#!/usr/bin/env python
# coding: utf-8

# https://influxdb-client.readthedocs.io/en/latest/usage.html#id4
# 
# or generate source code from Web UI： `Load Data` -> `Source`
# 
# ## Query
# Flux: https://docs.influxdata.com/influxdb/v2.0/query-data/flux/query-fields/

# In[1]:


import re, os

path = '/data/conf/init.sh' # influxdb_token=... (optional)

if os.path.exists(path):
    with open(path,'r',encoding='utf-8') as f:
        content = f.read()
        token = re.search("(?<=influxdb_token=).*", content).group(0)
else:
    token = input("influxdb_token=")
    
from influxdb_client import InfluxDBClient

client = InfluxDBClient(url="http://192.168.88.21:8086", token=token, org="ferro")
query_api = client.query_api()    


# In[2]:


import pandas as pd

query='''
from(bucket: "home")
  |> range(start: -3d)
  |> filter(fn: (r) => r["_measurement"] == "度数") 
  |> filter(fn: (r) => r["_field"] == "当前") 
  |> filter(fn: (r) => r["tag"] == "203" or r["tag"] == "205" )
  |> keep(columns: ["_time", "_value", "tag"])
'''

query = ''.join([ line for line in query.splitlines() if not line.startswith('#') ])

df  = client.query_api().query_data_frame(query=query).drop(['result', 'table'], axis=1)
df['_time'] =  pd.to_datetime(df['_time'], format='%Y-%m-%d %H:%M:%S.%f%z') # https://strftime.org/
df['tag'] = df['tag'].astype('string')

df['diff_value'] = df.groupby(['tag'])['_value'].diff().fillna(0)
df['diff_time']  = df.groupby(['tag'])['_time'].diff()


# In[3]:


df.dtypes


# In[4]:


df_last = df.groupby(['tag']).last()
df_last


# In[5]:


df_result = df[df.diff_time.notnull()]
df_result