#!/usr/bin/python

import os
import types
import random
import sys
import dcopext
import kdecore
from qt import QString

CONFIGURATION_FILENAME = "wallpaper.conf"
RENAME_SCRIPT = "numericnames"
DEFAULT_SRC = os.path.expanduser("~/Images/wallpaper")
DEFAULT_OPERATION_NAME = "change"
OPERATIONS = {}

def loadOperations(pattern="operation"):
	functions = {}
	for name, function in [(name, f) for name, f in globals().iteritems() if type(f) == types.FunctionType and pattern in name]:
		shortName = name.replace(pattern, "")
		shortName = shortName.lower()
		functions[shortName] = function
	return functions

def operationHelp(args):
	"""Prints this help"""
	global OPERATIONS
	ops = [(name, f.__doc__) for name, f in OPERATIONS.iteritems()]
	ops.sort()
	
	head, tail = os.path.split(__file__)
	
	print "USAGE: %s [operation] [arguments] [pattern]\n" % tail
	
	print "operation: the operation to execute (default: %s)" % DEFAULT_OPERATION_NAME
	print "pattern: if present, is used to select a subdirectory out of the source directory"
	print "arguments are operation dependant."
	
	for name, doc in ops:
		print "\n%s" % name
		if doc:
			for line in doc.split("\n"):
				print "\t%s" % line
			

def operationChange(args):
	"""Changes to a randomly selected wallpaper from the source folder
no arguments"""
	src = findSource(args)
	changeWallpaper(randomWallpaper(getWallpapers(src)))

def operationDelete(args):
	"""Changes to a randomly selected wallpaper from the source folder
Deletes the previous wallpaper
no arguments"""
	src = findSource(args)
	success, oldwall = changeWallpaper(randomWallpaper(getWallpapers(src)))
	if (success):
		print "removing", str(oldwall)
		os.remove(str(oldwall))

def operationRename(args):
	"""Runs the configured renaming scheme script in the source folder
no arguments"""
	src = findSource(args)
	os.chdir(src)
	os.execlp(RENAME_SCRIPT)

def operationLatest(args):
	"""Changes to a randomly selected wallpaper out of the N latest from the source folder
By default, using this without any arguments changes to the latest wallpaper
arguments
	N: number of latest wallpapers to choose from (default 1)"""
	nb = 1
	if args and args[0].isdigit():
		nb = int(args.pop(0))
	src = findSource(args)
	changeWallpaper(randomWallpaper(newestWallpapers(getWallpapers(src), nb)))

def loadConfiguration():
	global DEFAULT_OPERATION_NAME, DEFAULT_SRC
	head, tail = os.path.split(__file__)
	filename = head + os.path.sep + CONFIGURATION_FILENAME
	
	if (os.path.exists(filename)):
		execfile(filename, globals())
	else:
		print "Configuration file missing!"
		print "Creating from application built-in defaults."
		print "DEFAULT_SRC =", DEFAULT_SRC
		print "DEFAULT_OPERATION_NAME =", DEFAULT_OPERATION_NAME
		print "RENAME_SCRIPT =", RENAME_SCRIPT
		conf = open(filename, "w")
		conf.write("DEFAULT_SRC = '%s'\n" % DEFAULT_SRC)
		conf.write("DEFAULT_OPERATION_NAME = '%s'\n" % DEFAULT_OPERATION_NAME)
		conf.write("RENAME_SCRIPT = '%s'\n" % RENAME_SCRIPT)
		conf.flush()
		conf.close()
		
		operationHelp([])
	

def parseArgs():
	"""Parse the application arguments
	RETURN: operation to be executed, the rest of the arguments"""
	operation = None
	src = DEFAULT_SRC
	
	arguments = sys.argv[1:]
	
	if arguments:
		operationName = arguments[0]
		try:
			operation = OPERATIONS[operationName]
			arguments.pop(0)
		except KeyError, e: # operation name invalid, use default param
			operation = OPERATIONS[DEFAULT_OPERATION_NAME]
	else:
		operation = OPERATIONS[DEFAULT_OPERATION_NAME]
	
	return operation, arguments

def findSource(arguments):
	"""Given a list of arguments corresponding to a search phrase, returns the subdirectory matching the arguments"""
	src = DEFAULT_SRC
	
	# If there's any arguments left, it's a search path
	if arguments:
		target = " ".join(arguments)
		target = target.upper()
		content = os.listdir(src)
		for d in content:
			f = src + os.sep + d
			if os.path.isdir(f) and target in d.upper():
				src += os.sep + d
				break;
	
	return src

def getWallpapers(src):
	"""Given a source directory, recursively list all non-hidden files and returns it"""
	wallies = []
	content = os.listdir(src)
	for f in content:
		if f[0] == ".":
			continue

		f = src + os.sep + f
		if os.path.isfile(f):
			wallies.append(f)
		elif os.path.isdir(f):
			wallies.extend(getWallpapers(f))
	
	return wallies

def randomWallpaper(wallies):
	"""Select a random wallpaper from a list"""
	return wallies[int(random.random() * len(wallies))]

def newestWallpapers(wallies, N=1):
	"""Select the top N latest wallpaper from a list (using modification time"""
	wallies = [(os.path.getmtime(wall), wall) for wall in wallies]
	
	wallies.sort()
	wallies.reverse()
	
	return [wall for ctime, wall in wallies[:N]]

def changeWallpaper(wall, nb_desk=2):
	"""Change the current wallpaper to the one specified
	RETURN: Success, old wallpaper"""
	success, oldwall = kdesktop.KBackgroundIface.currentWallpaper(0)
	
	for i in range(nb_desk):
		kdesktop.KBackgroundIface.setWallpaper(i, wall, 6)

	return success, oldwall
	
# LOAD OPERATIONS FROM DEFINED FUNCTIONS
OPERATIONS = loadOperations()

# LOAD CONFIGURATION
loadConfiguration()

# PARSE THE ARGUMENTS, EXTRACT THE OPERATION
operation, args = parseArgs()

# STANDARD KDE COMMAND LINE APP STARTUP, TO BE ABLE TO USE DCOP INTERNALLY
aboutdata = kdecore.KAboutData("dcop_test", "dcop_test", "0.1", "foo", kdecore.KAboutData.License_GPL, "Copyleft")
kdecore.KCmdLineArgs.init([sys.argv[0]], aboutdata)
app = kdecore.KApplication(True, False)
dcop = app.dcopClient()
kdesktop = dcopext.DCOPApp("kdesktop", dcop)

# RUN THE OPERATION
operation(args)