import json
import os.path as osp
import re
import tempfile
from typing import List

from datasets import Dataset

from opencompass.openicl.icl_evaluator import BaseEvaluator
from opencompass.registry import LOAD_DATASET

from .base import BaseDataset


@LOAD_DATASET.register_module()
class HumanevalDataset(BaseDataset):

    @staticmethod
    def load(path: str, num_repeats: int = 1):
        """Load humaneval dataset for pass k mode.

        Note that you can use num_repeats > 1 when your model does not support
        `num_return_sequence` in generation, otherwise use the raw
        humaneval dataset and set `num_return_sequence` in model config to
        generate multiple responses for testing pass@k>1.

        It better to change your dataset abbr correspondingly if you want to
        change num_repeats>1, otherwise the number in
        `.cache/dataset_size.json` might be inconsistent.

        Args:
            num_repeats(int): Number of repetition for this dataset to get
        multiple responses in special cases.
        """
        dataset = []
        with open(path, 'r', encoding='utf-8') as f:
            for line in f:
                dataset.extend(
                    [json.loads(line.strip()) for _ in range(num_repeats)])
        return Dataset.from_list(dataset)


class HumanEvaluator(BaseEvaluator):
    """Evaluator for human eval."""

    def __init__(self, k: List[int] = [1, 10, 100]) -> None:
        try:
            from human_eval.data import HUMAN_EVAL, write_jsonl
            from human_eval.evaluation import evaluate_functional_correctness
            self.write_jsonl = write_jsonl
            self.HUMAN_EVAL = HUMAN_EVAL
            self.eval = evaluate_functional_correctness
        except ImportError:
            raise ImportError('Please install human_eval following'
                              'https://github.com/openai/human-eval/tree/'
                              'master#installation first.')
        self.k = k
        super().__init__()

    def score(self, predictions, references):
        humaneval_preds = []
        # create json file in human_eval format
        for preds, refer in zip(predictions, references):
            # suits for two case
            # 1. use repeated dataset
            # 2. use `num_return_sequences` to generate multiple responses
            if not isinstance(preds, list):
                preds = [preds]
            for pred in preds:
                humaneval_preds.append({'task_id': refer, 'completion': pred})
        with tempfile.TemporaryDirectory() as tmp_dir:
            out_dir = osp.join(tmp_dir, 'human_eval.json')
            self.write_jsonl(out_dir, humaneval_preds)
            score = self.eval(out_dir,
                              self.k,
                              n_workers=4,
                              timeout=3.0,
                              problem_file=self.HUMAN_EVAL)
            return {f'humaneval_{k}': score[k] * 100 for k in score}


def humaneval_postprocess(text: str) -> str:
    if '```' in text:
        blocks = re.findall(r'```(.*?)```', text, re.DOTALL)
        if len(blocks) == 0:
            text = text.split('```')[1]  # fall back to default strategy
        else:
            text = blocks[0]  # fetch the first code block
            if not text.startswith('\n'):  # in case starting with ```python
                text = text[max(text.find('\n') + 1, 0):]
    if text.strip().startswith('from') or text.strip().startswith('import'):
        def_idx = text.find('def')
        if def_idx != -1:
            text = text[max(text.find('\n', def_idx) + 1, 0):]
    text = text.split('\n\n')[0]
    text = text.lstrip('\n')
    if text.strip().startswith('def'):
        text = '\n'.join(text.split('\n')[1:])
    if not text.startswith('    '):
        if text.startswith(' '):
            text = '    ' + text.lstrip()
        else:
            text = '\n'.join(['    ' + line for line in text.split('\n')])
    return text


def humaneval_postprocess_v2(text: str) -> str:
    """This is an advanced version of previous postprocess to handle more
    situations, better to use this one."""
    text = text.lstrip('\n')
    if '```' in text:
        blocks = re.findall(r'```(.*?)```', text, re.DOTALL)
        if len(blocks) == 0:
            text = text.split('```')[1]  # fall back to default strategy
        else:
            text = blocks[0]  # fetch the first code block
            if not text.startswith('\n'):  # in case starting with ```python
                text = text[max(text.find('\n') + 1, 0):]
    if text.strip().startswith('from') or text.strip().startswith('import'):
        def_idx = text.find('def')
        if def_idx != -1:
            text = text[max(text.find('\n', def_idx) + 1, 0):]
    # remove empty lines
    text = '\n'.join([line for line in text.split('\n') if line != ''])
    text = text.lstrip('\n')
    if text.strip().startswith('def'):
        text = '\n'.join(text.split('\n')[1:])
    if not text.startswith('    '):
        if text.startswith(' '):
            text = '    ' + text.lstrip()
        else:
            text = '\n'.join(['    ' + line for line in text.split('\n')])
    text = text.split('\n')

    # If number of leading space reduces, we assume that the code block ends.
    min_leading_space = None
    end_index = None
    for index, line in enumerate(text):
        if line.strip() == '' or line.strip()[0] in ["'", '"', '#']:
            continue
        current_leading_space = len(line.rstrip()) - len(line.strip())
        if min_leading_space is None:
            min_leading_space = current_leading_space
        elif current_leading_space < min_leading_space:
            end_index = index
            break
    if end_index is not None:
        text = '\n'.join(text[:end_index])
    else:
        text = '\n'.join(text)
    return text


def humaneval_gpt_postprocess(text: str) -> str:
    """Better answer postprocessor for better instruction-aligned models like
    GPT."""
    if '```' in text:
        blocks = re.findall(r'```(.*?)```', text, re.DOTALL)
        if len(blocks) == 0:
            text = text.split('```')[1]  # fall back to default strategy
        else:
            text = blocks[0]  # fetch the first code block
            if not text.startswith('\n'):  # in case starting with ```python
                text = text[max(text.find('\n') + 1, 0):]
    if text.strip().startswith('from') or text.strip().startswith('import'):
        def_idx = text.find('def')
        if def_idx != -1:
            text = text[max(text.find('\n', def_idx) + 1, 0):]
    text = text.split('\n\n\n')[0]
    if text.strip().startswith('def'):
        text = '\n'.join(text.split('\n')[1:])
    if not text.startswith('    '):
        if text.startswith(' '):
            text = '    ' + text.lstrip()
        else:
            text = '\n'.join(['    ' + line for line in text.split('\n')])
    return text