#coding utf-8
import sys
import pandas as pd
import numpy as np
import faiss
import time

def gen_i2i(index_item, embeddings,i2i):
    fw=open(i2i,"w")
    #print(i2i)
    start_time = time.time()
    #xb = embeddings
    xb=np.array(embeddings).astype('float32')
    #print(xb)
    #index.add(xb)
    dim, measure = 64, faiss.METRIC_L2  
    param =  'IVF100,PQ16'
    index = faiss.index_factory(dim, param, measure) 
    #print(index.is_trained)                          # 此时输出为False，因为倒排索引需要训练k-means， 
    index.train(xb) 
    end_time = time.time()
    print("time:", (end_time-start_time))
    #index=faiss.IndexFlatL2(100)
    #index.add(embed_matrix)
    #the candicate matrix is embed_matrix,but the search matrix is the same.
    #if the search vector is in the candicate matrix, the return idx>> the first is the search vector itself
    #if the search vector is not in the candicate matrix, the return idx>>the first is the index of the candicate
    batch = 10000
    num = len(embeddings)
    per_rounds = int(num/batch)+1
    #index=faiss.IndexFlatL2(64)
    index.add(xb)
    print("cost time:", (end_time-start_time))
    #distence_matrix,recall_list=index.search(xb, 20)
    #print(distence_matrix)
    #print(recall_list)
    for i in range(per_rounds):
        per_embedding = xb[i:(i+1)*batch]
        #print(per_embedding)
        #print(len(per_embedding))
        distence_matrix,recall_list=index.search(per_embedding, 20)
        #print("distence_matrix:", distence_matrix)
        #print("recall_list:", recall_list)
       	for idx,rec_arr in enumerate(recall_list):
            #print("idx:", idx)
            orgin_item=str(index_item[idx])
            #print("orgin_item:", orgin_item)
            #print("rec_arr:", rec_arr)
            recall_str=""
            for re_id in rec_arr[1:]:
                if re_id in index_item:
                    recall_idstr=str(index_item[re_id])
                    recall_str=recall_str+","+recall_idstr
            fw.write(orgin_item+"\t"+recall_str[1:]+"\n")

if __name__ == '__main__':
    f = open(sys.argv[1])
    index = 0
    index_dict = {}
    index_arr = []
    while True:
        line = f.readline()
        if not line:
           break
        items = line.strip().split(" ")
        try:
            vid = int(items[0])
            vid_vec = eval(" ".join(items[1:]))
            vid_vec=np.array(vid_vec)
            float_arr = vid_vec.astype(np.float64).tolist()
            #print(float_arr)
            index_arr.append(float_arr)
            #index +=1
            index_dict[index] = vid
            index +=1
            #break
            #print(index_arr)
        except:
            #break
            continue
    f.close()
    #print(index_arr)
    gen_i2i(index_dict, index_arr, "i2i_result")