# -*- coding: utf-8 -*-
import logging
import string
from multiprocessing import Pool

import h5py
import joblib
import numpy as np
import pandas as pd
from tqdm import tqdm

logger = logging.getLogger('cisco_logger')

char2idx = dict((char, idx + 1) for (idx, char) in
                enumerate(string.ascii_lowercase + string.punctuation + string.digits + " "))

idx2char = {v: k for k, v in char2idx.items()}


def get_character_dict():
    return char2idx


def get_vocab_size():
    return len(char2idx) + 1


def encode_char(c):
    return char2idx.get(c, 0)


def decode_char(i):
    return idx2char.get(i, "")


encode_char = np.vectorize(encode_char)
decode_char = np.vectorize(decode_char)


def encode_domain(domain: string):
    return encode_char(list(domain))


def decode_domain(domain):
    return "".join(decode_char(domain))


def get_user_chunks(user_flow, window=10):
    result = []
    chunk_size = (len(user_flow) // window)
    for i in range(chunk_size):
        result.append(user_flow.iloc[i * window:(i + 1) * window])
    if result and len(result[-1]) != window:
        result.pop()
    return result


def get_domain_features(domain: string, max_length=40):
    encoding = np.zeros((max_length,))
    for j in range(min(len(domain), max_length)):
        c = domain[len(domain) - 1 - j]
        encoding[max_length - 1 - j] = encode_char(c)
    return encoding


def get_all_flow_features(features):
    flows = np.stack(
        map(lambda f: f[["duration", "bytes_up", "bytes_down"]], features)
    )
    return np.log1p(flows)


def filter_window_dataset_by_hits(domain, flow, name, hits, trusted_hits, server):
    # select only 1.0 and 0.0 from training data
    pos_idx = np.where(np.logical_or(hits == 1.0, trusted_hits >= 1.0))[0]
    neg_idx = np.where(hits == 0.0)[0]
    idx = np.concatenate((pos_idx, neg_idx))
    # choose selected sample to train on
    domain = domain[idx]
    flow = flow[idx]
    client = np.zeros_like(idx, float)
    client[:pos_idx.shape[-1]] = 1.0
    server = server[idx]
    name = name[idx]

    return domain, flow, name, client, server


def create_raw_dataset_from_flows(user_flow_df, max_len, window_size=10):
    logger.info("get chunks from user data frames")
    with Pool() as pool:
        results = []
        for user_flow in tqdm(get_flow_per_user(user_flow_df), total=len(user_flow_df['user_hash'].unique().tolist())):
            results.append(pool.apply_async(get_user_chunks, (user_flow, window_size)))
        windows = [window for res in results for window in res.get()]
    logger.info("create training dataset")
    domain, flow, hits, name, server, trusted_hits = create_dataset_from_windows(chunks=windows,
                                                                                 max_len=max_len)
    # make client labels discrete with 4 different values
    hits = np.apply_along_axis(lambda x: make_label_discrete(x, 3), 0, np.atleast_2d(hits))

    return domain, flow, name, hits, trusted_hits, server


def store_h5dataset(path, data: dict):
    f = h5py.File(path + ".h5", "w")
    for key, val in data.items():
        f.create_dataset(key, data=val)
    f.close()


def check_h5dataset(path):
    return open(path + ".h5", "r")


def load_h5dataset(path):
    f = h5py.File(path + ".h5", "r")
    data = {}
    for k in f.keys():
        data[k] = f[k]
    return data


def create_dataset_from_windows(chunks, max_len):
    """
    combines domain and feature windows to sequential training data
    :param chunks: list of flow feature windows
    :param vocab: 
    :param max_len: 
    :return: 
    """

    def get_domain_features_reduced(d):
        return get_domain_features(d[0], max_len)

    logger.info("  compute domain features")
    domain_features = []
    for ds in tqdm(map(lambda f: f.domain, chunks)):
        domain_features.append(np.apply_along_axis(get_domain_features_reduced, 2, np.atleast_3d(ds)))
    domain_features = np.concatenate(domain_features, 0)
    logger.info("  compute flow features")
    flow_features = get_all_flow_features(chunks)
    logger.info("  select hits")
    hits = np.max(np.stack(map(lambda f: f.virusTotalHits, chunks)), axis=1)
    logger.info("  select names")
    names = np.stack(map(lambda f: f.user_hash, chunks))
    assert (names[:, :1].repeat(10, axis=1) == names).all()
    names = names[:, 0]
    logger.info("  select servers")
    servers = np.stack(map(lambda f: f.serverLabel, chunks))
    logger.info("  select trusted hits")
    trusted_hits = np.max(np.stack(map(lambda f: f.trustedHits, chunks)), axis=1)

    return (domain_features, flow_features,
            hits, names, servers, trusted_hits)


def make_label_discrete(values, threshold):
    max_val = np.max(values)
    if max_val >= threshold:
        return 1.0
    elif max_val == -1:
        return -1.0
    elif 0 < max_val < threshold:
        return -2.0
    else:
        return 0.0


def get_user_flow_data(csv_file):
    types = {
        "duration": int,
        "bytes_down": int,
        "bytes_up": int,
        "domain": object,
        "timeStamp": float,
        "http_method": object,
        "server_ip": object,
        "user_hash": float,
        "virusTotalHits": int,
        "serverLabel": int,
        "trustedHits": int
    }
    df = pd.read_csv(csv_file, index_col=False)
    df = df[list(types.keys())]
    # df.set_index(keys=['user_hash'], drop=False, inplace=True)
    return df


def get_flow_per_user(df):
    users = df['user_hash'].unique().tolist()
    for user in users:
        yield df.loc[df.user_hash == user].dropna(axis=0, how="any")


def load_or_generate_h5data(train_data, domain_length, window_size):
    logger.info(f"check for h5data {train_data}")
    try:
        check_h5dataset(train_data)
    except FileNotFoundError:
        logger.info("load raw training dataset")
        domain, flow, name, hits, trusted_hits, server = load_or_generate_raw_h5data(train_data, domain_length,
                                                                                     window_size)
        logger.info("filter training dataset")
        domain, flow, name, client, server = filter_window_dataset_by_hits(domain.value, flow.value,
                                                                           name.value, hits.value,
                                                                           trusted_hits.value, server.value)
        logger.info("store training dataset as h5 file")
        data = {
            "domain": domain.astype(np.int8),
            "flow": flow,
            "name": name,
            "client": client.astype(np.bool),
            "server": server.astype(np.bool)
        }
        store_h5dataset(train_data, data)
    logger.info("load h5 dataset")
    data = load_h5dataset(train_data)
    return data["domain"], data["flow"], data["name"], data["client"], data["server"]


def load_or_generate_raw_h5data(train_data, domain_length, window_size):
    h5data = train_data + "_raw"
    logger.info(f"check for h5data {h5data}")
    try:
        check_h5dataset(h5data)
    except FileNotFoundError:
        logger.info("h5 data not found - load csv file")
        user_flow_df = get_user_flow_data(train_data)
        logger.info("create raw training dataset")
        domain, flow, name, hits, trusted_hits, server = create_raw_dataset_from_flows(user_flow_df, domain_length,
                                                                                       window_size)
        logger.info("store raw training dataset as h5 file")
        data = {
            "domain": domain.astype(np.int8),
            "flow": flow,
            "name": name,
            "hits_vt": hits.astype(np.int8),
            "hits_trusted": hits.astype(np.int8),
            "server": server.astype(np.bool)
        }
        store_h5dataset(h5data, data)
    logger.info("load h5 dataset")
    data = load_h5dataset(h5data)
    return data["domain"], data["flow"], data["name"], data["hits_vt"], data["hits_trusted"], data["server"]


def generate_names(train_data, window_size):
    user_flow_df = get_user_flow_data(train_data)
    with Pool() as pool:
        results = []
        for user_flow in tqdm(get_flow_per_user(user_flow_df),
                              total=len(user_flow_df['user_hash'].unique().tolist())):
            results.append(pool.apply_async(get_user_chunks, (user_flow, window_size)))
        windows = [window for res in results for window in res.get()]
    names = np.stack(map(lambda f: f.user_hash, windows))
    names = names[:, 0]

    return names


def load_or_generate_domains(train_data, domain_length):
    fn = f"{train_data}_domains.gz"

    try:
        logger.info(f"Load file {fn}.")
        user_flow_df = pd.read_csv(fn)
        logger.info(f"File successfully loaded.")
    except FileNotFoundError:
        logger.info(f"File {fn} not found, recreate.")
        user_flow_df = get_user_flow_data(train_data)
        # user_flow_df.reset_index(inplace=True)
        user_flow_df = user_flow_df[["domain", "serverLabel", "trustedHits", "virusTotalHits"]].dropna(axis=0,
                                                                                                       how="any")
        user_flow_df = user_flow_df.groupby(user_flow_df.domain).mean()
        user_flow_df.reset_index(inplace=True)

        user_flow_df["clientLabel"] = np.where(
            np.logical_or(user_flow_df.trustedHits > 0, user_flow_df.virusTotalHits >= 3), True, False)
        user_flow_df[["serverLabel", "clientLabel"]] = user_flow_df[["serverLabel", "clientLabel"]].astype(bool)
        user_flow_df = user_flow_df[["domain", "serverLabel", "clientLabel"]]

        user_flow_df.to_csv(fn, compression="gzip")

    logger.info(f"Extract features from domains")
    domain_encs = user_flow_df.domain.apply(lambda d: get_domain_features(d, domain_length))
    domain_encs = np.stack(domain_encs)

    return domain_encs, user_flow_df.domain, user_flow_df[["clientLabel", "serverLabel"]].as_matrix().astype(bool)


def save_predictions(path, results):
    joblib.dump(results, path + "/results.joblib", compress=3)


def load_predictions(path):
    return joblib.load(path + "/results.joblib")