# coding=utf-8
# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import unittest

import pytest
from datasets import Dataset

from alignment import DataArguments, ModelArguments, apply_chat_template, get_datasets, get_tokenizer


class GetDatasetsTest(unittest.TestCase):
    """Each of these test datasets has 100 examples"""

    def test_loading_data_args(self):
        dataset_mixer = {
            "HuggingFaceH4/testing_alpaca_small": 0.5,
            "HuggingFaceH4/testing_self_instruct_small": 0.3,
            "HuggingFaceH4/testing_codealpaca_small": 0.2,
        }
        data_args = DataArguments(dataset_mixer=dataset_mixer)
        datasets = get_datasets(data_args)
        self.assertEqual(len(datasets["train"]), 100)
        self.assertEqual(len(datasets["test"]), 300)

    def test_loading_data_dict(self):
        dataset_mixer = {
            "HuggingFaceH4/testing_alpaca_small": 0.5,
            "HuggingFaceH4/testing_self_instruct_small": 0.3,
            "HuggingFaceH4/testing_codealpaca_small": 0.2,
        }
        datasets = get_datasets(dataset_mixer)
        self.assertEqual(len(datasets["train"]), 100)
        self.assertEqual(len(datasets["test"]), 300)

    def test_loading_with_unit_fractions(self):
        dataset_mixer = {
            "HuggingFaceH4/testing_alpaca_small": 1.0,
            "HuggingFaceH4/testing_self_instruct_small": 1.0,
            "HuggingFaceH4/testing_codealpaca_small": 1.0,
        }
        datasets = get_datasets(dataset_mixer)
        self.assertEqual(len(datasets["train"]), 300)
        self.assertEqual(len(datasets["test"]), 300)

    def test_loading_with_fractions_greater_than_unity(self):
        dataset_mixer = {
            "HuggingFaceH4/testing_alpaca_small": 0.7,
            "HuggingFaceH4/testing_self_instruct_small": 0.4,
        }
        datasets = get_datasets(dataset_mixer)
        self.assertEqual(len(datasets["train"]), 70 + 40)
        self.assertEqual(len(datasets["test"]), 200)

    def test_loading_fails_with_negative_fractions(self):
        dataset_mixer = {
            "HuggingFaceH4/testing_alpaca_small": 0.7,
            "HuggingFaceH4/testing_self_instruct_small": -0.3,
        }
        with pytest.raises(ValueError, match=r"Dataset fractions cannot be negative."):
            get_datasets(dataset_mixer)

    def test_loading_single_split_with_unit_fractions(self):
        dataset_mixer = {
            "HuggingFaceH4/testing_alpaca_small": 1.0,
        }
        datasets = get_datasets(dataset_mixer, splits=["test"])
        self.assertEqual(len(datasets["test"]), 100)
        self.assertRaises(KeyError, lambda: datasets["train"])


class ApplyChatTemplateTest(unittest.TestCase):
    def setUp(self):
        model_args = ModelArguments(model_name_or_path="HuggingFaceH4/zephyr-7b-alpha")
        data_args = DataArguments()
        self.tokenizer = get_tokenizer(model_args, data_args)
        self.dataset = Dataset.from_dict(
            {
                "prompt": ["Hello!"],
                "messages": [[{"role": "user", "content": "Hello!"}, {"role": "assistant", "content": "Bonjour!"}]],
                "chosen": [[{"role": "user", "content": "Hello!"}, {"role": "assistant", "content": "Bonjour!"}]],
                "rejected": [[{"role": "user", "content": "Hello!"}, {"role": "assistant", "content": "Hola!"}]],
            }
        )

    def test_sft(self):
        dataset = self.dataset.map(
            apply_chat_template,
            fn_kwargs={"tokenizer": self.tokenizer, "task": "sft"},
            remove_columns=self.dataset.column_names,
        )
        self.assertDictEqual(
            dataset[0],
            {"text": "<|system|>\n</s>\n<|user|>\nHello!</s>\n<|assistant|>\nBonjour!</s>\n"},
        )

    def test_generation(self):
        # Remove last turn from messages
        dataset = self.dataset.map(lambda x: {"messages": x["messages"][:-1]})
        dataset = dataset.map(
            apply_chat_template,
            fn_kwargs={"tokenizer": self.tokenizer, "task": "generation"},
            remove_columns=self.dataset.column_names,
        )
        self.assertDictEqual(
            dataset[0],
            {"text": "<|system|>\n</s>\n<|user|>\nHello!</s>\n<|assistant|>\n"},
        )

    def test_rm(self):
        dataset = self.dataset.map(
            apply_chat_template,
            fn_kwargs={"tokenizer": self.tokenizer, "task": "rm"},
            remove_columns=self.dataset.column_names,
        )
        self.assertDictEqual(
            dataset[0],
            {
                "text_chosen": "<|system|>\n</s>\n<|user|>\nHello!</s>\n<|assistant|>\nBonjour!</s>\n",
                "text_rejected": "<|system|>\n</s>\n<|user|>\nHello!</s>\n<|assistant|>\nHola!</s>\n",
            },
        )

    def test_dpo(self):
        dataset = self.dataset.map(
            apply_chat_template,
            fn_kwargs={"tokenizer": self.tokenizer, "task": "dpo"},
            remove_columns=self.dataset.column_names,
        )
        self.assertDictEqual(
            dataset[0],
            {
                "text_prompt": "<|system|>\n</s>\n<|user|>\nHello!</s>\n<|assistant|>\n",
                "text_chosen": "Bonjour!</s>\n",
                "text_rejected": "Hola!</s>\n",
            },
        )