# server.py
# Simple non-object way to run server with multiple connetions and handle commands
# Sky Coyote for SWRI 2007

# Import modules used
import os
import socket
from PyQt4 import QtCore, QtGui
import plotimage

# Must have this to keep Python references to Qt objects, or they will disappear!
windowlist = []

# Timer timout: handle socket commands
def timeout():
    # Refer to vars in enclosing scope
    global app, c, sessions, count

    # Look for a socket command
    c.setblocking(0)
    try:
        # Peek for command without removal
        data = c.recv(1024, 2)
    except:
        # Return if no data or other error
        return
        
    # Get and remove data
    c.setblocking(1)
    data = c.recv(1024)
    
    count += 1
    print str(sessions) + ':' + str(count) + ': ' + data
    
    # Close socket session and kill PyQt app
    if data.upper().startswith('CLOSE'):
        c.send(str(sessions) + ':' + str(count) + ': ' + 'Connection closing')
        c.close()
        os._exit(0)

    # Plot a file in a new window
    elif data.upper().startswith('PLOTFILE'):
        fname = data.split()[1]
        c.send(str(sessions) + ':' + str(count) + ': ' + 'Plotting ' + fname)
        min = max = -1
        # Create new image window using previously defined class
        imageViewer = plotimage.ImageViewer(sessions, fname, min, max)
        # Add Qt data to Python list, or it will vanish!
        windowlist.append(imageViewer)
        imageViewer.show()

    else:
        c.send(str(sessions) + ':' + str(count) + ': (Unknown command) ' + data)

# Main program start
# Create a socket and set it to reuse addresses, or bind() may fail
s = socket.socket()
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

# Bind socket to port
host = socket.gethostname()
port = 1234
s.bind((host, port))

# Look for connections
sessions = 0
s.listen(5)
while True:
    # Get a new connection
    c, addr = s.accept()
    sessions += 1
    
    # Fork another Python process
    if os.fork() == 0:
        count = 0
        print str(sessions) + ':' + str(count) + ': ' + 'Got connection from', addr
        c.send(str(sessions) + ':' + str(count) + ': ' + 'Connected')
        
        # Create new PyQt app
        app = QtGui.QApplication([])
        # Create timer to handle incoming socket commands
        timer = QtCore.QTimer()
        QtCore.QObject.connect(timer, QtCore.SIGNAL("timeout()"), timeout)
        timer.start(500)
        # Run GUI
        app.exec_()
        c.close()
        os._exit(0)