import argparse
import dataclasses
import json
import math
import os
import warnings
from collections import OrderedDict
from pathlib import Path
from typing import Dict, Optional, Union

import requests
import torch
from torch import nn

from robustbench.model_zoo import model_dicts as all_models
from robustbench.model_zoo.enums import BenchmarkDataset, ThreatModel


ACC_FIELDS = {
    ThreatModel.corruptions: "corruptions_acc",
    ThreatModel.L2: "autoattack_acc",
    ThreatModel.Linf: "autoattack_acc"
}


def download_gdrive(gdrive_id, fname_save):
    """ source: https://stackoverflow.com/questions/38511444/python-download-files-from-google-drive-using-url """
    def get_confirm_token(response):
        for key, value in response.cookies.items():
            if key.startswith('download_warning'):
                return value

        return None

    def save_response_content(response, fname_save):
        CHUNK_SIZE = 32768

        with open(fname_save, "wb") as f:
            for chunk in response.iter_content(CHUNK_SIZE):
                if chunk:  # filter out keep-alive new chunks
                    f.write(chunk)

    print('Download started: path={} (gdrive_id={})'.format(
        fname_save, gdrive_id))

    url_base = "https://docs.google.com/uc?export=download&confirm=t"
    session = requests.Session()

    response = session.get(url_base, params={'id': gdrive_id}, stream=True)
    token = get_confirm_token(response)

    if token:
        params = {'id': gdrive_id, 'confirm': token}
        response = session.get(url_base, params=params, stream=True)

    save_response_content(response, fname_save)
    session.close()
    print('Download finished: path={} (gdrive_id={})'.format(
        fname_save, gdrive_id))


def rm_substr_from_state_dict(state_dict, substr):
    new_state_dict = OrderedDict()
    for key in state_dict.keys():
        if substr in key:  # to delete prefix 'module.' if it exists
            new_key = key[len(substr):]
            new_state_dict[new_key] = state_dict[key]
        else:
            new_state_dict[key] = state_dict[key]
    return new_state_dict


def add_substr_to_state_dict(state_dict, substr):
    new_state_dict = OrderedDict()
    for k, v in state_dict.items():
        new_state_dict[substr + k] = v
    return new_state_dict


def load_model(model_name: str,
               model_dir: Union[str, Path] = './models',
               dataset: Union[str,
                              BenchmarkDataset] = BenchmarkDataset.cifar_10,
               threat_model: Union[str, ThreatModel] = ThreatModel.Linf,
               norm: Optional[str] = None) -> nn.Module:
    """Loads a model from the model_zoo.

     The model is trained on the given ``dataset``, for the given ``threat_model``.

    :param model_name: The name used in the model zoo.
    :param model_dir: The base directory where the models are saved.
    :param dataset: The dataset on which the model is trained.
    :param threat_model: The threat model for which the model is trained.
    :param norm: Deprecated argument that can be used in place of ``threat_model``. If specified, it
      overrides ``threat_model``

    :return: A ready-to-used trained model.
    """

    dataset_: BenchmarkDataset = BenchmarkDataset(dataset)
    if norm is None:
        threat_model_: ThreatModel = ThreatModel(threat_model)
    else:
        threat_model_ = ThreatModel(norm)
        warnings.warn(
            "`norm` has been deprecated and will be removed in a future version.",
            DeprecationWarning)

    model_dir_ = Path(model_dir) / dataset_.value / threat_model_.value
    model_path = model_dir_ / f'{model_name}.pt'

    models = all_models[dataset_][threat_model_]

    if not isinstance(models[model_name]['gdrive_id'], list):
        model = models[model_name]['model']()
        if dataset_ == BenchmarkDataset.imagenet and 'Standard' in model_name:
            return model.eval()
        
        if not os.path.exists(model_dir_):
            os.makedirs(model_dir_)
        if not os.path.isfile(model_path):
            download_gdrive(models[model_name]['gdrive_id'], model_path)
        checkpoint = torch.load(model_path, map_location=torch.device('cpu'))

        if 'Kireev2021Effectiveness' in model_name or model_name == 'Andriushchenko2020Understanding':
            checkpoint = checkpoint['last']  # we take the last model (choices: 'last', 'best')
        try:
            # needed for the model of `Carmon2019Unlabeled`
            state_dict = rm_substr_from_state_dict(checkpoint['state_dict'],
                                                   'module.')
            # needed for the model of `Chen2020Efficient`
            state_dict = rm_substr_from_state_dict(state_dict,
                                                   'model.')
        except:
            state_dict = rm_substr_from_state_dict(checkpoint, 'module.')
            state_dict = rm_substr_from_state_dict(state_dict, 'model.')

        if dataset_ == BenchmarkDataset.imagenet:
            # so far all models need input normalization, which is added as extra layer
            state_dict = add_substr_to_state_dict(state_dict, 'model.')
        
        model = _safe_load_state_dict(model, model_name, state_dict, dataset_)

        return model.eval()

    # If we have an ensemble of models (e.g., Chen2020Adversarial)
    else:
        model = models[model_name]['model']()
        if not os.path.exists(model_dir_):
            os.makedirs(model_dir_)
        for i, gid in enumerate(models[model_name]['gdrive_id']):
            if not os.path.isfile('{}_m{}.pt'.format(model_path, i)):
                download_gdrive(gid, '{}_m{}.pt'.format(model_path, i))
            checkpoint = torch.load('{}_m{}.pt'.format(model_path, i),
                                    map_location=torch.device('cpu'))
            try:
                state_dict = rm_substr_from_state_dict(
                    checkpoint['state_dict'], 'module.')
            except KeyError:
                state_dict = rm_substr_from_state_dict(checkpoint, 'module.')

            model.models[i] = _safe_load_state_dict(model.models[i],
                                                    model_name, state_dict,
                                                    dataset_)
            model.models[i].eval()

        return model.eval()


def _safe_load_state_dict(model: nn.Module, model_name: str,
                          state_dict: Dict[str, torch.Tensor],
                          dataset_: BenchmarkDataset) -> nn.Module:
    known_failing_models = {
        "Andriushchenko2020Understanding", "Augustin2020Adversarial",
        "Engstrom2019Robustness", "Pang2020Boosting", "Rice2020Overfitting",
        "Rony2019Decoupling", "Wong2020Fast", "Hendrycks2020AugMix_WRN",
        "Hendrycks2020AugMix_ResNeXt", "Kireev2021Effectiveness_Gauss50percent",
        "Kireev2021Effectiveness_AugMixNoJSD", "Kireev2021Effectiveness_RLAT",
        "Kireev2021Effectiveness_RLATAugMixNoJSD", "Kireev2021Effectiveness_RLATAugMixNoJSD",
        "Kireev2021Effectiveness_RLATAugMix", "Chen2020Efficient",
        "Wu2020Adversarial", "Augustin2020Adversarial_34_10",
        "Augustin2020Adversarial_34_10_extra"
    }

    failure_messages = ['Missing key(s) in state_dict: "mu", "sigma".',
                        'Unexpected key(s) in state_dict: "model_preact_hl1.1.weight"',
                        'Missing key(s) in state_dict: "normalize.mean", "normalize.std"']

    try:
        model.load_state_dict(state_dict, strict=True)
    except RuntimeError as e:
        if (model_name in known_failing_models or dataset_ == BenchmarkDataset.imagenet
            ) and any([msg in str(e) for msg in failure_messages]):
            model.load_state_dict(state_dict, strict=False)
        else:
            raise e

    return model


def clean_accuracy(model: nn.Module,
                   x: torch.Tensor,
                   y: torch.Tensor,
                   batch_size: int = 100,
                   identifier = None,
                   device: torch.device = None):
    if device is None:
        device = x.device
    acc = 0.
    n_batches = math.ceil(x.shape[0] / batch_size)
    with torch.no_grad():
        for counter in range(n_batches):
            x_curr = x[counter * batch_size:(counter + 1) *
                       batch_size].to(device)
            y_curr = y[counter * batch_size:(counter + 1) *
                       batch_size].to(device)

            output = model(x_curr)
            acc += (output.max(1)[1] == y_curr).float().sum()

    return acc.item() / x.shape[0]


def list_available_models(
        dataset: Union[str, BenchmarkDataset] = BenchmarkDataset.cifar_10,
        threat_model: Union[str, ThreatModel] = ThreatModel.Linf,
        norm: Optional[str] = None):
    dataset_: BenchmarkDataset = BenchmarkDataset(dataset)

    if norm is None:
        threat_model_: ThreatModel = ThreatModel(threat_model)
    else:
        threat_model_ = ThreatModel(norm)
        warnings.warn(
            "`norm` has been deprecated and will be removed in a future version.",
            DeprecationWarning)

    models = all_models[dataset_][threat_model_].keys()

    acc_field = ACC_FIELDS[threat_model_]

    json_dicts = []

    jsons_dir = Path("./model_info") / dataset_.value / threat_model_.value

    for model_name in models:
        json_path = jsons_dir / f"{model_name}.json"

        # Some models might not yet be in model_info
        if not json_path.exists():
            continue

        with open(json_path, 'r') as model_info:
            json_dict = json.load(model_info)

        json_dict['model_name'] = model_name
        json_dict['venue'] = 'Unpublished' if json_dict[
            'venue'] == '' else json_dict['venue']
        json_dict[acc_field] = float(json_dict[acc_field]) / 100
        json_dict['clean_acc'] = float(json_dict['clean_acc']) / 100
        json_dicts.append(json_dict)

    json_dicts = sorted(json_dicts, key=lambda d: -d[acc_field])
    print('| <sub>#</sub> | <sub>Model ID</sub> | <sub>Paper</sub> | <sub>Clean accuracy</sub> | <sub>Robust accuracy</sub> | <sub>Architecture</sub> | <sub>Venue</sub> |')
    print('|:---:|---|---|:---:|:---:|:---:|:---:|')
    for i, json_dict in enumerate(json_dicts):
        if json_dict['model_name'] == 'Chen2020Adversarial':
            json_dict['architecture'] = json_dict[
                'architecture'] + ' <br/> (3x ensemble)'
        if json_dict['model_name'] != 'Natural':
            print(
                '| <sub>**{}**</sub> | <sub><sup>**{}**</sup></sub> | <sub>*[{}]({})*</sub> | <sub>{:.2%}</sub> | <sub>{:.2%}</sub> | <sub>{}</sub> | <sub>{}</sub> |'
                .format(i + 1, json_dict['model_name'], json_dict['name'],
                        json_dict['link'], json_dict['clean_acc'],
                        json_dict[acc_field], json_dict['architecture'],
                        json_dict['venue']))
        else:
            print(
                '| <sub>**{}**</sub> | <sub><sup>**{}**</sup></sub> | <sub>*{}*</sub> | <sub>{:.2%}</sub> | <sub>{:.2%}</sub> | <sub>{}</sub> | <sub>{}</sub> |'
                .format(i + 1, json_dict['model_name'], json_dict['name'],
                        json_dict['clean_acc'], json_dict[acc_field],
                        json_dict['architecture'], json_dict['venue']))


def _get_bibtex_entry(model_name: str, title: str, authors: str, venue: str, year: int):
    authors = authors.replace(', ', ' and ')
    return (f"@article{{{model_name},\n"
            f"\ttitle\t= {{{title}}},\n"
            f"\tauthor\t= {{{authors}}},\n"
            f"\tjournal\t= {{{venue}}},\n"
            f"\tyear\t= {{{year}}}\n"
            "}\n")


def get_leaderboard_bibtex(dataset: Union[str, BenchmarkDataset], threat_model: Union[str, ThreatModel]):
    dataset_: BenchmarkDataset = BenchmarkDataset(dataset)
    threat_model_: ThreatModel = ThreatModel(threat_model)

    jsons_dir = Path("./model_info") / dataset_.value / threat_model_.value

    bibtex_entries = set()

    for json_path in jsons_dir.glob("*.json"):

        model_name = json_path.stem.split("_")[0]

        with open(json_path, 'r') as model_info:
            model_dict = json.load(model_info)
            title = model_dict["name"]
            authors = model_dict["authors"]
            full_venue = model_dict["venue"]
            if full_venue == "N/A":
                continue
            venue = full_venue.split(" ")[0]
            venue = venue.split(",")[0]

            year = model_dict["venue"].split(" ")[-1]

            bibtex_entry = _get_bibtex_entry(
                model_name, title, authors, venue, year)
            bibtex_entries.add(bibtex_entry)

    str_entries = ''
    for entry in bibtex_entries:
        print(entry)
        str_entries += entry

    return bibtex_entries, str_entries


def get_leaderboard_latex(dataset: Union[str, BenchmarkDataset],
                          threat_model: Union[str, ThreatModel],
                          l_keys=['clean_acc', 'external', #'autoattack_acc',
                                  'additional_data', 'architecture', 'venue',
                                  'modelzoo_id'],
                          sort_by='external' #'autoattack_acc'
                          ):
    dataset_: BenchmarkDataset = BenchmarkDataset(dataset)
    threat_model_: ThreatModel = ThreatModel(threat_model)

    models = all_models[dataset_][threat_model_]
    print(models.keys())
    
    jsons_dir = Path("./model_info") / dataset_.value / threat_model_.value
    entries = []

    for json_path in jsons_dir.glob("*.json"):
        if not json_path.stem.startswith('Standard'):
            model_name = json_path.stem.split("_")[0]
        else:
            model_name = json_path.stem
        
        with open(json_path, 'r') as model_info:
            model_dict = json.load(model_info)

        str_curr = '\\citet{{{}}}'.format(model_name) if not model_name in ['Standard', 'Standard_R50'] \
            else model_name.replace('_', '\\_')

        for k in l_keys:
            if k == 'external' and not 'external' in model_dict.keys():
                model_dict[k] = model_dict['autoattack_acc']
            if k == 'additional_data':
                v = 'Y' if model_dict[k] else 'N'
            elif k == 'architecture':
                v = model_dict[k].replace('WideResNet', 'WRN')
                v = v.replace('ResNet', 'RN')
            elif k == 'modelzoo_id':
                # print(json_path.stem)
                v = json_path.stem.split('.json')[0]
                if not v in models.keys():
                    v = 'N/A'
                else:
                    v = v.replace('_', '\\_')
            else:
                v = model_dict[k]
            str_curr += ' & {}'.format(v)
        str_curr += '\\\\'
        entries.append((str_curr, float(model_dict[sort_by])))

    entries = sorted(entries, key=lambda k: k[1], reverse=True)
    entries = ['{} &'.format(i + 1) + a for i, (a, b) in enumerate(entries)]
    entries = '\n'.join(entries).replace('<br>', ' ')

    return entries


def update_json(dataset: BenchmarkDataset, threat_model: ThreatModel,
                model_name: str, accuracy: float, adv_accuracy: float,
                eps: Optional[float]) -> None:
    json_path = Path(
        "model_info"
    ) / dataset.value / threat_model.value / f"{model_name}.json"
    if not json_path.parent.exists():
        json_path.parent.mkdir(parents=True, exist_ok=True)

    acc_field = ACC_FIELDS[threat_model]

    acc_field_kwarg = {acc_field: adv_accuracy}

    model_info = ModelInfo(dataset=dataset.value, eps=eps, clean_acc=accuracy, **acc_field_kwarg)

    with open(json_path, "w") as f:
        f.write(json.dumps(dataclasses.asdict(model_info), indent=2))


@dataclasses.dataclass
class ModelInfo:
    link: Optional[str] = None
    name: Optional[str] = None
    authors: Optional[str] = None
    additional_data: Optional[bool] = None
    number_forward_passes: Optional[int] = None
    dataset: Optional[str] = None
    venue: Optional[str] = None
    architecture: Optional[str] = None
    eps: Optional[float] = None
    clean_acc: Optional[float] = None
    reported: Optional[float] = None
    corruptions_acc: Optional[str] = None
    autoattack_acc: Optional[str] = None
    footnote: Optional[str] = None


def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument('--model_name',
                        type=str,
                        default='Carmon2019Unlabeled')
    parser.add_argument('--threat_model',
                        type=str,
                        default='Linf',
                        choices=[x.value for x in ThreatModel])
    parser.add_argument('--dataset',
                        type=str,
                        default='cifar10',
                        choices=[x.value for x in BenchmarkDataset])
    parser.add_argument('--eps', type=float, default=8 / 255)
    parser.add_argument('--n_ex',
                        type=int,
                        default=100,
                        help='number of examples to evaluate on')
    parser.add_argument('--batch_size',
                        type=int,
                        default=500,
                        help='batch size for evaluation')
    parser.add_argument('--data_dir',
                        type=str,
                        default='./data',
                        help='where to store downloaded datasets')
    parser.add_argument('--model_dir',
                        type=str,
                        default='./models',
                        help='where to store downloaded models')
    parser.add_argument('--seed',
                        type=int,
                        default=0,
                        help='random seed')
    parser.add_argument('--device',
                        type=str,
                        default='cuda:0',
                        help='device to use for computations')
    parser.add_argument('--to_disk', type=bool, default=True)
    args = parser.parse_args()
    return args
