#!/usr/bin/env python3
from sklearn.cluster import AgglomerativeClustering
from sklearn.metrics import silhouette_score
import numpy as np
import glob
import os
import pandas as pd
import argparse
from k_means import cluster_kmeans
from hierarchical import cluster_hierarchical

DIR: str = os.path.dirname(os.path.realpath(__file__))
OUT_DIR: str = DIR + '/clustering'
IN_DIR: str = DIR + '/feature_vectors'

K_MAX: int = 65


def clean_output():
    filelist = glob.glob(OUT_DIR + '/*_silhouette.csv')
    for f in filelist:
        os.remove(f)


def validate(path: str, clazz_name: str, autorun: bool):
    df = pd.DataFrame(columns=['k_means', 'hierarchical'], dtype=float)

    # We bound the number of clusters by the number of distinct points in our dataset.
    # To count them, we compute the number of "distinct" feature vectors and we
    # bound to the minimum of K_MAX and this number.
    nodup = pd.read_csv(path, index_col=0).drop_duplicates()
    max_distinct = len(nodup)

    for n in range(2, min(K_MAX, max_distinct)):
        X_h, Y_h = cluster_hierarchical(path, n, save_to_disk=False)
        df.loc[n, 'k_means'] = silhouette_score(X_h, Y_h)
        
        X_k, Y_k = cluster_kmeans(path, n, save_to_disk=False)
        df.loc[n, 'hierarchical'] = silhouette_score(X_k, Y_k)

    k_kmeans = df[['k_means']].idxmax()[0]
    k_hierarchical = df[['hierarchical']].idxmax()[0]

    print("K_means optimal value: " + str(k_kmeans))
    print("Hierarchical optimal value: " + str(k_hierarchical))

    df.to_csv(OUT_DIR + '/' + clazz_name + '_silhouette.csv')

    if autorun:
        cluster_hierarchical(path, k_hierarchical)
        cluster_kmeans(path, k_kmeans)



def compute_silhouette(path: str, clazz_name: str, suffix: str):
    df_y = pd.read_csv(OUT_DIR + '/' + clazz_name + '_' + suffix + '.csv')
    Y = df_y.iloc[:, 1].values

    df = pd.read_csv(path)
    X = df.drop(df.columns[0], axis=1).to_numpy()

    print("Silhouette for " + suffix + ": " + str(silhouette_score(X, Y)))


def main():
    parser = argparse.ArgumentParser(description='Compute silhouette metric.')
    parser.add_argument('--validate', action='store_true',
                        help='compute optimal k for each algorithm')
    parser.add_argument('--autorun', action='store_true',
                        help='if validating, computes CSV for optimal clustering automatically')


    args = parser.parse_args()

    if args.validate:
        clean_output()

    filelist = glob.glob(IN_DIR + '/*.csv')
    for f in filelist:
        clazz_name = os.path.basename(f)
        clazz_name = clazz_name[:clazz_name.rfind('.')]

        print(clazz_name)

        if args.validate:
            validate(f, clazz_name, args.autorun)
        
        compute_silhouette(f, clazz_name, 'kmeans')
        compute_silhouette(f, clazz_name, 'hierarchical')
        
        print()


if __name__ == '__main__':
    main()