import re
import os
import torch
import json

from transformers import AutoTokenizer, AutoModelForTokenClassification, AutoConfig
from datasets import load_dataset


URL_RE = re.compile(r"https?:\/\/[\w\.\/\?\=\d&#%_:/-]+")
HANDLE_RE = re.compile(r"@\w+")


def preprocess_bernice(text):
    text = HANDLE_RE.sub("@USER", text)
    text = URL_RE.sub("HTTPURL", text)
    return text


def preprocess_timelm(text):
    text = HANDLE_RE.sub("@user", text)
    text = URL_RE.sub("http", text)
    return text


def preprocess(model_name, text):
    if model_name == "jhu-clsp/bernice":
        return preprocess_bernice(text)
    if "twitter-roberta-base" in model_name:
        return preprocess_timelm(text)
    return text


class NER:

    id_to_label = {
        0: 'B-corporation',
        1: 'B-creative_work',
        2: 'B-event',
        3: 'B-group',
        4: 'B-location',
        5: 'B-person',
        6: 'B-product',
        7: 'I-corporation',
        8: 'I-creative_work',
        9: 'I-event',
        10: 'I-group',
        11: 'I-location',
        12: 'I-person',
        13: 'I-product',
        14: 'O'
    }

    def __init__(self, model_name: str):
        self.model_name = model_name
        self.config = AutoConfig.from_pretrained(self.model_name)
        self.model = AutoModelForTokenClassification.from_pretrained(self.model_name, config=self.config)
        self.tokenizer = AutoTokenizer.from_pretrained(self.model_name)
        self.max_length = 128
        # GPU setup (https://github.com/cardiffnlp/tweetnlp/issues/15)
        if torch.cuda.is_available() and torch.cuda.device_count() > 0:
            self.device = torch.device('cuda')
        elif hasattr(torch.backends, "mps") and torch.backends.mps.is_available() and torch.backends.mps.is_built():
            self.device = torch.device("mps")
        else:
            self.device = torch.device('cpu')
        self.parallel = torch.cuda.device_count() > 1
        if self.parallel:
            self.model = torch.nn.DataParallel(self.model)
        self.model.to(self.device)
        self.model.eval()
        self.dataset = load_dataset("tweettemposhift/tweet_temporal_shift", "ner_temporal")
        self.tokenized_datasets = self.dataset.map(lambda x: self.tokenize_and_align_labels(x), batched=True)

    def get_prediction(self, export_dir: str, batch_size: int):
        os.makedirs(export_dir, exist_ok=True)
        for test_split in ["test_1", "test_2", "test_3", "test_4"]:
            predictions = self.predict(self.tokenized_datasets[test_split], batch_size)
            with open(f"{export_dir}/{test_split}.jsonl", "w") as f:
                f.write("\n".join([json.dumps(i) for i in predictions]))

    def predict(self, example, batch_size: int):
        input_keys = ['input_ids', 'attention_mask']
        indices = list(range(0, len(example), batch_size)) + [len(example) + 1]
        preds = []
        labels = []
        with torch.no_grad():
            for i in range(len(indices) - 1):
                encoded_input = example[indices[i]: indices[i + 1]]
                labels += [
                    [self.id_to_label[y] if y in self.id_to_label else y for y in x]
                    for x in encoded_input['labels']
                ]
                output = self.model(**{
                    k: torch.tensor(encoded_input[k]).to(self.device) for k in input_keys if k in encoded_input
                })
                prob = torch.softmax(output['logits'], dim=-1)
                pred = torch.max(prob, dim=-1)[1].cpu().detach().int().tolist()
                preds += [[self.id_to_label[_p] for _p in p] for p in pred]
        return [{"prediction": p, "label": i} for p, i in zip(preds, labels)]

    def tokenize_and_align_labels(self, examples):
        tokens = [[preprocess(self.model_name, w) for w in t] for t in examples["text_tokenized"]]
        tokenized_inputs = self.tokenizer(
            tokens,
            truncation=True,
            is_split_into_words=True,
            padding="max_length",
            max_length=128
        )
        all_labels = examples["gold_label_sequence"]
        new_labels = []
        for token, label in zip(tokens, all_labels):
            tmp_labels = [-100]
            for to, la in zip(token, label):
                to_tokenized = self.tokenizer.tokenize(to)
                tmp_labels += [la] * len(to_tokenized)
            if len(tmp_labels) > 128:
                tmp_labels = tmp_labels[:128]
            else:
                tmp_labels = tmp_labels + [-100] * (128 - len(tmp_labels))
            new_labels.append(tmp_labels)
        tokenized_inputs["labels"] = new_labels
        return tokenized_inputs


if __name__ == '__main__':
    model_list = [
        "roberta-base",
        "bertweet-base",
        "bernice",
        "roberta-large",
        "bertweet-large",
        "twitter-roberta-base-2019-90m",
        "twitter-roberta-base-dec2020",
        "twitter-roberta-base-2021-124m",
        "twitter-roberta-base-2022-154m",
        "twitter-roberta-large-2022-154m"
    ]
    for model_m in model_list:
        alias = f"tweettemposhift/ner-ner_temporal-{model_m}"
        NER(alias).get_prediction(export_dir=f"prediction_files/{os.path.basename(alias)}", batch_size=32)
        for random_r in range(4):
            for seed_s in range(3):
                alias = f"tweettemposhift/ner-ner_random{random_r}_seed{seed_s}-{model_m}"
                NER(alias).get_prediction(export_dir=f"prediction_files/{os.path.basename(alias)}", batch_size=32)