#!/usr/bin/python3

import sys
import os
import time
import shutil
from lxml import etree
import tempfile
import threading
import multiprocessing
from threading import Thread, Lock
from queue import Queue
import renderlib

# Project-Name
if len(sys.argv) < 2:
	print("you must specify a project-name as first argument, eg. './make.py sotmeu14'")
	sys.exit(1)

projectname = sys.argv[1].strip('/')
try:
	project = renderlib.loadProject(projectname)
except ImportError:
	print("you must specify a project-name as first argument, eg. './make.py sotmeu14'. The supplied value '{0}' seems not to be a valid project (there is no '{0}/__init__.py').".format(projectname))
	sys.exit(1)

# using --debug skips the threading, the network fetching of the schedule and
# just renders one type of video
renderlib.debug = ('--debug' in sys.argv)

def render(infile, outfile, sequence, parameters={}, workdir=os.path.join(projectname, 'artwork')):
	task = renderlib.Rendertask(infile=infile, outfile=outfile, sequence=sequence, parameters=parameters, workdir=workdir)
	return renderlib.rendertask(task)

# debug-mode selected by --debug switch
if renderlib.debug:
	print("!!! DEBUG MODE !!!")

	# expose debug-render method
	project.render = render

	# call into project which calls render as needed
	project.debug()

	# exit early
	sys.exit(0)



# threaded task queue
tasks = Queue()

# call into project which generates the tasks
project.tasks(tasks)

# one working thread per cpu
num_worker_threads = multiprocessing.cpu_count()
print("{0} tasks in queue, starting {1} worker threads".format(tasks.qsize(), num_worker_threads))

# put a sentinel for each thread into the queue to signal the end
for _ in range(num_worker_threads):
	tasks.put(None)

# this lock ensures, that only one thread at a time is writing to stdout
# and avoids output from multiple threads intermixing
printLock = Lock() 
def tprint(str):
	# aquire lock
	printLock.acquire()

	# print thread-name and message
	print(threading.current_thread().name+': '+str)

	# release lock
	printLock.release()


# thread worker
def worker():
	# generate a tempdir for this worker-thread and use the artwork-subdir as temporary folder
	tempdir = tempfile.mkdtemp()
	workdir = os.path.join(tempdir, 'artwork')

	# save the current working dir as output-dir
	outdir = os.path.join(os.getcwd(), projectname)

	# print a message that we're about to initialize our environment
	tprint("initializing worker in {0}, writing result to {1}".format(tempdir, outdir))

	# copy the artwork-dir into the tempdir
	shutil.copytree(os.path.join(projectname, 'artwork'), workdir)

	# loop until all tasks are done (when the thread fetches a sentinal from the queue)
	while True:
		# fetch a task from the queue
		task = renderlib.Rendertask.ensure(tasks.get())

		# if it is a stop-sentinal break out of the loop
		if task == None:
			break

		# print that we're about to render a task
		tprint('rendering {0} from {1}'.format(task.outfile, task.infile))

		# prepend workdir to input file
		task.infile = os.path.join(workdir, task.infile)
		task.outfile = os.path.join(outdir, task.outfile)
		task.workdir = workdir

		# render with these arguments
		renderlib.rendertask(task)

		# print that we're finished
		tprint('finished {0}, {1} tasks left'.format(task.outfile, max(0, tasks.qsize() - num_worker_threads)))

		# mark the task as finished
		tasks.task_done()

	# all tasks from the queue done, clean up
	tprint("cleaning up worker")

	# remove the tempdir
	shutil.rmtree(tempdir)

	# mark the sentinal as done
	tasks.task_done()

# List of running threads
threads = []

# generate and start the threads
for i in range(num_worker_threads):
	t = Thread(target=worker)
	t.daemon = True
	t.start()
	threads.append(t)

# wait until they finished doing the work
# we're doing it the manual way because tasks.join() would wait until all tasks are done,
# even if the worker threads crash due to broken svgs, Ctrl-C termination or whatnot
while True:
	if tasks.empty() == True:
		break

	# sleep while the workers work
	time.sleep(1)

print("all worker threads ended")