#!/usr/bin/python3
import logging
from gi.repository import Gst
from enum import Enum

from lib.config import Config

class CompositeModes(Enum):
	fullscreen = 0
	side_by_side_equal = 1
	side_by_side_preview = 2
	picture_in_picture = 3

class PadState(object):
	noScaleCaps = Gst.Caps.from_string('video/x-raw')

	def __init__(self):
		self.reset()

	def reset(self):
		self.alpha = 1.0
		self.xpos = 0
		self.ypos = 0
		self.zorder = 1
		self.scaleCaps = PadState.noScaleCaps

class VideoMix(object):
	log = logging.getLogger('VideoMix')

	def __init__(self):
		self.caps = Config.get('mix', 'videocaps')

		self.names = Config.getlist('mix', 'sources')
		self.log.info('Configuring Mixer for %u Sources', len(self.names))

		pipeline = """
			videomixer name=mix !
			{caps} !
			identity name=sig !
			queue !
			tee name=tee

			intervideosrc channel=mixer_background !
			{caps} !
			mix.

			tee. ! queue ! intervideosink channel=video_mix_out
		""".format(
			caps=self.caps
		)

		if Config.getboolean('previews', 'enabled'):
			pipeline += """
				tee. ! queue ! intervideosink channel=video_mix_preview
			"""

		for idx, name in enumerate(self.names):
			pipeline += """
				intervideosrc channel=video_{name}_mixer !
				{caps} !
				videoscale !
				capsfilter name=caps_{idx} !
				mix.
			""".format(
				name=name,
				caps=self.caps,
				idx=idx
			)

		self.log.debug('Creating Mixing-Pipeline:\n%s', pipeline)
		self.mixingPipeline = Gst.parse_launch(pipeline)

		self.log.debug('Binding Error & End-of-Stream-Signal on Mixing-Pipeline')
		self.mixingPipeline.bus.add_signal_watch()
		self.mixingPipeline.bus.connect("message::eos", self.on_eos)
		self.mixingPipeline.bus.connect("message::error", self.on_error)

		self.log.debug('Binding Handoff-Handler for Synchronus mixer manipulation')
		sig = self.mixingPipeline.get_by_name('sig')
		sig.connect('handoff', self.on_handoff)

		self.padStateDirty = False
		self.padState = list()
		for idx, name in enumerate(self.names):
			self.padState.append(PadState())

		self.log.debug('Initializing Mixer-State')
		self.compositeMode = CompositeModes.fullscreen
		self.sourceA = 0
		self.sourceB = 1
		self.recalculateMixerState()
		self.applyMixerState()

		bgMixerpad = self.mixingPipeline.get_by_name('mix').get_static_pad('sink_0')
		bgMixerpad.set_property('zorder', 0)

		self.log.debug('Launching Mixing-Pipeline')
		self.mixingPipeline.set_state(Gst.State.PLAYING)

	def getInputVideoSize(self):
		caps = Gst.Caps.from_string(self.caps)
		struct = caps.get_structure(0)
		_, width = struct.get_int('width')
		_, height = struct.get_int('height')

		return width, height

	def recalculateMixerState(self):
		if self.compositeMode == CompositeModes.fullscreen:
			self.recalculateMixerStateFullscreen()

		elif self.compositeMode == CompositeModes.side_by_side_equal:
			self.recalculateMixerStateSideBySideEqual()

		elif self.compositeMode == CompositeModes.side_by_side_preview:
			self.recalculateMixerStateSideBySidePreview()

		elif self.compositeMode == CompositeModes.picture_in_picture:
			self.recalculateMixerStatePictureInPicture()

		self.log.debug('Marking Pad-State as Dirty')
		self.padStateDirty = True

	def recalculateMixerStateFullscreen(self):
		self.log.info('Updating Mixer-State for Fullscreen-Composition')

		for idx, name in enumerate(self.names):
			pad = self.padState[idx]

			pad.reset()
			pad.alpha = float(idx == self.sourceA)

	def recalculateMixerStateSideBySideEqual(self):
		self.log.info('Updating Mixer-State for Side-by-side-Equal-Composition')

		width, height = self.getInputVideoSize()
		self.log.debug('Video-Size parsed as %ux%u', width, height)

		try:
			gutter = Config.getint('side-by-side-equal', 'gutter')
			self.log.debug('Gutter configured to %u', gutter)
		except:
			gutter = int(width / 100)
			self.log.debug('Gutter calculated to %u', gutter)

		targetWidth = int((width - gutter) / 2)
		targetHeight = int(targetWidth / width * height)

		y = (height - targetHeight) / 2
		xa = 0
		xb = width - targetWidth

		scaleCaps = Gst.Caps.from_string('video/x-raw,width=%u,height=%u' % (targetWidth, targetHeight))

		for idx, name in enumerate(self.names):
			pad = self.padState[idx]
			pad.reset()

			if idx == self.sourceA:
				pad.xpos = xa
				pad.ypos = y
				pad.zorder = 1
				pad.scaleCaps = scaleCaps

			elif idx == self.sourceB:
				pad.xpos = xb
				pad.ypos = y
				pad.zorder = 2
				pad.scaleCaps = scaleCaps

			else:
				pad.alpha = 0

	def recalculateMixerStateSideBySidePreview(self):
		self.log.info('Updating Mixer-State for Side-by-side-Preview-Composition')

		width, height = self.getInputVideoSize()
		self.log.debug('Video-Size parsed as %ux%u', width, height)

		try:
			asize = [int(i) for i in Config.get('side-by-side-preview', 'asize').split('x', 1)]
			self.log.debug('A-Video-Size configured to %ux%u', asize[0], asize[1])
		except:
			asize = [
				int(width / 1.25), # 80%
				int(height / 1.25) # 80%
			]
			self.log.debug('A-Video-Size calculated to %ux%u', asize[0], asize[1])

		try:
			apos = [int(i) for i in Config.get('side-by-side-preview', 'apos').split('/', 1)]
			self.log.debug('B-Video-Position configured to %u/%u', apos[0], apos[1])
		except:
			apos = [
				int(width / 100), # 1%
				int(width / 100)  # 1%
			]
			self.log.debug('B-Video-Position calculated to %u/%u', apos[0], apos[1])

		try:
			bsize = [int(i) for i in Config.get('side-by-side-preview', 'bsize').split('x', 1)]
			self.log.debug('B-Video-Size configured to %ux%u', bsize[0], bsize[1])
		except:
			bsize = [
				int(width / 4), # 25%
				int(height / 4) # 25%
			]
			self.log.debug('B-Video-Size calculated to %ux%u', bsize[0], bsize[1])

		try:
			bpos = [int(i) for i in Config.get('side-by-side-preview', 'bpos').split('/', 1)]
			self.log.debug('B-Video-Position configured to %u/%u', bpos[0], bpos[1])
		except:
			bpos = [
				width - int(width / 100) - bsize[0],
				height - int(width / 100) - bsize[1]  # 1%
			]
			self.log.debug('B-Video-Position calculated to %u/%u', bpos[0], bpos[1])

		aCaps = Gst.Caps.from_string('video/x-raw,width=%u,height=%u' % tuple(asize))
		bCaps = Gst.Caps.from_string('video/x-raw,width=%u,height=%u' % tuple(bsize))

		for idx, name in enumerate(self.names):
			pad = self.padState[idx]
			pad.reset()

			if idx == self.sourceA:
				pad.xpos, pad.ypos = apos
				pad.zorder = 1
				pad.scaleCaps = aCaps

			elif idx == self.sourceB:
				pad.xpos, pad.ypos = bpos
				pad.zorder = 2
				pad.scaleCaps = bCaps

			else:
				pad.alpha = 0

	def recalculateMixerStatePictureInPicture(self):
		self.log.info('Updating Mixer-State for Picture-in-Picture-Composition')

		width, height = self.getInputVideoSize()
		self.log.debug('Video-Size parsed as %ux%u', width, height)

		try:
			pipsize = [int(i) for i in Config.get('picture-in-picture', 'pipsize').split('x', 1)]
			self.log.debug('PIP-Size configured to %ux%u', pipsize[0], pipsize[1])
		except:
			pipsize = [
				int(width / 4), # 25%
				int(height / 4) # 25%
			]
			self.log.debug('PIP-Size calculated to %ux%u', pipsize[0], pipsize[1])

		try:
			pippos = [int(i) for i in Config.get('picture-in-picture', 'pippos').split('/', 1)]
			self.log.debug('PIP-Position configured to %u/%u', pippos[0], pippos[1])
		except:
			pippos = [
				width - pipsize[0] - int(width / 100), # 1%
				height - pipsize[1] -int(width / 100)  # 1%
			]
			self.log.debug('PIP-Position calculated to %u/%u', pippos[0], pippos[1])

		scaleCaps = Gst.Caps.from_string('video/x-raw,width=%u,height=%u' % tuple(pipsize))
		noScaleCaps = Gst.Caps.from_string('video/x-raw')

		for idx, name in enumerate(self.names):
			pad = self.padState[idx]
			pad.reset()

			if idx == self.sourceA:
				pass
			elif idx == self.sourceB:
				pad.xpos, pad.ypos = pippos
				pad.zorder = 2
				pad.scaleCaps = scaleCaps

			else:
				pad.alpha = 0

	def getMixerpadAndCapsfilter(self, idx):
		# mixerpad 0 = background
		mixerpad = self.mixingPipeline.get_by_name('mix').get_static_pad('sink_%u' % (idx+1))
		capsfilter = self.mixingPipeline.get_by_name('caps_%u' % idx)
		return mixerpad, capsfilter

	def applyMixerState(self):
		for idx, state in enumerate(self.padState):
			mixerpad, capsfilter = self.getMixerpadAndCapsfilter(idx)
			self.log.debug('Reconfiguring Mixerpad %u to x/y=%u/%u, alpha=%0.2f, zorder=%u', idx, state.xpos, state.ypos, state.alpha, state.zorder)
			self.log.debug('Reconfiguring Capsfilter %u to %s', idx, state.scaleCaps.to_string())
			mixerpad.set_property('xpos', state.xpos)
			mixerpad.set_property('ypos', state.ypos)
			mixerpad.set_property('alpha', state.alpha)
			mixerpad.set_property('zorder', state.zorder)
			capsfilter.set_property('caps', state.scaleCaps)

	def on_handoff(self, object, buffer):
		if self.padStateDirty:
			self.padStateDirty = False
			self.log.debug('[Streaming-Thread]: Pad-State is Dirty, applying new Mixer-State')
			self.applyMixerState()

	def on_eos(self, bus, message):
		self.log.debug('Received End-of-Stream-Signal on Mixing-Pipeline')

	def on_error(self, bus, message):
		self.log.debug('Received Error-Signal on Mixing-Pipeline')
		(error, debug) = message.parse_error()
		self.log.debug('Error-Details: #%u: %s', error.code, debug)


	def setVideoSourceA(self, source):
		# swap if required
		if self.sourceB == source:
			self.sourceB = self.sourceA

		self.sourceA = source
		self.recalculateMixerState()

	def setVideoSourceB(self, source):
		# swap if required
		if self.sourceA == source:
			self.sourceA = self.sourceB

		self.sourceB = source
		self.recalculateMixerState()

	def setCompositeMode(self, mode):
		self.compositeMode = mode
		self.recalculateMixerState()