'''
FILE NAME
lab_app.py
Version 9

1. WHAT IT DOES
This version adds support for Plotly.
 
2. REQUIRES
* Any Raspberry Pi

3. ORIGINAL WORK
Raspberry Full Stack 2015, Peter Dalmaris

4. HARDWARE
* Any Raspberry Pi
* DHT11 or 22
* 10KOhm resistor
* Breadboard
* Wires

5. SOFTWARE
Command line terminal
Simple text editor
Libraries:
from flask import Flask, request, render_template, sqlite3

6. WARNING!
None

7. CREATED 

8. TYPICAL OUTPUT
A simple web page served by this flask application in the user's browser.
The page contains the current temperature and humidity.
A second page that displays historical environment data from the SQLite3 database.
The historical records can be selected by specifying a date range in the request URL.
The user can now click on one of the date/time buttons to quickly select one of the available record ranges.
The user can use Jquery widgets to select a date/time range.
The user can explore historical data to Plotly for visualisation and processing.

 // 9. COMMENTS
--
 // 10. END
'''

from flask import Flask, request, render_template
import time
import datetime
import arrow
import json
import plotly
import sqlite3
from plotly.graph_objs import *

app = Flask(__name__)
app.debug = True # Make this False if you are no longer debugging

@app.route("/")
def lab_temp():
	import sys
	import Adafruit_DHT
	humidity, temperature = Adafruit_DHT.read_retry(Adafruit_DHT.AM2302, 17)
	temperature = temperature * 9/5.0 + 32
	if humidity is not None and temperature is not None:
		return render_template("live.html",temp=temperature,hum=humidity)
	else:
		return render_template("no_sensor.html")

@app.route("/history", methods=['GET'])  #Add date limits in the URL #Arguments: from=2015-03-04&to=2015-03-05
def history():
	temperatures, humidities, timezone, from_date_str, to_date_str = get_records()

    
# 	Create new record tables so that datetimes are adjusted back to the user browser's time zone.
	time_series_adjusted_temperatures  = []
	time_series_adjusted_humidities 	= []
	time_series_temperature_values 	= []
	time_series_humidity_values 		= []

	for record in temperatures:
		local_timedate_series = arrow.get(record[0], "YYYY-MM-DD HH:mm")
		time_series_adjusted_temperatures.append(local_timedate_series.format('YYYY-MM-DD HH:mm'))
		time_series_temperature_values.append(round(record[2],2))

	for record in humidities:
		local_timedate_series = arrow.get(record[0], "YYYY-MM-DD HH:mm")
		time_series_adjusted_humidities.append(local_timedate_series.format('YYYY-MM-DD HH:mm')) #Best to pass datetime in text
																						  #so that Plotly respects it
		time_series_humidity_values.append(round(record[2],2))

	
	temp = Scatter(
				x=time_series_adjusted_temperatures, 
				y=time_series_temperature_values,
				name='Temperature',
				mode='lines',
				line=Line(color='red')
					)
	hum = Scatter(
				x=time_series_adjusted_humidities,
				y=time_series_humidity_values,
				name='Humidity',
				line=Line(color='aqua')
					)

	data = Data([temp, hum])

	layout = Layout(
					title="Temperature and Humidity",
					xaxis=XAxis(
						type='date',
						autorange=True
					),
					yaxis=YAxis(
						title='Fahrenheit / Percent',
						type='linear',
						autorange=True
					),
					)

	fig = Figure(data=data, layout=layout)
	graphJSON = json.dumps(fig, cls=plotly.utils.PlotlyJSONEncoder)

	return render_template("history.html",	timezone = timezone,
											graphJSON = graphJSON,
											)

def get_records():
	from_date_str 	= request.args.get('from',time.strftime("%Y-%m-%d 00:00")) #Get the from date value from the URL
	to_date_str 	= request.args.get('to',time.strftime("%Y-%m-%d %H:%M"))   #Get the to date value from the URL
	timezone 		= request.args.get('timezone','Etc/UTC');
	range_h_form	= request.args.get('range_h','');  #This will return a string, if field range_h exists in the request
	range_h_int 	= "nan"  #initialise this variable with not a number

	print "REQUEST:"
	print request.args
	
	try: 
		range_h_int	= int(range_h_form)
	except:
		print "range_h_form not a number"


	print "Received from browser: %s, %s, %s, %s" % (from_date_str, to_date_str, timezone, range_h_int)
	
	if not validate_date(from_date_str):			# Validate date before sending it to the DB
		from_date_str 	= time.strftime("%Y-%m-%d 00:00")
	if not validate_date(to_date_str):
		to_date_str 	= time.strftime("%Y-%m-%d %H:%M")		# Validate date before sending it to the DB
	print '2. From: %s, to: %s, timezone: %s' % (from_date_str,to_date_str,timezone)
	# Create datetime object so that we can convert to UTC from the browser's local time
	from_date_obj       = datetime.datetime.strptime(from_date_str,'%Y-%m-%d %H:%M')
	to_date_obj         = datetime.datetime.strptime(to_date_str,'%Y-%m-%d %H:%M')

	# If range_h is defined, we don't need the from and to times
	if isinstance(range_h_int,int):	
		arrow_time_from = arrow.utcnow().replace(hours=-range_h_int)
		arrow_time_to   = arrow.utcnow()
		from_date_utc   = arrow_time_from.strftime("%Y-%m-%d %H:%M")	
		to_date_utc     = arrow_time_to.strftime("%Y-%m-%d %H:%M")
		from_date_str   = arrow_time_from.to(timezone).strftime("%Y-%m-%d %H:%M")
		to_date_str	    = arrow_time_to.to(timezone).strftime("%Y-%m-%d %H:%M")
	else:
		#Convert datetimes to UTC so we can retrieve the appropriate records from the database
		from_date_utc   = arrow.get(from_date_obj, timezone).to('Etc/UTC').strftime("%Y-%m-%d %H:%M")	
		to_date_utc     = arrow.get(to_date_obj, timezone).to('Etc/UTC').strftime("%Y-%m-%d %H:%M")

	conn 			    = sqlite3.connect('pi_temp.db')
	curs 			    = conn.cursor()
	curs.execute("SELECT * FROM temperatures WHERE rDateTime BETWEEN ? AND ?", (from_date_utc.format('YYYY-MM-DD HH:mm'), to_date_utc.format('YYYY-MM-DD HH:mm')))
	temperatures 	    = curs.fetchall()
	curs.execute("SELECT * FROM humidities WHERE rDateTime BETWEEN ? AND ?", (from_date_utc.format('YYYY-MM-DD HH:mm'), to_date_utc.format('YYYY-MM-DD HH:mm')))
	humidities 		    = curs.fetchall()
	conn.close()

	return [temperatures, humidities, timezone, from_date_str, to_date_str]

def validate_date(d):
    try:
        datetime.datetime.strptime(d, '%Y-%m-%d %H:%M')
        return True
    except ValueError:
        return False

if __name__ == "__main__":
    app.run(host='0.0.0.0', port=8080)
