#!/usr/bin/env python

import datetime
import re
import sys
import time

import matplotlib
matplotlib.use('GTKAgg')
from matplotlib.backends.backend_gtkagg import FigureCanvasGTKAgg as \
     FigureCanvas
from matplotlib.backends.backend_gtk import NavigationToolbar2GTK as \
     NavigationToolbar
from matplotlib.axes import Subplot
from matplotlib.figure import Figure

import gtk

# Make sure we're been given a filename as a command line argument.
if len(sys.argv) < 2:
    print 'Usage: temp_plotter.py <filename>'
    sys.exit(2)
# Now attempt to open the file.
filename = sys.argv[1]
try:
    log_file = file(filename, 'r')
except IOError:
    print 'Error: Failed to open file %s' % filename
    sys.exit(1)
    
# Grab the data and release the file.
lines = log_file.readlines()
log_file.close()

# Now parse the data.
# Need these in order to parse the date/times.
pattern = re.compile(r'(?P<time>^\d+\w+\d+\s+\d+:\d+:\d+)\s+' \
                     r'(?P<cjt>\d+\.\d*)\s+' \
                     r'(?:(\d+\.\d*)(?:\s+))+')
timefmt = '%d%b%y %H:%M:%S'

# Run the lines through the regex
matches = [pattern.match(line) for line in lines]
# Now construct a data array
data = [\
    # Converting from a string to a datetime.datetime object is stupidly
    # awkward, have to use time.strptime to convert into a time.struct_time
    # but even that's not usable for constructing a datetime, first convert
    # to a POSIX timestamp using time.mktime.
        [datetime.datetime.fromtimestamp(\
        time.mktime(time.strptime(match.group('time'), timefmt)) \
        )] \
        + [float(temp) for temp in match.groups()[1:]] \
        for match in matches]

# Now output it.

win = gtk.Window()
win.set_default_size(800,600)
win.set_title("Test temperatures")
win.connect("destroy", lambda x: gtk.main_quit())

vbox = gtk.VBox()
win.add(vbox)

fig = Figure(figsize=(5,4), dpi=100)
ax = fig.add_subplot(111)

ax.plot_date(matplotlib.dates.date2num([entry[0] for entry in data]), [\
    entry[2] for entry in data], 'b-', label='Temperature 1')
ax.plot_date(matplotlib.dates.date2num([entry[0] for entry in data]), [\
    entry[1] for entry in data], 'r-', label='Cold Junction')
ax.legend()
ax.set_xlabel('Date/time')
ax.set_ylabel('Temperature (degrees Celsius)')

canvas = FigureCanvas(fig)
vbox.pack_start(canvas)

toolbar = NavigationToolbar(canvas, win)
vbox.pack_start(toolbar, False, False)

win.show_all()
gtk.main()