import json
import os
import pickle
import subprocess
from functools import partial
from pathlib import Path
from tempfile import gettempdir
from textwrap import dedent
from types import FunctionType
from unittest import TestCase
from unittest.mock import patch

import numpy as np
import pytest
from multiprocess import Pool

import datasets
from datasets import config
from datasets.fingerprint import Hasher, fingerprint_transform
from datasets.table import InMemoryTable

from .utils import (
    require_not_windows,
    require_numpy1_on_windows,
    require_regex,
    require_spacy,
    require_tiktoken,
    require_torch,
    require_torch_compile,
    require_transformers,
)


class Foo:
    def __init__(self, foo):
        self.foo = foo

    def __call__(self):
        return self.foo


class DatasetChild(datasets.Dataset):
    @fingerprint_transform(inplace=False)
    def func1(self, new_fingerprint, *args, **kwargs):
        return DatasetChild(self.data, fingerprint=new_fingerprint)

    @fingerprint_transform(inplace=False)
    def func2(self, new_fingerprint, *args, **kwargs):
        return DatasetChild(self.data, fingerprint=new_fingerprint)


class UnpicklableCallable:
    def __init__(self, callable):
        self.callable = callable

    def __call__(self, *args, **kwargs):
        if self.callable is not None:
            return self.callable(*args, **kwargs)

    def __getstate__(self):
        raise pickle.PicklingError()


if config.TORCH_AVAILABLE:
    import torch
    import torch.nn as nn
    import torch.nn.functional as F

    class TorchModule(nn.Module):
        def __init__(self):
            super().__init__()
            self.conv1 = nn.Conv2d(1, 20, 5)
            self.conv2 = nn.Conv2d(20, 20, 5)

        def forward(self, x):
            x = F.relu(self.conv1(x))
            return F.relu(self.conv2(x))
else:
    TorchModule = None


class TokenizersHashTest(TestCase):
    @require_transformers
    @pytest.mark.integration
    def test_hash_tokenizer(self):
        from transformers import AutoTokenizer

        def encode(x):
            return tokenizer(x)

        # TODO: add hash consistency tests across sessions
        tokenizer = AutoTokenizer.from_pretrained("bert-base-uncased")
        hash1 = Hasher.hash(tokenizer)
        hash1_lambda = Hasher.hash(lambda x: tokenizer(x))
        hash1_encode = Hasher.hash(encode)
        tokenizer = AutoTokenizer.from_pretrained("bert-base-cased")
        hash2 = Hasher.hash(tokenizer)
        hash2_lambda = Hasher.hash(lambda x: tokenizer(x))
        hash2_encode = Hasher.hash(encode)
        tokenizer = AutoTokenizer.from_pretrained("bert-base-uncased")
        hash3 = Hasher.hash(tokenizer)
        hash3_lambda = Hasher.hash(lambda x: tokenizer(x))
        hash3_encode = Hasher.hash(encode)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)
        self.assertEqual(hash1_lambda, hash3_lambda)
        self.assertNotEqual(hash1_lambda, hash2_lambda)
        self.assertEqual(hash1_encode, hash3_encode)
        self.assertNotEqual(hash1_encode, hash2_encode)

    @require_transformers
    @pytest.mark.integration
    def test_hash_tokenizer_with_cache(self):
        from transformers import AutoTokenizer

        tokenizer = AutoTokenizer.from_pretrained("gpt2")
        hash1 = Hasher.hash(tokenizer)
        tokenizer("Hello world !")  # call once to change the tokenizer's cache
        hash2 = Hasher.hash(tokenizer)
        self.assertEqual(hash1, hash2)

    @require_regex
    def test_hash_regex(self):
        import regex

        pat = regex.Regex("foo")
        hash1 = Hasher.hash(pat)
        pat = regex.Regex("bar")
        hash2 = Hasher.hash(pat)
        pat = regex.Regex("foo")
        hash3 = Hasher.hash(pat)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)


class RecurseHashTest(TestCase):
    def test_recurse_hash_for_function(self):
        def func():
            return foo

        foo = [0]
        hash1 = Hasher.hash(func)
        foo = [1]
        hash2 = Hasher.hash(func)
        foo = [0]
        hash3 = Hasher.hash(func)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

    def test_hash_ignores_line_definition_of_function(self):
        def func():
            pass

        hash1 = Hasher.hash(func)

        def func():
            pass

        hash2 = Hasher.hash(func)
        self.assertEqual(hash1, hash2)

    def test_recurse_hash_for_class(self):
        hash1 = Hasher.hash(Foo([0]))
        hash2 = Hasher.hash(Foo([1]))
        hash3 = Hasher.hash(Foo([0]))
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

    def test_recurse_hash_for_method(self):
        hash1 = Hasher.hash(Foo([0]).__call__)
        hash2 = Hasher.hash(Foo([1]).__call__)
        hash3 = Hasher.hash(Foo([0]).__call__)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

    def test_hash_ipython_function(self):
        def create_ipython_func(co_filename, returned_obj):
            def func():
                return returned_obj

            code = func.__code__
            # Use _create_code from dill in order to make it work for different python versions
            code = code.replace(co_filename=co_filename)
            return FunctionType(code, func.__globals__, func.__name__, func.__defaults__, func.__closure__)

        co_filename, returned_obj = "<ipython-input-2-e0383a102aae>", [0]
        hash1 = Hasher.hash(create_ipython_func(co_filename, returned_obj))
        co_filename, returned_obj = "<ipython-input-2-e0383a102aae>", [1]
        hash2 = Hasher.hash(create_ipython_func(co_filename, returned_obj))
        co_filename, returned_obj = "<ipython-input-5-713f6613acf3>", [0]
        hash3 = Hasher.hash(create_ipython_func(co_filename, returned_obj))
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

        co_filename, returned_obj = os.path.join(gettempdir(), "ipykernel_12345", "321456789.py"), [0]
        hash4 = Hasher.hash(create_ipython_func(co_filename, returned_obj))
        co_filename, returned_obj = os.path.join(gettempdir(), "ipykernel_12345", "321456789.py"), [1]
        hash5 = Hasher.hash(create_ipython_func(co_filename, returned_obj))
        co_filename, returned_obj = os.path.join(gettempdir(), "ipykernel_12345", "654123987.py"), [0]
        hash6 = Hasher.hash(create_ipython_func(co_filename, returned_obj))
        self.assertEqual(hash4, hash6)
        self.assertNotEqual(hash4, hash5)

    def test_recurse_hash_for_function_with_shuffled_globals(self):
        foo, bar = [0], [1]

        def func():
            return foo, bar

        func.__module__ = "__main__"

        def globalvars_mock1_side_effect(func, *args, **kwargs):
            return {"foo": foo, "bar": bar}

        def globalvars_mock2_side_effect(func, *args, **kwargs):
            return {"bar": bar, "foo": foo}

        with patch("dill.detect.globalvars", side_effect=globalvars_mock1_side_effect) as globalvars_mock1:
            hash1 = Hasher.hash(func)
            self.assertGreater(globalvars_mock1.call_count, 0)
        with patch("dill.detect.globalvars", side_effect=globalvars_mock2_side_effect) as globalvars_mock2:
            hash2 = Hasher.hash(func)
            self.assertGreater(globalvars_mock2.call_count, 0)
        self.assertEqual(hash1, hash2)


class HashingTest(TestCase):
    def test_hash_simple(self):
        hash1 = Hasher.hash("hello")
        hash2 = Hasher.hash("hello")
        hash3 = Hasher.hash("there")
        self.assertEqual(hash1, hash2)
        self.assertNotEqual(hash1, hash3)

    def test_hash_class_instance(self):
        hash1 = Hasher.hash(Foo("hello"))
        hash2 = Hasher.hash(Foo("hello"))
        hash3 = Hasher.hash(Foo("there"))
        self.assertEqual(hash1, hash2)
        self.assertNotEqual(hash1, hash3)

    def test_hash_update(self):
        hasher = Hasher()
        for x in ["hello", Foo("hello")]:
            hasher.update(x)
        hash1 = hasher.hexdigest()
        hasher = Hasher()
        for x in ["hello", Foo("hello")]:
            hasher.update(x)
        hash2 = hasher.hexdigest()
        hasher = Hasher()
        for x in ["there", Foo("there")]:
            hasher.update(x)
        hash3 = hasher.hexdigest()
        self.assertEqual(hash1, hash2)
        self.assertNotEqual(hash1, hash3)

    def test_hash_unpicklable(self):
        with self.assertRaises(pickle.PicklingError):
            Hasher.hash(UnpicklableCallable(Foo("hello")))

    def test_hash_same_strings(self):
        string = "abc"
        obj1 = [string, string]  # two strings have the same ids
        obj2 = [string, string]
        obj3 = json.loads(f'["{string}", "{string}"]')  # two strings have different ids
        self.assertIs(obj1[0], string)
        self.assertIs(obj1[0], obj1[1])
        self.assertIs(obj2[0], string)
        self.assertIs(obj2[0], obj2[1])
        self.assertIsNot(obj3[0], string)
        self.assertIsNot(obj3[0], obj3[1])
        hash1 = Hasher.hash(obj1)
        hash2 = Hasher.hash(obj2)
        hash3 = Hasher.hash(obj3)
        self.assertEqual(hash1, hash2)
        self.assertEqual(hash1, hash3)

    def test_set_stable(self):
        rng = np.random.default_rng(42)
        set_ = {rng.random() for _ in range(10_000)}
        expected_hash = Hasher.hash(set_)
        assert expected_hash == Pool(1).apply_async(partial(Hasher.hash, set(set_))).get()

    def test_set_doesnt_depend_on_order(self):
        set_ = set("abc")
        hash1 = Hasher.hash(set_)
        set_ = set("def")
        hash2 = Hasher.hash(set_)
        set_ = set("cba")
        hash3 = Hasher.hash(set_)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

    @require_tiktoken
    def test_hash_tiktoken_encoding(self):
        import tiktoken

        enc = tiktoken.get_encoding("gpt2")
        hash1 = Hasher.hash(enc)
        enc = tiktoken.get_encoding("r50k_base")
        hash2 = Hasher.hash(enc)
        enc = tiktoken.get_encoding("gpt2")
        hash3 = Hasher.hash(enc)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

    @require_numpy1_on_windows
    @require_torch
    def test_hash_torch_tensor(self):
        import torch

        t = torch.tensor([1.0])
        hash1 = Hasher.hash(t)
        t = torch.tensor([2.0])
        hash2 = Hasher.hash(t)
        t = torch.tensor([1.0])
        hash3 = Hasher.hash(t)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

    @require_numpy1_on_windows
    @require_torch
    def test_hash_torch_generator(self):
        import torch

        t = torch.Generator(device="cpu").manual_seed(42)
        hash1 = Hasher.hash(t)
        t = t = torch.Generator(device="cpu").manual_seed(50)
        hash2 = Hasher.hash(t)
        t = t = torch.Generator(device="cpu").manual_seed(42)
        hash3 = Hasher.hash(t)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

    @require_spacy
    @pytest.mark.integration
    def test_hash_spacy_model(self):
        import spacy

        nlp = spacy.blank("en")
        hash1 = Hasher.hash(nlp)
        nlp = spacy.blank("fr")
        hash2 = Hasher.hash(nlp)
        nlp = spacy.blank("en")
        hash3 = Hasher.hash(nlp)
        self.assertEqual(hash1, hash3)
        self.assertNotEqual(hash1, hash2)

    @require_not_windows
    @require_torch_compile
    def test_hash_torch_compiled_function(self):
        import torch

        def f(x):
            return torch.sin(x) + torch.cos(x)

        hash1 = Hasher.hash(f)
        f = torch.compile(f)
        hash2 = Hasher.hash(f)
        self.assertEqual(hash1, hash2)

    @require_not_windows
    @require_torch_compile
    def test_hash_torch_compiled_module(self):
        m = TorchModule()
        next(iter(m.parameters())).data.fill_(1.0)
        hash1 = Hasher.hash(m)
        m = torch.compile(m)
        hash2 = Hasher.hash(m)
        m = TorchModule()
        next(iter(m.parameters())).data.fill_(2.0)
        m = torch.compile(m)
        hash3 = Hasher.hash(m)
        self.assertEqual(hash1, hash2)
        self.assertNotEqual(hash1, hash3)
        self.assertNotEqual(hash2, hash3)


@pytest.mark.integration
def test_move_script_doesnt_change_hash(tmp_path: Path):
    dir1 = tmp_path / "dir1"
    dir2 = tmp_path / "dir2"
    dir1.mkdir()
    dir2.mkdir()
    script_filename = "script.py"
    code = dedent(
        """
    from datasets.fingerprint import Hasher
    def foo():
        pass
    print(Hasher.hash(foo))
    """
    )
    script_path1 = dir1 / script_filename
    script_path2 = dir2 / script_filename
    with script_path1.open("w") as f:
        f.write(code)
    with script_path2.open("w") as f:
        f.write(code)
    fingerprint1 = subprocess.check_output(["python", str(script_path1)])
    fingerprint2 = subprocess.check_output(["python", str(script_path2)])
    assert fingerprint1 == fingerprint2


def test_fingerprint_in_multiprocessing():
    data = {"a": [0, 1, 2]}
    dataset = DatasetChild(InMemoryTable.from_pydict(data))
    expected_fingerprint = dataset.func1()._fingerprint
    with Pool(2) as pool:
        fingerprints = pool.map(
            lambda _: DatasetChild(InMemoryTable.from_pydict(data)).func1()._fingerprint, range(10)
        )
    assert all(f == expected_fingerprint for f in fingerprints)


def test_temp_cache_dir_with_tmpdir_nonexistent(tmp_path, caplog):
    """Test that _TempCacheDir creates TMPDIR if it doesn't exist."""
    import os

    # Set TMPDIR to a non-existent directory
    tmpdir_path = tmp_path / "custom_tmpdir"
    assert not tmpdir_path.exists(), "TMPDIR should not exist initially"

    # Save original TMPDIR and set new one
    original_tmpdir = os.environ.get("TMPDIR")
    try:
        os.environ["TMPDIR"] = str(tmpdir_path)

        # Clear any existing temp cache dir to force recreation
        import datasets.fingerprint

        datasets.fingerprint._TEMP_DIR_FOR_TEMP_CACHE_FILES = None

        # Import and test _TempCacheDir directly
        from datasets.fingerprint import _TempCacheDir

        with caplog.at_level("INFO", logger="datasets.fingerprint"):
            temp_cache = _TempCacheDir()
            cache_dir = temp_cache.name

        # The key test: verify the cache directory is within the TMPDIR we set
        # This proves that TMPDIR was respected and the directory was created
        tmpdir_path_str = str(tmpdir_path)
        assert cache_dir.startswith(tmpdir_path_str), (
            f"Cache dir {cache_dir} should be in TMPDIR {tmpdir_path_str}. TMPDIR env var: {os.environ.get('TMPDIR')}"
        )
        # Verify the directory was created
        assert tmpdir_path.exists(), (
            f"TMPDIR directory {tmpdir_path} should have been created. Cache dir is: {cache_dir}"
        )
        # Verify logging
        assert f"Created TMPDIR directory: {tmpdir_path_str}" in caplog.text

        # Cleanup
        temp_cache.cleanup()
    finally:
        # Restore original TMPDIR
        if original_tmpdir is not None:
            os.environ["TMPDIR"] = original_tmpdir
        elif "TMPDIR" in os.environ:
            del os.environ["TMPDIR"]


def test_temp_cache_dir_with_tmpdir_existing(tmp_path, monkeypatch):
    """Test that _TempCacheDir works correctly when TMPDIR exists."""
    from datasets.fingerprint import get_temporary_cache_files_directory

    # Set TMPDIR to an existing directory
    tmpdir_path = tmp_path / "existing_tmpdir"
    tmpdir_path.mkdir()
    monkeypatch.setenv("TMPDIR", str(tmpdir_path))

    # Clear any existing temp cache dir
    import datasets.fingerprint

    datasets.fingerprint._TEMP_DIR_FOR_TEMP_CACHE_FILES = None

    cache_dir = get_temporary_cache_files_directory()

    # Verify the cache directory is within the TMPDIR
    assert cache_dir.startswith(str(tmpdir_path)), f"Cache dir {cache_dir} should be in TMPDIR {tmpdir_path}"


def test_temp_cache_dir_without_tmpdir(monkeypatch):
    """Test that _TempCacheDir works correctly when TMPDIR is not set."""
    from datasets.fingerprint import get_temporary_cache_files_directory

    # Remove TMPDIR if it exists
    monkeypatch.delenv("TMPDIR", raising=False)

    # Clear any existing temp cache dir
    import datasets.fingerprint

    datasets.fingerprint._TEMP_DIR_FOR_TEMP_CACHE_FILES = None

    cache_dir = get_temporary_cache_files_directory()

    # Verify it uses the default temp directory
    from tempfile import gettempdir

    default_temp = gettempdir()
    assert cache_dir.startswith(default_temp), f"Cache dir {cache_dir} should be in default temp {default_temp}"


def test_temp_cache_dir_tmpdir_creation_failure(tmp_path, monkeypatch, caplog):
    """Test that _TempCacheDir raises if TMPDIR cannot be created."""
    from unittest.mock import patch

    from datasets.fingerprint import _TempCacheDir

    # Set TMPDIR to a path that will fail to create (e.g., invalid permissions)
    # Use a path that's likely to fail on creation
    tmpdir_path = tmp_path / "nonexistent" / "nested" / "path"
    monkeypatch.setenv("TMPDIR", str(tmpdir_path))

    # Mock os.makedirs to raise an error
    with patch("datasets.fingerprint.os.makedirs", side_effect=OSError("Permission denied")):
        with pytest.raises(OSError) as excinfo:
            _TempCacheDir()

    # Verify the error message gives clear context about TMPDIR
    msg = str(excinfo.value)
    assert "TMPDIR is set to" in msg
    assert "could not be created" in msg


def test_temp_cache_dir_tmpdir_not_directory(tmp_path, monkeypatch):
    """Test that _TempCacheDir raises if TMPDIR points to a non-directory."""
    from datasets.fingerprint import _TempCacheDir

    # Create a regular file and point TMPDIR to it
    file_path = tmp_path / "not_a_dir"
    file_path.write_text("not a directory")
    monkeypatch.setenv("TMPDIR", str(file_path))

    with pytest.raises(OSError) as excinfo:
        _TempCacheDir()

    msg = str(excinfo.value)
    assert "TMPDIR is set to" in msg
    assert "is not a directory" in msg


def test_fingerprint_when_transform_version_changes():
    data = {"a": [0, 1, 2]}

    class DummyDatasetChild(datasets.Dataset):
        @fingerprint_transform(inplace=False)
        def func(self, new_fingerprint):
            return DummyDatasetChild(self.data, fingerprint=new_fingerprint)

    fingeprint_no_version = DummyDatasetChild(InMemoryTable.from_pydict(data)).func()

    class DummyDatasetChild(datasets.Dataset):
        @fingerprint_transform(inplace=False, version="1.0.0")
        def func(self, new_fingerprint):
            return DummyDatasetChild(self.data, fingerprint=new_fingerprint)

    fingeprint_1 = DummyDatasetChild(InMemoryTable.from_pydict(data)).func()

    class DummyDatasetChild(datasets.Dataset):
        @fingerprint_transform(inplace=False, version="2.0.0")
        def func(self, new_fingerprint):
            return DummyDatasetChild(self.data, fingerprint=new_fingerprint)

    fingeprint_2 = DummyDatasetChild(InMemoryTable.from_pydict(data)).func()

    assert len({fingeprint_no_version, fingeprint_1, fingeprint_2}) == 3


def test_dependency_on_dill():
    # AttributeError: module 'dill._dill' has no attribute 'stack'
    hasher = Hasher()
    hasher.update(lambda x: x)
