.STRATEGY_BTOPT))

    class TestCompressionParametersHypothesis(unittest.TestCase):

        @hypothesis.given(s_windowlog, s_chainlog, s_hashlog, s_searchlog,

                          s_searchlength, s_targetlength, s_strategy)

        def test_valid_init(self, windowlog, chainlog, hashlog, searchlog,

                            searchlength, targetlength, strategy):

            p = zstd.CompressionParameters(windowlog, chainlog, hashlog,

                                           searchlog, searchlength,

                                           targetlength, strategy)

            self.assertEqual(tuple(p),

                             (windowlog, chainlog, hashlog, searchlog,

                              searchlength, targetlength, strategy))

            # Verify we can instantiate a compressor with the supplied values.

            # ZSTD_checkCParams moves the goal posts on us from what's advertised

            # in the constants. So move along with them.

            if searchlength == zstd.SEARCHLENGTH_MIN and strategy in (zstd.STRATEGY_FAST, zstd.STRATEGY_GREEDY):

                searchlength += 1

                p = zstd.CompressionParameters(windowlog, chainlog, hashlog,

                                searchlog, searchlength,

                                targetlength, strategy)

            elif searchlength == zstd.SEARCHLENGTH_MAX and strategy != zstd.STRATEGY_FAST:

                searchlength -= 1

                p = zstd.CompressionParameters(windowlog, chainlog, hashlog,

                                searchlog, searchlength,

                                targetlength, strategy)

            cctx = zstd.ZstdCompressor(compression_params=p)

            with cctx.write_to(io.BytesIO()):

                pass

        @hypothesis.given(s_windowlog, s_chainlog, s_hashlog, s_searchlog,

                          s_searchlength, s_targetlength, s_strategy)

        def test_estimate_compression_context_size(self, windowlog, chainlog,

                                                   hashlog, searchlog,

                                                   searchlength, targetlength,

                                                   strategy):

            p = zstd.CompressionParameters(windowlog, chainlog, hashlog,

                                searchlog, searchlength,

                                targetlength, strategy)

            size = zstd.estimate_compression_context_size(p)