import pickle
import pytest
from hypothesis import given
import hypothesis.strategies as st
from spacy import util
from spacy.lang.en import English
from spacy.language import Language
from spacy.pipeline._edit_tree_internals.edit_trees import EditTrees
from spacy.training import Example
from spacy.strings import StringStore
from spacy.util import make_tempdir


TRAIN_DATA = [
    ("She likes green eggs", {"lemmas": ["she", "like", "green", "egg"]}),
    ("Eat blue ham", {"lemmas": ["eat", "blue", "ham"]}),
]

PARTIAL_DATA = [
    # partial annotation
    ("She likes green eggs", {"lemmas": ["", "like", "green", ""]}),
    # misaligned partial annotation
    (
        "He hates green eggs",
        {
            "words": ["He", "hat", "es", "green", "eggs"],
            "lemmas": ["", "hat", "e", "green", ""],
        },
    ),
]


def test_initialize_examples():
    nlp = Language()
    lemmatizer = nlp.add_pipe("trainable_lemmatizer")
    train_examples = []
    for t in TRAIN_DATA:
        train_examples.append(Example.from_dict(nlp.make_doc(t[0]), t[1]))
    # you shouldn't really call this more than once, but for testing it should be fine
    nlp.initialize(get_examples=lambda: train_examples)
    with pytest.raises(TypeError):
        nlp.initialize(get_examples=lambda: None)
    with pytest.raises(TypeError):
        nlp.initialize(get_examples=lambda: train_examples[0])
    with pytest.raises(TypeError):
        nlp.initialize(get_examples=lambda: [])
    with pytest.raises(TypeError):
        nlp.initialize(get_examples=train_examples)


def test_initialize_from_labels():
    nlp = Language()
    lemmatizer = nlp.add_pipe("trainable_lemmatizer")
    lemmatizer.min_tree_freq = 1
    train_examples = []
    for t in TRAIN_DATA:
        train_examples.append(Example.from_dict(nlp.make_doc(t[0]), t[1]))
    nlp.initialize(get_examples=lambda: train_examples)

    nlp2 = Language()
    lemmatizer2 = nlp2.add_pipe("trainable_lemmatizer")
    lemmatizer2.initialize(
        # We want to check that the strings in replacement nodes are
        # added to the string store. Avoid that they get added through
        # the examples.
        get_examples=lambda: train_examples[:1],
        labels=lemmatizer.label_data,
    )
    assert lemmatizer2.tree2label == {1: 0, 3: 1, 4: 2, 6: 3}
    assert lemmatizer2.label_data == {
        "trees": [
            {"orig": "S", "subst": "s"},
            {
                "prefix_len": 1,
                "suffix_len": 0,
                "prefix_tree": 0,
                "suffix_tree": 4294967295,
            },
            {"orig": "s", "subst": ""},
            {
                "prefix_len": 0,
                "suffix_len": 1,
                "prefix_tree": 4294967295,
                "suffix_tree": 2,
            },
            {
                "prefix_len": 0,
                "suffix_len": 0,
                "prefix_tree": 4294967295,
                "suffix_tree": 4294967295,
            },
            {"orig": "E", "subst": "e"},
            {
                "prefix_len": 1,
                "suffix_len": 0,
                "prefix_tree": 5,
                "suffix_tree": 4294967295,
            },
        ],
        "labels": (1, 3, 4, 6),
    }


def test_no_data():
    # Test that the lemmatizer provides a nice error when there's no tagging data / labels
    TEXTCAT_DATA = [
        ("I'm so happy.", {"cats": {"POSITIVE": 1.0, "NEGATIVE": 0.0}}),
        ("I'm so angry", {"cats": {"POSITIVE": 0.0, "NEGATIVE": 1.0}}),
    ]
    nlp = English()
    nlp.add_pipe("trainable_lemmatizer")
    nlp.add_pipe("textcat")

    train_examples = []
    for t in TEXTCAT_DATA:
        train_examples.append(Example.from_dict(nlp.make_doc(t[0]), t[1]))

    with pytest.raises(ValueError):
        nlp.initialize(get_examples=lambda: train_examples)


def test_incomplete_data():
    # Test that the lemmatizer works with incomplete information
    nlp = English()
    lemmatizer = nlp.add_pipe("trainable_lemmatizer")
    lemmatizer.min_tree_freq = 1
    train_examples = []
    for t in PARTIAL_DATA:
        train_examples.append(Example.from_dict(nlp.make_doc(t[0]), t[1]))
    optimizer = nlp.initialize(get_examples=lambda: train_examples)
    for i in range(50):
        losses = {}
        nlp.update(train_examples, sgd=optimizer, losses=losses)
    assert losses["trainable_lemmatizer"] < 0.00001

    # test the trained model
    test_text = "She likes blue eggs"
    doc = nlp(test_text)
    assert doc[1].lemma_ == "like"
    assert doc[2].lemma_ == "blue"

    # Check that incomplete annotations are ignored.
    scores, _ = lemmatizer.model([eg.predicted for eg in train_examples], is_train=True)
    _, dX = lemmatizer.get_loss(train_examples, scores)
    xp = lemmatizer.model.ops.xp

    # Missing annotations.
    assert xp.count_nonzero(dX[0][0]) == 0
    assert xp.count_nonzero(dX[0][3]) == 0
    assert xp.count_nonzero(dX[1][0]) == 0
    assert xp.count_nonzero(dX[1][3]) == 0

    # Misaligned annotations.
    assert xp.count_nonzero(dX[1][1]) == 0


def test_overfitting_IO():
    nlp = English()
    lemmatizer = nlp.add_pipe("trainable_lemmatizer")
    lemmatizer.min_tree_freq = 1
    train_examples = []
    for t in TRAIN_DATA:
        train_examples.append(Example.from_dict(nlp.make_doc(t[0]), t[1]))

    optimizer = nlp.initialize(get_examples=lambda: train_examples)

    for i in range(50):
        losses = {}
        nlp.update(train_examples, sgd=optimizer, losses=losses)
    assert losses["trainable_lemmatizer"] < 0.00001

    test_text = "She likes blue eggs"
    doc = nlp(test_text)
    assert doc[0].lemma_ == "she"
    assert doc[1].lemma_ == "like"
    assert doc[2].lemma_ == "blue"
    assert doc[3].lemma_ == "egg"

    # Check model after a {to,from}_disk roundtrip
    with util.make_tempdir() as tmp_dir:
        nlp.to_disk(tmp_dir)
        nlp2 = util.load_model_from_path(tmp_dir)
        doc2 = nlp2(test_text)
        assert doc2[0].lemma_ == "she"
        assert doc2[1].lemma_ == "like"
        assert doc2[2].lemma_ == "blue"
        assert doc2[3].lemma_ == "egg"

    # Check model after a {to,from}_bytes roundtrip
    nlp_bytes = nlp.to_bytes()
    nlp3 = English()
    nlp3.add_pipe("trainable_lemmatizer")
    nlp3.from_bytes(nlp_bytes)
    doc3 = nlp3(test_text)
    assert doc3[0].lemma_ == "she"
    assert doc3[1].lemma_ == "like"
    assert doc3[2].lemma_ == "blue"
    assert doc3[3].lemma_ == "egg"

    # Check model after a pickle roundtrip.
    nlp_bytes = pickle.dumps(nlp)
    nlp4 = pickle.loads(nlp_bytes)
    doc4 = nlp4(test_text)
    assert doc4[0].lemma_ == "she"
    assert doc4[1].lemma_ == "like"
    assert doc4[2].lemma_ == "blue"
    assert doc4[3].lemma_ == "egg"


def test_lemmatizer_requires_labels():
    nlp = English()
    nlp.add_pipe("trainable_lemmatizer")
    with pytest.raises(ValueError):
        nlp.initialize()


def test_lemmatizer_label_data():
    nlp = English()
    lemmatizer = nlp.add_pipe("trainable_lemmatizer")
    lemmatizer.min_tree_freq = 1
    train_examples = []
    for t in TRAIN_DATA:
        train_examples.append(Example.from_dict(nlp.make_doc(t[0]), t[1]))

    nlp.initialize(get_examples=lambda: train_examples)

    nlp2 = English()
    lemmatizer2 = nlp2.add_pipe("trainable_lemmatizer")
    lemmatizer2.initialize(
        get_examples=lambda: train_examples, labels=lemmatizer.label_data
    )

    # Verify that the labels and trees are the same.
    assert lemmatizer.labels == lemmatizer2.labels
    assert lemmatizer.trees.to_bytes() == lemmatizer2.trees.to_bytes()


def test_dutch():
    strings = StringStore()
    trees = EditTrees(strings)
    tree = trees.add("deelt", "delen")
    assert trees.tree_to_str(tree) == "(m 0 3 () (m 0 2 (s '' 'l') (s 'lt' 'n')))"

    tree = trees.add("gedeeld", "delen")
    assert (
        trees.tree_to_str(tree) == "(m 2 3 (s 'ge' '') (m 0 2 (s '' 'l') (s 'ld' 'n')))"
    )


def test_from_to_bytes():
    strings = StringStore()
    trees = EditTrees(strings)
    trees.add("deelt", "delen")
    trees.add("gedeeld", "delen")

    b = trees.to_bytes()

    trees2 = EditTrees(strings)
    trees2.from_bytes(b)

    # Verify that the nodes did not change.
    assert len(trees) == len(trees2)
    for i in range(len(trees)):
        assert trees.tree_to_str(i) == trees2.tree_to_str(i)

    # Reinserting the same trees should not add new nodes.
    trees2.add("deelt", "delen")
    trees2.add("gedeeld", "delen")
    assert len(trees) == len(trees2)


def test_from_to_disk():
    strings = StringStore()
    trees = EditTrees(strings)
    trees.add("deelt", "delen")
    trees.add("gedeeld", "delen")

    trees2 = EditTrees(strings)
    with make_tempdir() as temp_dir:
        trees_file = temp_dir / "edit_trees.bin"
        trees.to_disk(trees_file)
        trees2 = trees2.from_disk(trees_file)

    # Verify that the nodes did not change.
    assert len(trees) == len(trees2)
    for i in range(len(trees)):
        assert trees.tree_to_str(i) == trees2.tree_to_str(i)

    # Reinserting the same trees should not add new nodes.
    trees2.add("deelt", "delen")
    trees2.add("gedeeld", "delen")
    assert len(trees) == len(trees2)


@given(st.text(), st.text())
def test_roundtrip(form, lemma):
    strings = StringStore()
    trees = EditTrees(strings)
    tree = trees.add(form, lemma)
    assert trees.apply(tree, form) == lemma


@given(st.text(alphabet="ab"), st.text(alphabet="ab"))
def test_roundtrip_small_alphabet(form, lemma):
    # Test with small alphabets to have more overlap.
    strings = StringStore()
    trees = EditTrees(strings)
    tree = trees.add(form, lemma)
    assert trees.apply(tree, form) == lemma


def test_unapplicable_trees():
    strings = StringStore()
    trees = EditTrees(strings)
    tree3 = trees.add("deelt", "delen")

    # Replacement fails.
    assert trees.apply(tree3, "deeld") == None

    # Suffix + prefix are too large.
    assert trees.apply(tree3, "de") == None


def test_empty_strings():
    strings = StringStore()
    trees = EditTrees(strings)
    no_change = trees.add("xyz", "xyz")
    empty = trees.add("", "")
    assert no_change == empty