#!/usr/bin/python3

# based on https://github.com/cnvogelg/ardu/blob/master/datalog/tools/plot_log.py

# This script plots a log file of the format
# "unix_timestamp key=value key2=value key3=value ..."
# using rrdtool. Keys are arbitrary values of the format "type:number"
# (e.g. t:1, t:2, h:1 for temperature and humidity) used to identify each sample.
# Note that the keys currently ignored.
#
# The whole log is plotted into one graph.

import sys
import subprocess
import os

if len(sys.argv) != 3:
  print("Usage: plot.py <log> <png>", file=sys.stderr)
  sys.exit(1)

log_file = sys.argv[1]
png_file = sys.argv[2]
rrd_file = "tmp.rrd"

#### start of config

# If you change this you also need to change the create and graph lists below.
# Also note that samples have to be in the same order every time (the key is currently ignored).
samples_per_line=3

# The 4th field of the DS lines is the heartbeat. If you sample at an
# interval < that value you will not see a graph. Simply adjust if necessary.
create = [
	# Index of the 0 after --start is used below. Adjust code if you
	# change the amount of values before it.
	'rrdtool','create',rrd_file,'--step','30','--start',0,

	'DS:temp1:GAUGE:50:U:U',
	'DS:temp2:GAUGE:50:U:U',
	'DS:hum1:GAUGE:50:U:U',

	'RRA:AVERAGE:0.5:1:20000',
	'RRA:MIN:0.5:1:20000',
	'RRA:MAX:0.5:1:20000',
]

graph = [
	# Indices of the two Nones are used below. Adjust the code if you
	# change the amount of values before them..
	'rrdtool','graph',png_file,
	'-s',None,'-e',None,
	'--height=500','--width=1000',
	'--color=BACK#FFFFFF',
	#'--title','Temperature',
	'--vertical-label', 'Temperature °C',
	'--right-axis-label', 'Humidity %',
	'--right-axis', '2:0',
	'--alt-autoscale',
	#'-l','25','-u','30',
	# --left-axis-format is only supported in rrdtool-git
	#'--left-axis-format', '%4.2lf',
	'--right-axis-format', '%4.2lf',

	'DEF:temp1='+rrd_file+':temp1:AVERAGE',
	'LINE1:temp1#339966:temp 1\l',
	'DEF:temp2='+rrd_file+':temp2:AVERAGE',
	'LINE1:temp2#663399:temp 2\l',
	'DEF:hum1='+rrd_file+':hum1:AVERAGE',
	'CDEF:hum11=hum1,2,/',
	'LINE1:hum11#996633:hum 1\l',
]

#### end of config


# load samples
samples = []
f = open(log_file,"r")
for line in f:
	elem = line.split(' ')
	values = []
	# timestamp
	values.append(int(elem[0]))
	# values
	for i in range(1, samples_per_line + 1):
		values.append(float(elem[i].split("=")[1]))
	samples.append(values)
f.close()


# create rrd
start_ts = samples[0][0]
end_ts = samples[-1][0]
create[6] = str(start_ts - 1)
#print("creating rrdb:",create)
ret = subprocess.call(create)
if ret != 0:
	#print("ERROR calling: {}".format(" ".join(create)))
	sys.exit(1)


# update rrd
# TODO: multiple calls in case of too many arguments
n = len(samples)
cmd = ['rrdupdate', rrd_file, '--']
for i in range(n):
	entry = ":".join(map(str, samples[i]))
	cmd.append(entry);

ret = subprocess.call(cmd)
if ret != 0:
	#print("ERROR calling: {}".format(" ".join(cmd)))
	sys.exit(1)


# graph
graph[4] = str(start_ts)
graph[6] = str(end_ts)
ret = subprocess.call(graph)
if ret != 0:
	#print("ERROR calling: {}".format(" ".join(graph)))
	sys.exit(1)

os.unlink(rrd_file)

# vim: set noet: