import os

import numpy as np
import pytest
from absl.testing import parameterized

from keras.src import backend
from keras.src import constraints
from keras.src import export
from keras.src import layers
from keras.src import models
from keras.src import ops
from keras.src import quantizers
from keras.src import saving
from keras.src.testing import test_case


class EmbeddingTest(test_case.TestCase):
    @pytest.mark.requires_trainable_backend
    def test_embedding_basics(self):
        self.run_layer_test(
            layers.Embedding,
            {"input_dim": 4, "output_dim": 3},
            input_shape=(2,),
            input_dtype="int32",
            expected_output_shape=(2, 3),
            expected_num_trainable_weights=1,
            expected_num_non_trainable_weights=0,
            expected_num_seed_generators=0,
            expected_num_losses=0,
            supports_masking=False,
        )
        self.run_layer_test(
            layers.Embedding,
            {"input_dim": 5, "output_dim": 4, "mask_zero": True},
            input_shape=(2, 3),
            input_dtype="int64",
            expected_output_shape=(2, 3, 4),
            expected_num_trainable_weights=1,
            expected_num_non_trainable_weights=0,
            expected_num_seed_generators=0,
            expected_num_losses=0,
            supports_masking=True,
        )

    @pytest.mark.skipif(
        not backend.SUPPORTS_SPARSE_TENSORS,
        reason="Backend does not support sparse tensors.",
    )
    def test_sparse(self):
        self.run_layer_test(
            layers.Embedding,
            {"input_dim": 5, "output_dim": 4},
            input_shape=(2, 3),
            input_dtype="int32",
            input_sparse=True,
            expected_output_shape=(2, 3, 4),
            expected_num_trainable_weights=1,
            expected_num_non_trainable_weights=0,
            expected_num_seed_generators=0,
            expected_num_losses=0,
            supports_masking=False,
        )

    @pytest.mark.skipif(
        not backend.SUPPORTS_RAGGED_TENSORS,
        reason="Backend does not support ragged tensors.",
    )
    def test_ragged(self):
        self.run_layer_test(
            layers.Embedding,
            {"input_dim": 5, "output_dim": 4},
            input_shape=(2, 3),
            input_dtype="int32",
            input_ragged=True,
            expected_output_shape=(2, None, 4),
            expected_output_ragged=True,
            expected_num_trainable_weights=1,
            expected_num_non_trainable_weights=0,
            expected_num_seed_generators=0,
            expected_num_losses=0,
            supports_masking=False,
            # run_training_check=False,
        )

    def test_correctness(self):
        layer = layers.Embedding(input_dim=3, output_dim=2)
        layer.build()
        layer.embeddings.assign(np.array([[0.0, 0.0], [2.0, 2.0], [3.0, 3.0]]))
        out = layer(np.array([2, 1, 0]))
        self.assertAllClose(out, np.array([[3.0, 3.0], [2.0, 2.0], [0.0, 0.0]]))

    @pytest.mark.skipif(
        not backend.SUPPORTS_SPARSE_TENSORS,
        reason="Backend does not support sparse tensors.",
    )
    def test_correctness_sparse(self):
        layer = layers.Embedding(input_dim=3, output_dim=2)
        layer.build()
        layer.embeddings.assign(np.array([[0.0, 0.0], [2.0, 2.0], [3.0, 3.0]]))

        if backend.backend() == "tensorflow":
            import tensorflow as tf

            x = tf.SparseTensor([[0, 0], [1, 2]], [2, 1], (2, 3))
        elif backend.backend() == "jax":
            import jax.experimental.sparse as jax_sparse

            x = jax_sparse.BCOO(([2, 1], [[0, 0], [1, 2]]), shape=(2, 3))
        else:
            self.fail(f"Sparse is unsupported with backend {backend.backend()}")

        self.assertAllClose(
            layer(x),
            np.array(
                [
                    [[3.0, 3.0], [0.0, 0.0], [0.0, 0.0]],
                    [[0.0, 0.0], [0.0, 0.0], [2.0, 2.0]],
                ]
            ),
        )

    def test_masking(self):
        layer = layers.Embedding(input_dim=3, output_dim=2, mask_zero=True)
        layer.build()
        out = layer.compute_mask(np.array(([2, 1, 0])))
        self.assertAllClose(out, np.array([True, True, False]))

    def test_compute_mask_no_masking(self):
        layer = layers.Embedding(input_dim=3, output_dim=2, mask_zero=False)
        input_data = np.array([2, 1, 0])
        mask = layer.compute_mask(input_data)
        self.assertIsNone(mask)

    def test_embedding_constraints(self):
        layer = layers.Embedding(3, 2, embeddings_constraint="non_neg")
        layer.build((None, 2))
        self.assertIsInstance(layer.embeddings.constraint, constraints.NonNeg)

    def test_weights_constructor_arg(self):
        layer = layers.Embedding(3, 4, weights=np.ones((3, 4)))
        self.assertAllClose(layer.embeddings.numpy(), np.ones((3, 4)))
        layer = layers.Embedding(3, 4, weights=[np.ones((3, 4))])
        self.assertAllClose(layer.embeddings.numpy(), np.ones((3, 4)))

    @pytest.mark.requires_trainable_backend
    def test_enable_lora(self):
        layer = layers.Embedding(10, 16)
        layer.build()
        layer.enable_lora(4)
        self.assertLen(layer.trainable_weights, 2)
        self.assertLen(layer.non_trainable_weights, 1)
        if backend.backend() == "torch":
            self.assertLen(layer.torch_params, 3)
        # Try eager call
        x = np.random.randint(0, 9, size=(64, 3))
        y = np.random.random((64, 3, 16))
        _ = layer(x[:2])

        init_lora_a_embeddings_value = layer.lora_embeddings_a.numpy()
        init_lora_b_embeddings_value = layer.lora_embeddings_b.numpy()

        # Try calling fit()
        model = models.Sequential(
            [
                layer,
            ]
        )
        model.compile(optimizer="sgd", loss="mse")
        model.fit(x, y)

        final_lora_a_embeddings_value = layer.lora_embeddings_a.numpy()
        final_lora_b_embeddings_value = layer.lora_embeddings_b.numpy()
        diff_a = np.max(
            np.abs(init_lora_a_embeddings_value - final_lora_a_embeddings_value)
        )
        diff_b = np.max(
            np.abs(init_lora_b_embeddings_value - final_lora_b_embeddings_value)
        )
        self.assertGreater(diff_a, 0.0)
        self.assertGreater(diff_b, 0.0)

        # Try saving and reloading the model
        temp_filepath = os.path.join(self.get_temp_dir(), "lora_model.keras")
        model.save(temp_filepath)

        new_model = saving.load_model(temp_filepath)
        self.assertTrue(new_model.layers[0].lora_enabled)
        self.assertAllClose(model.predict(x), new_model.predict(x))

        # Try saving and reloading the model's weights only
        temp_filepath = os.path.join(
            self.get_temp_dir(), "lora_model.weights.h5"
        )
        model.save_weights(temp_filepath)

        # Load the file into a fresh, non-lora model
        new_model = models.Sequential(
            [
                layers.Input((3,), dtype="int32"),
                layers.Embedding(10, 16),
            ]
        )
        new_model.load_weights(temp_filepath)
        self.assertAllClose(model.predict(x), new_model.predict(x))

        # Try loading a normal checkpoint into a lora model
        new_model.save_weights(temp_filepath)
        model.load_weights(temp_filepath)
        self.assertAllClose(model.predict(x), new_model.predict(x))

    @pytest.mark.requires_trainable_backend
    def test_enable_lora_with_alpha(self):
        # Create an `Embedding` layer without specifying `lora_rank`
        layer = layers.Embedding(input_dim=3, output_dim=2)
        layer.build((None,))  # Build the layer

        # Set the base embeddings to known values.
        base_emb = np.array(
            [[0.1, 0.2], [0.3, 0.4], [0.5, 0.6]], dtype=np.float32
        )
        layer.embeddings.assign(base_emb)

        # Enable LoRA with a custom alpha: `rank`=2, `lora_alpha`=3.0.
        layer.enable_lora(2, lora_alpha=3.0)
        self.assertEqual(layer.lora_rank, 2)
        self.assertEqual(layer.lora_alpha, 3.0)

        # Manually assign known values to lora weights.
        a_val = np.array([[0.1, 0.1], [0.2, 0.2], [0.3, 0.3]], dtype=np.float32)
        b_val = np.array([[0.5, 0.5], [0.6, 0.6]], dtype=np.float32)
        layer.lora_embeddings_a.assign(a_val)
        layer.lora_embeddings_b.assign(b_val)

        # Compute the expected delta.
        # Scaling factor: (3.0 / 2) = 1.5
        effective_delta = 1.5 * np.matmul(a_val, b_val)
        expected_embeddings = base_emb + effective_delta

        # Verify that the effective embeddings match expectation.
        actual_embeddings = ops.convert_to_numpy(layer.embeddings)
        self.assertAllClose(actual_embeddings, expected_embeddings)

    @pytest.mark.requires_trainable_backend
    def test_lora_rank_argument(self):
        self.run_layer_test(
            layers.Embedding,
            init_kwargs={"input_dim": 5, "output_dim": 4, "lora_rank": 2},
            input_shape=(2, 3),
            input_dtype="int32",
            expected_output_shape=(2, 3, 4),
            expected_num_trainable_weights=2,
            expected_num_non_trainable_weights=1,
            expected_num_seed_generators=0,
            expected_num_losses=0,
            supports_masking=False,
        )

    def test_enable_lora_with_embeddings_constraint(self):
        layer = layers.Embedding(
            input_dim=10, output_dim=16, embeddings_constraint="max_norm"
        )
        with self.assertRaisesRegex(
            ValueError, "incompatible with embedding constraints"
        ):
            layer.enable_lora(rank=2)

    def test_enable_lora_when_already_enabled(self):
        layer = layers.Embedding(input_dim=10, output_dim=16)
        layer.build()
        layer.enable_lora(rank=2)
        with self.assertRaisesRegex(ValueError, "lora is already enabled"):
            layer.enable_lora(rank=2)

    # Test quantization-related methods.

    @parameterized.named_parameters(
        ("int8", "int8"),
        ("int4", "int4"),
    )
    def test_quantize_int(self, mode):
        layer = layers.Embedding(10, 16)
        layer.build()
        x = np.random.randint(0, 9, size=(64, 3))
        y_float = layer(x)
        layer.quantize(mode)

        # Verify the dtype of the weights.
        # The embeddings's dtype is int8, despite the int4 quantization, because
        # we pack the int4 values into int8.
        self.assertEqual(
            backend.standardize_dtype(layer._embeddings.dtype), "int8"
        )
        self.assertEqual(
            backend.standardize_dtype(layer.embeddings_scale.dtype),
            layer.variable_dtype,
        )

        # Verify the unpacked embeddings for int4 quantization.
        if mode == "int4":
            self.assertAllClose(
                layer.embeddings,
                quantizers.unpack_int4(
                    layer._embeddings, layer.output_dim, axis=-1
                ),
            )

        # Verify the correctness of the outputs.
        y_quantized = layer(x)
        mse = ops.mean(ops.square(y_float - y_quantized))
        self.assertLess(mse, 1e-3)  # A weak correctness test

        # Check model save / load round-trip.
        model = models.Sequential([layer])
        temp_filepath = os.path.join(
            self.get_temp_dir(), "quantized_model.keras"
        )
        model.save(temp_filepath)
        new_model = saving.load_model(temp_filepath)
        self.assertAllClose(model.predict(x), new_model.predict(x))

        # Check weights-only save / load round-trip.
        temp_filepath = os.path.join(
            self.get_temp_dir(), "quantized_model.weights.h5"
        )
        model.save_weights(temp_filepath)
        new_model = models.Sequential([layers.Embedding(10, 16)])
        new_model.build((None, 3))
        new_model.quantize(mode)
        new_model.load_weights(temp_filepath)
        self.assertAllClose(model.predict(x), new_model.predict(x))

    @parameterized.named_parameters(
        ("int8", "int8"),
        ("int4", "int4"),
    )
    def test_quantize_on_unbuilt_layer(self, mode):
        layer = layers.Embedding(10, 16)
        with self.assertRaisesRegex(
            ValueError, "Cannot quantize a layer that isn't yet built."
        ):
            layer.quantize(mode)

    @parameterized.named_parameters(
        ("int8", "int8"),
        ("int4", "int4"),
    )
    def test_quantize_on_subclass(self, mode):
        class MyEmbedding(layers.Embedding):
            pass

        layer = MyEmbedding(10, 16)
        layer.build()
        with self.assertRaises(NotImplementedError):
            layer.quantize(mode)

        layer.quantize(mode, type_check=False)  # No error

    @parameterized.named_parameters(
        ("int8", "int8"),
        ("int4", "int4"),
    )
    def test_quantize_when_already_quantized(self, mode):
        layer = layers.Embedding(10, 16)
        layer.build()
        layer.quantize(mode)
        for m in ("int8", "int4"):
            with self.assertRaisesRegex(
                ValueError, "is already quantized with dtype_policy="
            ):
                layer.quantize(m)

        layer = layers.Embedding(10, 16, dtype=f"{mode}_from_float32")
        layer.build()
        for m in ("int8", "int4"):
            with self.assertRaisesRegex(
                ValueError, "is already quantized with dtype_policy="
            ):
                layer.quantize(m)

    @parameterized.named_parameters(
        ("int8", "int8_from_float32", 2),
        ("int4", "int4_from_float32", 2),
    )
    def test_quantize_by_setting_dtype_policy(
        self, policy, expected_num_variables
    ):
        layer = layers.Embedding(10, 16)
        layer.build()
        layer.dtype_policy = policy
        self.assertLen(layer.variables, expected_num_variables)

    @parameterized.named_parameters(
        ("int7", "int7"),
        ("float7", "float7"),
    )
    def test_quantize_invalid_mode(self, mode):
        layer = layers.Embedding(10, 16)
        layer.build()
        x = np.random.randint(0, 9, size=(1, 3))
        # dtype_policy should not be altered by failed quantization
        original_dtype_policy = layer.dtype_policy

        # Test quantize
        with self.assertRaisesRegex(ValueError, "Invalid quantization mode."):
            layer.quantize(mode)
        self.assertEqual(layer.dtype_policy, original_dtype_policy)

        # Test quantized_build
        with self.assertRaisesRegex(
            NotImplementedError, "Invalid quantization mode."
        ):
            layer.quantized_build((None, 2), mode)
        self.assertEqual(layer.dtype_policy, original_dtype_policy)

        # Test quantized_call
        with self.assertRaisesRegex(
            NotImplementedError, "Invalid quantization mode."
        ):
            # Explicitly set quantization_mode
            layer._dtype_policy._quantization_mode = mode
            layer.quantized_call(x)
        self.assertEqual(layer.dtype_policy, original_dtype_policy)

    @parameterized.named_parameters(
        ("int8", "int8_from_mixed_bfloat16", 0, 2),
        ("int4", "int4_from_mixed_bfloat16", 0, 2),
    )
    @pytest.mark.requires_trainable_backend
    def test_quantize_dtype_argument(
        self, dtype, num_trainable_weights, num_non_trainable_weights
    ):
        self.run_layer_test(
            layers.Embedding,
            {"input_dim": 4, "output_dim": 3, "dtype": dtype},
            input_shape=(2,),
            input_dtype="int32",
            expected_output_shape=(2, 3),
            expected_num_trainable_weights=num_trainable_weights,
            expected_num_non_trainable_weights=num_non_trainable_weights,
            expected_num_seed_generators=0,
            expected_num_losses=0,
            supports_masking=False,
        )
        self.run_layer_test(
            layers.Embedding,
            {
                "input_dim": 5,
                "output_dim": 4,
                "mask_zero": True,
                "dtype": dtype,
            },
            input_shape=(2, 3),
            input_dtype="int64",
            expected_output_shape=(2, 3, 4),
            expected_num_trainable_weights=num_trainable_weights,
            expected_num_non_trainable_weights=num_non_trainable_weights,
            expected_num_seed_generators=0,
            expected_num_losses=0,
            supports_masking=True,
        )

    @parameterized.named_parameters(
        ("int8", "int8", 2, 2, 4),
        ("int4", "int4", 2, 2, 4),
    )
    @pytest.mark.requires_trainable_backend
    def test_quantize_lora_integration(
        self,
        mode,
        num_trainable_weights,
        num_non_trainable_weights,
        num_torch_params,
    ):
        layer = layers.Embedding(10, 16)
        layer.build()
        layer.enable_lora(4)
        layer.quantize(mode)
        self.assertLen(layer.trainable_weights, num_trainable_weights)
        self.assertLen(layer.non_trainable_weights, num_non_trainable_weights)
        if backend.backend() == "torch":
            self.assertLen(layer.torch_params, num_torch_params)

        # Try calling fit()
        init_lora_a_embeddings_value = layer.lora_embeddings_a.numpy()
        init_lora_b_embeddings_value = layer.lora_embeddings_b.numpy()
        x = np.random.randint(0, 9, size=(64, 3))
        y = np.random.random((64, 3, 16))
        model = models.Sequential([layer])
        model.compile(optimizer="sgd", loss="mse")
        model.fit(x, y)

        final_lora_a_embeddings_value = layer.lora_embeddings_a.numpy()
        final_lora_b_embeddings_value = layer.lora_embeddings_b.numpy()
        diff_a = np.max(
            np.abs(init_lora_a_embeddings_value - final_lora_a_embeddings_value)
        )
        diff_b = np.max(
            np.abs(init_lora_b_embeddings_value - final_lora_b_embeddings_value)
        )
        self.assertGreater(diff_a, 0.0)
        self.assertGreater(diff_b, 0.0)

        # Try saving and reloading the model
        temp_filepath = os.path.join(
            self.get_temp_dir(), "quantized_lora_model.keras"
        )
        model.save(temp_filepath)
        new_model = saving.load_model(temp_filepath)
        self.assertTrue(new_model.layers[0].lora_enabled)
        self.assertAllClose(model.predict(x), new_model.predict(x), atol=0.5)

        # Try saving and reloading the model's weights only
        temp_filepath = os.path.join(
            self.get_temp_dir(), "quantized_lora_model.weights.h5"
        )
        model.save_weights(temp_filepath)
        new_model = models.Sequential(
            [layers.Input((3,), dtype="int32"), layers.Embedding(10, 16)]
        )
        new_model.quantize(mode)
        new_model.load_weights(temp_filepath)
        self.assertFalse(new_model.layers[0].lora_enabled)
        self.assertAllClose(model.predict(x), new_model.predict(x), atol=0.5)

        # Try loading a normal checkpoint into a lora model
        new_model.save_weights(temp_filepath)
        model.load_weights(temp_filepath)
        self.assertAllClose(model.predict(x), new_model.predict(x), atol=0.5)

        # Test export and TFSMLayer reloading when using tensorflow backend
        if backend.backend() == "tensorflow":
            import tensorflow as tf

            temp_filepath = os.path.join(self.get_temp_dir(), "exported_model")
            ref_input = tf.random.normal((32, 3))
            ref_output = model(ref_input)
            model.export(temp_filepath, format="tf_saved_model")
            reloaded_layer = export.TFSMLayer(temp_filepath)
            self.assertAllClose(
                reloaded_layer(ref_input), ref_output, atol=1e-7
            )
            self.assertLen(reloaded_layer.weights, len(model.weights))
            self.assertLen(
                reloaded_layer.trainable_weights, len(model.trainable_weights)
            )
            self.assertLen(
                reloaded_layer.non_trainable_weights,
                len(model.non_trainable_weights),
            )

    def test_legacy_load_own_variables(self):
        # In previous versions, `load_own_variables` accepted a store with
        # numeric keys.
        float32_store = {
            "0": np.random.random((10, 16)).astype("float32"),
        }
        int8_store = {
            "0": np.random.randint(-128, 127, size=(10, 16), dtype="int8"),
            "1": np.random.random((10,)).astype("float32"),
        }
        int4_store = {
            "0": np.random.randint(-128, 127, size=(10, 8), dtype="int8"),
            "1": np.random.random((10,)).astype("float32"),
        }

        # Test float32 layer.
        layer = layers.Embedding(10, 16)
        layer.build()
        layer.load_own_variables(float32_store)
        self.assertAllClose(layer._embeddings, float32_store["0"])

        # Test int8-quantized layer.
        layer = layers.Embedding(10, 16, dtype="int8_from_float32")
        layer.build()
        layer.load_own_variables(int8_store)
        self.assertAllClose(layer._embeddings, int8_store["0"])
        self.assertAllClose(layer.embeddings_scale, int8_store["1"])

        # Test int4-quantized layer.
        layer = layers.Embedding(10, 16, dtype="int4_from_float32")
        layer.build()
        layer.load_own_variables(int4_store)
        self.assertAllClose(layer._embeddings, int4_store["0"])
        self.assertAllClose(layer.embeddings_scale, int4_store["1"])
