import numpy as np
import gensim
import torch
import pandas as pd
import csv
import seaborn as sns
from sklearn.model_selection import train_test_split

from torchtext.vocab import Vocab
from collections import Counter

from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.metrics import accuracy_score

DATA_PATH = ['train/train.tsv', 'dev-0/in.tsv', 'dev-0/expected.tsv', 'test-A/in.tsv']
DATA_PATH_OUTPUT = ['dev-0/out.tsv', 'test-A/out.tsv']

def get_data(path):
  train = pd.read_table(path, error_bad_lines=False, header=None, quoting=csv.QUOTE_NONE)
  return train

def split(x):
    return x.split()

def replace(x):
    newList = []
    for word in x:
        if word == 'O':
            newList.append(0)
        if word == 'B-LOC':
            newList.append(1)
        if word == 'I-LOC':
            newList.append(2)
        if word == 'B-MISC':
            newList.append(3)
        if word == 'B-ORG':
            newList.append(4)
        if word == 'I-ORG':
            newList.append(5)
        if word == 'B-PER':
            newList.append(6)
        if word == 'I-PER':
            newList.append(7)
    return newList

def build_vocab(dataset):
    counter = Counter()
    for document in dataset:
        counter.update(document)
    return Vocab(counter, specials=['<unk>', '<pad>', '<bos>', '<eos>'])

def labels_process(dt):
    return [ torch.tensor([0] + document + [0], dtype = torch.long) for document in dt]

def data_process(dt, vocab):
    return [ torch.tensor([vocab['<bos>']] +[vocab[token]  for token in  document ] + [vocab['<eos>']], dtype = torch.long) for document in dt]

class NeuralNetwork(torch.nn.Module):
    def __init__(self, train_tokens_ids):
        super(NeuralNetwork, self).__init__()
        self.fc1 = torch.nn.Linear(10_000,len(train_tokens_ids))
        self.softmax = torch.nn.Softmax(dim=0)
        
    def forward(self, x):
        x = self.fc1(x)
        x = self.softmax(x)
        return x

    
class NERModel(torch.nn.Module):
    def __init__(self,):
        super(NERModel, self).__init__()
        self.emb = torch.nn.Embedding(23627,200)
        self.fc1 = torch.nn.Linear(600,9)

    def forward(self, x):
        x = self.emb(x)
        x = x.reshape(600) 
        x = self.fc1(x)
        return x

def configure(train, vocab):
  train_labels = labels_process(train[0])
  train_tokens_ids = data_process(train[1], vocab)
  ner_model = NERModel()
  criterion = torch.nn.CrossEntropyLoss()
  optimizer = torch.optim.Adam(ner_model.parameters())
  nn_model = NeuralNetwork(train_tokens_ids)

  return train_labels, train_tokens_ids, ner_model, criterion, optimizer, nn_model

def training(nn_model, train_labels, train_tokens_ids, ner_model, optimizer, criterion):
  for epoch in range(2):
    loss_score = 0
    acc_score = 0
    prec_score = 0
    selected_items = 0
    recall_score = 0
    relevant_items = 0
    items_total = 0
    nn_model.train()
    for i in range(100):
        for j in range(1, len(train_labels[i]) - 1):
            X = train_tokens_ids[i][j-1: j+2]
            Y = train_labels[i][j: j+1]
            
            Y_predictions = ner_model(X)
            
            acc_score += int(torch.argmax(Y_predictions) == Y)
            
            if torch.argmax(Y_predictions) != 0:
                selected_items +=1
            if  torch.argmax(Y_predictions) != 0 and torch.argmax(Y_predictions) == Y.item():
                prec_score += 1
            
            if  Y.item() != 0:
                relevant_items +=1
            if  Y.item() != 0 and torch.argmax(Y_predictions) == Y.item():
                recall_score += 1
                
            items_total += 1
            
            optimizer.zero_grad()
            loss = criterion(Y_predictions.unsqueeze(0), Y)
            loss.backward()
            optimizer.step()
            loss_score += loss.item()

def eval_dev(nn_model, dev_tokens_ids, dev_labels, ner_model):
  result = []
  nn_model.eval()

  for i in range(len(dev_tokens_ids)):
      result.append([])
      for j in range(1, len(dev_labels[i]) - 1):

          X = dev_tokens_ids[i][j-1: j+2]
          Y = dev_labels[i][j: j+1]

          Y_predictions = ner_model(X)
          
          result[i].append(int(torch.argmax(Y_predictions)))

  return result

def eval_test(nn_model, test_tokens_ids, ner_model):
  result = []
  nn_model.eval()

  for i in range(len(test_tokens_ids)):
      result.append([])
      for j in range(1, len(test_tokens_ids[i]) - 1):

          X = test_tokens_ids[i][j-1: j+2]
          Y_predictions = ner_model(X)

          result[i].append(int(torch.argmax(Y_predictions)))

  return result

def generate_result(result,path):
    features = ['O', 'B-LOC', 'I-LOC', 'B-MISC', 'B-ORG', 'I-ORG', 'B-PER', 'B-PER', 'I-PER']
    final_result = []
    
    for i in range(len(result)):
        final_result.append([])
        for j in range(len(result[i])):
            final_result[i].append(features[result[i][j]])
            
    f = open(path, "a")
    for i in final_result:
        f.write(' '.join(i) + '\n')
    f.close()

def main():
  #prepare train
  train = get_data(DATA_PATH[0])
  train[0] = train[0].map(split)
  train[1] = train[1].map(split)
  train[0] = train[0].map(replace)

  #configure
  vocab = build_vocab(train[1])
  train_labels, train_tokens_ids, ner_model, criterion, optimizer, nn_model = configure(train, vocab)

  #train
  training(nn_model, train_labels, train_tokens_ids, ner_model, optimizer, criterion)

  #dev
  dev_in = get_data(DATA_PATH[1])
  dev_ex = get_data(DATA_PATH[2])
  dev_in[0] = dev_in[0].map(split)
  dev_ex[0] = dev_ex[0].map(split)
  dev_ex[0] = dev_ex[0].map(replace)
  dev_labels = labels_process(dev_ex[0])
  dev_tokens_ids = data_process(dev_in[0], vocab)
  result_dev = eval_dev(nn_model, dev_tokens_ids, dev_labels, ner_model)

  #test
  test_in = get_data(DATA_PATH[3])
  test_in[0] = test_in[0].map(split)
  test_tokens_ids = data_process(test_in[0], vocab)
  result_test = eval_test(nn_model, test_tokens_ids, ner_model)

  #results
  generate_result(result_dev, DATA_PATH_OUTPUT[0])
  generate_result(result_test, DATA_PATH_OUTPUT[1])

if __name__ == '__main__':
  main()